Kitchen smoke is a major source of indoor pollution in rural areas and threatens to harm China's 900 million farmers, warn experts. 

Song Guangsheng, director of the China Indoor Environment Test Center, said many rural households in China still burn stalks, wood and low-quality coal with high sulfur content as fuel every day.

"Unscientifically designed cooking facilities used by farmers often cause incomplete combustion of these fuels, which can generate dense smoke and heavily pollute the indoor air if there is no exhaust system," Song said.

The smoke contains a number of toxic gases, including nitrogen dioxide, sulfur dioxide, carbon monoxide and some carcinogens.

An official with the State Environmental Protection Administration (SEPA) said that kitchen smoke is made up of minute particles that can enter the blood and lungs and cause pulmonary and respiratory diseases.

"At dusk or on foggy days, temperatures near the ground are usually lower than those of upper air in rural areas, which will exacerbate the pollution because it hinders the diffusion of kitchen smoke," the official said.

The World Health Organization and the United Nations Development Program report that thick, acrid smoke from stoves and fires inside homes is associated with approximately 1.6 million deaths per year in developing countries.

Song cited a 1995 report by the World Bank, which said that more than 100,000 people in China die from indoor air pollution each year. "A considerable proportion of them are rural residents," Song said.

Experts also point out that China's environmental protection efforts in rural areas now mainly target pollution by farm pesticides and fertilizers, animal waste, water pollution and wastewater discharge by township enterprises. Little emphasis has been placed on kitchen smoke.

Song suggested that local governments help rural residents upgrade their stoves and build exhaust systems to improve ventilation.

He also considered it important to develop clean and renewable energy sources, such as marsh gas, solar energy, wind, mini-hydropower and other environmentally friendly energies.

In 2000, the central government began a trial project to help rural residents build marsh gas pits and rebuild toilets, sties and stoves.

In 2003 and 2004, the Ministry of Finance allocated 1 billion yuan (US$145 million) per year to building household-use methane-generating pits.

According to an ambitious plan for the use of methane as fuel, by the end of 2004 more than 20 million such pits will have been built in rural China.

The figure is expected to reach 50 million by 2010. By then, 200 million rural residents will benefit from the use of methane.

There have also been rapid advances in research on solar energy, wind, and mini-hydropower energy.

"The use of renewable energy has altered centuries-old cooking habits of millions of Chinese farmers, and improved rural sanitation and farmers' living standards," said Yan Cheng, deputy director of the Ministry of Agriculture's rural renewable energy division.

(China Daily October 22, 2004)