Any time you want to achieve something great, collaboration and teamwork are a necessity, not an option. You learn this one way or another if you have ever pursued greatness, whether in the form of athletics, entrepreneurship, artistry, or academics. As there will inevitably be obstacles along the way, it would be impossible for one person to know how to solve each and every problem encountered.

In the 1969 book 鈥淚nterdisciplinary Relationships in the Social Sciences鈥�, Donald T. Campbell argues that science is conducted most effectively when researchers from different areas and disciplines collaborate on projects of overlapping interest (Campbell, 1969). As another student blog writer, Joel Sprunger, puts it, At the heart of Campbell鈥檚 idea is that with academic collaboration, we are greater than the sum of our parts. This is the concept that we will be exploring in this blog, based on our experiences in a collaborative research effort to study air pollution in Grenada.

According to the 2017 edition of the , ambient air pollution presents one of the greatest environmental-related health risks. All-cause mortality relating to air pollution rose 5.8% from 4.6 million deaths in 2007 to 4.9 million deaths in 2017, most of which stems from increases in cardiovascular, cerebrovascular, and respiratory disease (Stanaway et al., 2018). While much of the world seems to be dealing with urban air pollution problems, a closer look reveals subtle differences based on geographical location.

Satellite image showing desert dust from the Sahara blowing west across the Atlantic Ocean

Take Grenada for example: they are a non-industrialized island nation that disposes of waste via burial and burning. A relatively large portion of their motor vehicle fleet is quite old, resulting in more fuel consumption, higher greenhouse gas emissions, and greater emissions of carbon monoxide and respirable particles. In addition, on a daily basis, large cruise ships visit the port in St. George鈥檚, Grenada鈥檚 largest town. This poses an environmental health issue as these cruise ships idle their generators to maintain electrical supply. Perhaps the most intriguing component of air pollution in Grenada (and possibly the Caribbean) is the presence of Saharan dust. At certain times of the year, the Caribbean is exposed to masses of desert dust that are transported from the Saharan region of northern Africa. Due to a sustained drought period in the Sahara since the early 1970鈥檚, there has been a sharp increase in the amounts of this desert dust being transported around the world. This component of air pollution is of particular interest because it coincides with a rise in Caribbean respiratory disease since the early 1970鈥檚. Altogether, Grenada and other Caribbean states present an opportunity for better understanding sources of air pollution and their impacts on human health.

Our interest in this project stems from our experiences studying air pollution in the Canadian context. Julia鈥檚 undergraduate thesis involved looking into the impact of street design on local air pollution levels in Halifax, Nova Scotia. She conducted a study collecting baseline data on the levels of air pollutants in the downtown area. From traffic count data, the majority of vehicles present in the study were SUVs and regular cars. The air pollutants she measured for this study were PM _2.5 (particulate matter with an aerodynamic diameter of < 2.5 um) and UFP (ultra-fine particles, particulate matter with an aerodynamic diameter of < 0.1 um), both of which are parameters of traffic pollution from automotive exhaust.

Nick based his undergraduate thesis on studying air pollution in urban areas of Mississauga, Ontario. He took measurements of NO_X (nitrogen oxides), NO₂ (nitrogen dioxide), and NO (nitrous oxide), all of which are indicators of traffic pollution. As is common in most urban areas of Canada, traffic is usually the largest source of air pollution. Using these data, he produced a land use regression model to predict NO_X, NO₂, and NO concentrations in previously unmonitored areas of Mississauga. These predictions were used to estimate health risks for residents of Mississauga based on their exposure to these pollutants.

In addition to the two of us, we were accompanied to Grenada by our respective supervisors (Dr. Paul Villeneuve from 杏吧原创 University and from Dalhousie University), as well as collaborating project members from St. George鈥檚 University (SGU) in Grenada (, , and their respective master鈥檚 students, Tania Khan and Solanie Bogollagama). Just as Campbell鈥檚 model for science suggested, we all had overlapping interests that involved the study of environmental health. In collaboration, we brought separate areas of expertise to the table to make our trip to Grenada a successful one.

Air quality research team composed of faculty and students from 杏吧原创 University, Dalhousie University, and St. George鈥檚 University

Going to Grenada, we had four objectives:

1. To set up PurpleAir monitors (air quality monitors that measure PM) around the island that will take continuous air quality measurements. Setting up these monitors will help us quantify how the Saharan dust affects air quality in Grenada on a daily basis as dust passes through the Caribbean region.
2. To perform mobile monitoring of black carbon (BC) and UFP.
3. To meet with Grenada鈥檚 Medical Officer of Health to explain our plans for this project, secure his support, and start the processes to obtain necessary hospitalization data.
4. To meet with staff of the meteorological office at Grenada鈥檚 Maurice Bishop International Airport to discuss getting access to the climate variable data which they measure (such as visibility, rainfall, wind speed, humidity, and mean sea level pressure).

Our work in Grenada began with meeting Dr. Forde and his master鈥檚 student Solanie at SGU. There we scouted for potential locations for installing a PurpleAir monitor on SGU campus. After realizing that it was difficult to satisfy our requirements for a good monitor location, Dr. Forde suggested an alternate location on the southern tip of the island. This location presented a good environment as it was at high elevation and isolated from human activity, had consistent air flow without the influence of urban pollution, and had access to WIFI which allows us to view current and past measurements on. This marked the installation of the first PurpleAir monitor in Grenada.

View of St. George’s, Grenada

After installing Grenada鈥檚 first PurpleAir monitor, our Canadian research team drove around the island to conduct mobile monitoring for BC and UFP. During this excursion we witnessed high levels of both particle types. This could be due to the several trash disposal trucks, construction sites, and high proportion of diesel cars that we passed during our mobile monitoring. Also, as noted earlier, the automotive fleet in Grenada is aging and produces more emissions than newer, more fuel-efficient vehicles.

During our second day of mobile monitoring we obtained consistently low levels of UFP. It was only from Julia鈥檚 past experience using this technology that she was able to determine the monitor wasn鈥檛 working properly. For example, large diesel trucks driving past us no longer caused spikes in measured UFP. For the monitor to function normally, it relies on a filter cartridge that must be soaked in alcohol before measurements can be taken. Julia made the connection that the high humidity was likely affecting alcohol absorption which could have caused the incorrect UFP measurements we saw that day.

Next on our agenda was to meet with Grenada鈥檚 Chief Medical Officer, Dr. Francis Martin to explain the premise of our project. It helped that Dr. Martin had previously done research on the . A key piece of information that we learned from this meeting was that the hospital records at Grenada General Hospital are paper based. We will need to convert these data to digital records if we want to analyze how daily Saharan dust exposure relates to daily hospital visits for respiratory disease. Fortunately, the two master鈥檚 students at SGU volunteered to do this conversion.

Maurice Bishop International Airport

Later that day we had a meeting with the manager of the meteorological office at Maurice Bishop International Airport. We inquired about getting access to meteorological data for Grenada, and chatted with the meteorologists working there about how they identify periods of Saharan dust exposure. An exciting outcome of the meeting was getting permission to eventually install a PurpleAir monitor at this airport! Permission to install an air pollution monitor at any international airport is incredibly rare. All that was accomplished this day couldn鈥檛 have been done without the meeting arrangements made by Dr. Forde and Dr. Mitchell.

Our trip to Grenada was a productive one. While only one monitor was installed, four more locations (the airport, the Ministry of Health building, the SGU faculty members house, and a spot on Grenada鈥檚 neighbouring island, Carriacou) were identified and with the help of the SGU team, four more monitors will be installed. The mobile monitoring of BC and UFP that we completed can be used as a baseline for further research related to these particles. Moreover, as there is minimal research on the relation of BC and UFP, and this study will help fill in that knowledge gap. In addition, the prospect of installing a PurpleAir monitor at the Maurice Bishop airport is novel.

