S.J. County pesticide use highest since 1990s

STOCKTON — Pesticide use in San Joaquin County has increased in recent years to levels not seen since the late 1990s, new state data show.

The “why” part of the story, however, is much more complex.

About 12.8 million pounds of chemicals were used across the county in 2015, the most recent year for which numbers are available, according to the state Department of Pesticide Regulation.

That’s a modest 7 percent increase from the previous year, but a more than 80 percent increase since a dip in the late 2000s.

The chemicals are largely to support the county’s $2.7 billion agricultural industry, though treatment of public rights-of-way, efforts to control mosquitoes and other uses are included in the totals.

Chemical use by private residents is not. And that’s important to remember, said Bruce Blodgett, head of the San Joaquin Farm Bureau Federation.

“I think if people want something really eye-opening, they should look over their back fence,” Blodgett said. “People should be more concerned with what their neighbor is putting on their yard than what farmers are using to protect crops.”

And, he added, they should be more concerned with crops imported from other countries that may not regulate pesticides as strictly.

San Joaquin County ranked fourth in the state for pesticide use in 2015 and is one of four counties — along with Fresno, Kern and Tulare — that account for nearly half of the statewide total.

Pesticide use topped 213 million pounds across California that year. In a prepared statement, advocacy group Pesticide Action Network called that a “staggering” sum, one which includes the use of some chemicals that are known to cause cancer and have the potential to drift away from fields and toward nearby homes or schools.

Some details about chemical use in San Joaquin, according to the new data and local agricultural officials:

• More than half of the county’s total use can be attributed to one substance: Sulfur, a natural powder dug out of mines and commonly applied to control mildew in grapes and tomatoes. Sulfur is of low toxicity to humans, though it can cause eye irritation. Sulfur can even be used on crops labeled as organic.

“Organic growers do use pesticides,” San Joaquin County Agricultural Commissioner Tim Pelican said. “That’s important for people to understand.”

• Use of a more toxic, likely cancer-causing fumigant known as 1,3-D did increase in 2015, topping 1 million pounds across the county. That’s still substantially less than the amount of sulfur used.

• Farmers have relied more on 1,3-D in part because of the federal phase-out of methyl bromide, which was known to damage humans’ central nervous and respiratory systems. That change, and other changes concerning which chemicals are allowed, may be another reason that overall usage is up.

“A lot of the chemicals being used now are not as effective, so you’ll see them used more often as a result of that,” Pelican said.