Shifting to an organic diet can significantly reduce synthetic pesticide levels within a week, according to a study published Feb. 12 in the journal Environmental Research.
Researchers from the University of California-Berkeley, UC-San Francisco and Friends of the Earth found average pesticide and pesticide metabolite levels detected in urine samples from four families fell 60.5% after six days of eating an all-organic diet.
The most significant declines involved organophostates such as malathion, which researchers said dropped by 95%, and chlorpyrifos, which they said fell by nearly two-thirds. Scientists have recommended banning such pesticides because of their toxicity to children’s developing brains.
The California researchers noted previous studies have shown an organic diet can reduce organophosphate pesticide levels. However, knowledge gaps have existed about how an organic diet might impact levels of neonicotinoid and pyrethroid insecticides, which they said are increasingly being used in the U.S. and globally.
The researchers found levels of clothiandin, a neonicotinoid pesticide, fell by 83% among the four families, while levels of pyrethroids dropped by 43% to 57%. Both of those pesticide classes are associated with endocrine disruption, they said, adding that neonicotinoids are a cause of massive pollinator and insect losses.
This study gives a boost to the organic industry, which has long touted the health and environmental advantages of an organic diet. Producers don't have to make a big argument on that score since many consumers already believe organic produce grown without synthetic pesticides is better for them — and they're willing to pay a premium to get it.
Producers and marketers of conventionally grown foods are likely to criticize this study because of the relatively small sample size. Still, it raises the question of how much pesticide residues are in conventional foods, since the levels dropped by quite a bit after the study participants switched to an all-organic diet.
Evidence of pesticide residues on food continues to emerge. The California Department of Pesticide Regulation has found chlorpyrifos residue on fruits and vegetables being sold in the state. While organic produce made up a small amount of the total samples tested, only 1% of the organic produce had illegal pesticide residues, according to The Salinas Californian.
In 2017, a federal appeals court ordered chlorpyrifos removed from the market within 60 days because of its association with developmental disabilities and other health problems. However, the U.S. Justice Department has asked for a rehearing of that decision. Friends of the Earth is supporting H.R. 230, a bill to ban chlorpyrifos introduced last month by U.S. Rep. Nydia Velazquez, D-NY.
Some farm groups, including the California Farm Bureau Federation, support the continued use of chlorpyrifos because they say it's effective on multiple pests and in some cases, "is the only line of defense, with no alternatives." Agriculture Secretary Sonny Perdue has said "chlorpyrifos helps farmers and consumers by improving production efficiency and contributing to public health and safety."
Consumers would rather not have any pesticide residues on their produce, however, regardless of whether the levels are within federal limits. A 2015 Consumer Reports survey found pesticides in produce are a concern for 85% of Americans, even if there are no other feasible ways to control pests and diseases.
Organic producers are in a good position to use these study results to their advantage. For producers of conventionally grown foods, it might be a smart move to shift to other pesticides without the questionable reputation of organophostates such as malathion and chlorpyrifos.
It could also bolster companies' sustainability credentials to find alternatives to neonicotinoid and pyrethroid insecticides to demonstrate their concern for pollinators and the environment in general. Consumers tend to appreciate businesses that show a commitment to environmental and human health in their operations, and they may reciprocate in tangible ways — including buying those companies' products.