Collaboration is what bound this project together, with each individual bringing their own expertise to the table. There was also specific knowledge about the island learned by talking with locals; this aided immensely in finding suitable locations to install the PurpleAir monitors. The success of this project will rest on the partnerships that have been established between universities. Thank you to everyone who made this project possible and to 杏吧原创 University for the International Seed Grant that was awarded to Dr. Villeneuve to provide funding support to this research.

Nick is a 1^st year M.Sc. student in Health Sciences at 杏吧原创 University in Ottawa.

Julia is a 4^th year B.Sc. student in Earth and Environmental Sciences at Dalhousie University in Halifax.

References:

Campbell, D. T. (1969). Ethnocentrism of disciplines and the fish-scale model of omniscience. In M. Sherif & C. W. Sherif (Eds.), Interdisciplinary relationships in the social sciences. Routledge.

Sprunger, J. G. (2017, December). The benefits of engaging in collaborative research relationships. APS Observer. https://www.psychologicalscience.org/observer/the-benefits-of-engaging-in-collaborative-research-relationships

Stanaway, J., Afshin, A., Gakidou, E., Lim, S., Abate, D., Abate, K., 鈥� Abrham, A. (2018). Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990鈥�2017: A systematic analysis for the Global Burden of Disease Study 2017. The Lancet, 392(10159), 1923鈥�1994.

Wittig, R., K枚nig, K., Schmidt, M., & Szarzynski, J. (2007). A study of climate change and anthropogenic impacts in West Africa. Environmental Science and Pollution Research, 14(3), 182鈥�89.

At least once a week, I make the mistake of looking at videos of dogs on Instagram and promptly text my boyfriend to tell him that I want a dog. When I drive by someone walking a dog, I seriously consider pulling over and asking to pet the dog. The biggest challenge in moving away from home for university was leaving behind my two dogs and three cats. I am pretty sure one of my parent鈥檚 biggest concerns is me adopting a dog or cat that I am not able to take care of. My future plans include raising a puppy and baby goat together so they grow up to become best friends.

So you might say I really like animals. More accurate, though, is that I love animals.

I especially find a certain kind of hope and love in rescue animals. Through the years, my family has been able to foster several dogs and several litters of kittens for various rescue organizations. All the pets we鈥檝e owned have been rescued. Sometimes our pets proved challenging. When you have a rescue animal, there can be a lot of curveballs thrown your way. Some animals have had bad experiences with people, and you have to work to gain their trust. They might not have been trained properly or may have developed bad habits along their journey, and you have to train them to have proper manners. You might lose a few pairs of shoes and run outside in your bathrobe calling your pet鈥檚 name more often than you鈥檇 like, but that love in the animal鈥檚 eyes is so worth it in the end.

Growing up with animals, I took their presence for granted. I loved them and used them for support, but I never really considered the effect they had on my life until I moved away. Looking back, I see how my pets helped me through depression and anxiety. They were always there to listen and offer me their paw in support. Other times, I took comfort in seeing them bounce up to me and lick my face all over. Their happiness and love for life was contagious. Honestly, a few tears come to my eyes as I write this. The bond with them was so strong. Having animals that loved me so unconditionally truly gave me a reason to live. They were with me, and I knew I could face the day.

I was excited to move away from home for university. I looked forward to new experiences and challenges. But I underestimated how much I would miss my pets. My parents have even said that I probably miss the pets more than my human family. Facing the stressors of studies and relationship challenges without that constant, non-judgemental support and love was harder than I anticipated. I compensated for this by having pictures of my pets everywhere. When I skyped my family, I always had them bring the dogs and cats to the camera so I could talk to their very confused (and adorable) faces. I also visited the therapy dog in residence several times. My bond with my pets is one of the reasons I am so excited about this research. Given that I hadn鈥檛 even realized how they impacted me until I took time to consciously reflect, I am excited to see what data collection and analysis will reveal about the human animal bond.

I am a Neuroscience and Mental Health student. My own battles with mental health have made me extremely passionate about this issue. I want to both directly help people as well as research new ways of helping individuals that struggle. I am also passionate about rescuing animals and giving them the quality of life they deserve. When Dr. Matheson started describing the Pets and Our Health research project, I was beyond excited. I hadn鈥檛 heard of the One Health framework, the idea that the health of humans, animals, and the environment are related, or the Community Veterinary outreach, which provides veterinary services to individuals who would otherwise be unable to access animal care while also providing human health services. I didn鈥檛 know people were actually researching how animals effect our health.

Knowing the impact that animals have had in my life, even when I had a strong support network around me, I can only imagine how individuals who are homeless or vulnerably housed value their pets. During my internship, I鈥檝e been reading journal articles about the relationship between vulnerable individuals and their pets. My eyes have been opened. For many of these individuals, their pets truly are their only supporters. They value the pets to the extent that it鈥檚 common to put the animal鈥檚 needs ahead of their own needs.

My hope through this research is that we are able to help to improve the quality of life for both people and their pets. I hope that the data that is collected will fuel further studies and provide a spark for future programs to help people and their pets in new ways. I hope that partnerships will form between different healthcare providers and animal organizations so that new, innovative ways of battling homelessness, mental illness, and animal neglect can be developed.

More than Farmland:聽

By Keith Van Ryswyk & Paul Villeneuve, Department of Health Sciences

Cities internationally recognize that features of the urban built environment have dramatic impacts on a number of environmental exposures that, in turn, are linked to human health. The Public Health Agency of Canada has defined the urban built environment as 鈥溾�� part of our physical surroundings and includes the buildings, parks, schools, road systems, and other infrastructure that we encounter in our daily lives鈥�. Urban built environmental exposures that affect health are varied and include air pollution, noise, heat islands, and access to parks and green spaces. As diverse as these exposures are, so too are the health outcomes they鈥檝e been linked to. Long term exposure to air pollution has been linked to premature mortality, cardiovascular and respiratory disease, diabetes, and more recently cognitive decline. Noise has similarly been linked to many of these same health outcomes, as well as to mental health and stress. In the last few years, epidemiological studies have shown that some built environment features, parks and green spaces can help mitigate some of these harmful exposures, and on their own, offer some tangible health benefits. For these reasons, the (CEF) plays a vital role for the health of Ottawa residents.

The CEF was created in 1886. It was one of five experimental farms across Canada developed to promote agricultural development in a time when most people lived and worked on farms. Here, government scientists would modify and develop new strains of wheat that best adapt to Canadian soils, and conduct research on animal and poultry breeding, insect and identification control measures, as well as many other activities. In 2016, the CEF still maintains a large footprint in the city of Ottawa, and is an unusual feature of the city, as most North American cities do not have such an expansive green space located centrally. It captures an area, 1100 acres, that is approximately the same size of New York City鈥檚 Central Park. Nearly one quarter of Ottawa鈥檚 population lives within the 5 km buffer that stretches out from its center. For these reasons, it is a valuable piece of land, and even more so given that Ottawa is a growing city that needs to deliver services to its residents. Consideration is being given to develop parts of the CEF including the possibility that it would serve as the home to a newly constructed hospital.

Decisions on future development of the farm are influenced by a number of competing interests, and would not be straightforward at the best of times. In the case of the CEF, the possible environmental benefits that it provides the city have not been well studied. The population health impact may be considerable as green spaces have been shown to absorb air pollution, reduce noise, and mediate heat island effect. Other potential impacts include reducing obesity, increasing physical activity, and enhance social networks in the surrounding area. Canadian studies have also shown that individuals who live in greener areas have reduced rates of mortality, and have healthier babies. At this time, it is not possible to fully understand these CEF impacts as there has been no coordinated effort to assess and describe CEF impacts on environmental exposures of air pollution, noise, and temperature in surrounding neighbourhoods. There also has been little attempt to describe historically how temperature and air pollution trends have differed between the area of the CEF and more developed downtown areas of the city.

