Parental occupational exposure to pesticides and the risk of childhood leukemia in Costa Rica.
OBJECTIVE
Parental exposure to pesticides and the risk of leukemia in offspring were examined in a population-based case-control study in Costa Rica.


METHODS
All cases of childhood leukemia (N=334), in 1995-2000, were identified at the Cancer Registry and the Children's Hospital. Population controls (N=579) were drawn from the National Birth Registry. Interviews of parents were conducted using conventional and icon-based calendar forms. An exposure model was constructed for 25 pesticides in five time periods.


RESULTS
Mothers' exposures to any pesticides during the year before conception and during the first and second trimesters were associated with the risk [odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0-5.9; OR 22, 95% CI 2.8-171.5; OR 4.5, 95% CI 1.4-14.7, respectively] and during anytime (OR 2.2, 95% CI 1.0-4.8). An association was found for fathers' exposures to any pesticides during the second trimester (OR 1.5, 95% CI 1.0-2.3). An increased risk with respect to organophosphates was found for mothers during the first trimester (OR 3.5, 95% CI 1.0-12.2) and for fathers during the year before conception and the first trimester (OR 1.5, 95% CI 1.0-2.2 and OR 1.6, 95% CI 1.0-2.6, respectively), and benzimidazoles during the first, second, and third trimesters of pregnancy (OR 2.2, 95% CI 1.0-4.4; OR 2.2, 95% CI 1.0-5.0; OR 2.2, 95% CI 1.0-5.2, respectively). There was a suggestion of an exposure-response gradient for fathers as regards picloram, benomyl, and paraquat. Age at diagnosis was positively associated with fathers' exposures and inversely associated with mothers' exposures.


CONCLUSIONS
The results suggest that parental exposure to certain pesticides may increase the risk of leukemia in offspring.
Monge
Patricia
P
Central American Institute for Studies on Toxic Substances (IRET), Universidad Nacional, PO Box 86-3000, Heredia, Costa Rica. pmonge@una.ac.cr
Wesseling
Catharina
C
Guardado
Jorge
J
Lundberg
Ingvar
I
Ahlbom
Anders
A
Cantor
Kenneth P
KP
Weiderpass
Elisabete
E
Partanen
Timo
T
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003364:Costa Rica / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007407:Interviews as Topic; D007938:Leukemia / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D016273:Occupational Exposure; D016017:Odds Ratio; D010290:Parents; D010575:Pesticides / Q000009:adverse effects*; D012042:Registries; D018570:Risk Assessment
D010575:Pesticides