Cutting through the smog: Is pollution getting worse?

 作者:刁旁     |      日期:2019-04-04 06:19:05
plainpicture/robertharding/Jon Purcell By Nic Fleming In rapidly growing economies, the amount of pollution in the air is undeniably rising, but it is a different story in most rich countries. Take, for instance, PM2.5 particulates – believed to account for most of the health burden of air pollution (see “What’s in the air“). Worldwide, average concentrations rose 11 per cent between 1990 and 2015, according to a report by the Health Effects Institute and the Institute for Health Metrics and Evaluation, both in the US. The trend reflects large increases in India, Bangladesh and China: concentrations in the US, the European Union, Canada and Australia fell over the same period (see graph). Media reports on air pollution in the West frequently don’t mention the major improvements made since the 1950s. But the rate of progress has slowed and Europe, including the UK, is showing no signs of meeting WHO guidelines for clean air any time soon. “The data from monitoring sites across western Europe shows PM2.5 levels are going down,” says Gavin Shaddick of the University of Bath, UK, who develops air pollution models for the WHO. “But they are not falling quickly enough.” Comes from: power plants, factories, gas cookers, industry, volcanoes, dust storms, forest fires, car exhaust. Health effects: