A study conducted by Greenpeace has revealed that taxi drivers suffer the greatest levels of exposure to PM2.5 air pollution: three times that of the average person, and five times the world standard.
The study, carried out by Greenpeace in partnership with the Beijing University School of Public Health, looked at four individuals: a child, an environmentalist, a taxi driver, and an outdoor enthusiast. The four individuals’ daily activity over twenty-four hours was recorded and their exposure to pollution was contrasted with China’s National Ambient Air Quality Standard. It showed that both the taxi driver and the athlete suffered levels of exposure higher than the national standard.
More worrying still was the comparison with the WHO’s guideline values on particulate matter: the taxi driver’s exposure to the levels of PM2.5 in Beijing’s air was equivalent to five times the standard set for mean exposure over a twenty-four-hour period, with the athlete exposed to six times the standard.
Within the report, Greenpeace indicated that it estimates atmospheric particulates to account for 3 percent of cardiovascular deaths in young people worldwide, as well as around 5 percent of deaths due to bronchitis and lung cancer, and around 1 percent of deaths due to acute respiratory infection.
Generally, the longer subjects spent outdoors, the greater the threat posed to their health by PM2.5 pollution, though staying indoors did not eliminate the exposure.
For taxi drivers, who come into more contact with car exhaust fumes, this effect is likely to be greater. As data cited in the Greenpeace report shows, long-term exposure to traffic pollution is an independent risk factor in the onset of coronary heart disease.
The hazards are even greater for those who take exercise in severely polluted air. An individual’s rate of pulmonary ventilation during periods of intense physical activity is ten to sixteen times the rate when at rest; the effect of air pollution on those who exercise outdoors is therefore especially high.