22 August 1999

Flea Collars May Expose Children To Insecticides

by Kate Melville

When children pet the family dog, are they exposed to flea collar insecticides present in the animal's coat? That's the subject of a novel study by Mississippi researchers described here today at the national meeting of the American Chemical Society, the world's largest scientific society. The study takes particular note of flea collars with organophosphate insecticides, which also are commonly used on garden and farm plants.

The study is one of 30 being presented at this meeting in a wave of new research into children's environmental health issues, a relatively new area of scientific exploration intended to determine whether and how children may be more vulnerable to health threats from a wide variety of environmental pollutants.

"When some collars are very fresh, the insecticide residues that can be transferred are pretty high, though we saw no evidence of any adverse effects in the dogs," says Janice Chambers, Ph.D., Director of the Center for Environmental Health Sciences at Mississippi State University's College of Veterinary Medicine, where the study is being conducted.

Preliminary analysis shows that the levels of the insecticide residues that collect on the fur of dogs vary with the flea collar's design. With one type of collar, the level declines for several days after the collar is put in place. With another type of collar, the level is lower and steady over several weeks. (Residues were collected by rubbing the backs of dogs with white gloves.)

Chambers is recruiting families with small children and dogs for an in-home biomonitoring study. "We're going to be looking at urine samples from the adults and the children to find out how much of that insecticide actually gets into the bodies of the people."

How much of a health risk, if any, flea collars present to either children or adults is still to be determined, according to Chambers. "We don't know at this point if residue on a glove translates to absorption by a person. That's why we're doing this biomonitoring study."

While not all flea collars use the same organophosphate chemicals farmers apply to their crops, Chambers urges caution. "If the collar is going to be effective, it's going to have to release insecticide that can contact the fleas, so it's logical to assume that it would be releasing insecticide that could get on the dog and then on the person." By law, the active ingredients used in flea collars sold in this country must be registered with the U.S. Environmental Protection Agency, which determines the appropriate level of the organophosphates or other insecticide formulations that can be used in products.

Emphasizing that she doesn't want to be an alarmist, Chambers urges parents to keep children from close contact with the family pet when flea collars are first put in place, at least for a few days, until more information is available. "Don't let the kid hug and sleep with the dog while the collar is real fresh." Primarily funded by EPA, the flea collar study responds to the data collection requirements of the Food Quality Protection Act of 1996, which stipulates that all sources of exposures to pesticides must be considered when determining overall risk.