A new study released by the California Department of Pesticide Regulation (CDPR) published its Annual Pesticide Use Report last week, which specified that pesticide use increased by 6.4 million pounds in 2013. California uses 178 million pounds of pesticides annually.
Use of oil pesticides increased in both amount and area treated (7.1-million-pound increase, 25 percent; 508,000-acre increase, 13 percent; Table 15 on page 49 and Table 16 on page 50). Oils include many different chemicals, but the category used here includes only those derived from petroleum distillation. Some of these oils may be on the State’s Proposition 65 list of chemicals “known to cause cancer” but most serve as alternatives to other pesticides. Oils are also used by organic growers.
Crops treated with the greatest amount of pesticides in 2013 were almond, wine grape, table and raisin grape, strawberry, and processing tomato. Major crops or sites with an increase in amount applied from 2012 to 2013 include almond, soil fumigation, pistachio, walnut, and processing tomato. For all these crops, the increase in pesticide use was larger than the increase in area planted. Crops with a decrease in amount applied include strawberry, carrot, fruiting peppers, cotton, and table and raisin grape.
Use of biopesticides increased in both amount and area treated (653,000-pound increase, 17 percent; 870,000-acre treated increase, 16 percent; Table 17 on page 52 and Table 18 on page 60). Use of most biopesticide AIs increased. The most-used biopesticide AI by amount was kaolin and it also accounted for most of the increase in amount. Citric acid, propylene glycol, and ammonium nitrate were the most-used biopesticides by area treated and accounted for most of the increase in area treated. Kaolin is used both as a fungicide and an insecticide and citric acid, propylene glycol, and ammonium nitrate are used as adjuvants. In general, biopesticides are derived from or synthetically mimic natural materials such as animals, plants, bacteria and minerals and fall into three major classes: microbial, plant-incorporated protectant, or naturally occurring substances that control pests by non-toxic mechanisms.
The research raises some troubling public health concerns including the the increased use of organophosphates, and more specifically, the insecticide chlorpyrifos. Chlorpyrifos was banned by the Environmental Protection Agency (EPA) for nearly all residential uses in 2000, but since then has remained widely available for agricultural use. Chlorpyrifos is an organophosphate insecticide with neurotoxic action. It is a cholinesterase inhibitor, binding irreversibly to acetylcholine esterase (AchE), an essential enzyme for normal nerve impulse transmission in the brain, inactivating the enzyme.
Scientific studies have documented that exposure to even low levels of organophosphates like chlorpyrifos during pregnancy can impair learning, change brain function and alter thyroid levels of offspring into adulthood. A study from the University of California, Berkeley, examined families in the intensive agricultural region of Salinas Valley, California, and determined that IQ levels for children with the most organophosphate exposure were a full seven IQ points lower than those with the lowest exposure levels. The Berkeley team also found that every tenfold increase in measures of organophosphates detected during a mother’s pregnancy corresponded to a 5.5 point drop in overall IQ scores in the 7-year-olds. Researchers from Mount Sinai School of Medicine also found that prenatal exposure to organophosphates is negatively associated with cognitive development, particularly perceptual reasoning, with evidence of effects beginning at 12 months and continuing through early childhood.
Chlorpyrifos, was classified for ‘restrictive use’ by California. With the submission of the regulation on May 6, 2015 (effective as of July 1, 2015), now only trained and licensed professionals who file a notice of intent to apply, and have a permit from a local county agricultural commissioner (CAC) will be able to use products containing chlorpyrifos, adding an additional regulatory step not required in the federal regulatory scheme under EPA. However, the regulation will not minimize the chemical’s use and falls far short of a more stringent program that would ban the use of chlorpyrifos altogether.
The EPA recently released a safety study illustrating potential hazardous consequences to agricultural workers, specifically it determined that workers who mix, load and apply chlorpyrifos, had an increased risk of suffering from adverse health effects and that there is a toxic risk to drinking water in small watersheds.