State Reports Higher Farm Pesticide Use : Agriculture: New accounting method increases annual figure. Experts say it may still be too low.

In the most comprehensive accounting of pesticide use in California, state authorities said that farmers annually spread 163 million pounds of herbicides, insecticides and fumigants on soil and crops, 57 million more than previously reported.

As large as that number may be, state officials say pesticide use may still be underreported. But if the number turns out to be accurate, experts will need to reduce their estimate that agriculture accounts for half of the pesticide used in the state.

The compilation released this week covers pesticide use in 1990, the first year of a new system that attempts to document each application of every pesticide used commercially, including some that are inert and others that are relatively harmless to humans.

Under the previous reporting system, farmers reported only their use of so-called restricted pesticides, generally the ones that are most toxic. The new system requires farmers to report their use of all pesticides.

Among these newly reportable “non-restricted” chemicals are many potentially dangerous substances such as metam sodium, the insecticide and soil fumigant that devastated 60 miles of the upper Sacramento River ecosystem last year after a train derailment.

The new report discloses that almost 6 million pounds of metam sodium were used on 75 food crops in 1990--compared to only 157,000 pounds listed in reports under the old system of tracking chemicals.

The new system also detected more use of the controversial insecticide malathion, commonly used to kill Medflies and other insects. Previous reports had said about 663,000 pounds of malathion, a non-restricted chemical, were used yearly on farms. The new system documented 1.9 million pounds.

When commercial use of chemicals to control household pests such as termites was included, the total statewide application of pesticides under the new reporting system reached 182 million pounds, compared to 105 million pounds under the old system.

James Wells, director of the state Department of Pesticide Regulation, said there is a possibility that there was underreporting.

“Look at how many people don’t file their taxes,” he said.

A separate report by the Department of Pesticide Regulation states that 605 million pounds of pesticides were sold in California in 1990, a figure which suggests that farmers underreported their use. But the sales report also includes largely non-agricultural pesticides, including 227 million pounds of chlorine used for water treatment in 1990. Neither report seeks to count home and garden pesticide use.

Previous reports have estimated that California, the nation’s top agricultural state with annual sales of $18 billion, uses about one-fourth of the nation’s pesticides.

“There’s no vision to try to change (reliance on pesticides) over time,” said Ralph Lightstone of California Rural Legal Assistance in Sacramento. “To the contrary, the main effort of the Administration and industry is to accept this massive amount of use.”

Wells said that although there may have been underreporting, the higher level of detail in the new system will allow officials to better track sources of ground-water contamination and investigate cancer clusters in the Central Valley.

Environmentalists also praised the report, noting that California is the first state in the nation to require full reporting on the use of all agricultural chemicals.

Chemical industry officials said they hope the report will prove what they long have contended--that less pesticide is used in agriculture than many consumer groups and environmentalists charge.

“This will show what is actually being used versus what is perceived,” said Elin Miller, of the pesticide manufacturer DowElanco.

The new system notes that by weight, at least, sulfur is the most heavily used farm pesticide, accounting for 55.5 million pounds, followed by 21 million pounds of petroleum oil, which is used to smother pests. Neither chemical is particularly controversial.

The third most-used chemical, methyl bromide, also is among the most poisonous. In 1990, 20 million pounds of methyl bromide were used. As a “restricted” chemical, methyl bromide’s use had been reported under the old system at 18.3 million pounds in 1988.

The report notes that in 1990 farmers used 32.9 million pounds of 27 pesticides that are characterized as “acutely toxic” in a bill being considered by the state Legislature. The bill seeks to ban the chemicals, which can cause death when ingested in small amounts.

Despite the tonnage of pesticides in the field, health authorities rarely find pesticide residue in produce at markets. One reason is that the industry uses chemicals that dissipate quickly, but are highly toxic when first applied.