title: Exposure to professional pest control treatments and the risk of childhood acute lymphoblastic leukemia.
abstract: Previous studies suggest that exposure to pesticides increases the risk of childhood acute lymphoblastic leukemia (ALL). The aim of this analysis was to investigate whether professional pest treatments in or around the home before birth or during childhood increased the risk of childhood ALL. Data from 388 cases and 870 frequency-matched controls were analyzed using unconditional logistic regression, adjusting for study matching variables and potential confounders, to calculate odds ratios (ORs). A meta-analysis of our findings with the published findings of previous studies was also conducted. The ORs for any professional pest control treatments were 1.19 (95% CI 0.83, 1.69) in the year before pregnancy, 1.30 (95% CI 0.86, 1.97) during pregnancy and 1.24 (95% CI 0.93, 1.65) for those done after the child's birth. The ORs for exposure after birth were highest when it occurred between the ages of two and three years. ORs were elevated for termite treatments before birth. ORs were higher for pre-B than T cell ALL and for t(12;21) (ETV6-Runx-1) than other cytogenetic sub-types. The pooled OR from a meta-analysis of our study with three previous studies of professional pest control treatments during pregnancy was 1.37 (95% CI 1.00, 1.88). Our results, and those of our meta-analysis, provide some evidence of a modestly increased risk of ALL for professional pest control treatments done during the index pregnancy and possibly in the child's early years. The analysis of pooled data from international collaborations may provide more certainty regarding these potentially important associations.
authors.affiliation: Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Western Australia, Australia. helenb@ichr.uwa.edu.au
authors.forename: Helen D
authors.initials: HD
authors.lastname: Bailey
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: de Klerk
authors.forename: Lin
authors.initials: L
authors.lastname: Fritschi
authors.forename: John
authors.initials: J
authors.lastname: Attia
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Scott
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Smibert
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Milne
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010571:Pest Control / Q000379:methods*; D010575:Pesticides / Q000633:toxicity*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000139:chemically induced / Q000453:epidemiology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced; D012307:Risk Factors
chemical_list: D010575:Pesticides