EAT, DRINK--but be wary. A Congressional panel has found that, despite a variety of federal programs designed to screen contaminated food, just about everything you eat contains residues of synthetic substances, which have been linked to cancer, birth defects and permanent genetic mutations.

Occasionally, these chemicals enter the food chain by accident, as when the chemical PBB, a poisonous fire retardant, which was not clearly labeled, was mixed in with cattle feed in 1973--and was eventually eaten by 90 per cent of Michigan. Sometimes chemicals become part of what we eat through negligence, as when the pilots of dust-cropping planes forgot to turn off their sprayers when they flew over houses, rivers and schools in Maine, Arizona, Oregon and several other states this spring.

But often, chemical companies deliberately poison the environment. Beginning in 1966, Allied Chemical dumped tons of the banned pesticide Kepone into the James River for several years, ending fishing in the entire river and its tributaries all the way to the Chesapeake Bay. Abetted by government regulators lacking both the resources and the inclination to monitor it, the chemical industry's corner-cutting has had disastrous effects on the food supply of the United States.

Each of the four food grains--meat, dairy products, grains, and fruits and vegetables--has been polluted in its own way because of industry and regulatory negligence, callousness or profit-mongering. At least 143 pesticides and drugs--some deliberately injected into animals, others accumulated when livestock are fed pesticide-treated grain--are known to leave residues in meat and poultry. Only 46 of these are now monitored by the USDA, the agency responsible for inspecting meat, even though 40 are suspected of causing cancer and 18 are suspected of causing birth defects. Antibiotic arsenic compounds, sulfa drugs (long ago linked to cancer), and the infamous diethylstilbestrol (DES), which was found to cause cervical cancer way back in 1971 in daughters of women who used the drug, are still fed and injected into the animals we eat. Despite the existence of safer alternative drugs, the meat industry continues to pour these certified poisons into the food chain. Ironically, they are used for the prevention and cure of animal diseases.

IF YOU AVOID red meat, you won't find any refuge in eating fish. At the top of the food chain, fish can accumulate chemicals at up to 300 times the level in surrounding waters. If you eat fish regularly, chances are you've swallowed more than your share of the chemical PCB. Non-biodegradable, carcinogenic and shown to cause stillbirth, numbness in limbs and bone deformities, PCBs have been found in over 90 per cent of all Americans. Leaking from unprotected industrial dumps, gushing from factory pipelines and pouring out of the tank trucks of illegal dumpers, PCBs have permeated more places and people than DDT ever reached. The chemical has even been found in fish 11,000 feet down in the Atlantic Ocean.

PCBs have been repeatedly discovered in mothers' milk, as well as in the pasteurized milk and dairy products you buy packaged in the supermarket. Pesticides, too, have been found on your grocery shelves. In 1974, for instance, the Food and Drug Administration found the carcinogenic pesticide dieldrin in 85 per cent of all dairy products sampled.

THE CHEMICAL INDUSTRY continues to reap profits from the fumigant carbon tetrachloride--used on corn, wheat, rice, barley, oats, rye, sorghum and even popcorn--even though it is toxic to embryos, livers and kidneys, and may cause mutations, birth defects and cancer.

Even fresh fruits and vegetables--especially fresh fruits and vegetables--often contain many dangerous pesticide residues. The number one pesticide in the U.S., toxaphene, encompassing one-fifth of all pesticide use, has long been known to cause cancer, and the Environmental Protection Agency found in 1975 that it drastically alters bone growth and bone composition in fish, birds and animals. Yet it is still applied to livestock and just about every food crop in the nation, including soybeans and a wide variety of fruits, even though EPA has banned its use on lettuce and cabbage crops, which are less lucrative for growers and refused to certify toxaphene's safety for permanent use.

Another pesticide frontrunner, ethylene dibromide, was years ago shown to cause some chromosome damage, to induce tumor formation, and to cause reproductive problems in several species. The EPA has only begun to look at the pesticide's safety, even though EDB is used on peaches, grapes, beans, peas and other fruits, as well as soybeans and cotton.

