A parent's use of pesticides around the home, or workplace exposure to any of several classes of chemicals (especially chlorinated solvents) can increase children's risk of developing leukemia, according to a new study reported in the July issue of the JOURNAL OF THE NATIONAL CANCER INSTITUTE (pgs. 39-46).

Authors of the study are a team of researchers at the Medical School, University of Southern California at Los Angeles. They studied 123 pairs of families; each pair contained one family with a child less than 10 years old with leukemia, and one family with a healthy child (matched for age, race or ethnicity, socioeconomic status and sex).

Parental exposure to pesticides inside the home, or in a family garden, increase children's risk of leukemia, the study shows. The use of incense in the home also increased the risk. Because they did not expect to find an association between household chemicals and leukemia, the researchers did not inquire about the types of pesticides used. They are re-interviewing the families now to improve their understanding of the problem. Previous studies have linked pesticide use to leukemia among farmers; this is the first study showing a link between household pesticides and leukemia in children.

This is only the second study showing a cancer link between humans and chlorinated solvents. Many studies of animals have shown carbon tetrachloride, tetrachloroethylene and trichloroethylene to be animal carcinogens, and one earlier study linked children's brain tumors to parental exposures to these solvents. [See J.M. Peters and others, "Brain Tumors in Children and Occupational Exposure of Parents." SCIENCE Vol. 213 (1981), pgs. 235-237.]

The present study also showed that parents' exposures to spray paint, cutting oil, methyl ethyl ketone, and to dyes and pigments, increased the risk of leukemia in their children.

Parents bring the chemicals home on their skin and clothing and on their breath. An adult's breath can carry chlorinated solvents for hours after exposure has ceased. Mothers may expose their infant children through breast milk. The greatest risk is to exposed infants and very young children. The parental occupations with strongest links to children's leukemia were machinery manufacture and airplane manufacture for the fathers and personal service (beauty shop operators, domestic servants, and laundry operators) for the mothers.

For a reprint, contact J.M. Peters, Department of Preventive Medicine, University of Southern California School of Medicine, 1420 San Pablo St., PMB B-306, Los Angeles, CA 90033. Ask for "Childhood Leukemia and Parents' Occupational and Home Exposures."
--Peter Montague, Ph.D.

Descriptor terms: pesticides; indoor air pollution; occupational safety and health; cancer; leukemia; incense; carbon tetrachloride; trichloroethylene; dyes; pigments; methyl ethyl ketone;