China Reports More Cities Suffering Acid Rain, Rivers and Lakes Polluted
Published on , Source : Environment News Network
Acid Articles
Booming China Awash in 'Out of Control' Acid Rain
Published on , Source : Environment News Network
BEIJING − China's explosive economic growth is outpacing environmental protection efforts, leaving the country awash in "out of control" acid rain, the China Daily said Tuesday.
Acid rain fell on more than 250 cities nationwide and caused direct annual economic losses of 110 billion yuan ($13.3 billion), equal to nearly three percent of the country's gross domestic product, the state-run newspaper said.
"The regional acid rain pollution is still out of control and even worse in some southern cities," Wang Jian, an official with the State Environmental Protection Administration, was quoted as saying.
Two major causes were the rapidly growing number of cars and increasing consumption of cheap, abundant coal as the country struggles to cope with energy shortages and meet power demand.
China is the world's largest source of soot and sulphur dioxide (SO2) emissions from coal, which fires three-quarters of the country's power plants.
More than 21 tonnes of SO2 were discharged in China in 2003, up 12 percent from the year earlier, the paper said.
"It is estimated that the country will consume more than 1.8 billion tonnes of coal in 2005, emitting an additional six million tonnes of SO2," Wang said.
The paper said the government was planning steps to rein in the problem, including setting quotas for SO2 emissions from thermal power plants and urging them to install desulphurisation facilities, through Wang admitted earlier efforts had led to no obvious improvements.
China has already banned the use of coal in some areas most severely affected by SO2 emissions, but sulphur is not the only enemy in the fight against acid rain.
"The amazing growth of nitrates, thanks to a swift rise of automobile and coal consumption plus overuse of fertilisers, is playing an increasing role in the country's acid rain pollution," Tang Dagang, director of the Chinese Research Academy of Environmental Sciences, was quoted as saying.
A government official told the paper that China had yet to set special regulations to control nitric acid.
Acid rain fell on more than 250 cities nationwide and caused direct annual economic losses of 110 billion yuan ($13.3 billion), equal to nearly three percent of the country's gross domestic product, the state-run newspaper said.
"The regional acid rain pollution is still out of control and even worse in some southern cities," Wang Jian, an official with the State Environmental Protection Administration, was quoted as saying.
Two major causes were the rapidly growing number of cars and increasing consumption of cheap, abundant coal as the country struggles to cope with energy shortages and meet power demand.
China is the world's largest source of soot and sulphur dioxide (SO2) emissions from coal, which fires three-quarters of the country's power plants.
More than 21 tonnes of SO2 were discharged in China in 2003, up 12 percent from the year earlier, the paper said.
"It is estimated that the country will consume more than 1.8 billion tonnes of coal in 2005, emitting an additional six million tonnes of SO2," Wang said.
The paper said the government was planning steps to rein in the problem, including setting quotas for SO2 emissions from thermal power plants and urging them to install desulphurisation facilities, through Wang admitted earlier efforts had led to no obvious improvements.
China has already banned the use of coal in some areas most severely affected by SO2 emissions, but sulphur is not the only enemy in the fight against acid rain.
"The amazing growth of nitrates, thanks to a swift rise of automobile and coal consumption plus overuse of fertilisers, is playing an increasing role in the country's acid rain pollution," Tang Dagang, director of the Chinese Research Academy of Environmental Sciences, was quoted as saying.
A government official told the paper that China had yet to set special regulations to control nitric acid.
Rain drain
Published on , Source :Down to Earth
ACID rain leaches essential metal nutrients such as potassium, calcium and magnesium from the top soil, posing a far graver threat to forests than previously estimated. This was discovered by Martin Kennedy, a scientist at the US-based University of California, and his colleagues.
The researchers experimented on trees in the unpolluted forests of southern Chile. "We went to the cleanest atmosphere on Earth so that we could find the closest thing to a long-term sustainable forest," Kennedy said. "There, we sampled soils, stream water, rain and plants, and analysed the strontium isotope composition of each one." Strontium isotopes indicate very accurately which fraction of nutrient comes from rain and which fraction comes from the rock. "We found that in the dominant tree species -- the southern beech -- approximately 90 per cent of the strontium, and other similar nutrient elements were brought in by the rain and did not come from soil or rocks, as just about everyone had assumed," said Kennedy.