As a team of graduate students enrolled in the at 杏吧原创 University we have begun to try and tackle this controversial topic. There are four of us (myself (Keith), Erika Brisson, Mona Ahmad, and Natasha Prince). Armed with a fleet of our own personal vehicles, including a beat-up 2003 GMC聽Astro van, that have been adapted to include personal monitoring devices that measure exposures on a second-by-second basis, we鈥檝e designed an environmental sampling campaign to measure air pollution, noise and temperature in and around the CEF. For one hour聽every morning and another聽at night, we have driven in and around the CEF so that we will be able map these exposures across the farm and in the surrounding neighborhoods. In the time between our 1 hour tours, we are scampering up or down ladders to maintain a network of 41 air pollution monitors that have been scattered throughout our study area. We do this because we recognize how important an issue this is to our community. We are aware but not distracted by media reports of the debates of a new hospital location that seemingly appear on a daily basis.

Our typical sampling day begins with Erika and I arriving at Natasha鈥檚 apartment. Natasha is the equipment manager while the daily mobile monitoring is performed by the rest of us. While we focus on driving the same circuit around the farm each day, Natasha is our team sparkplug and ensures that all of our monitors have the power, memory and various fluids they needed to continuously measure air pollution and temperature while we drive. Erika and I finish our morning sampling and replace the monitoring equipment in our passenger seats with Mona and Natasha, respectively. We must now tour our study area again and take down all of our passive monitors. On setup day, we strapped them to lamp poles and left them there for two weeks to fend for themselves. For fourteen days they have sat there, like eggs in inverted tin nests (rain shelters). Natasha and I are discovering that some of the noise meters have been stolen. Their small blinking LED lights must have been too much to resist for some. In these three instances, we are at least grateful that they spared our NO₂ (nitrogen dioxide 鈥� a marker of traffic exhaust) and VOC (volatile organic compounds 鈥� markers of many anthropogenic sources) samples. Arriving at one site, we learn that an entire sampling set up was confiscated by the police, tin nest and all. It was eventually returned to us, encased in an evidence bag, but too late to make use of the data it collected. While our 鈥楩arm Squad鈥� has found this work mentally and physically challenging, we have completed our fall campaign and are now recharging ourselves for another two week sampling campaign in the dead of winter.

While the use of our minivan with our sampling tube聽sticking out the window has attracted attention from more than a few passer-bys, this form of mobile air monitoring has proven to be an effective way to describe how air pollution concentrations vary within city blocks. Ultimately, we will consolidate the data from the loops we take each day and describe how they change within and around the CEF. Our data will be used to describe how the green space of the CEF impacts nearby concentrations of air pollution, heat and noise. Importantly, they will also provide the opportunity for a future group of students to assess what impact redevelopment of CEF has on these environmental exposures. Such redevelopment seems unavoidable now with the announcement on December 2 by Heritage聽 on the grounds of the CEF be made available for the new hospital.

With our data, the community will now be well positioned to monitor some of the environmental impacts of such a decision. While our next sampling campaign will be done in frigid winter conditions, we can鈥檛 think of a better place to conduct fieldwork than in a National Historic Site in the center of our city.

Note. This project is being conducted under the supervision of Dr. Paul Villeneuve and Dr David Miller at 杏吧原创 University.

Ever paid attention to the black smoke rising out of the stack pipe of a transport truck? Caught that unmistakable hydrocarbon smell that goes along with it? Transportation of people and their goods is a major culprit for deteriorating the quality of our air. And it doesn鈥檛 stop there. A long list of other activities, such as heating our homes, electricity generation at power plants, agriculture, and construction of buildings and roads, contributes to ambient air pollution. Because of the wide range of activities responsible and the complex pathways between what is emitted and what we are exposed to, air pollution is a major challenge for environmental managers.

Why all the fuss over air pollution? Well, for a long time, the fields of toxicology and epidemiology have provided evidence that our health is negatively affected by air pollution. Exposure to ambient particulate matter (PM) and ozone carries risks of premature death and illness, both in the short and long-term. In Canada, evidence also exists that NO₂ is an important risk factor for death. Collectively, data from these fields are used to support environmental policies to protect public health. Policies have been developed that limit the levels of pollution in ambient air, such as the Canadian Ambient Air Quality Standards (CAAQS) for PM and ozone set by Environment Canada. Other policies that directly limit emissions at their source have also been set, such as vehicle emission standards that limit tailpipe emissions in Canada.

Imagine a world where we don鈥檛 need vehicle emission standards because cars don鈥檛 have tailpipes. Imagine a world where energy is renewable and non-polluting. Imagine a cleaner environment. It seems nearly impossible to achieve, right? Well, it may not be as far away as we think. Emissions of pollutants in North America have been on the decline over the past few decades thanks to stricter environmental policies. Take, for example, NO_x emissions [nitrogen oxide (NO) + nitrogen dioxide (NO₂)] produced in combustion of fuels, such as from power plants or motor vehicles. NO_x undergoes changes in the atmosphere before affecting the air we breathe and has the potential to form PM. NO_x is also a major contributor to NO₂ and ozone (O₃) in the air we breathe 鈥� both powerful oxidants in the human body. Since 1990, according to Environment Canada, Canada鈥檚 NO_x emissions have declined roughly 28% as a result of policies to clean exhaust from vehicles and power plants. The result has been a steady decline in ozone and NO₂ and an overall improvement in air quality.

Clearly, if exposure to air pollution affects our health, then as policies become stricter, the health of Canadians benefits. But just how much does society benefit? And how far should policies go before they are sufficient?
Last year, our research team at 杏吧原创 University sought to answer these questions. Our findings challenged a fundamental and long-held view in environmental economics 鈥� the law of diminishing returns. According to this law, we should strive only to reduce our emissions by so much, because the benefit of further efforts to reduce emissions diminishes the more and more we reduce. At some point, our efforts to achieve better air quality no longer make sense financially: it costs more to clean the air than it benefits society. But in a study published in 2015, we instead found quite the opposite: the cleaner the air gets, the larger the benefit of reducing our emissions a little bit more. In other words, the less and less we emit, the more effective the next ton of emission control is at reducing ozone pollution. For more, see the blog on

So why do our findings differ from the conventional view? Atmospheric chemistry dictates compounding benefits for pollutants like ozone that are formed through chemical reactions rather than being emitted directly. It tells us how things move and transform in the atmosphere up to the point where we are exposed. But there is another part to this story. How does the human body respond to pollution it is exposed to? Does the body鈥檚 response argue for compounding benefits or diminishing returns?

Characterizing the dose-response curve between pollutants like PM or NO₂ and mortality gives us insight into these questions. Epidemiologists have believed for a long time that the dose-response relationship between exposure and mortality is linear. In other words, in an already pristine environment, making the air a little bit cleaner yields the same reduction in risk as if we cleaned a dirty environment by the same amount. We would get the same benefits to health regardless of how clean the air is initially, as long as we clean it by a comparable amount. But with large cohorts tracking millions of people and their health status over time, epidemiologists now have the power to better delineate the true dose-response relationship. And more and more, studies are finding that the assumed linear relationship may just not be the case. Studies in Canada, such as the Canadian Census, Environment, and Health Cohort (CanCHEC) study have instead found non-linear dose-response relationships for the pollutants NO₂ and PM and mortality. This alternative form of dose-response curve implies that people become more sensitive to pollution as the air becomes cleaner. Or alternatively, if we continue cleaning the atmosphere by progressively reducing our emissions, we get larger and larger reductions in health risks for each small improvement in air quality. The next unit of improved air quality yields more benefit than the previous unit. Sound familiar?

