By Ariel Root

Air pollution, green space, and wind turbines. Cardiovascular disease, diabetes, dementia, and cancer. Formal training in statistics, and epidemiology. And partnerships across mathematics, chemistry, geography, and biological disciplines. Paul Villeneuve reflects back on an inspirational co-op work term at Health Canada during his statistics undergraduate training. He was required to apply statistics to better understand specific health issues, but found it much more appealing than theoretical statistics. “I guess,” he laughs, “that’s when I thought epidemiology would be more fun.”

Villeneuve is an Associate Professor in the Department of Health Sciences, and cross-appointed to the School of Mathematics and Statistics at ĐÓ°ÉÔ­´´ University. He is also an Affiliate Scientist at the Ontario Occupational Cancer Research Centre (OCRC) in Toronto, Senior Editor for the Canadian Journal of Public Health, and an Associate Editor for Health Promotion and Chronic Disease Prevention in Canada.

From the beginning of his time at the Laboratory Centre for Disease Control at Health Canada in 1988, Villeneuve has been involved in controversial health issues that are interwoven with political implications, such as the taxation of cigarettes. Being part of such a strong team of epidemiologists, Villeneuve recalls their high caliber research on topics including physical activity, pesticide use, exposure to radon, and cigarette smoking, including second hand exposure. “It generated a lot of attention [because] we didn’t understand the risks like we do now. These things were extremely relevant to many developing policies; it was easy to become excited about the research.”

Today, Villeneuve’s primary research interests assess the link between environmental and occupational exposures on the health of Canadians. His combined expertise in epidemiology and biostatistics have resulted in close collaborations with Health Canada, the Public Health Agency of Canada, the OCRC, Cancer Care Ontario, and academic researchers across disciplines in both Canada and the US.

“Much of my work [focuses] on the health impacts from long-term exposure to air pollution, and the health benefits of green space in urban areas.” His expertise has been applied to several large-scale cohort studies examining the association between ambient air pollution and green space, and chronic diseases. Specifically, associations between outdoor air pollution and the risk of cardiovascular disease, hypertension and diabetes; air pollution and its role on oxidative stress mechanisms related to dementia and neurodegenerative disease; urban green space access and its association with obesity and physical activity; the built environment and development of chronic disease; wind turbines and the potential health impacts and implications; and occupational causes of cancer.

Villeneuve’s research is influenced by stakeholder concerns, and the emerging literature. His health research continues to strengthen his belief that multi-disciplinary research teams are critical in developing in-depth health research perspectives and skills. “Think of all the many projects that involve clinicians, statisticians, geographers… you always need to draw from different disciplines. The nice thing is that people bring different perspectives, and you can then adapt [your research] as you learn from others. I’ve been able to work with many different researchers over long periods of time, and feel lucky to have developed both professional and personal relationships with them”. At ĐÓ°ÉÔ­´´, both the Department of Health Science and The CHAIM Centre combine disciplines, providing opportunities for continuing his engagement in existing and emerging collaborations with various health researchers.

Community engagement and involvement has heavily inspired his research passions. Villeneuve recalls his twenty-year involvement in evaluating the relationship between occupational exposure to radon and lung cancer among Newfoundland fluorspar miners. “We went into communities, talked with and engaged people, including the miners, and did the analysis.” Villeneuve recalls this as one the first projects that he felt truly excited about his work, “because for the first time, it was more than just looking at data. It was [about] going out and talking to people, and hearing of their stories.” A cemetery across the street from the museum of the Newfoundland Fluorspar miners contained many of the individuals who were included in the research.  “My visit there taught me that there are important stories behind the lines of data that I typically run across in an office in Ottawa. Hearing first hand of some of these struggles, and the interest in re-opening the mine because of potential impacts of its closure provided me with a different perspective on how my research could matter at a local level.”

In fact, Villeneuve identifies this as one of the most satisfying results of his research; “interacting with communities, actual residents.” Publications as academic acknowledgement and recognition are satisfying, but “explaining the research— what it means, getting [community] feedback… that level of engagement” is more rewarding for Villeneuve. The general public “doesn’t usually read our papers, so town-hall meetings or workshops that bring together more senior community members is important”.

Villeneuve notes that online articles have become a very important and widely used method of knowledge translation “that wasn’t there 10 to 15 years ago”.  He also acknowledges the evolution of the epidemiology field, especially in air pollution research. Satellites can now estimate ground level concentrations of pollution, and GPS and other apps provide better estimated exposures at an individual-level. As “the field continues to evolve, we continue to do things better and better, and [it continues to be] something that appeals to me”; an appeal that he doesn’t see fading out anytime soon.

Here for contact information for Paul Villeneuve

By Anna Tomczak, Department of Health Sciences, ĐÓ°ÉÔ­´´ University

It seems like we, as a society, are constantly being warned against disease-causing products, whether it be the dangers of BPA found in our water bottles or the associated risks of getting vaccinated. Rarely are these “findings” of danger found to be true. In fact, such warnings tend to create more public disorder than the alleged dangerous products themselves. Recently however, studies have indicated that what was previously considered as “safe” levels of (PM_2.5), may actually be associated with an increased risk of adverse health effects.