The researchers also applied a distinctive artificial chemical tracer to the soil in a small portion of the forest. The tracer mimics the natural nutrients in the soil and trees with the advantage that it can be measured and observed as it moves throughout the soil-plant system. By sampling the tree parts and soil over a period of time, and by analysing the samples of the tracer, the scientists found that within three years most of the tracer was quickly leached from the top soil. The loss of this element within such a short amount of time surprised the researchers because it implies that a far smaller pool of nutrients is available to the trees from the upper soil than they had imagined.
The researchers say that the small size of the upper nutrient pool has important implications for forests influenced by industries. "Our study not only challenges the dominant paradigm that rocks and soil mineral weathering provide a majority of some important plant nutrients," said Kennedy, "but it also proposes that acid rain is a much bigger problem, potentially, than we had ever imagined."
The researchers experimented on trees in the unpolluted forests of southern Chile. "We went to the cleanest atmosphere on Earth so that we could find the closest thing to a long-term sustainable forest," Kennedy said. "There, we sampled soils, stream water, rain and plants, and analysed the strontium isotope composition of each one." Strontium isotopes indicate very accurately which fraction of nutrient comes from rain and which fraction comes from the rock. "We found that in the dominant tree species -- the southern beech -- approximately 90 per cent of the strontium, and other similar nutrient elements were brought in by the rain and did not come from soil or rocks, as just about everyone had assumed," said Kennedy.
The researchers also applied a distinctive artificial chemical tracer to the soil in a small portion of the forest. The tracer mimics the natural nutrients in the soil and trees with the advantage that it can be measured and observed as it moves throughout the soil-plant system. By sampling the tree parts and soil over a period of time, and by analysing the samples of the tracer, the scientists found that within three years most of the tracer was quickly leached from the top soil. The loss of this element within such a short amount of time surprised the researchers because it implies that a far smaller pool of nutrients is available to the trees from the upper soil than they had imagined.
The researchers say that the small size of the upper nutrient pool has important implications for forests influenced by industries. "Our study not only challenges the dominant paradigm that rocks and soil mineral weathering provide a majority of some important plant nutrients," said Kennedy, "but it also proposes that acid rain is a much bigger problem, potentially, than we had ever imagined."
Less acidic rain
Published on, Source : Down to Earth
In the 1970s, western Europe, Sweden in particular, was in the grip of a severe environmental crisis: acid rain. Eastern usa faced the same phenomenon in the 1980s. Ever since, many developed nations have undertaken efforts to avert the threat of acid rain. However, a number of polluted areas around the world are still subjected to the phenomenon. Belo Horizonte Metropolitan Region (rmbh) in Brazil's Minas Gerias state is one such area.
But, besides pollutants from vehicular and industrial sources, rmbh is also subjected to prevailing winds from an area where intensive calcareous exploitation occurs. Large emissions of sulphur dioxide (so 2) and nitrogen oxide (no x) gases react with water vapour in the air to form sulphuric and nitric acids, which come down with the rainwater.
But, on the other hand, these winds contain alkaline dust generated by wind erosion, calcareous dust from cement and lime processing units and ammonia gas emissions neutralise the acid rain.
Debora Vallory Figueredo, a chemical engineer and a senior researcher at Fundacao Centro Technologico de Minas Gerias in rmbh , Brazil, has reported on how calcareous soil particulates influence acid rain in the region. Rainwater samples were collected from three sites of rmbh - Belo Horizonte, Contagem and Betim cities. Belo Horizonte, capital of rmbh , is engulfed by vehicular emissions, while Betim and Contagem suffer from industrial pollution. The large calcareous area is located near the sampling stations and, therefore, all of them are influenced by the prevailing winds ( Ambio , Vol 26, No 6).
Ninety-one rainwater samples (32 from Belo Horizonte, 25 from Contagem and 34 from Betim) were collected during the wet seasons of October to February. Almost half the samples (48 per cent) were found to be acidic.
Sixty-five per cent of the samples from Bentim and 30 per cent of the samples from Belo Horizonte and Contagem stations were found to be acidic.
The primary conclusion arrived at was that the most polluted and industrialised area of Minas Gerias state, rmbh , is subjected to acid rain. However, the rainfall in rmbh is a dilute solution of minerals and acids, primarily sulphuric and nitric acids. It contains five major ions - calcium, sulphate, ammonium, nitrate and hydrogen.
Since the calcium ion is the major component of rmbh precipitation, the acid-neutralising capacity by calcium particulates becomes enormous. In the dry periods, these alkaline particles (calcium, for instance) are continuously emitted into the atmosphere and neutralise the acid gases from the industries and vehicles. Therefore, the acidity of the first rain is considerably low. However, the removal of these alkaline particles from the atmosphere by frequent rains reflects directly in the increase in rain acidity.