In a newer research project, we worked collaboratively with experts at Health Canada to examine the policy implications of this newer, non-linear form of dose-response relationship. We linked data from CanCHEC with engineered models that track the movement and transformation of air pollutants in the atmosphere from the time they are emitted. The result? A comprehensive set of information that gives insight into how the health of Canadians is directly affected by pollution emitted at its source, whether from the tailpipe of a car or the stack of a power plant.

Our findings indicate that reducing emissions of NO_x brings health benefits of up to $1,400,000 per ton of emission. Where does this benefit come from? When we reduce NO_x, NO₂ in ambient air immediately decreases, and NO₂ is linked to death. But this is just part of the story. With the new, non-linear dose-response model found in CanCHEC, the benefits of reducing emissions increase dramatically as policies become more stringent. With Canada-wide reductions in emissions from all sources, the benefits of reducing each additional ton of emission can grow by 3 or more times. And the benefits are, more often than not, larger than what we would have predicted based on the traditional, linear dose-response curve.

In light of these increasing benefits, we might wonder how much it actually costs to reduce emissions. We have to change our technologies, and even our behaviours, to bring about these changes. So what is the price tag? Well, the answer may not be straightforward. Such costs vary with the type of source (such as vehicles and power plants), and even more so from one place to another. But, on average, the cost of reducing 1 ton of NO_x from industrial stacks can be anywhere from a few hundred dollars to a few thousand. And the costs of reducing the next ton will rise nonlinearly with stricter and stricter policies.

So, is it worth paying? Even without precise estimates of these costs, benefits clearly outweigh the costs by at least an order of magnitude. And even if costs rise as we move towards a cleaner environment, so do the benefits. It鈥檚 a race between benefits and costs and the point at which one catches the other may be much farther away than we thought previously.

The intersection of atmospheric science, epidemiology, and economics is a rapidly advancing niche of research. And one thing is clear: whether you approach this problem from an atmospheric science angle or an epidemiology one, we are finding that we ought to be doing more to emit less. Our policies ought to be stricter. We ought to take better control of our environment and our health.

Key references:

Pappin AJ, Mesbah SM, Hakami A, Schott S. 2015. Diminishing returns or compounding benefits of air pollution control? The case of NO_x and ozone. Environ Sci Technol. 49(16):9548-9556.

Pappin AJ, Hakami A, Blagden P, Nasari M, Szyszkowicz M, Burnett RT. The impact of a nonlinear concentration-response function in estimating the benefits of emissions abatement. Environ Res Lett. Under review.

鈥�The land is everything. It鈥檚 family, it鈥檚 kin, it鈥檚 friends. It鈥檚 a part of you.鈥澛�— Ashlee Cunsolo Willox, , Nov 25 2014.

Health geographer, community researcher, and environmental advocate, Ashlee Cunsolo Willox visited 杏吧原创 University on February 5th to help convey the strong connections the Inuit have to the land, and the direct and indirect impacts of climate change.

In 2008, Cunsolo Willox was invited by the Rigolet community government to conduct narrative research regarding the impacts of climate change on health, where she identified, with the community, that mental health was a primary concern of community residents. Since then, she has worked with all five Inuit communities in Nunatsiavut, Labrador on a variety of community-led and community-identified research initiatives, including cultural reclamation and intergenerational knowledge transmission, suicide reduction and prevention, and land-based education and healing programs. 鈥淚鈥檝e always said, that I work at a university, but [I work] for the communities.鈥�

The Canadian Arctic has the fastest changing annual temperatures, and 鈥渢his is a big deal鈥� because of the sea ice, and it鈥檚 impacted ability to form,鈥� says Cunsolo Willox. In 2012, Cunsolo Willox and a team of Inuit researchers from the communities launched the Inuit Mental Health and Adaptation to Climate Change聽project, to examine the relationships between people, places, cultures, environments, and mental health in the region.

There are approximately 2600 people living in Nunatsiavut, spread between five communities: Nain,听Hopedale, Postville,听Makkovik, and聽Rigolet. Each community is located on the coast, and winter freezing is critical for transportation, obtaining supplies, and following traditional hunting patterns and sea ice is incredibly important for each community.

Nunatsiavut Inuit communities rely on, and thrive from, their natural environment; however, condition changes within the recent years has impacted their ability to access the land. Changes in annual temperatures have impacted animal migration patterns, weather behaviours, and sea ice integrity. Some Arctic animals are seeking cooler temperatures and migrating further north, while new animals, such as moose, are migrating into the Nunatsiavut communities. Changes in weather patterns, including increasing fog levels, wind speeds, and precipitation, are especially of concern as they impact sea ice formation and quality; sea ice that has traditionally supported travel, has a much shorter annual season.

Each change has an impact all aspects of Inuit lives and livelihoods and, as Cunsolo Willox and the research team discovered, the changes also have profoundly affected mental health, eliciting a major emotional responses across the region. Cunsolo Willox and the team identified from interviews with 120 people that 鈥渢he biggest [effects] were those in mental health. The psychological impact of the changing climate was [initially] a big surprise.鈥� Cunsolo Willox relayed one story about learning from an Elder in Rigolet: 鈥淪he was telling me about鈥ow the ice had changed. But what she wanted me to know most鈥� was to understand the strong connections that Inuit have to the land. It鈥檚 everything鈥� if you can鈥檛 get out on that land, it鈥檚 like you鈥檝e lost a part of yourself. The land provides healing. It provides solace. It provides peace. So what happens if you can鈥檛 access that land anymore?鈥�

These findings inspired production of the documentary film, 鈥�.鈥� The film used interviews, scenery, and action shots throughout Nunatsiavut to conceptualize the deep connection between the Labrador Inuit and their homelands through their voices and lived experiences.

Interviews for 鈥溾�� revealed the importance of being able to access and connect with the land as a coping mechanism. Denied access to the land because of changing weather patterns meant loss of access to a place that supported reflection, and provided comfort. The inability to access the land due to insufficient sea ice formation directly and indirectly affects mental, and overall, health.

鈥�Inuit are people of the sea ice. If there鈥檚 no more sea ice, how can we be people of the sea ice?鈥�

Cunsolo Willox identified that these rapidly changing conditions impact the already over-burdened health systems, the path to health sovereignty, and the overall Inuit culture. Climate changes have yet added another colonial stressor that is out of their control. 鈥淚t鈥檚 important to understand the past,鈥� suggests Cunsolo Willox. Residents in Labrador were the first to have contact with European settlers more than 300 years ago. There is a long history of interaction, which includes residential schools, and relocation, and has resulted in intergenerational trauma. 鈥淎nd yet, they have such a rich culture. There is so much beauty in the region.鈥�

Both Cunsolo Willox鈥檚 鈥渉eart and mind are in Labrador because [she鈥檚] been there so long, [she has] relationships, and [has] seen so much evolution.鈥� When asked what continues to inspire her, Cunsolo Willox simply responds 鈥渆verything; it鈥檚 the beauty of the land; it鈥檚 the list of endless questions; it鈥檚 the discovery and sense of pride; the shared ownership of research; the communities.鈥� While respect and willingness within the communities have eliminated most challenges, there are still barriers and hurdles at the provincial and federal governance level, especially as they relate to the funding of such interdisciplinary work. Despite these challenges, Cunsolo Willox 鈥渃annot imagine life without this work. I never expected it, and now, I cannot imagine working anywhere else. It鈥檚 changed me as an individual and my world-views; my interconnectedness. What I鈥檝e learned from the people I鈥檝e worked with, to listen to their wisdom, [it] has been a huge privilege.鈥�

Photos by A. Cunsolo Willox

By Anna Tomczak, Department of Health Sciences, 杏吧原创 University

Although the saying 鈥渟leep is for the weak鈥� was a common theme throughout high school and university, sleep has become more of a luxury 鈥� something we always want and can never get enough of. This is especially true considering that Canadians鈥� quality of sleep has been on the decline for the last couple of decades (Canadian Medical Association, 2012). It is no wonder then, that people take their sleep seriously 鈥� so when something disrupts their sleep, such as a neighbor鈥檚 loud dog, a snoring partner, or perhaps some noise from wind turbines, they get frustrated and may start complaining. Sometimes these complaints are valid; however, at other times they may be pointing a finger in the wrong direction.

