High levels of an illegal and toxic pesticide continue to be found in purchased samples of Mexican prickly pear cactus pads, despite fines, border advisories and health notices, according to a statewide inspection report released Wednesday.
Nearly 47% of the cactus samples showed high enough chemical traces to cause the state to issue warnings to consumers last year. The cactus pads, known as nopales, have shown up for several years running on the Department of Pesticide Regulation's annual list of tainted produce.
"Cactus pads by far were the ones of major concern," said George Farnsworth, assistant director of the agency's pesticide programs division.
The cactus harbored enough of an organophosphate compound, monocrotophos, to cause flu-like symptoms to those who ate large amounts, according to the agency. The highly toxic chemical has been banned in the U.S. since 1989, largely for the exposure hazard it posed to farm laborers.
"We're looking at consumers, but these levels also mean that workers are getting hurt," Farnsworth said.
Chinese ginger showed traces of a chemical, aldicarb sulfoxide, that is not approved for the root and is a notorious water pollutant, according to the agency. Chinese ginger also has been a perennial problem for the agency, and in 2007, pesticide residue findings sparked a statewide warning to consumers to avoid it.
California-grown spinach and kale, which also made the list, likely was exposed to approved chemicals sprayed on adjacent crops, while the nectarines probably picked up traces from improperly cleaned packing equipment used for other fruit, Farnsworth said.
The mode of contamination for the Mexican produce was not known, but the agency suspects the chemicals were directly applied to those crops. More than a quarter of the Mexican lime samples had higher-than-acceptable levels of pesticides, while about 17% of the samples of Mexican papaya and summer squash and Chinese ginger tested above legal tolerances.
Nopales, as the paddles of the prickly pear (opuntia) cactus are known, are generally grilled, pickled or added to a variety of stews, soups and other Mexican dishes.
This year's dirtiest produce stood out in a report that found about 93% of 3,472 samples complied with state and federal tolerances for agricultural chemicals. About two thirds of the samples were domestically grown.
Concentrations of pesticides found in the failed tests were generally very low - on the order of fractions of a part per million - and posed little immediate health hazard, according to the report.
"We have a very vigorous regulatory program around pesticides, and it works," said Brian Leahy, director of the pesticide agency. "We've been able, through these regulations and enforcement, to create a market that provides safe, reliable food."
The agency also found that about 2% of 234 samples marketed as organic had pesticide residue levels that violate state labeling guidelines.
The repeated violations by Mexican produce have sparked a cross-border visit from officials of the agency, which also levied $38,000 in fines this year against three Los Angeles produce companies that it accused of disregarding warnings and repeatedly selling produce from lots that failed pesticide tests.
The agency also fined three other companies it accused of similar sales of Asian products, including ginger, that came from batches with illegal pesticide residue.
In previous years, the agency has fined companies for selling unapproved pesticides. In 2013, it also forced a Santa Cruz strawberry grower to destroy a crop valued at $200,000 and fined the company $15,000 after detecting the illegal pesticide methomyl, an insecticide whose use is under review by the federal Environmental Protection Agency.
"We're really stepping up enforcement" Leahy said. "We look at the whole supply chain and make sure that everyone has an understanding that when you're selling food you have a responsibility to make sure it's safe and reliable."
State regulators track down produce implicated in failed pesticide tests, making it unlikely consumers would have eaten much of the tainted produce.
"We always track the commodity down by lot number and it's always destroyed," Farnsworth said. "By law they have the option of reconditioning, but it's very rarely ever used."
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