But, besides pollutants from vehicular and industrial sources, rmbh is also subjected to prevailing winds from an area where intensive calcareous exploitation occurs. Large emissions of sulphur dioxide (so 2) and nitrogen oxide (no x) gases react with water vapour in the air to form sulphuric and nitric acids, which come down with the rainwater.
But, on the other hand, these winds contain alkaline dust generated by wind erosion, calcareous dust from cement and lime processing units and ammonia gas emissions neutralise the acid rain.
Debora Vallory Figueredo, a chemical engineer and a senior researcher at Fundacao Centro Technologico de Minas Gerias in rmbh , Brazil, has reported on how calcareous soil particulates influence acid rain in the region. Rainwater samples were collected from three sites of rmbh - Belo Horizonte, Contagem and Betim cities. Belo Horizonte, capital of rmbh , is engulfed by vehicular emissions, while Betim and Contagem suffer from industrial pollution. The large calcareous area is located near the sampling stations and, therefore, all of them are influenced by the prevailing winds ( Ambio , Vol 26, No 6).
Ninety-one rainwater samples (32 from Belo Horizonte, 25 from Contagem and 34 from Betim) were collected during the wet seasons of October to February. Almost half the samples (48 per cent) were found to be acidic.
Sixty-five per cent of the samples from Bentim and 30 per cent of the samples from Belo Horizonte and Contagem stations were found to be acidic.
The primary conclusion arrived at was that the most polluted and industrialised area of Minas Gerias state, rmbh , is subjected to acid rain. However, the rainfall in rmbh is a dilute solution of minerals and acids, primarily sulphuric and nitric acids. It contains five major ions - calcium, sulphate, ammonium, nitrate and hydrogen.
Since the calcium ion is the major component of rmbh precipitation, the acid-neutralising capacity by calcium particulates becomes enormous. In the dry periods, these alkaline particles (calcium, for instance) are continuously emitted into the atmosphere and neutralise the acid gases from the industries and vehicles. Therefore, the acidity of the first rain is considerably low. However, the removal of these alkaline particles from the atmosphere by frequent rains reflects directly in the increase in rain acidity.
Acid rain arriving soon in India
Published on , Source : Down to Earth
When it rains it burns
Acid rain has already been reported in some parts of India, and the situation is likely to get worse.
INDIA faces an increasing threat from acid rain -- earlier believed to be the scourge of the West. The large-scale industrial growth and reliance on the use of coal and crude oil distillates like diesel have led to acidification of the atmosphere.The burning of fossil fuels is mainly responsible for creation of sulphur dioxide ( SO 2 ) and oxides of nitrogen ( NO x ) which lead to the formation of acid rain. Automobile exhaust fumes are partly to blame, but the worst culprits are coal-burning thermal power plants and the steel industry. Already, a low pH has been observed at Chembur, Maharashtra and Delhi. This is the conclusion of a study conducted by Manju Mohan and Sanjay Kumar of the Centre for Atmospheric Sciences, Indian Institute of Technology ( IIT ), New Delhi.
The phenomenon of rain is caused when heat from the Sun's rays on the surface of seas, lakes and rivers induces evaporation. The water vapour formed in the process rises to a height where it condenses into moisture. If ambient conditions prevail it comes down as rain. But in the case of acid rain, water vapour reaches the atmosphere, condenses, and reacts with atmospheric gases like SO 2 and NO x . When it rains, these atmospheric pollutants are deposited on the soil, vegetation, surface water or reservoirs. The deposition ultimately results in damage because of the acidity of the pollutants (see chart: What goes up must come down ).
The problem is very real in the sub-continent. India enjoys the dubious distinction of releasing the maximum pollutants in the atmosphere after China. Total sulphur emissions are expected to rise from 4,400 kilotonnes (kt) in 1990 to 6,500 kt in 2000, 10,900 kt in 2010 and 18,500 in 2020. It is, therefore, not surprising that low pH levels have been reported from Delhi, Uttar Pradesh, Maharashtra, Madhya Pradesh, Tamil Nadu and even the Andaman Islands. While this will not result in acid rain, the stage has been set for it and if conditions worsen like the setting up of a highly polluting thermal power plant in the vicinity or an industrial estate there may be acid rain. After analysing data from 10 Indian Background Air Pollution Monitoring Stations (BAPMONS ), scientists have confirmed that rain in and around these cities is getting increasingly acidic in nature.
