A new Canadian study suggests common household insecticides such as bug sprays may be linked to behavior problems in children.
According to the Scientific American, the study by researchers in Quebec is one of the first to examine potential human health problems associated with pyrethroids, which are used in thousands of commercial products including roach sprays and flea bombs. More than 3,500 commercial products contain the compound.
Pyrethroids, which kill insects by interfering with their nervous systems, have gained greater use recently and been touted as a safer replacement for organophosphate pesticides, due to pyrethroids being a synthetic adaptation of a compound naturally occurring in chrysanthemum flowers. Since pyrethroids are used for mosquito control and on farms, homes and schools, humans are frequently exposed to them.
The study compared the urine of 779 Canadian children between ages 6 and 11, and their parents answered questions about each child’s behavior, the Scientific American reported. The urine of nearly all children (97 percent) had traces of pyrethroid breakdown products, while 91 percent tested positive for traces of organophosphates.
A 10-fold rise in one pyrethroid breakdown product (cis-DCCA) in the urine was linked to a doubling of the odds that a child would score high for parent-reported behavioral problems, such as hyperactivity and inattention.
Another breakdown product, trans-DCCA, was linked with behavior problems, although this could be due to chance since the association was not statistically significant, according to the Scientific American. Organophosphate breakdown products did not affect behavior scores.
Pyrethroid use has increased dramatically in recent years as organophosphates are being phased out due to health concerns, the Scientific American reported. Prenatal exposure to organophosphates has been associated with lower IQ scores, attention problems and delays in neurodevelopment.
Very little work has been done to determine potential health effects of pyrethroids on children, according to the Scientific American. A study of 348 mother-child pairs in New York City found that toddlers who had been exposed to pyrethroids in the womb scored lower on development measures, and studies of young laboratory animals found that low levels of some pyrethroids affected development of the nervous system.
“Children are at greatest risk from pesticide toxicity because the developing brain is more susceptible to neurotoxicants and they interact with their environment in particular ways such as frequent hand-to-mouth behavior and outside play,” the study’s authors wrote.
According to the Scientific American, the study faced limitations in that only 6.8 percent of the children sampled scored high for behavioral issues, along with the fact that one urine sample may not give an accurate picture of a child’s exposure to pesticides, since the body can metabolize them quickly.
The study offers no proof that pyrethroids cause behavior issues, the Scientific American reported, but the study’s authors said their findings indicate more research should be done to get to the bottom of the matter.