Motor vehicles produced more than 52 million tons of pollutants in China last year, a government report indicates.

The pollutants -- including 40.8 million tons of carbon monoxide, 5.99 million tons of nitrogen oxide, 4.87 million tons of hydrocarbon and 598,000 tons of particulate matters -- are believed to be among the major contributors to air pollution problems like smog, says the China Motor Vehicle Pollution Control Report of 2011 issued by Ministry of Environmental Protection.

Car ownership in China, the world's largest emitter of greenhouse gases, continues to skyrocket, with the number of cars on China's roads rising from 30.88 million to 77.22 million in the past five years.

An editorial in China Daily newspaper, in response to the report, called for a carbon tax on drivers "to remind them of the harm their cars do," noting that such a tax would help cover the medical expenses caused by environmental problems. It also urged the government to improve public transport options.

The World Bank estimates that in 2009 the effects of air pollution in China were equivalent to about 3.3 percent of China's gross domestic product, with the impact on health alone, including premature deaths, amounting to about $110.2 billion.

Currently, China measures air quality based on PM 10, which doesn't detect smaller particulate pollutants.

But the U.S. Embassy in Beijing does measure the more reliable levels of PM2.5 -- hazardous particulate pollutants of 2.5 microns -- posting its findings via Twitter nearly on the hour. Levels of more than 300 are considered hazardous. Earlier this month those levels reached more than 500, a measure of "beyond index."

Pollution was so thick in Beijing Dec. 4 that more than 200 flights out of Capital International Airport were canceled.

Speaking at a Beijing conference on environmental protection Tuesday, Chinese Vice-Premier Li Keqiang said the government's pollution monitoring agency should include PM 2.5 in its monitoring system.

The Ministry of Environmental Protection has said that new monitoring standards and air quality appraisal systems would be released soon, to be adopted throughout the country by 2016.

Li called for a better balance between China's economic development and protection of the environment.

"Providing basic environmental quality for its people is an essential public service for any government. It is necessary to improve the quality of life and provide a favorable environment with clear water, blue skies and uncontaminated soil," he said.