WHEN grasshoppers invaded some Midwest grazing lands a few years ago, the Environmental Protection Agency granted emergency approval for the use of toxaphene, a chemical pesticide on which EPA's safety reviews were not yet completed.
Farmers ''have to do something if their crops are dying of insects,'' says Don Rawlins, an official with the American Farm Bureau Federation.
But before the pesticide could be applied, the National Audubon Society, concerned about the risk to people and wildlife from exposure to toxaphene, won a court order temporarily blocking its use. As a result, says Mr. Rawlins, ''the grasshoppers mowed through and made the ground bare.''
Then last October, after EPA had calculated that toxaphene was a suspected cause of cancer in people, the the agency announced plans to cancel most uses of the pesticide (except for existing stocks) in the US.
As in this case of grasshoppers and toxaphene, the EPA tries to balance the needs of farmers and ranchers with the need to assure American consumers, farmworkers, and others that pesticides used on crop and grazing lands in the United States are not harmful to them or to the environment.
In Monitor interviews with representatives of farmers, pesticide manufacturers, environmentalists, and a variety of state and federal officials, the EPA's efforts drew both praise and strong criticism. They spoke of two trends which are at the heart of the pesticide debate:
1. Faster approval by the EPA in the past year or so of pesticides for national use. Pesticide manufacturers welcome this trend; critics, including some in the EPA, say the approval process is using less stringent safety criteria.
2. Increasing temporary approval by EPA during the past five to seven years of widespread use of pesticides whose environmental effects had not been determined by the EPA. More than 10,000 such uses have been approved since 1977, according to preliminary findings by a House agricultural subcommittee.
In the interviews there were several predominant themes. Among them: the public's need to know the risk associated with pesticides vs. the manufacturers' need to keep out of the hands of competitors the risk data their company has produced, usually at considerable cost.
Today, most of the risk assessment process conducted by EPA is done behind closed doors. Even toxicity data, legally available, are difficult to obtain. In the case of temporary approval by the EPA of a chemical not yet registered by EPA as environmentally safe, no public justification is required.
Environmentalists, among others, would like to see the whole process opened more to public scrutiny. Manufacturers would like to see even tighter controls put on risk data so that competitors who manufacture similar products cannot use that data without reimbursing the company that produced the data.
Another issue is who is responsible for screening out unsafe pesticides.
Jack Early, president of the National Agricultural Chemicals Association, says state officials need to be ''more responsible'' in their requests to the EPA to approve pesticide uses requested by farmers. But state pesticide officials like Georgia's Ron Conley say most of the pressure for the use of unregistered pesticides comes from chemical companies trying to sell products, and that ''the primary responsibility'' for screening pesticides is the company's.
Various environmentalists, including Maureen Hinkle of the National Audubon Society, blame the EPA for a lack of rigor in keeping pesticides out of use until they have been found environmentally safe.
Says Mr. Early: ''All people in the process are a little concerned.'' But they are concerned for different reasons. Solutions differ according to who is asked.
Don Rawlins of the American Farm Bureau, which represents agricultural industries as well as farmers, agrees with manufacturers that EPA review requirements on pesticide safety should be pruned back. ''Many of the tests required are figments of environmentalists' imaginations - not necessary,'' he said.
But some experts recommend less reliance on chemical pesticides and greater reliance on alternative pest-control methods, such as pest-eating insects and use of natural secretions from pests. Sheldon Samuels of the Industrial Union Department of the AFL-CIO calls for a ban on the import of products grown with untested or misused pesticides. And he calls for criminal prosecution of public officials not enforcing pesticide safety laws already on the books in the US.
The debate is likely to pick up even more with the completion of a congressional report by a House agricultural subcommittee chaired by Rep. George Brown Jr. (D) of Texas. The report, expected soon, is critical of the way the EPA has been filling its watchdog role on pesticide safety. The report will document the widespread - and increasing - approval by the EPA of pesticides not yet proved to be environmentally safe.
Hundreds of thousands of acres of range and croplands, especially fruits and vegetables, have been sprayed with such pesticides, according to preliminary findings by a House subcommittee, says subcommittee staff director Charles M. Benbrook.
The increased use of emergency approvals by EPA ''should not be considered as evidence of abuse,'' says Arthur Yocom, a spokesman for FMC Corporation, a major pesticide manufacturer. Robert Ridsdale, in charge of product registration for ICI Inc., another major pesticide manufacturer, says, ''Most companies wouldn't allow it (their product) to be used if they didn't think it was safe.''
The use of pesticides that haven't been thoroughly tested is justified by manufacturers and some farm organizations as a way of meeting what federal law calls ''emergency'' and ''special local'' needs.
Congressional and environmental critics contend the ''emergencies'' are often not true emergencies, because alternative pesticides registered by the EPA as environmentally safe are available, though sometimes at higher cost.
The subcommittee's preliminary findings see a close link between emergency use approvals by the EPA and the lack of success in combating pests for certain crops, particularly fruits and vegetables. And according to some analysts of the issue, companies sometimes do not apply for full national registration for a pesticide because the risk testing is too costly to justify it for smaller markets.
