Discoveries and Data: Exposures and Risk Factors



From interviews with over 2000 mothers, we learned that pesticide exposure is very common. More than 3/4 reported at least 1 source of contact with pesticides while pregnant; 15% were exposed to 3 or more sources.

bullet-3141890 Household exposure was frequent. About half of homes were treated for pests, using substances applied by

the mother, a professional or others.

bullet-3141890 18% of women reported gardening
where weed killers or insecticides were used.
bullet-3141890 Pets lived in 42% of households; most had flea collars or other treatments to manage fleas.
bullet-3141890 Nearly 25% of women reported living within 1/4 mile of agricultural crops, including orchards and commercial flower fields.
bullet-3141890 Occupational exposure was relatively rare—only 5% of mothers had jobs involving contact with pesticides. Half of these women worked in agriculture; others had jobs such as florist or animal handler.

Scientifically, it is almost impossible to prove an exposure is safe. However, we observed no increased risk for the birth defects studied (oral clefts, neural tube defects, conotruncal heart defects or limb defects) with the pesticide exposures expected to be the most intense: occupation and self-applied home pest control.

We did identify several promising leads warranting further study. We observed modest risk increases for these birth defects and exposures:

bullet-3141890 Household gardening and certain types of oral clefts, neural tube defects, heart defects and limb defects.
bullet-3141890 Living within 1/4 mile of agricultural crops and neural tube defects.

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Malathion spraying in 1981-1982 to eradicate the agriculture-threatening Medfly in urban areas was part of the impetus for the Program’s creation. Follow-up of 35,000 births showed families in sprayed areas were no more likely to have a child with birth defects than those in nearby communities. There was also no difference when compared to the years before spraying began. This information was helpful to policymakers evaluating the need for similar 1989-1991 spraying in Southern California.