The recent increase in wind turbine farms has generated a lot of controversy in communities where they have been built. Many residents are worried over the possible effects the wind turbines will have on their health, including sleep. It is quite evident that noise can disrupt sleep and studies have shown that sleep loss is implicated in several negative health outcomes. A lack of sleep has been shown to increase the risk of obesity, workplace injuries, and is a risk factor for a number of health conditions including stress, cardiovascular disease, and stroke. It is for this reason that the World Health Organization (WHO) has created guidelines for community noise. These guidelines recommend that indoor sound levels should not exceed 30 dBA of continuous noise, and that the outdoor levels of noise should average no more than 40 dBA (WHO, 1999). Effectively, outdoor noise levels should be no higher than noise levels in a quiet office (Figure 1).

Figure 1. Decibel levels of familiar sounds.
Gerrig, R. J., Zimbardo, P. G., Campbell, A. J., Cumming, S. R., & Wilkes, F. J. (2011). Psychology and life. Pearson Higher Education AU

Since wind turbine farms are fairly recent, very few studies have looked at the relationship between wind turbine noise and sleep disturbance. Undertaking studies in the vicinity of wind turbine farms can be challenging given that typically, there are relatively few individuals who live close to them. However, given that wind turbine farms are increasingly common, and anticipated to start producing larger and larger amounts of energy, it is important to study their impacts on our health. The few studies that have looked at the effects that wind turbines had on sleep quality relied on participants to report their own sleeping patterns. These subjective interpretations of sleep may be biased in several important ways. Individuals may not be able to accurately recollect sleeping patterns. For example, individuals with insomnia often report much worse quality of sleep than what actually occurred (Dittoni et al., 2013). Self-reported measures of sleeping patterns may also be influenced by individuals鈥� perceptions of the impacts that the wind turbines may have on their health. This may be an important source of bias, and several studies have shown that individuals often have a tendency to over-report certain types of outcomes if they are aware and concerned about a nearby potential health hazard. To overcome this bias, studies often try to use both subjective and objective measures of sleep quality to obtain a more accurate estimate of the association between noise and sleep quality. Objective measures of sleep quality are more challenging to obtain as they require the use of monitoring devices. Health Canada recently reported on findings from their epidemiological study examining the impacts of wind turbine noise on a number of health outcomes including sleep quality. To our knowledge it is the only study to report on these associations between wind turbine noise and both subjective and objective measures of sleep.

Assessing Sleep Quality and Wind Turbine Noise

The Health Canada study included a total of 1238 participants, between the ages of 18-79 years, who lived between 0.25 and 11.22 kilometers away from an operational wind turbine in southwestern Ontario and Prince Edward Island. In order to minimize bias stemming from any previous misconceptions residents may have had on wind turbines, the study did not focus on wind turbines alone, and was more broadly referred to as the Community Noise and Health Study. Data collection took place through in-person interviews, during which participants filled out questionnaires on noise annoyance, health effects, quality of life, sleep quality, perceived stress, lifestyle behaviours and prevalence of chronic disease. Participants sleep patterns were measured in two ways. The first, a self-reported method, measured sleep disturbance using a widely used series of questions referred to as the Pittsburgh Sleep Quality Index (PSQI). In order to obtain a longer term measure of sleep quality, participants were asked to describe their level of sleep disturbance over the last year. The second method was objective in nature and used an Actiwatch2鈩� to measure sleep patterns of a sub-group of participants over a seven night period. This type of device is based on movement and can measure timing and duration of sleep, as well as awakenings. This enables it to provide a more accurate and reliable measure of sleep disruption when compared to self-report measures.

The study estimated participants exposure to wind turbine noise by placing sound pressure receptors near the wind turbines that were located in their communities. Outdoor sound pressure levels were estimated from receptors located near 315 wind turbines in southwestern Ontario and 84 in PEI. The investigators were then able to estimate the wind turbine noise in the homes of these participants by applying models that took into account the distance between the home and the wind turbine and measured noise.

Is Wind Turbine Noise Too Loud?

Using the receptors found near the wind turbines, the study found that the majority of dwellings fell below the WHO recommended outdoor night time sound pressure levels (40 dB). On this basis, the findings suggest that noise from the wind turbines is unlikely to cause sleep disturbance. The average bedroom noise level among those who indicated they kept their windows open was 32 dB, which is close to the 30 dBA indoor threshold in the WHO鈥檚 Guidelines for Community Noise. With windows closed however, indoor wind turbine noise levels remain below 26 dB 鈥� low enough to avoid any sleep disturbance. Only 19% of dwellings exceeded the 40 dB limit, reaching a maximum of 46 dB 鈥� 6 dB above the recommended annual average nighttime limit.

Does Wind Turbine Noise Affect Our Sleep?

The Health Canada study evaluated the association between wind turbine noise and sleep by using several measures of sleep disturbance. The findings are compelling given that they found no association between wind turbine noise and of the different sleep measures. They did, however, find that sleep quality was affected by a number of other factors.

The first measure of sleep looked at sleep efficiency (having trouble initiating and maintaining sleep) and although it was found to be associated with being male, having less than high school education, being obese and drinking 3-4 cups of coffee a day, no significant associations with exposure to wind turbine noise were observed.

Individuals who were 65+ years of age, obese, or did not have asthma were more likely to take longer to transition from being awake to being asleep (sleep latency). Sleep latency was not associated with wind turbine noise.

As with the other dimensions of sleep, wind turbine noise had no impact on total sleep time. Shorter sleep time was associated with factors such as physical pain, being diagnosed with a sleeping disorder and having a stand-alone air conditioning unit in the bedroom.

Wake time after sleep onset tended to be longer for those who were not employed, had a lower education level, had bedroom located in basement, being a former smoker, and not taking sleep medication at least once a week. Once again, wind turbine noise had no effect on sleep.

The last sleep factor looked at was how often individuals would wake after having fallen asleep. As with total sleep time, the main factors associated with the rate of awakening were physical pain, drinking 3-4 cups of coffee and being single.

So what鈥檚 the Problem?

These findings suggest that the noise created by wind turbines does not have a significant impact on our quality of sleep. However the findings from this study are being met with skepticism. Why is this issue still so controversial? Seeing as research is still relatively new in relation to the health effects of wind turbines, some elements may still not be fully explained. Although this study was one of the first to take into consideration both subjective and objective measures of sleep, it had other limitations. Because it focused on the long-term effects of wind turbine noise on sleep quality, the estimates of wind turbine noise was based on an average generated over a period of time, and was not estimate of noise exposure that occurred on the same night participants鈥� sleeping characteristics were being measured. Future studies that measure noise exposure and sleep on the same night may yield more clues about subtle impacts that were not detected in this study. The study did, however, find that it is not necessarily the noise but rather was the annoyance with the blinking lights on wind turbines used to signal low flying airplanes, which might affect sleep quality. Either way, the study does suggest that long term measures of wind turbine noise are not related to several measures of sleep quality. However, we are still at an early stage of understanding the impacts that wind turbines might have on our sleeping patterns and overall health. For now though, next time you wake up from a bad sleep, remember that the neighbour鈥檚 barking聽dog is probably more at fault than the wind turbine down the street.

Based on:

Michaud, D. et al. (2016). Impacts of wind turbine noise on self-reported and objective measures of sleep. Sleep, 39, 91 鈥� 109.

