Feature stories
Pollution, health and what little we know so far
An Interview with Dr. Ray Copes by Larry Pellizzari
Why is there so little emphasis on the effects that air pollution have on our health?
Probably because the evidence of direct links is pretty limited. We know that CO2 emissions are going up, carbon dioxide concentrations in the atmosphere are going up and average temperatures are going up. But linking that directly to effects on public or individual health is difficult.
If, for example, you look at heat events, they certainly are associated with increased mortality. But if people are in an air conditioned building, that heat wave may be going on outside, but the people inside are protected.
The irony is of course that some of those protective measures may cause further pressure on energy supplies. Very clearly putting people in air conditioned environments is going to be protective but the question becomes “How do we generate the power that will run our air conditioning and our protective measures?”
Are there urban / rural differences in levels and types of air pollution?
One can make an argument that the highest levels of, say, PM2.5 (fine particulate matter) are east of the Coast Mountains and tend to be in smaller communities. On the other hand, I think you’ll find that the stations reporting the highest levels of nitrogen dioxide, which comes mainly from transportation sources, are located in the central core of the GVRD.
One very important source of pollution in BC is wood smoke. That tends to be more of a problem in smaller communities. Wood smoke we know is not good for you but it doesn’t necessarily have the same effect as exposure to diesel exhaust or coal burning or other pollutants that are really fossil-fuel-based rather than biomass.
The evidence linking wood smoke to cardiovascular effects is nowhere near as strong as the evidence we have for pollution from fossil fuels, for which we are finding links to cardiovascular effects.
We are becoming an increasingly urbanized nation. Does this hold any significance for how the sources and types of pollution will affect us.
The intriguing thing is that overall health status of city dwellers tends to be better than that of smaller community residents, sSo while urbanization may certainly affect our activity patterns, and to some extent our exposures, overall health indicators for people in the Lower Mainland are better than in many parts of Northern and rural BC. To a large extent that may reflect differences in economic opportunity for city residents versus rural and small town. Socioeconomic factors are incredibly important. It’s interesting to note that if you look at things like particulate air pollution—PM2.5—the parts of the province that are better off socio-economically tend to have lower levels of that pollutant than the areas that are less well off.
What do we know about how toxic pollutants affect our bodies?
Traditionally people have understood a link between exposure to air pollution and effects on the lungs and respiratory disease. There’s also good research now showing that very fine particulate air pollution may actually be absorbed through the lung and taken elsewhere in the body through the circulatory system. That very clearly opens up the potential for systemic effects or effects on other organ systems.
What’s really interesting in research today is the evidence that exposure to air pollution is also a significant risk factor for cardiovascular disease. And in that respect it’s really no different than smoking. We linked smoking to lung cancer early on, but later research indicated that it also increased the risk of coronary artery disease and many other serious illnesses.
What types of research are going on in BC with regards to air pollution and health?
There’s an interesting study in the planning stages looking at the effects of woodstove change-out: the effects and benefits, if any, of changing from regular woodstoves to certified woodstoves. We’re focusing on those communities that have the highest PM2.5 levels and the effectiveness of interventions that bring those pollutant levels down. Wood smoke is arguably one of the largest problems in air pollution in BC.
One of the major findings in the last decade has been that risks from air pollution aren’t equal throughout an entire airshed or an entire urban area. There are differences in risks related to exposure in a city or a metropolitan area.
There’s a lot of work in the Lower Mainland urban areas looking at the neighbourhood-level effects of traffic-related air pollution so looking at neighbourhoods where there’s major traffic arteries and higher levels of exposure to transportation-related pollutants, comparing health outcomes for those neighbourhoods with parts of the Lower Mainland where there isn’t as much traffic.
The message from the last 10 years of research is not only that air pollution varies day to day overtime, but it also varies in space to a much greater extent than we previously recognized and neighbourhood to neighbourhood variations in air pollution are important.
Who should be most concerned about the effects of air pollution on our health?
Certainly the evidence is that people whose health is already compromised are likely at greater risk from the same exposure to air pollution. But I’d argue that we all should be concerned.
Where does the responsibility lie to raise awareness of air pollution and its effects on our health? Is it our personal responsibility or the responsibility of government and policy makers?
The question is whether the responsibility is to raise awareness about effects on health or whether the responsibility is to take action. I’d argue for the latter, that there’s probably a need to take responsibility both individually and collectively. That requires both government and individual action.
So as individuals we can look at ways of reducing the number of trips we make by car and using cleaner technology, but from a societal perspective, unless there are regulations, requirements and standards in place, individual action alone is clearly not going to be sufficient to deal with this problem. Individuals are not going to be setting standards for combustion devices such as lawnmowers, motor vehicles, and stationary sources such as power plants, refineries, factories and facilities. That’s the responsibility of government.
What measures are in place to minimize the health impact of air pollution in BC, to sustain and improve our air quality?
There have been efforts to get groups like air shed planning committees going in many BC communities. There are differences in the contributions to air pollution in different communities and to leave it all up to the government or the Ministry of Environment to deal with, without any input or action from other organizations, is probably placing the burden far too narrowly. So getting other folks involved, looking at tools that can be used to address local air pollution, such as land use and community planning, can have a major effect on levels of air pollution in that community and on the exposure of people in that community to air pollution. That by and large is the responsibility of municipal government.
But bringing these folks into air shed management committees and sharing the information and making that set of decision-makers aware of the results of air pollution and health research and some of the tools that they have available to them is a good thing.
Do you think that in the public mind, air quality isn’t given enough importance?
That’s a really tough question. From what I have seen, people understand that air pollution is important. Whether we’re taking enough action I think is debatable, particularly in some communities. And you need more than awareness—awareness by itself isn’t going to do anything; only the actions that can stem from that awareness are going to make a difference. Are we doing enough individually and collectively to bring down levels of air pollution? There are a lot of folks who would argue that we should be doing more.
Dr. Ray Copes is the Medical Director of Environmental Health for the BC Centre for Disease Control as well as a professor of health care and epidemiology at the University of British Columbia. The BC Lung Association works closely with Dr. Copes around issues of public education, air quality and health.