The BAPMONS data collected during 1974-1984 shows that a few areas are already under stress conditions. During two decades, the acidic content of rain in Delhi increased, which means its pH level decreased from 7.0 (1965) to 6.1 (1984), and in nearby Agra from 9.1 (1963) to 6.3 (1984). The data also showed that pH levels in the Andaman Islands fluctuated between 5.6 and 8.9. Acidity and alkalinity are measured on the pH scale from 0 to 14. Normal water is 7 on the scale. Decreasing values on the pH scale denotes increasing acidity and, conversely, higher values show increasing alkalinity. A value below 5.6 denotes acid rain (see graph: Scale of acidity ).
C K Varshney, professor, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, warns 'Acid rain may cause irreparable damage to the country's biodiversity and even damage the food chain.' Moreover, the use of diesel is causing a high amount of sulphur and nitrogen emissions in the metros. Indian diesel has a sulphur content of 0.5 per cent by weight. Delhi and Agra are supplied with diesel that has a lower sulphur content. "But even this is far higher than sulphur levels in diesel used in countries like Sweden (0.001 per cent). Swedish diesel is 250 times cleaner. It means that with the rising number of diesel vehicles, the government's objective to bring down sulphur emissions may not be achievable," says H B Mathur, professor emeritus, Delhi College of Engineering. "If the government continues to encourage diesel usage, the prediction made by the IIT study may well come true," adds K P Nyati, head (environmental division), Confederation of Indian Industries ( CII ), New Delhi.
The only good news for India is that chances of acid rain occuring are unlikely. This is because tropical climatic conditions and predominantly alkaline-rich soils of the country have a neutralising effect on the pollutants, says R N Gupta, director, Environmental Meteorology Unit, Indian Meteorological Department ( IMD). As dust particles in the country are alkaline in nature, acid rain-causing gases such as SO 2 and NO x get neutralised. But there is the possibility of the phenomenon occurring in the Northeast and some parts of south India, he says. The IMD has, however, not confirmed these findings.
Acid rain has already been reported in some parts of India, and the situation is likely to get worse.
INDIA faces an increasing threat from acid rain -- earlier believed to be the scourge of the West. The large-scale industrial growth and reliance on the use of coal and crude oil distillates like diesel have led to acidification of the atmosphere.The burning of fossil fuels is mainly responsible for creation of sulphur dioxide ( SO 2 ) and oxides of nitrogen ( NO x ) which lead to the formation of acid rain. Automobile exhaust fumes are partly to blame, but the worst culprits are coal-burning thermal power plants and the steel industry. Already, a low pH has been observed at Chembur, Maharashtra and Delhi. This is the conclusion of a study conducted by Manju Mohan and Sanjay Kumar of the Centre for Atmospheric Sciences, Indian Institute of Technology ( IIT ), New Delhi.
The phenomenon of rain is caused when heat from the Sun's rays on the surface of seas, lakes and rivers induces evaporation. The water vapour formed in the process rises to a height where it condenses into moisture. If ambient conditions prevail it comes down as rain. But in the case of acid rain, water vapour reaches the atmosphere, condenses, and reacts with atmospheric gases like SO 2 and NO x . When it rains, these atmospheric pollutants are deposited on the soil, vegetation, surface water or reservoirs. The deposition ultimately results in damage because of the acidity of the pollutants (see chart: What goes up must come down ).
The problem is very real in the sub-continent. India enjoys the dubious distinction of releasing the maximum pollutants in the atmosphere after China. Total sulphur emissions are expected to rise from 4,400 kilotonnes (kt) in 1990 to 6,500 kt in 2000, 10,900 kt in 2010 and 18,500 in 2020. It is, therefore, not surprising that low pH levels have been reported from Delhi, Uttar Pradesh, Maharashtra, Madhya Pradesh, Tamil Nadu and even the Andaman Islands. While this will not result in acid rain, the stage has been set for it and if conditions worsen like the setting up of a highly polluting thermal power plant in the vicinity or an industrial estate there may be acid rain. After analysing data from 10 Indian Background Air Pollution Monitoring Stations (BAPMONS ), scientists have confirmed that rain in and around these cities is getting increasingly acidic in nature.
