The State Environmental Protection Administration (SEPA) warned recently that the country's efforts to hold acid rain and sulfur dioxide (SO2) at bay might be a mission impossible if no further endeavor is to be taken.

It is estimated that the country will discharge 28 million tons of SO2 in 2020, 16 million tons more than the amount the country's environment can accommodate.

The damage to the environment and human health caused by acid rain and SO2 pollution translates into economic losses of 110 billion yuan (US$13.3 billion) annually.

Such losses will increase continuously, officials said.

In 1995 the country designated major regions with high SO2 emissions and serious pollution of acid rain as "two controls" regions.

The designated regions include Beijing, Shanghai and 21 provincial capitals, covering nearly 1.1 million square kilometers. Most are developed regions.

Environment experts say SO2 irritates respiratory organs and inhalation of high-density sulfur dioxide can cause larynx dropsy and bronchitis.

Acid rain, meaning precipitation with a pH lower than 5.6, can erode buildings and harm crops. It can also lead to diseases like lung dropsy. Pure water has a pH of 7.0, while normal rain has a pH of 5.6.

According to statistics from the administration, the overall discharge of SO2 in the "two controls" regions decreased from 13.2 million tons in 2000 to about 11.5 million tons in 2002, while the total SO2 discharge in the whole country dropped from 19.9 million tons in 2000 to 19.3 million tons in 2002.

However, due to last year's significant increase of coal consumption in the country from 2002's 1.37 billion tons to 1.58 billion tons, SO2 emissions in the "two controls" regions and in the whole country rose to 13.3 million tons and 22.2 million tons respectively.

At the same time, acid rain in some regions worsened last year. Within the "two controls" regions, the number of cities where the pH of precipitation was lower than 4.5 accounted for 16.5 percent of the total number of cities, a 12.6 percent increase from 2000.

In some cities, including Shaoxing and Ningbo in East China's Zhejiang Province, acid rain accounted for more than 90 per cent of the total precipitation last year.

"In recent years, acid rain has been more and more serious in Ningbo," said a chief engineer of the Ningbo Environment Monitoring Center, who only gave his surname Xu.

Xu attributed the phenomenon to the industrial sector in the city, especially coal-fueled power plants.

Few of the plants are equipped with adequate desulfurization facilities because of the high cost.

"They would rather be fined than buy such expensive facilities," he said.

Wang Jirong, vice-minister of SEPA, said the main hurdles for SO2 and acid rain controls lie in the country's excessive demand for energy, failure in building enough pollution treatment projects and a large number of small coal-burning power plants.

The current economic growth and need for energy have surpassed expectations, she said.

Current development trends indicate coal consumption in the country will exceed 1.8 billion tons in 2005, 400 million tons more than expected.

Therefore, SO2 emissions in 2005 will be 6 million tons more and in the "two controls" regions, there will be more than 3 million tons of additional SO2 discharges.

On the other hand, pollution treatment projects are being constructed at a very slow pace, Wang said.

According to the country's 10th Five-Year Plan (2001-2005), 279 SO2 control projects would need to be constructed during the period, which would reduce SO2 discharges by more than 3 million tons a year.

However, by 2003, only 61 projects had been completed and 72 were being built. Another 89 are in the initial design or feasibility study stages, while 57 have not been launched at all.

In addition, due to the power supply shortage, the plan to shut down small coal-burning power generators by the end of last year was not fulfilled. In fact, some generators that had been shut down resumed operation.

Wang said the administration will strengthen supervision and management so SO2 discharges can be reduced to the fullest.

More effort will be made to ensure that 80 percent of the planned pollution treatment projects are built and put into operation and more coal-burning power plants are equipped with desulfurization facilities.

(China Daily April 27, 2004)