IN THE first half of the 20th century, burning coal for heat and to power factories were the primary sources of air pollution. Today burning coal (now to produce electricity) still causes air pollution, however, vehicle emissions have, now become the major cause of air pollution.

The World Health Organisation reports that 3 million people now die each year, from the effects of air pollution. This is three times the number of people who die each year in automobile accidents. The study concludes that air pollution in France, Austria, and Switzerland is responsible for more than 40,000 deaths annually in these three countries.

In Pakistan, an estimated 1,800 people die every year due to air pollution, says a United Nations report. About 6.4 million hospital admissions and 418,000 cases of minor sickness occur every year due to diseases caused by air pollution. The report says the main reason for the deaths is the quality of air in big cities, which is getting worse because of haphazard industrialization and a rapid increase in the number of vehicles. Pakistan had 0.85 million cars in 1982 and 2.6 million in 1994. Now, there are more than five million cars clogging the roads.

Air pollutants include carbon monoxide, ozone, sulphur dioxide, nitrogen oxides, and particulates. These pollutants come, primarily, from the combustion of fossil fuels, used in coal-fired power plants and gasoline-powered automobiles. Nitrogen oxides can lead to the formation of ground-level ozone. Particulates are emitted from a variety of sources, mostly diesel engines. ‘Smog’- a hybrid word used to describe the mixture of smoke and fog that blankets some cities - is primarily composed of ozone and particulates.

Exposure to carbon monoxide slows reflexes and causes drowsiness.. Nitrogen dioxide can aggravate asthma and reduce lung function, besides making airways more sensitive to allergents. Ozone also causes lung inflammation and reduces lung function and exercise capacity.

In the Canadian province of Ontario, which has a population of 11.9 million, air pollution costs citizens at least $1 billion annually in hospital admissions, emergency room visits, and worker absenteeism. According to the World Bank, the social costs of exposure to airborne dust and lead in Jakarta, Bangkok, and Manila approached 10 percent of average incomes in the early 1990s. In China, which has some of the world’s worst urban air pollution, the illnesses and deaths of urban residents due to air pollution, are estimated to cost 5 percent of the gross domestic product.

The economic costs of air pollution presents a sound argument for reducing income taxes and raising taxes on fossil fuels. This would encourage more efficient fuel use, a shift to clean energy sources, and the adoption of pollution controls.— Samina Iqbal