The BAPMONS data collected during 1974-1984 shows that a few areas are already under stress conditions. During two decades, the acidic content of rain in Delhi increased, which means its pH level decreased from 7.0 (1965) to 6.1 (1984), and in nearby Agra from 9.1 (1963) to 6.3 (1984). The data also showed that pH levels in the Andaman Islands fluctuated between 5.6 and 8.9. Acidity and alkalinity are measured on the pH scale from 0 to 14. Normal water is 7 on the scale. Decreasing values on the pH scale denotes increasing acidity and, conversely, higher values show increasing alkalinity. A value below 5.6 denotes acid rain (see graph: Scale of acidity ).
C K Varshney, professor, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, warns 'Acid rain may cause irreparable damage to the country's biodiversity and even damage the food chain.' Moreover, the use of diesel is causing a high amount of sulphur and nitrogen emissions in the metros. Indian diesel has a sulphur content of 0.5 per cent by weight. Delhi and Agra are supplied with diesel that has a lower sulphur content. "But even this is far higher than sulphur levels in diesel used in countries like Sweden (0.001 per cent). Swedish diesel is 250 times cleaner. It means that with the rising number of diesel vehicles, the government's objective to bring down sulphur emissions may not be achievable," says H B Mathur, professor emeritus, Delhi College of Engineering. "If the government continues to encourage diesel usage, the prediction made by the IIT study may well come true," adds K P Nyati, head (environmental division), Confederation of Indian Industries ( CII ), New Delhi.
The only good news for India is that chances of acid rain occuring are unlikely. This is because tropical climatic conditions and predominantly alkaline-rich soils of the country have a neutralising effect on the pollutants, says R N Gupta, director, Environmental Meteorology Unit, Indian Meteorological Department ( IMD). As dust particles in the country are alkaline in nature, acid rain-causing gases such as SO 2 and NO x get neutralised. But there is the possibility of the phenomenon occurring in the Northeast and some parts of south India, he says. The IMD has, however, not confirmed these findings.
To save the future
Published on , Source : Down to Earth
Human activities have made the sky a sewer. Subhash J Rele, writing in The Hindustan Times , estimates that each year, the global atmosphere is on the receiving end of 20 billion tonnes of carbon dioxide, 130 million tonnes (mt) of sulphur dioxide, 97 mt of hydrocarbons, 53 mt of oxides of nitrogen, more than three mt of arsenic, cadmium, lead, mercury, nickel, zinc and other toxic metals and a host of synthetic organic compounds, including polychlorinated biphenyls. There are also problems posed by the interaction among pollutants. In addition to contribution to acid precipitation, oxides of nitrogen can react with hydrocarbons to produce ozone, a major air pollutant.
Experts believe that if we use the latest technology available, such as the flue-gas desulphurisation technology, as is being done in Europe with existing and new power plants (coal and oil), an investment of Rs 72,910 crore per annum will be required to counter the acid rain problem in India after 2020. "But if we use basic control technology (emissions from large point sources controlled by domestic technology such as limestone injection), then India may require Rs 26,545 crore every year for pollution control measures,' says T S Panwar of the Centre for Environmental Studies, teri .
According to Varshney, a very concerted but determined effort is needed to produce environmentally clean energy by encouraging flue-gas desulphurisation technologies and also the use of low- no x burners. "It is high time we institute a dependable monitoring network for measuring acidification of rainwater in order to remedy the problem as it develops,' he says.
In India, almost 70 per cent of coal produced is used by power stations. "If India develops a technology to provide desulphurised coal to power stations, a major part of the acid rain problem would be addressed,' says Nyati.
According to S N Kaul, director, National Environment Engineering Research Institute (neeri ), Nagpur, "We have developed a technology to remove sulphur from coal. Until today, it has only been demonstrated in the laboratory. There is a need to conduct a pilot plant study before making the technology available for mass use.' But there are reports that Western Coalfields Limited and the Union ministry of environment and forests ( mef ) have already turned down neeri 's proposal to fund the setting up of a pilot plant project in this regard.
Experts say that it is important to address the problem of urban air pollution as well. According to a Supreme Court order, all the refineries will have to produce diesel with a sulphur content of less than 0.25 per cent by the end of 1999. Another apex court judgement of July 1998 orders replacement of all pre-1990 autos and taxis with new vehicles running on cleaner fuels, no eight-year-old bus to ply except on compressed natural gas ( cng) or other clean fuels and replacement of the entire Delhi Transport Corporation buses to cng by 2001. The Delhi government has also been asked not to register any new diesel taxis.
