CHONGQING, China -- Frequent acid rains make this industrial powerhouse China's "rust capital" -- a hot spot within the environmental disaster spreading through the world's largest nation.

Perched on hills along the Yangtze River in southwest China, Chongqing (formerly Chunking) is drenched in acid rain more than once every five days. The tainted rains result from a bad combination: the city's steep terrain, its wet climate and the high sulfur content of the coal burned by its heavy industries.

Chongqing's 4 million residents are also afflicted with acid fogs and acid dust. Sometimes, they even receive nasty "black rains," rainfalls turned ink-black by airborne industrial ash.

New buildings quickly look old because of the dark streaks left by the polluted rains. Withered trees along the city's streets have been replaced three times since the 1960s. Parts of its TV tower have been changed three times since the 1970s.

A report by the city's environmental protection bureau claims that Chongqing is China's most polluted big city. But even if that is true, the problems here represent only a small part of the environmental debacle building in China because of its explosive industrial growth and inattention to pollution controls.

China's environmental problems "are more severe than at comparable periods of economic development in industrialized countries," a World Bank report found. And these problems bode poorly for the quality of life of more than a fifth of the world's population:

* Most urban ground water sources are polluted. Many cities, particularly in north China, face dire water shortages. Most waste water is dumped untreated into waterways. Only 40 percent of urban Chinese and one in seven rural Chinese have safe drinking water. Inland fisheries are dying; red tides and other signs of contaminated coastal waters are on the rise.

* The air in several Chinese cities is among the worst in the world. Because of China's heavy reliance on burning coal for energy, sulfur dioxide levels in virtually all its cities far exceed international standards. Air pollution is the leading cause of disease, with pulmonary obstructive disease responsible for 1 in 4 deaths -- a rate five times that in the United States.

* Despite large-scale tree-planting campaigns in recent years, forest cover has shrunk to about 13 percent of China's total area, compared to the world average of 31 percent. This has led to increased droughts, flooding, erosion and silting of waterways. A sixth of China's arable land has been damaged by erosion. Soil fertility is dropping, deserts growing and grasslands and wetlands shrinking.

* Garbage, industrial wastes and toxic wastes are piling up on the edges of China's cities. Booming but often primitive rural industries are rapidly polluting the countryside. China's remaining wild lands, valuable sources of biodiversity, are dwindling so fast that most may be gone within a few decades.

Within this bleak picture, China is making some efforts to protect its environment.

Enacted comprehensive laws

Unlike most developing nations, it has put in place a comprehensive set of environmental laws over the last 15 years and, at least on the national level, a fairly extensive regulatory apparatus.

Authorities published an ambitious plan, called Agenda 21, this year for doing much more to control pollution, a plan that has Western vendors of environmental-protection technologies viewing the China market with huge hopes.

Environmental problems are also getting a lot more attention in China's state-controlled media, including some relatively aggressive investigative reporting. And statements about the need to control pollution are cropping up more in leading officials' rhetoric.

Even one of Deng Xiaoping's daughters, Deng Nan, a state technology official, told an international environment conference here this summer: "It is a must for China to choose a sustainable development strategy because it is the only way out."

But China wants the world's richer nations to provide money and technology so it can find ways to develop without more environmental damage. Even with a recent World Bank loan, such aid has not arrived on a large scale, though it may be in the long-term interest of developed nations, since China is one of the world's major producers of the gases linked to global warming.

But despite some progress, any environmental gains in recent years have been more than offset by China's rapid industrial growth. And with the Communist Party's legitimacy staked on providing an ever-rising living standard, most local officials these days still emphasize economic growth at any cost.

In Chongqing, the city's environmental protection bureau has never closed a polluting factory, and it only fines about 10 to 20 companies a year, says Wang Gang, the bureau's planning chief.

200-300 polluters

The bureau's inspectors concentrate on the most serious 200-300 polluters among Chongqing's 8,000 factories. But with many aged polluters, Mr. Wang says, the best his bureau can do is hope these factories go bankrupt and shut down.

"We're just spread too thin," he says. "We can't keep up with economic growth."

As a sign of progress, Mr. Wang cites a drop in incidence of the city's acid rains over the last five years from 90 to 78 a year.

But only one facility in Chongqing, a large power plant, has installed modern scrubbers on its smokestacks to clean its emissions. And average levels of sulfur dioxide and suspended particles in the city's air remain far above the safety standards set by the World Health Organization.

Likely a result of the high concentration of airborne particles, the cancer rate in Chongqing's central district is twice that of its rural areas.

Bronchitis also is at high levels. "I often have a cough and I don't even smoke," complains Zhou Shihong, another city environmental protection official.

And Chongqing's environmental problems aren't limited to air pollution. Lacking a sizable sewage processing plant, the city pumps more than a billion tons of largely untreated industrial and household waste into the waters of the upper Yangtze River, central China's lifeline.

"The people in the factories just don't want to spend any money on pollution-control equipment," Mr. Wang says.

The World Bank report, released two years ago, predicts that saving money this way may turn out to be very costly as China's pollution problems eventually could have a "severe braking effect" on the nation's economic growth rate.

Importance stressed

This mounting environmental degradation ultimately will be more important "in determining China's fate" than its political arrangements, a leading Western expert on China's ecology, Vaclav Smil of the University of Manitoba, has predicted.

"One can hope for the eventual transition from one-party dictatorship to genuine democracy," he wrote shortly after the 1989 Tiananmen Square massacre, "but this evolution may bring little relief to China's environmental ills."

Some dissidents here believe that China's environmental problems could provide fertile ground for the growth of popular opposition to Communist rule, much as democratic activists used Taiwan's pollution problems to help end the autocratic rule of the Nationalist Party there.

But China remains a long way from allowing environmental activists to organize, let alone challenge the Communist Party.

The nation's first major environmental movement, formed to oppose the planned Three Gorges Dam project on the Yangtze, was crushed in 1989 along with the Tiananmen Square protests.

Dai Qing, a journalist who was jailed for 10 months leading that movement, says the Chinese government suppresses awareness of environmental problems because the party fears that "green" activists will rise to power as in Europe.

"The government only thinks about protecting its power," she says. "Environmentalists in China almost can do nothing."

'Friends of Nature'

This summer, a Beijing intellectual recently was allowed by the government to form China's first quasi-independent environmental organization. But in inaugurating his group, "Friends of Nature," Liang Congjie has had to vow to sidestep political issues.

"Essentially, you can't separate environment problems from the government's policies," Mr. Liang says. "But we're going to try our best to stay away from politics.

"We have enough work to do without that, because in China the environmental consciousness is so low that most people still don't even know about the need to protect the environment."