But critics say the emergency and special local needs process is little more than a way to bypass the full EPA safety reviews required to ''register'' a pesticide for national use.
Critics also say that the EPA does little in-depth analysis to verify state assertions that an emergency or special local need exists and that the pesticide in question is safe.
In most cases the original risk testing is done by the companies themselves or laboratories they contract with. In the late 1970s, federal inspectors charged the major testing laboratory, Industrial Bio-Test Laboratories, with conducting poor quality, possibly fraudulent tests. The laboratory is being prosecuted by the Justice Department.
More than 100 chemicals were approved by EPA on the basis of these now-disputed tests, according to EPA documents. And many of them remain on the market today, according to the Rachel Carson Council, an environmental organization.
Pesticide manufacturers and some state pesticide regulatory officials, as well as the American Farm Bureau Federation, say that in the past the EPA's safety reviews have taken too long because they involved many unnecessary queries not pertinent to human or environmental safety.
Critics say EPA officials are making faster decisions on the safety of pesticides on the basis of a less thorough examination of important health and environmental effects. ''They're not taking an in-depth look,'' says Robert LaRue, of the Montana Department of Agriculture.
John A. Todhunter, EPA assistant administrator for pesticides and toxic substances, denied this in an interview. ''We are not requiring any less testing than we had.'' The same scientific review time is being given on pesticides as in the past, he added. The EPA review is ''one of the most rigorous in the world ,'' he said. The speed-up, he said, is due primarily to better management.
When the Reagan team took over EPA there were some 1600 decisions pending on pesticide safety. Now there are only about 15, he said.
But others - M. Adrian Gross, EPA's senior science adviser in the pesticide hazard evaluation division; Herbert Harrison, chief of the EPA insecticide and rodenticide branch; and former EPA pesticides attorney Stanley Weissman - gave the Monitor a different assessment.
''We're turning out much faster reviews with fewer people,'' said Mr. Gross.
''There has been some lessening of the amount of reviews done and the depth of review,'' said Mr. Harrison, though ''not much quality change.'' The change has come in the interpretation of the data, he said. (Gross contends that EPA risk evaluators whose findings show a higher risk than their superiors at EPA see are ignored, as he says he has been since warning of high cancer risk in permethrin, a chemical recently approved by EPA for expanded use.)
And there has been a change in EPA to less conservative cancer risk assessments, Harrison indicated, a point on which Dr. Todhunter said exactly the opposite. This change has drawn criticism from Representatives Brown and Albert Gore Jr. (D) of Tennessee.
Mr. Weissman, now an attorney in Montgomery, Ala., says he quit the EPA in May after two years because he did not agree with what was happening in the pesticides program under Reagan administration officials. There were ''terrible problems,'' he says. ''There has been a lessening of the stringency'' of pesticide safety reviews.
And little in-depth analysis is made of state requests to determine if an ''emergency'' or ''special local need'' exists to justify use of an unregistered pesticide, Weissman adds.
The General Accounting Office made a similar finding in a report last year. The GAO recommended the EPA do better in eliminating nonemergency requests. Dr. Todhunter says the EPA is trying to tighten up on its approvals.
Emergency and special local need uses can be approved only after the EPA has determined that the amount of pesticide residue on the crop after spraying will not be harmful to people. But environmental effects, such as the effect of pesticide runoffs on streams and wildlife, usually have not been determined by the time such use is allowed.
States initiate the request for emergency uses. They approve ''special local need'' cases, subject to disapproval by the EPA within 90 days. But the quality of state reviews on health and environmental questions about pesticides varies among states, says congressional staffer Benbrook.
The number of emergency approvals granted by EPA rose from about 150 in fiscal year 1978 to about 670 in the year ending last October, according to preliminary findings by Mr. Brown's subcommittee. Between 1975 and late 1982, some 8,560 uses of nonregistered pesticides for ''special local needs'' were approved by EPA, the findings show.
California has a more stringent pesticide safety review process than the EPA, says Sue Moreland of the California governor's office in Washington. It researches such questions as how soon a worker can safely reenter a sprayed field and what the accumulated effect of pesticides in an area might be. ''The state does not consider federal registration adequate,'' she says.
Pesticide manufacturers this year proposed an amendment that would have made it more difficult for a state to have more stringent review requirements than the EPA. The measure was defeated.
Pesticides approved most often by EPA before environmental testing ('78-'82) Trade Active Major crops No. uses name ingredient sprayed approved Pounce/Ambush permethrin vegetables 197 Pydrin fenvalerate peas; lettuce 101 Mesurol methiocarb fruits 76 Bayleton triadimefon wheat; grapes 57 Ridomil metalaxyl tobacco; potatoes 54 Orthene acephate peppers; cranberry; citrus 48 Paraquat paraquat beans; onions 47 Benlate benomyl wheat; vegetables 43 Source: House agricultural subcommittee on department operations, research, and foreign agriculture, based on data submitted by EPA.