Despite this, the number of diesel vehicles is growing with most automobile manufacturers introducing diesel versions of their products. No day goes by without an automobile company introducing a variant running on the cheaper fuel. Manufacturers are confident that the temptation to possess a car with a running cost almost as cheap as that of a scooter will be too much for a car-buyer to ignore. This fuels their drive to produce more diesel cars. The power situation in the country has also set off a spurt in the sale of gensets
Experts believe that if we use the latest technology available, such as the flue-gas desulphurisation technology, as is being done in Europe with existing and new power plants (coal and oil), an investment of Rs 72,910 crore per annum will be required to counter the acid rain problem in India after 2020. "But if we use basic control technology (emissions from large point sources controlled by domestic technology such as limestone injection), then India may require Rs 26,545 crore every year for pollution control measures,' says T S Panwar of the Centre for Environmental Studies, teri .
According to Varshney, a very concerted but determined effort is needed to produce environmentally clean energy by encouraging flue-gas desulphurisation technologies and also the use of low- no x burners. "It is high time we institute a dependable monitoring network for measuring acidification of rainwater in order to remedy the problem as it develops,' he says.
In India, almost 70 per cent of coal produced is used by power stations. "If India develops a technology to provide desulphurised coal to power stations, a major part of the acid rain problem would be addressed,' says Nyati.
According to S N Kaul, director, National Environment Engineering Research Institute (neeri ), Nagpur, "We have developed a technology to remove sulphur from coal. Until today, it has only been demonstrated in the laboratory. There is a need to conduct a pilot plant study before making the technology available for mass use.' But there are reports that Western Coalfields Limited and the Union ministry of environment and forests ( mef ) have already turned down neeri 's proposal to fund the setting up of a pilot plant project in this regard.
Experts say that it is important to address the problem of urban air pollution as well. According to a Supreme Court order, all the refineries will have to produce diesel with a sulphur content of less than 0.25 per cent by the end of 1999. Another apex court judgement of July 1998 orders replacement of all pre-1990 autos and taxis with new vehicles running on cleaner fuels, no eight-year-old bus to ply except on compressed natural gas ( cng) or other clean fuels and replacement of the entire Delhi Transport Corporation buses to cng by 2001. The Delhi government has also been asked not to register any new diesel taxis.
Despite this, the number of diesel vehicles is growing with most automobile manufacturers introducing diesel versions of their products. No day goes by without an automobile company introducing a variant running on the cheaper fuel. Manufacturers are confident that the temptation to possess a car with a running cost almost as cheap as that of a scooter will be too much for a car-buyer to ignore. This fuels their drive to produce more diesel cars. The power situation in the country has also set off a spurt in the sale of gensets
Two-thirds of the nation's household sewage was untreated last year, while "heavy pollution" tainted some cities' air, said a report by the State Environmental Protection Agency, or SEPA.
Acid rain -- blamed on smoke from coal-burning factories and power plants -- is spreading, with the number of cities suffering from levels considered severe rising last year to 218, compared with 210 in 2003, the report said.
China's environment has been ravaged by two decades of breakneck growth, and by the pressure of feeding and housing a population of 1.3 billion. Official efforts to reduce pollution in recent years have had limited success.
"Rapid economic growth has intensified China's environmental problems," Wang Jirong, a deputy director of the environmental agency, said at a news conference. "All the problems that developed countries have seen over the past century, China has suffered in the past 20 years."
Public anger at pollution damage to farmland, crops, drinking water and fishing grounds has become a volatile issue for the communist government.
In April, scores of people were injured when police clashed with villagers who occupied an industrial complex, which they said ruined their crops by polluting water supplies.
The government has forced polluting factories to close, and is spending heavily on switching its power generation from abundant but dirty coal to cleaner natural gas.
In Beijing, the government is pouring money into moving polluting industries out of the city in an effort to clean up the Chinese capital before the 2008 Summer Olympics.
But economic growth, projected to pass 9 percent this year, has fed soaring demand for power, causing shortages nationwide and forcing China to keep older coal-fired plants in service.
Conservation efforts also have been undercut by local authorities who resist shutting down paper mills, chemical plants and other polluting facilities for fear of losing jobs and tax revenue.
"Local governments and environmental protection bureaus in particular are insufficient in implementing and enforcing laws," said Wang Yuqing, another SEPA deputy director. "As a result, pollution from industry cannot be solved effectively."
Wang said public complaints to the agency about violations have been rising by 30 percent a year, which he said reflected both growing popular understanding of the law, and the scale of problems.
Wang Jirong, the other official, said regulators have recorded minor successes.
"The water quality in China has remained stable, and in selected regions the water quality is improving," she said. "I believe that is the limited progress we have achieved after years of effort."