title: Multiple pesticide exposures and the risk of multiple myeloma in Canadian men.
abstract: Multiple myeloma (MM) has been linked to certain agricultural exposures, including pesticides. This analysis aimed to investigate the association between lifetime use of multiple pesticides and MM risk using two exposure metrics: number of pesticides used and days per year of pesticide use. A frequency-matched, population-based case-control study was conducted among men in six Canadian provinces between 1991 and 1994. Data from 342 MM cases and 1,357 controls were analyzed using logistic regression to calculate odds ratios (OR) and 95% confidence intervals. Pesticides were grouped by type, chemical class and carcinogenic potential, using a composite carcinogenic probability score. Selected individual pesticides were also examined. Regression models were adjusted for age, province of residence, use of proxy respondents, smoking and selected medical history variables. The overall pattern of results was complex. Positive trends in risk were observed for fungicides (ptrend=0.04) and pesticides classified as probably carcinogenic or higher (ptrend=0.03). Excess risks of MM were observed among men who reported using at least one carbamate pesticide (OR=1.94, 1.16-3.25), one phenoxy herbicide (OR=1.56, 1.09-2.25) and ≥3 organochlorines (OR=2.21, 1.05-4.66). Significantly higher odds of MM were seen for exposure to carbaryl (OR=2.71, 1.47-5.00) and captan (OR=2.96, 1.40-6.24). Use of mecoprop for >2 days per year was also significantly associated with MM (OR=2.15, 1.03-4.48). Focusing on multiple pesticide exposures is important because this more accurately reflects how exposures occur in occupational settings. Significant associations observed for certain chemical classes and individual pesticides suggest that these may be MM risk factors.
authors.affiliation: Occupational Cancer Research Centre, Toronto, ON, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Kachuri
authors.forename: Paul A
authors.initials: PA
authors.lastname: Demers
authors.forename: Aaron
authors.initials: A
authors.lastname: Blair
authors.forename: John J
authors.initials: JJ
authors.lastname: Spinelli
authors.forename: Manisha
authors.initials: M
authors.lastname: Pahwa
authors.forename: John R
authors.initials: JR
authors.lastname: McLaughlin
authors.forename: Punam
authors.initials: P
authors.lastname: Pahwa
authors.forename: James A
authors.initials: JA
authors.lastname: Dosman
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Harris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000382:Agricultural Workers' Diseases / Q000453:epidemiology*; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000139:chemically induced* / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure; D010575:Pesticides / Q000633:toxicity*; D012306:Risk; D012307:Risk Factors
chemical_list: D010575:Pesticides
keywords: carbamates; case-control study; multiple myeloma; occupational cancer; pesticides