Dichlorvos Carcinogenicity Update

The National Toxicology Program (NTP) has recently published a report (NTP Technical Report No. 342), describing the toxicology and carcinogenicity of dichlorvos as evidenced by research in rats and mice.  Dichlorvos is one of several pesticides commonly used in museums to protect specimens and collections.  It is an organo-phosphate available in liquid preparations as well as in pest-control products, such as pest-strips, that are often used in display cases.  Common names include DDVP and Vapona.  Research included both short-term (13-week), and long-term (2-year) studies in male and female animals.  While body weight and survival rates were the same in both the test group and the control group, there are reported differences in neoplastic effects.   Results of these studies conclude that there was some evidence of carcinogenic activity as shown by increased incidence of adenomas of the exocrine pancreas and mononuclear cell leukemia.  There was equivocal evidence of carcinogenic activity of dichlorvos for a certain strain of female rats as shown by the increased incidence of adenomas of the endocrine pancreas and mammary gland fibroadenomas.  Also reported was some evidence of carcinogenic activity in a certain strain of male mice as shown by an increase in the incidence of forestomach squamous cell papillomas.  Lastly, there was clear evidence of carcinogenic activity of dichlorvos for a certain strain of female mice shown by an increase in the incidence of forestomach squamous cell papillomas.

 
In this report, dichlorvos was found to be mutagenic in one bacterial strain and not another, mutagenic in one assay, and induced sister chromatid exchanges and chromosomal aberrations in hamster ovary cells.

The carcinogenicity of dichlorvos is now firmly established. Conservators and museum workers should not use this chemical since there is no safe level of exposure to carcinogens.  Also, dichlorvos should not be used in the control of pests in household pets. Even though pest strips and pet pest control products contain 0.5% or less active dichlorvos, use of these products should be stopped since dichlorvos is both carcinogenic and mutagenic. 

Both the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL), and the American Conference of Governmental Industrial Hygienists (ACGIH), Threshold Limit Value (TLV), are set at 1 mg/m3 averaged over an 8-hour work shift.  Results from earlier animal studies indicated an increased risk of cancer, adverse liver effects, and nervous system intoxication.  Health hazards from exposure to dichlorvos included mutations (genetic changes), nervous system damage (cholinesterase inhibition), and personality changes such as depression, anxiety, and irritability. - A.B.

 

Art Hazard News, Volume 13, No. 6, 1990

This article was originally printed for Art Hazard News, © copyright Center for Safety in the Arts 1990. It appears on CAR courtesy of the Health in the Arts Program, University of Illinois at Chicago, who have curated a collection of these articles from their archive which are still relevant to artists today.