When most of us think of air pollution, images of factories belching smoke or vehicles leaving behind a cloud of soot often come to mind.
Such conditions led to historical episodes of deadly air pollution -- the most notorious being the great London smog in December of 1952 when there were approximately 12,000 excess deaths resulting from a 5-day period of intense air pollution.
With growing worldwide industrialization, emissions have increased and become more widespread. The introduction of more complex fuels, and combustion occurring in a wider range of conditions, has led to growing toxicity of emissions, and increasingly evident effects on ecosystems.
Modern power plants, factories and cars produce far less pollution than even 30 years ago and air quality in many cities throughout world (including Vancouver) has improved dramatically.
This success has occurred primarily in cities in Western Europe and North America, and is exemplified by the introduction of smokeless fuels for space heating and the removal of lead as an anti-knock agent in motor vehicle fuels. These examples show that appropriate legislation and management initiatives combined with new technologies and population education can have dramatic effects.
Yet all is not well. Today, half of the world’s population, primarily the rural poor of developing countries, still cooks over open fires. The resulting smoke exposure leaves non-smoking women with lung disease typical of smokers and is a major contributor to infant pneumonia -- the number one cause of infant mortality in the world.
The World Health Organization estimates that such air pollution is responsible for 2 million deaths per year. This inefficient burning of fuel is also a major source of greenhouse gas emissions contributing to climate change. There are many current initiatives to mitigate this problem but they have only scratched the surface given the huge numbers of people involved.
Many decades of research have led to huge advances in our understanding of meteorological, and chemical factors underlying the formation of air pollution and the complexities involved in its fate and impacts on humans and ecosystems. This understanding has made it clear that our activities and lifestyle contribute to costly air pollution locally, regionally and globally. Living close to one of the many roads in our cities results in increased risks for numerous respiratory and cardiovascular diseases.
For the convenience afforded by the car, we pay by emitting fine particles in our neighbourhoods and producing precursors that form ozone which damages cash crops, stunts the growth of our trees and affects human lungs hundreds of kilometres downwind.
Our “just-in-time delivery” economy and sprawling cities result in more localized truck traffic and its carcinogenic diesel exhaust. Our thirst for inexpensive consumer products leading to increased emissions from Chinese factories and the container vessels traversing the world and idling in ports has both local and global implications. Since the most severe impacts are felt in the growing economies of Asia -- where air pollution in urban areas leads to hundreds of thousands of deaths per year - our purchases are linked to global health inequity.
Further, the west coasts of Europe and North America now receive measurable quantities of air pollutants from across the Atlantic and Pacific oceans respectively. This is evidence that the entire lower atmosphere in the Northern Hemisphere is becoming increasingly polluted, even in “pristine” oceanic areas.
So, if we are the problem, then we must work towards solutions. These solutions depend on emissions reductions through technological advances such as fuel cells, and also the use of solar, wind and other alternative energy sources. Technological advances alone are unlikely to be sufficient - changes in land use and urban structure and transportation will be needed. But most importantly we must realize that it is our lifestyle and all of its conveniences that ultimately must be the key to sustainable air quality.
Source: UBC Reports, April 6 2006
Text by Douw Steyn, Professor, Department of Earth and Ocean Sciences, and Michael Brauer, Professor, School of Occupational and Environmental Hygiene
Photo by Darin Dueck