This is a guest post by David Suzuki.
Beijing’s 21 million residents live in a toxic fog of particulate matter, ozone, sulphur dioxide, mercury, cadmium, lead and other contaminants, mainly caused by factories and coal burning. Schools and workplaces regularly shut down when pollution exceeds hazardous levels. People have exchanged paper and cotton masks for more elaborate, filtered respirators. Cancer has become the leading cause of death in the city and throughout the country.