Flash! EPA protects environment!

Public protest can have an effect. This was the immediate reaction of a former Washington official when he heard that the Reagan administration intended to reverse course and tighten rules against air-polluting lead in gasoline. A few more episodes like this, and the administration could reduce the threat of a ''growing polarization'' between it and defenders of the American environment.

According to a major private report on the state of the environment, this polarization is distracting the nation from environmental problems that can impair public health. It has been fed by an administration that ''has pursued its domestic goals with such single-mindedness, so aggressively, as to allow conservationists no alternative to protest.''

These are the words not of some wild-eyed ''environmentalists'' but of the research-oriented Conservation Foundation. It committed so much of its resources to this 439-page report in order to fill a vacuum left by what it sees as administration failure to collect and disseminate sufficient information for developing environmental policy.

The gravity of the situation in conservationists' eyes is underscored by ''Ronald Reagan and the American Environment,'' a shorter document sponsored by ten organizations including the Wilderness Society, National Audubon Society, and Friends of the Earth. It notes that political conservatives have helped to shape the environmental role of government and charges that the Reagan attack on that role is not conservative but radical. Among many other warnings, it says that pollution will increase because of a systematic weakening of rules designed to control it and of the agencies to enforce them. This is where the reported new attitude toward lead in gasoline offers encouragement. Earlier in the year the Environmental Protection Agency received an onslaught of protest when it proposed to lessen or eliminate controls on lead in gasoline. Just last month the EPA was sued in federal district court to require it to ensure that states carry out programs to control the lead in the air caused by fuel in cars and industrial installations. The plaintiffs include three New York children who are victims of lead poisoning. A recent survey found 675,000 American children suffering lead levels higher than the specified safe maximum. Levels have been found to decline in keeping with mandated decline in lead in gasoline.

Now conservationists are cautiously welcoming an EPA switch toward strengthening the rules against lead at least in gasoline. One question involves a dubious proposal that two companies can average out their lead pollution: the one that cuts more could sell its margin to the other, permitting it to cut less. This could result in levels too high in certain local areas. But in general it sounds as if, in this case, the Environmental Protection Agency would actually be protecting the environment.

An EPA spokesman denied that the protests had played a role in causing a switch on lead that was based instead on ''information we received.'' Indeed, the information on lead should have been sufficient to forestall proposals for weakening the rules in the first place. But further steps in the direction of firm environmental protection would surely reduce protests - as well as that damaging and unnecessary ''polarization'' between the President and his country's widespread conservation constituency.