Note: Several other papers from this Health Canada led study are expected to be published later in 2016, and these papers will focus on various health endpoints.

By Mary Daniel, Department of Biology, 杏吧原创 University

It鈥檚 a simple question, is it not? Well, no not really. There are many theories behind why organisms age. Is it something planned and carried out? Or is it something random that occurs due to damage? In this blog, I will go through four main theories that explain the internal biological mechanisms that give rise to the aging process and the reasons why all organisms age.

First, let me tell you why I am so interested in this topic. The average Canadian lives to be 85 years old (Statistics Canada) and some would say this is a long time. But to me 85 years is just not enough time to make a difference, to make a contribution to society. Some live and die and no one knows what their name is. I feel that we need more time, to learn, to read, to explore, to be curious, and to also give back.

The Genetic Theory of Aging

The genetic theory of aging states that there are programmed signals with timed functional changes that cause the cell to age, through the shortening of telomeres and declines in hormonal and immunologic function. (The medical dictionary)

After a certain period of time, our bodies send out a signal to reduce the repair process and to start the degradation process. The specific time is different for different organisms; for example a fruit fly lives for 30 days, a mouse for 3 years, a turtle for 100 years, and a Redwood tree lives for 1000 years. The signal that is given has unknown genetic origins and research has still to uncover the downstream proteins that stop the repair process and start the break down process.

These signal genes are called genetic timers and they are specific sequences of DNA that govern each stage of the body鈥檚 development and determine the next appropriate step in the aging

process. These genes keep track of the body鈥檚 progress and thus control the age at which certain events occur (the Hayflick Limit). There are other genes that are called death genes, and these genes tell the body to deteriorate and die. Another theory states that the shortening of telomeres, or the caps at the end of each strand of DNA that protect our chromosomes, allows cells to keep track of their age.

To expand this theory, a study in 1993 at the University of California found that mutations in a single gene can double the lifespan of Caenorhabitis elegans, a small worm often used in genetic studies. Since then, the genetic theory of aging has interested the masses and sparked a wave of research, especially with the growing concern of the aging human population.

The key stages of the aging process occur when mutations happen to the DNA sequence. If these mutations are not corrected, or are not corrected properly due to the slowing down of repair mechanisms, these mutations are passed down cellular generations and lead to incorrect protein formation. This buildup of non-functioning proteins is a marker of an aged cell, a cell that can鈥檛 fulfill its proper function, and thus an organ is not doing its job.

The Wear-and-Tear Theory of Aging

Biological aging due to the wear-and-tear theory is simply the outcome of many deteriorating events (accumulation of injuries and damage) that affect the body. Factors like use, accidents, disease, radiation, toxins and other detrimental factors may adversely affect different parts of the body in a stochastic manner. Just like how cars and outdoor paint break down over time, this theory proposes that the same thing and in the same way humans age.

According to this theory, aging occurs through small and random damaging events in a cell that add up over time. These damaging events may come from our own metabolism, as the basic mechanism of metabolism sometimes causes damage to molecules within our cells. Thus, over time, all 鈥榤atter鈥� starts to 鈥榙ecay鈥� and reverts back into its less ordered and more minuscule state.

The Free Radical Theory of Aging

Atoms or molecules with an unpaired electron are known as free radicals. Some small free radicals that can be found in the body include hydroxyl radical (HO路) and nitric oxide radical (NO路). Reactive oxygen species cause the formation of free radicals because of their highly reactive nature, and these include hydrogen peroxide (H₂O₂) and peroxynitrite (NO₃^–). Reactive oxygen species and free radicals, many of which come from our own metabolism, are the main reasons behind the damage leading to aging and age related disease. Which particular free radical behind the push towards aging is not yet known, but there are clear observations supporting this theory, they include: the positive correlations between free radical production and metabolic rate, age, and cataracts. Free radicals cause this damage by removing electrons from the body鈥檚 molecules in a process called oxidation. Oxidation changes the shape of molecules, which often leads to loss of function. Free radicals cause oxidative damage to DNA, lipids, and proteins. This oxidative damage, or better known as oxidative stress, causes inflammation, excess blood blotting, cataracts, and atherosclerosis. We have antioxidants in our cells that protect from such damage (e.g. vitamin C, vitamin E, protein antioxidants), but over time, even these are depleted or damaged themselves, leading to cellular aging.

The Environmental Theory of Aging

Aging caused by environmental stress starts in the womb and continues through life and has the most effect on health as we start to age. Effectively, health in old age is a reflection of health in earlier life, beginning at the very moment of conception. Thus, the road to healthy aging starts with healthy pregnancies, infants, children, and adults.

Due to the rapid industrial development in the late 20^th century, chemicals used in agriculture threatened entire food webs and the health of ecological systems. Contamination of air, soil, and water with hazardous waste, byproducts of resource extraction, fossil fuel combustion, and synthetic chemicals continued to corrupt the environment. As well, pesticides and other industrial chemicals, some of which are persistent and bioaccumulative (concentrating in living organisms), contaminate people, wildlife, and the general environment. During the same time, public health measures had better control over infectious diseases, and thus new disease patterns related to activity, diet, work, housing, exposure to environmental contaminants, and social organization emerged.

With all of that said, let me tell you a bit about my project. I study how environmental contaminants may accelerate the aging process through the production of reactive oxygen species. Environmental contaminants may lead to some of the damaging events mentioned above, contributing to the aging process. Many environmental contaminants are free radicals themselves. Others lead to DNA damage and mutations, often binding directly to DNA itself. Still others produce reactive oxygen species, either directly themselves or indirectly through affecting our metabolism. Thus environmental contaminants may contribute to the aging process in the cell through the accumulation of damage.

The environment contaminants that I am focusing on are the polybrominated flame retardants. These chemicals are found in consumer products such as insulation, textiles, building materials, plastics, electronics, and foams, basically anything that you want to prevent from combusting. This project interested me because we come into contact with these products every day, even many times per day, and industry manufactures these chemicals without acknowledging their potential harmful effects. As I said earlier, there is just not enough time in a person鈥檚 lifespan, and if we can increase that time by eliminating such chemicals by demonstrating their impacts and finding alternatives to them, wouldn鈥檛 you be on board with that?

Based on:

By Natalie Linklater, Dept. of Civil and Environmental Engineering, 杏吧原创 University

Wastewater; it鈥檚 the term we use to denote anything and everything that gets flushed in toilets, rinsed down drains and washed off our streets. It can include residue from soaps and creams, residual pharmaceuticals, pollution from streets, and yes鈥� poop. Tucked away near the banks of rivers and lakes, treatment facilities have a number of steps that aim to clean wastewater before returning it back to the environment.

Wait?! What?!

You read that right. The ultimate goal is to return treated wastewater back into the environment. I know this may come as a bit of a shock but remember that the teaches us that 鈥渁ll the water on earth today, every drop, is all the water there has ever been on the planet鈥� (National Science Foundation, 2013). To keep our natural waters flowing and drinking water sources clean, treated wastewater needs to be returned back to the environment. There is no secret holding space or second magic flush. It all has to go somewhere, but before it does, we want to make sure it is as clean as possible. That鈥檚 why engineers and researchers are continuously re-examining and re-imagining every step of the treatment process to try and find new perspectives to the age old problem: what to do with all this poop!

Water treatment plant

Disinfection is the final stage of the wastewater treatment and is important because it reduces disease causing microorganisms to safe levels before wastewater is released into the wild. The ideal disinfectant is one that would accomplish the required amount of microorganism reduction while being easy to apply, inexpensive, leave little to no chemical residual and have little to no interaction with organic matter, which is abundant in natural and waste waters. This is one tall order! Of the disinfectants that are used today, chlorine is by far the most popular in North America.

