New Research Links Propoxur to Abnormal Neurodevelopment in Children

(Beyond Pesticides, December 9, 2011)

A recent study published in the journal NeuroToxicology has found a positive link between exposure to the pesticide propoxur and poor motor development in infants. At the age of two, children exposed to propoxur in the womb experience poor development of motor skills, according to a test of mental development. The study joins numerous others that consistently show birth defects and developmental problems when fetuses and infants are exposed to pesticides.

The study, undertaken by researchers at Wayne State University in Michigan, the University of the Philippines, and Davao Regional Hospital in the Philippines, is entitled “Fetal exposure to propoxur and abnormal child neurodevelopment at 2 years of age.” It examines levels of exposure to multiple pesticides in pregnant women living in areas of high pesticide use in the Philippines. Pesticide exposure was monitored by measuring the pesticide content of hair and blood for both mothers and children. The researchers then compare these exposure levels to adverse outcomes regarding the health of the infants once they were born. To accomplish this, the team used a method called path analysis modeling in order to determine what effects the pesticides might have on fetal development. The striking findings show that, controlling for a number of variables, there is a strong connection between high fetal exposure to propoxur and poor development of motor skills at two years of age.

Propoxur is a carbamate insecticide first registered in the U.S. in 1963 for the control of household pests, such as ants, cockroaches, and bed bugs. It is also commonly used in flea and tick collars. Propoxur can be very dangerous to humans and the environment. Common symptoms of poisoning include malaise, muscle weakness, dizziness, and sweating. Headache, nausea, and diarrhea may also result. The U.S. Environmental Protection Agency (EPA) considers propoxur a possible human carcinogen, while the state of California classifies it as a known human carcinogen. Propoxur is also highly toxic to beneficial insects such as honey bees as well as crustaceans, fish, and aquatic insects.

Although banned for indoor uses to which children would be exposed in 2007 due to concerns over potential health effects, propoxur has recently begun to be touted again as the answer to resurgent bed bug infestations. In 2009, the state of Ohio asked EPA for a special exemption to begin using propoxur again to eradicate bed bugs. Ohio was joined in its petition by 25 other states. Fortunately, the agency wisely denied the states petition citing concerns over potential ill effects and the unacceptable risk to children.

As many pest control operators now know, chemical treatments for bed bugs are not actually necessary and are often more harmful than the pests themselves. Additionally, due to an over-reliance on chemical controls over the years, bed bugs are now evolving resistance to pyrethroid chemicals. However, these pests can be effectively controlled with non-toxic approaches. An IPM approach, which includes methods such as vacuuming, steaming, and exposing the bugs to high heat, can control an infestation without the dangerous side effects. This approach, as well as taking steps such as sealing cracks and crevices, reducing clutter and encasing mattresses, can also help to prevent an infestation in the first place.