While cities offer economic opportunities, this often comes at a cost of significant hazards, such as downgraded air quality. Low-income cities, as can be seen from the graph, suffer the most from poor air quality. Most low-income and high-pollution cities are located in Southeast Asia and Western Pacific. High population density, poor handling of city waste, old vehicle fleets and household burning of fossil fuels for heating and cooking are among the reasons for the poor air quality in these cities. Some low-income cities do manage to keep their air quality in check: most of them are located in Eastern Europe where infrastructure is in place to provide central heating and ensure handling of city waste.
Air quality and average income per household in 89 major cities of the world, 2010
Understanding Air Quality Impact
Air quality has a substantial effect on human health worldwide. Particulate matter, usually measured as up to 10 micrometres in size (PM10), is the key driver of increased mortality rates due to air pollution. Particulate matter has an impact on human mortality rates even at very low rates of concentration, and long-term exposure to particulate matter was shown to consistently increase mortality rates in the respective urban areas. Other pollutants, such as sulphur dioxide or nitrogen dioxide, are mainly dangerous at particularly high levels of concentration.
As displayed in the graph above, exceeding certain thresholds of average annual concentration of PM10 results in corresponding spikes in mortality rates. In 2011, 16 of the world’s major cities in the Passport: Cities database had annual average concentrations of PM10 at 50 microgrammes per cu m or above, which effectively implies the mortality rate was around 9% higher than it would otherwise have been in those cities. In 2012, the overall EU death toll from outdoor air pollution reached 100,000 according to figures from the World Health Organization. In comparison, traffic accidents caused 33,000 deaths in the same year. In China, the respective figures were 350,000-500,000 deaths from air pollution and 311,000 deaths from traffic accidents.
Air Quality Places Constraints on Consumer Lifestyles
Besides the perceptible impact on health, downgraded air quality also shapes other aspects of city life. For example, in Beijing officials take measures to close down factories and schools or limit transportation intensity in cases of particularly poor air conditions. City dwellers are also much more likely to stay indoors in polluted cities instead of spending their leisure time pursuing outdoor activities. As income per household is rising fast in China, the country also witnessed a surge in demand for air purifiers and indoor plants that help improve air quality in the home at least.
Based on its research findings in 2014, the World Health Organization (WHO) claimed that air quality in cities is generally deteriorating and only 12% of urban dwellers live in cities where air quality does not exceed guideline levels set by the WHO. As consumers are becoming increasingly environmentally conscious and aware of the impact of pollution on health, the deteriorating air quality in the world’s cities can have important consequences for consumer lifestyle preferences.