The numbers tell a story of China's growing air pollution menace. Claiming 1.2 million lives so far, the data from a new scientific study looking into the leading causes of death worldwide, China's latest figure accounted for 40 per cent of the world's total number of deaths.

Published in December in The Lancet, a British medical journal, the study aimed to detail the numbers for specific countries so as to be able to be presented at international conferences. The China statistics were presented on Sunday during a forum in Beijing.

PM2.5, airborne particles with a diameter of less than 2.5 microns, was the fourth major cause of deaths in China two years ago. Before it were dietary risks, high blood pressure and smoking.

On a global scale, air pollution was number seven, claiming 3.2 million deaths in 2010 worldwide.

Bob O'Keefe, vice president of the Health Effect Institute, a US nonprofit organization, said on Sunday just how air pollution is affecting the lives of not only people in China but other developing countries in Asia as well.

"It means that we have to take effective actions to reduce people's exposure to air pollution," he said.

Two thirds of the world's health concerns caused by air pollution, the report noted, occurred in developing nations in South, Southeast and East Asia.

In just the early part of this year, Beijing weathered periods of heavy smog, and on several occasions, PM2.5 readings in Beijing reached 1,000, far above the recommended reading for good health of 20 that was suggested by the World Health Organization.

Incidentally, the Shanghai municipal government has released on Monday a set of anti-pollution measures seen as tougher than the ones made by its Beijing counterpart.

Among the measures included were the forced reduction of vehicle use by 30 per cent on days when air quality index readings reach above 300.

Education outdoor activities will likewise be banned on days when the city's air quality index readings range between 201 to 300.

Coal-consuming power plants and other industries have been instructed to reduce operations.