Gary Simmons Photography

Fine particulate matter consists of airborne particles found in polluted air, resulting from chemical reactions in the atmosphere and through fuel combustion. Exposure to this particulate matter has observable effects on human health, and it has been identified as one of the top 10 health risks worldwide. Long-term exposure to PM_2.5 has been specifically linked to increased risk of cardiovascular disease, diabetes, hypertension, and non-accidental mortality. In 2013, fine particulate matter was declared a human carcinogen by the International Agency for Research on Cancer due to findings of increased risks of lung cancer reported in several epidemiological studies Alarmingly, more studies are finding that concentrations of fine particulate matter at levels less than 10 µg/m³ have a direct association on the risk of both cardiovascular disease and non-accidental mortality. These findings have important public health implications as these levels of pollution are common in most Canadian cities.

Findings from a recent paper provide more evidence that these low levels of air pollution are affecting Canadians’ health. Villeneuve et al. (2015), conducted a study looking at long-term exposure to fine particulate matter air pollution and mortality among Canadian women. The study followed 89,835 healthy women between the ages of 40 and 59 for 25 years. They grouped women according to their exposure to PM2.5 at their homes, and compared mortality rates across different levels of pollution. They were able to adjust their comparisons for other risk factors that are associated with mortality such as smoking, obesity and other characteristics, They assigned air pollution exposures by taking satellite-based measures of PM_2.5 between the years 1998 and 2006 and linked these to participants postal codes. They were able to determine which women died, and their cause of death by linking participants’ information to the Canadian Mortality Database

Image courtesy of samarttiw at FreeDigitalPhotos.net

As with any study looking to define a relationship between an exposure and an outcome, outside factors that may play a role in explaining the outcome must be considered and controlled for. Building off of previous studies, where socio-demographic and occupational characteristics were analyzed with regards to PM_2.5 exposure and mortality, Villeneuve et al., looked to expand the already existing knowledge through the analysis of four additional factors: smoking, obesity, place of birth and whether the participants had moved within 5 years of the initial recruitment. Furthermore, dose-response models were created to better understand how the concentration of PM_2.5 relates to mortality.

This is great, but what does this all mean? Are we in danger or not? The study revealed several key findings that shed the impact of fine particulate matter on daily life.

Residential PM_2.5 Concentration

Using the satellite-based surface readings of PM_2.5 and the residential postal codes of the participants, the median exposure to PM_2.5 across all participants was determined to be 9.1µg/m³, which is considered to be a fairly low concentration.

Are Low Concentrations of PM_2.5 Dangerous?

Unlike the tales of the dangers of BPA in water bottles, low doses of fine particulate matter do in fact increase the risk of cardiovascular disease, specifically ischemic heart disease and nonaccidental mortality. Villeneuve et al estimated that an increase of 10 µg/m³ of PM_2.5 increases the risk of ischemic heart disease and non-accidental mortality by 30% and 15%, respectively. Considering that such low doses were thought to be safe is shocking! Even after adjusting for the socio-demographic, occupational and risk factors, these results remain the same, indicating that these mortalities can be explained by the exposure to fine particulate matter. These results were further confirmed by the dose-response model that indicated a linear trend between PM_2.5 concentration and ischemic heart disease mortality, where an increase in exposure leads to an increase in risk of mortality. The findings of this study are very similar to risk estimates obtained from a separate Canadian cohort study that was done using census data.

Another Reason to Stay in Shape

Interestingly, and maybe not so surprisingly, obesity was found to play a role in modifying the relationship between exposure to PM_2.5 and mortality by cardiovascular disease. Associations between PM_2.5 and mortality were found to be stronger for obese women compared to nonobese women. This suggests that women who are more obese may be more susceptible to the harmful effects from long term exposure to air pollution.

Was I Born in the Wrong Country?

Luckily, where you are born does not have an effect on the risk estimates of mortality outcomes. Women who were born outside of Canada had no observable disadvantage or advantage compared to those born in Canada. Similarly, having moved in the first five years of the study also did not have an effect on the risk estimates.

This study adds to the findings of recent studies showing mortality impacts at air pollution levels commonly observed in Canadian cities. Additionally it expanded this knowledge by identifying obesity as an important modifier in this relationship. It becomes quite evident that even low concentrations of fine particulate matter can have a visible impact on human health. Having these new insights on the influences of fine particulate matter at very low levels begs the question of what can be done to lower pollution levels, and how low can we go. Because low concentrations of PM_2.5 have an observable influence on human health, new policies may need to be put into place to help protect the population.

These findings are yet another indication that the pollution we help create, whether it be through our reliance on industrial processes, or our own driving habits, has a significant impact on our health. It is important to remember that even though that paper mill down the street may seem harmless, it can be quite dangerous.

Based on:

Villeneuve, P. J., Weichenthal, S. A., Crouse, D., Miller, A. B., To, T., Martin, R. V., . . . Burnett, R. T. (2015). Long-term Exposure to Fine Particulate Matter Air Pollution and Mortality Among Canadian Women. Epidemiology. doi: 10.1097/EDE.0000000000000294

Ontario Ministry of the Environment and Climate Change. (2010). Fine Particulate Matter. Retrieved from: 

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