One third of China is suffering from acid rain caused by rapid industrial growth, an official report quoted by the state media says.
Local leaders are accused of putting economics before environment
Pollution levels have risen and air quality has deteriorated, the report found. This comes despite a pledge by the authorities to clean up the air.
In the latest incident, a reservoir serving 100,000 people in north-west China was polluted by a chemical spill.
China has some of the world's most polluted cities and rivers.
The pollution inspection report to the standing committee of parliament found that 25.5 million tonnes of sulphur dioxide were spewed out, mainly from the country's coal-burning factories last year - up 27% from 2000.
Emissions of sulphur dioxide - the chemical that causes acid rain - were double the safe level, the report said. In some areas, rainfall was 100% acid rain, it added.
"Increased sulphur dioxide emissions meant that one-third of China's territory was affected by acid rain, posing a major threat to soil and food safety," Sheng Huaren of the standing committee, was quoted by state media as saying.
Local governments were accused of overlooking environmental regulations in the rush for economic development.
"It is especially worrying that most local governments base economic growth on energy consuming industries, disregarding the environment's capacity to sustain industrial expansion," Mr Sheng said.
His report echoes the findings from the State Environmental Protection Administration (SEPA) released earlier this month.
In July, China announced it planned to spend 1.4 trillion yuan ($175bn) over the next five years on protecting its environment.
The sum - equivalent to 1.5% of China's annual economic output - will be used to improve water quality, and cut air and land pollution and soil erosion.
Meanwhile, water supplies to the city of Hancheng in Shaanxi province were due to resume on Sunday, following an emergency when a nearby reservoir was polluted with 25 tonnes of caustic soda.
Officials brought in 10 tonnes of hydrochloric acid to neutralise the caustic soda, which was being carried by a tanker that fell into the Xuefeng reservoir on Friday, killing one person.