China develops rules on curbing world's highest ammonia emission levels

The photo taken on August 11 shows a blanket of brown haze has settled over Zhengzhou, capital of central China's Henan province. (Photo: Chinanews.com)

(ECNS) -- China's environmental authority has issued a guidance note on ammonia emission inventories as one of the main precursors to high levels of pollutant particulate matter in the air, according to caixin.com.

China has become the world's largest emitter of ammonia over the past 20 years. Last year, a study by scholars at Harvard showed the country emitted 1,020 tons of ammonia between 2005 and 2008, compared to 340 tons in the US and 376 tons in the EU.

Ammonia, the only alkaline gas in the atmosphere, can dissolve in water and react with sulfur dioxide as well as nitric oxide to produce secondary particles such as ammonium nitrate and ammonium sulfate, which account for 40 to 60 percent of Particulate Matter 2.5.

The guidance lists seven main sources of ammonia emission, which include farming, livestock and poultry rearing, biomass burning, the chemical industry, human waste, motor emissions and waste disposal. The first two sources make up over 70 percent of the total.