Remember I said that engineers and researchers are continuously trying to re-imagine treatment processes? Now, imagine a disinfection process that uses no chemicals but is still able to reduce microbes to below target levels. is just such a process. The same type of light that radiates from the sun to cause sunburns can also be used to cause damage to microbial DNA rendering them inactive. In practice, we place UV light bulbs into large tanks and turn on the light for a set amount of time.

The difficulty arises during heavy rain storms. In these instances, extra water from the rain gets funnelled to treatment plants and risks flooding tanks and taking the entire treatment process offline. To prevent this, treatment plants make adjustments to accommodate larger volumes but do so by sacrificing a certain amount of quality. To assure that treatment plants still meet required targets, my research looks at supplementing UV with a secondary disinfectant such as ferrate, peracetic acid or hydrogen peroxide. You may have noticed that these are not your typical disinfectants. These chemicals are all chlorine-free and leave little to no residuals. As an added bonus, using two disinfectants has been shown to have synergistic effects.

E.coli sample

For the purpose of this blog post let鈥檚 discuss results obtained with ferrate, which are very promising! I鈥檝e examined the use of UV and ferrate both individually and in sequence using a number of different parameters. First, UV light in combination with ferrate reduced E.coli bacteria by an additional 80% compared to the use of UV light alone. Using a molecular stain to examine live and dead bacteria after treatment, ferrate also considerably decreased the number of living bacteria. This means that ferrate not only acts on E.coli, but is also effective at reducing a broader spectrum of bacteria. While I was looking at samples under the microscope I observed clumps of live and dead bacteria, which was unexpected.

Clumps of live and dead bacteria

This lead to questions such as: what are these clumps, why are they forming and are they a bad thing? The addition of ferrate to wastewater also increased the cloudiness or murkiness of the wastewater. This is because ferrate acts as a coagulant, or a substance that encourages smaller particles in wastewater to agglomerate into larger ones. During the process, bacteria and even larger pollution molecules can get trapped into these larger particles. Thankfully, this clumping isn鈥檛 necessarily a bad thing. Larger particles can be removed from wastewater by allowing gravity and time to pull these larger and heavier particles to the bottom of tanks taking trapped bacteria and pollutants with them. So, while wastewater may need to spend more time in the treatment facility to allow for this settling to take place, it means a cleaner wastewater in the end.

The take home message here is that wastewater treatment is important to maintain the health of our beaches, rivers, lakes and drinking water sources. UV is an effective non-chemical and chlorine-free method for wastewater disinfection. Secondary disinfectants such as ferrate have the potential to offer treatment plants the operational flexibility they need to maintain the highest treatment standards.

Based on a paper presented by Linklater, N. & 脰谤尘别肠颈, B. at聽the聽听(2015).

References

National Science Foundation, (2013). The Water Cycle. [online] Available at: [Accessed 19 Aug. 2015].

By Marie-Claire Flores Pajot, Dept. of Health Sciences, 杏吧原创 University

No child should be left out from going to school for the very first time, playing at recess with new friends, or having the opportunity to learn about what the world will offer them in life. And no family should lose these or other precious moments with their children. Unfortunately, this is the case for some. Planning visits to the oncologist as opposed to birthday parties; cheering as they see their brave children succeed a battle through chemotherapy as opposed to cheering for scoring a goal in a soccer game.

Estimates from the Canadian Cancer Society in 2014 indicate that in the next few years approximately 1450 new cases of cancer will occur annually in Canadian children under the age of 19. Thankfully, many childhood cancers can now be treated and even cured. However, treatment does not remediate the significant psychosocial and financial burden to patients and families; not to mention the dreadful journey through chemotherapy: pain, emotional distress and sleepless nights for both the young patient, and their families.

It is often forgotten that overcoming treatment is not crossing the finish line; unfortunately, quite often the battle continues. Late-effects are common and can accompany survivors for months or even decades after their cancer treatment has ended. Some of the late-effects can be emotional complications, such as anxiety and depression; other late-effects are reproductive or sexual development problems, that can affect both boys and girls well into adulthood; learning and memory difficulties are also common; and there are many physical complications such as heart problems caused by the use of anthracycline drugs during treatment, hearing problems due to radiation therapy, as well as muscle and nerve damage that can result in pain or weakness (National Cancer Institute, 2015).

New advances are aiming for early diagnosis to improve patient outcomes (Weller et al., 2012). The causes of the different cancers are complex and elusive but continue to be investigated in clinical settings, laboratories and epidemiological studies (Danaei et al., 2005). Nonetheless, there is likely a combination of genetics, lifestyle, environment and random error in cell replication and control, which influence an individual’s cancer risk (Buka, Koranteng, & Vargas, 2007; Stiller, 2004). In order to implement cancer prevention initiatives, it is important to better understand how many of the new cancer cases in a population are due to modifiable risk factors that could be prevented.

The role of the environment
The importance of our environment has been recognized to play an important role in our physical and mental health (Evans, 2003; McMorris, Villeneuve, Su, & Jerrett, 2015). Yet, we often forget that even the filtered water used for the morning coffee or tea, the background noise, the air conditioning at the office, all impacts our overall wellbeing to some degree. The significant implication of our environment shaping our health has motivated researchers to investigate possible causes to cancer at different spatial scales, from the particles that linger in our bedroom (Zhang & Smith, 2003), to the neighbourhood we live in (Eschbach, Mahnken, & Goodwin, 2005).

Environmentally derived chemicals entering the human body via food, drink or air that have been shown to, or suspected to, increase risk of developing cancer are called 鈥榚nvironmental carcinogens鈥� (Hemminki, 1990). To date, some of the well-studied environmental carcinogens include electromagnetic fields, pesticides, and air pollution (Cancer; Zahm & Devesa, 1995). Canadian studies that have looked at recognized carcinogens emitted to the environment, found that the amounts varied considerably by province. Interestingly, the rate of new adult cancer cases is also observed to vary by province, with a declining rates moving across Canada from east to west, with the highest incidence rates in Quebec and the Atlantic provinces and the lowest rates in Alberta and BC (Canadian Cancer Society鈥檚 Advisory Committee on Cancer Statistics, 2015). These differences in incidence rates of cancer by geographic location can be driven by multiple factors, most notably differences in the age demographic of those who live in different locations. However, neither demographic differences nor lifestyle-related factors, like smoking, can fully explain these geographic variations. Exposure to environmental carcinogens has been recognized to have a significant impact on new cancer rates, and due to the observed patterns of variability of exposure across the nation, studying the extent to which these patterns co-occur with childhood cancer rates may give insight into the etiology of some cancers.

These questions have motivated researchers Drs. Alvaro Osornio-Vargas, Osmar Zaiane, David Eisenstat from the University of Alberta, and Paul Villeneuve from 杏吧原创 University, to take a further step and investigate the associations between exposure to environmental carcinogens and the incidence of childhood cancer in Canada. This study is being funded by the聽 and . Using a special technique called data mining, they will study the national patterns and trends of childhood cancer and assess the relationship with multiple chemicals. Nineteen known carcinogens and 51 potential carcinogens emitted into the air by industries between 2001 and 2011 will be studied to better understand their association with cancer in children under the age of 19 years. The International Agency for Research on Cancer (IARC) classifies outdoor air pollution as a carcinogen (Simon, 2013). In urban areas, traffic is often the main source of ambient air pollution and there are increasing reports of the risks associated with proximity to high-density traffic, including risk of childhood leukemia (Raaschou-Nielsen, Hertel, Thomsen, & Olsen, 2001). Therefore, in addition to industrial emissions, this project will also examine impacts of meteorological conditions that play a role in dispersing emissions, as well as the impact of proximity to major roads.