With every dinner table a chamber of dietary horrors, Congress has been asking what the three government agencies responsible for monitoring food are doing. They've found some disturbing answers. The House Commerce Oversight Committee points out that "a distressingly large number" of chemicals known to leave meat residues simply aren't looked for by the USDA, probably because less than 1 per cent of USDA's total inspection budget is devoted to residue monitoring. In addition, the USDA uses a "wholly inadequate" data base to determine permissible levels of chemical residues. Called the Total Diet Study, the data consists of a mere 30 supposedly representitive grocery carts of food, which the USDA uses to estimate the levels of chemicals in all foods. The problem is that the Total diet Study is based on the average diet of a teenage male--even though its findings will be used to calculate the amount of chemicals eaten by all persons, of both sexes and all ages.

The Food and Drug Administration isn't much better. A Congressional panel remarks that the FDA's formal rulemaking procedures "are complex, cumbersome, and time-consuming." As a result, the FDA usually relies on informal "action levels" if a chemical is present at levels above a certain level, the contaminated food can be seized. The action levels, however, can be set with little or no public input and little or no supporting scientific evidence. The result: possible dangerous levels of chemicals may be passing through the FDA's regulatory machinery with the FDA's blessing.

Even when a chemical does exceed one of the few limits set by the agency, Congress has found that the FDA "investigates few of the residue violations...and rarely prosecutes violators." Both the FDA and the USDA, the Congressional study adds, "almost never result in meat or poultry recalls." In fact, the highly-touted USDA "stamp of approval" has frequently been given to meat known to be illegally contaminated--but sold to consumers anyway.

The Environmental Protection Agency, however, is the worst of the three agencies. Some carcinogenic pesticides continue to be used, although many scientists believe there is no safe level of use. The EPA entirely exempts from regulation what it calls "inert" chemicals, which may be mixed with pesticides to increase their effectiveness, even though many inert chemicals are poisonous. The EPA also uses a data base collected 15 years ago to estimate how much of what foods the average individual consumes today--data which Congress says "borders on the absurd." Since the EPA study was made in 1965, Congress reports, "We have seen some major shifts in food consumption in the U.S.... Consumption of poultry, chicken, cheese, margarine, shortening and oils, fresh and frozen vegetables and corn syrup and sweeteners has increased." Finally, the EPA supports many of its decisions with data supplied by the chemical industry itself--which obviously has an interest in pooh-poohing the dangers of its products. The EPA's program, Congress concludes, "is abysmal and needs a complete overhaul."

NOW THAT CONGRESS has been alerted though, it has decided to shelve the issue and "study" the problem some more. Chairman Henry Waxman (D-Cal.) and ranking Republican Tim Lee Carter (R-Ken.) "have to be convinced first by public pressure," says one subcommittee aide, before Congress and its Health and Environment Subcommittee even begin to pressure the three delinquent regulatory agencies and a negligent chemical industry.

Even if Congress is stirred into action, though, the Office of Technology Assessment notes that increased regulation by the FDA, USDA, and EPA "are not likely to prevent the deliberate or accidental misuse or disposal of the thousands of toxic substances manufactured in the U.S." The answer, then, is to create incentives within industry, and so to encourage industry to regulate itself. This answer has been proposed in a bill coming up in the House of Representatives. Sponsored by Rep. George Miller (D-Cal.), H.R. 4973 imposes a minimum of two years in jail and a fine of $50,000 on corporate executives who are aware that a product or business practice poses "a serious danger" to the public, but who fail to warn the government or warn affected employees. This comprehensive deterrent, striking personally at the corporate executive as well as the corporation, could quite literally revolutionize industry's present misuses and sloppy disposal of toxic substances, while public pressure on Congress, if relayed to the three regulatory agencies, could eliminate the more flagrant cases of food contamination.