The Environmental Protection Agency has backed away from ambitious plans to tighten regulation of lead in air and water, ignoring its studies documenting dangers of the metal.

Within the past 2 1/2 years, the agency outlined proposals to eliminate lead additives in gasoline and to reduce sharply the amount of lead permitted in household drinking water -- with both regulatory initiatives originally slated for early 1988.

As the new year approaches, however, the EPA has indefinitely shelved the lead additive ban and put off completion of new lead limits for drinking water until at least September. The agency also has relaxed its planned requirements for water suppliers to meet stricter lead standards.

Once regarded as a danger restricted to smelter workers and ghetto children who ate peeling paint, lead has emerged in recent years as a health hazard to millions of Americans. Absorbed in low levels, the metal can complicate pregnancies, raise blood pressure in men and retard the intellectual and physical growth of youngsters, including 17 percent of the urban preschool children pinpointed by a Public Health Service report being prepared for Congress.

"In the face of this extraordinary data base on lead's toxicity, EPA is retreating," said Dr. Herbert Needleman, who pioneered studies on health effects of the metal. "They should be finding lead in the environment and reducing it with urgency."

The EPA proposed in 1985 to reduce concentrations of the metal in the two most common sources of exposure -- air and drinking water.

Efforts to cleanse the air began in the mid-1970s when the agency ordered reductions of lead additives in gasoline. By April 1985, the EPA unveiled a proposal to ban lead, a cheap octane booster, as early as Jan. 1, 1988. Over the next seven months, the EPA twice directed refineries to lower the lead content of gasoline from 1.1 grams per gallon to 0.1 grams in January 1986.

The efforts have reduced lead emissions to one percent of the 210 billion grams released in the early 1970s.

But the agency has decided against the ban proposed for Jan. 1 because many old vehicles, including farm equipment, cannot run on lead-free gasoline, said Rich Kozlowski, of the EPA's air office. Moreover, he said, the natural discarding of old vehicles and dropoff in illegal use of leaded gas may achieve the same effect.

"If lead is going down on its own, no need for government intervention," he said.

Stephanie Pollack, a lead specialist at the Conservation Law Foundation, accused the EPA of "backpedaling." She cited a 1985 study by the agency showing that lowering the standard from 0.1 grams to zero would prevent 123,000 cases of high blood pressure in men and reduce health risks for 7,000 children. Health savings were estimated at $635 million, compared to $149 million in costs to refineries.

"Even if you believe in the Reagan administration philosophy that "In the face of this extraordinary data base on lead's toxicity, EPA is retreating."

-- Dr. Herbert Needleman

the benefits must substantially exceed the costs before you take any regulatory action," Pollack said, "we should still ban lead in gasoline."

Plans to clean up drinking water were announced in November 1985 with a proposal to lower the lead standard to 20 parts per billion (ppb) from the 50 ppb limit set in the 1960s. The agency released a study a year later to justify the reduction, estimating that excessive concentrations of the metal in the household tap water of 42 million people annually lowered the intelligence of 240,000 children, caused hypertension among 130,000 middle-aged men and increased the risk of miscarriages and other pregnancy dangers for 680,000 women.

The new regulations were to complete the regulatory cycle by early 1988. But the EPA had backed off of earlier plans to control lead in drinking water, and Congress acted in 1986 to mandate new standards for the metal along with other drinking water pollutants in three phases to end in June 1989. The agency pledged to promulgate lead standards within the second phase, which ends next June.

Two weeks ago, the EPA announced that the new standards would not be ready by the second phase. A new target of next September was set, but specialists inside and outside the agency said they doubt the regulations will be ready before 1989.

Joseph Cotruvo, of the EPA's office of drinking water, blamed the delay on the "unique" problems of controlling a pollutant that comes mainly from the lead pipes and lead solder of residential plumbing. The problem, he said, is holding public water suppliers responsible for "plumbing they don't control or own."

The EPA originally planned to require suppliers to meet the 20 ppb limit at the household tap by applying the best available technology, such as controlling the corrosive elements of water that cause lead to dissolve and leach.

Suppliers unable to meet the standard could have obtained an exemption from the state in which they operate after proving that the lead level did not pose an unreasonable health risk. But the state could have required the supplier to replace lead service pipes or provide bottled water.

A new strategy outlined in a November memorandum would not require suppliers to achieve the standard at the tap. Instead, they would only have to reduce the corrosivity of water in the hope of reducing levels of the metal. If lead exceeded 10 ppb, they would have to conduct what the the memo called "targeted public education." Cotruvo said that means advising residents how to handle the problem.

Pollack said the plan "lets the water suppliers off the hook. The EPA is telling people they cannot be assured that when they turn on their tap, safe drinking water will come out."