The release of toxic wastes into the air represents a clear and present danger, particularly to residents of the Texas Gulf Coast. While toxic waste dumps have claimed substantial publicity and the lion's share of environmental funds, many of those same substances are being routinely - and sometimes accidentally - released into the atmosphere.

In a series entitled "The air we breathe," Chronicle reporter Bill Dawson detailed the immense complexity of the problem. What emerges are questions that are crucial to the health and safety of Houston-area residents: Should chemicals only suspected of causing harm be regulated, or should we wait until that harm is proved? Can we have safety without sacrificing jobs? What are the risks, and can they be held to reasonable limits? What are the responsibilities of government, of industry?

The answers will not be found without many more years of scientific research. That research must be done. However, even the limited data now available argue that when there is doubt, the decisions of government officials and industry executives must come down strongly on the side of public health.

The Environmental Protection Agency says its resources are limited and it must concentrate on a few of the most hazardous toxic chemicals. But some chemicals that are known hazards remain unregulated. The EPA also wants the states to play a greater role in regulating their industries. That seems reasonable, but Texas must be prepared to strengthen its ability to do so.

As a result of the Bhopal disaster in India, industry is more aware of the danger. It is taking extra precautions against catastrophic accidents and has made voluntary reductions in the toxic wastes it emits into the air. New technologies and processes have been developed to minimize the risk. Unfortunately, there is a pattern in which dangerous accidents occur, and only then is there a flurry of concern and preventive measures.

There is no such thing as a safe level of toxic waste in the air we breathe. Even at low levels, some risk is inherent. The line must be drawn somewhere. In drawing it to the best of our knowledge, we must err on the side of caution.

While we can never be absolutely sure about the harm threatened by some toxic wastes, we must never be satisfied with our lack of knowledge.