Photo credit: USDA

Unfortunately, we rarely are exposed to a single pesticide residue at a time. Most products are sprayed with a cocktail of chemicals, and, according to new research, these cocktails can often have a synergistic negative effect on human health, where the sum of the adverse effects is greater than the additive effects of the individual pesticides. Researchers reviewed published literature, and found several concerning trends. For example, they found that 90 percent of studies on the effects of fungicide mixtures were associated with impacts on endocrine regulation and reproduction. They also found synergistic interactions were predominant in insecticide mixtures. The toxicity and safety of pesticides are regulated based on single-pesticide exposures, so this paper highlights the importance of developing more in-depth analyses to determine how pesticides might interact in their impacts on human health. The researchers concluded that for most mixtures investigated, further validation data are still needed before making decisions about health impacts.