Overall, this study hopes to improve our understanding of the extent to which the geographic variability of childhood cancer rates in Canada is associated with industrial and traffic-related pollution. The knowledge gained might support future prevention strategies for specific types of cancer. More epidemiological studies, such as this one, in conjunction with clinical studies, will identify areas where action can be taken to prevent childhood cancer, and perhaps one day children will not have to choose between which toy to bring to chemo, but instead which park to play in next.

References
Buka, I., Koranteng, S., & Vargas, A. R. O. (2007). Trends in childhood cancer incidence: review of environmental linkages. Pediatric Clinics of North America, 54(1), 177-203.

Canadian Cancer Society鈥檚 Advisory Committee on Cancer Statistics. (2015). Canadian Cancer Statistics 2015. Canadian Cancer Society.

Cancer, I. A. f. R. o. Overall Evaluations of Carcinogenicity to Humans. List of all agents, mixtures and exposures evaluated to date.

Danaei, G., Vander Hoorn, S., Lopez, A. D., Murray, C. J., Ezzati, M., & group, C. R. A. c. (2005). Causes of cancer in the world: comparative risk assessment of nine behavioural and environmental risk factors. The Lancet, 366(9499), 1784-1793.

Eschbach, K., Mahnken, J. D., & Goodwin, J. S. (2005). Neighborhood composition and incidence of cancer among Hispanics in the United States. Cancer, 103(5), 1036-1044.

Evans, G. W. (2003). The built environment and mental health. Journal of Urban Health, 80(4), 536-555.

Hemminki, K. (1990). Environmental carcinogens Chemical Carcinogenesis and Mutagenesis I (pp. 33-61): Springer.

McMorris, O., Villeneuve, P. J., Su, J., & Jerrett, M. (2015). Urban greenness and physical activity in a national survey of Canadians. Environmental research, 137, 94-100.

National Cancer Institute. (2015). Late Effects of Treatment for Childhood Cancer. Childhood Cancers.

Raaschou-Nielsen, O., Hertel, O., Thomsen, B. L., & Olsen, J. H. (2001). Air pollution from traffic at the residence of children with cancer. American journal of epidemiology, 153(5), 433-443.

Simon, S. (2013). World Health Organization: Outdoor Air Pollution Causes Cancer. American Cancer Society.

Stiller, C. A. (2004). Epidemiology and genetics of childhood cancer. Oncogene, 23(38), 6429-6444.

Weller, D., Vedsted, P., Rubin, G., Walter, F., Emery, J., Scott, S., . . . Olesen, F. (2012). The Aarhus statement: improving design and reporting of studies on early cancer diagnosis. British Journal of Cancer, 106(7), 1262-1267.

Zahm, S. H., & Devesa, S. S. (1995). Childhood cancer: overview of incidence trends and environmental carcinogens. Environmental health perspectives, 103(Suppl 6), 177.

Zhang, J. J., & Smith, K. R. (2003). Indoor air pollution: a global health concern. British medical bulletin, 68(1), 209-225.

By Amanda Pappin, Dept. of Civil and Environmental Engineering, 杏吧原创 University.

We have all experienced the law of diminishing returns. It shows up in various scientific disciplines and in our everyday lives. Weight loss is one example that often comes to mind. If you cut your food intake by a fixed amount, initially weight comes off quickly. But with each pound that disappears from the scale, it seems that you have to work even harder to lose the next. Your diet hasn鈥檛 changed, and other factors like exercise are the same as before, but that scale just isn鈥檛 budging. Frustrating, right?

Well, the law of diminishing returns also applies to various topics in economics. At least that鈥檚 what we thought was the case for air pollution economics.

Air pollution poses a significant challenge to environmental managers because what is emitted from the tailpipe of a car, or the stack of an industrial facility, can undergo profound changes in the atmosphere before affecting the air we breathe. Some of the major pollutants that pose risks to our health are not emitted directly, but rather formed in the atmosphere through complex physical and chemical processes. These include pollutants that we often hear about, such as ozone or small airborne particles (particulate matter or PM). Epidemiologists have shown that both pollutants affect human health and increase our risks of illness and even death.

For a long time, economists who study air pollution have believed that the societal payback of reducing pollutant emissions is a battle against diminishing returns. Cleaning up polluted air brings large benefits to our health and the environment. Cleaning up less polluted air by the same amount yields much smaller benefits. Economists have argued that the environment has a natural ability to cleanse itself of pollution 鈥� an ability that works best when pollution is at low levels. As the air becomes more polluted, the environment becomes overwhelmed and cannot remove added pollution as effectively.

My colleagues and I at 杏吧原创 University have tested the validity of the theory of diminishing returns as it relates to air pollution. For the first time, we attached numbers to the benefits of reducing emissions to see how they change as we strive to emit less pollution. Our work, just published in the , sheds new light on the topic.

We used a numerical air quality model, infused with epidemiological and economic data, to estimate the benefits of reducing emissions on a per-ton basis. We defined 鈥渂enefits鈥� as the number of deaths avoided in the population because of reduced ozone, which we converted to dollar values. We focused on the benefits of reducing emissions of nitrogen oxides (NO_x), which are major players in formation of ground-level ozone. NO_x is emitted from motor vehicles and industrial facilities when air comes into contact with high temperatures in fuel combustion.

Our objective was to test whether the per-ton benefits of reducing NO_x emissions decline over time, as environmental economists have suggested. And we found just the opposite. We showed that instead, benefits increase substantially as we continue to emit less. In other words, each additional ton of NO_x emission reduction becomes more beneficial than the previous ton. While looking for diminishing returns, we instead found compounding benefits!

Los Angeles smog

We found that, on average in the U.S., reducing NO_x from vehicles yields benefits of $13,000 per ton of NO_x. On an average per-vehicle basis, the price tag of NO_x emissions can be as high as $870 per year. This number varies depending on where the vehicle is driven, with benefits tending to be larger around populous urban areas than in the countryside. What about diminishing returns? On average, the benefits of reducing NO_x emissions would almost double if we reduce emissions across the country by 60%. Further, if we reached a level of zero man-made emissions, this benefit would quadruple, on average, yielding benefits of $51,000 per ton. The 4-fold average increase in benefits means that adjusting our way of life not only benefits society now, but will also bring benefits for the future. Every dollar that we spend to clean up our air makes the next dollar invested even more valuable.

So why do our findings disagree with the conventional view of diminishing returns in economics? It comes down to a lack of data, resources, and models to assess the adequacy of the theory in question. Only recently have engineers and atmospheric scientists used their comprehensive numerical models for economic applications. And those who have done so had not fully explored the assumptions used in this theory.

To an atmospheric chemist or air pollution scientist, the idea of diminishing returns in air pollution is counterintuitive for pollutants like ozone. Ozone is formed through photochemical reactions in the atmosphere, and its formation depends on how much NO_x and other pollutants are emitted. In polluted air, each emitted NO_x molecule has to compete with many others to form ozone. As the air becomes cleaner, and NO_x less abundant, these molecules are in higher demand. It is for this reason that our results come as little surprise to researchers in atmospheric chemistry and air pollution. But for economists, our findings are surprising, and frankly, a bit bizarre.

A challenge facing environmental managers is that while cleaning the air entails indisputable health and environmental benefits, doing so also costs money. Not only does it cost money, the cost increases as we emit less and less, and at some point, surpasses the expected societal benefits. Economists argue that it is to society鈥檚 benefit for environmental policies to progress to the point of equilibrium where incremental benefits equal costs, and no further. The question of whether benefits diminish or compound is one of great importance to finding this target level of emission reduction. Under the long-held view of diminishing returns, there is less incentive to keep reducing emissions, and the point of equilibrium is closer to our current habits. Our findings offer a new perspective. Compounding benefits provide further incentive to reduce emissions, and to keep reducing, towards an equilibrium point further down the policy trajectory.

So while you opt more and more to commute by bike or by foot to achieve that next pound of weight loss, know that society will increasingly benefit as you do.

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