Parental Occupational Pesticide Exposure Research Articles

Parental occupational pesticide exposure and nonsyndromic orofacial clefts

Nonsyndromic orofacial clefts are common birth defects. Reported risks for orofacial clefts associated with parental occupational pesticide exposure are mixed. To examine the role of parental pesticide exposure in orofacial cleft development in offspring, this study compared population-based case-control data for parental occupational exposures to insecticides, herbicides, and fungicides, alone or in combinations, during maternal (1 month before through 3 months after conception) and paternal (3 months before through 3 months after conception) critical exposure periods between orofacial cleft cases and unaffected controls. Multivariable logistic regression was used to estimate odds ratios, adjusted for relevant covariables, and 95% confidence intervals for any (yes, no) and cumulative (none, low [<median exposure level in controls], high [≥median exposure level in controls]) occupational pesticide exposures and cleft lip ± cleft palate and cleft palate. Associations for cleft lip ± cleft palate tended to be near unity for maternal or paternal occupational pesticide exposures, except for low paternal exposure to any pesticide, which produced a statistically significant inverse association with this subtype. Associations for cleft palate tended to be near unity for maternal exposures and mostly positive, but non-significant, for paternal exposures; a significant positive association was observed between paternal low exposure to insecticide + herbicide + fungicide and cleft palate. Combined parental exposure produced non-significant associations near or below unity for all orofacial cleft cases combined and cleft lip ± cleft palate and positive, but non-significant, associations for cleft palate. This study observed associations mostly near unity between maternal occupational pesticide exposure and orofacial clefts. Associations for paternal occupational pesticide exposures were mostly near or below unity for cleft lip ± cleft palate, and mostly positive for cleft palate. However, due to the limitations of this study, these subtype-specific results should be interpreted cautiously. Future research examining parental occupational pesticide exposure and orofacial clefts should attempt to improve exposure assessment and increase sample size to better facilitate risk estimation.

A task-based assessment of parental occupational exposure to pesticides and childhood acute lymphoblastic leukemia

ObjectivesAssociations between parental occupational pesticide exposure and childhood acute lymphoblastic leukemia (ALL) vary across studies, likely due to different exposure assessment methodologies. MethodsWe assessed parental occupational pesticide exposure from the year before pregnancy to the child's third year of life for 669 children diagnosed with ALL and 1021 controls. We conducted expert rating using task-based job modules (JM) to estimate exposure to pesticides among farmer workers, gardeners, agricultural packers, and pesticide applicators. We compared this method to (1) partial JM using job titles and a brief description, but without completing the task-based questionnaire, and (2) job exposure matrix (JEM) linking job titles to the International Standard Classifications of Occupation Codes. We used unconditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for ALL cancer risk and pesticide exposure adjusting for child's sex, age, race/ethnicity and household income. ResultsCompared to complete JMs, partial JMs and JEM led to 3.1% and 9.4% of parents with pesticide exposure misclassified, respectively. Misclassification was similar in cases and controls. Using complete JMs, we observed an increased risk of ALL for paternal occupational exposure to any pesticides (OR=1.7; 95% CI=1.2, 2.5), with higher risks reported for pesticides to treat nut crops (OR=4.5; 95% CI=0.9, 23.0), and for children diagnosed before five years of age (OR=2.3; 95% CI: 1.3, 4.1). Exposure misclassification from JEM attenuated these associations by about 57%. Maternal occupational pesticide exposure before and after birth was not associated with ALL. ConclusionsThe risk of ALL was elevated in young children with paternal occupational pesticide exposure during the perinatal period, using more detailed occupational information for exposure classification.

Paternal and joint parental occupational pesticide exposure and spina bifida in the National Birth Defects Prevention Study, 1997 to 2002.

Because of persistent concerns over the association between pesticides and spina bifida, we examined the role of paternal and combined parental occupational pesticide exposures in spina bifida in offspring using data from a large population-based study of birth defects. Occupational information from fathers of 291 spina bifida cases and 2745 unaffected live born control infants with estimated dates of delivery from 1997 to 2002 were collected by means of maternal report. Two expert industrial hygienists estimated exposure intensity and frequency to insecticides, herbicides, and fungicides. Multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for exposure to any pesticide and to any class of pesticide (yes/no; and by median), and exposure to combinations of pesticides (yes/no) and risk of spina bifida. Adjusted odds ratios were also estimated by parent exposed to pesticides (neither, mother only, father only, both parents). Joint parental occupational pesticide exposure was positively associated with spina bifida (aOR, 1.5; 95% CI, 0.9-2.4) when compared with infants with neither maternal nor paternal exposures; a similar association was not observed when only one parent was exposed. There was a suggested positive association between combined paternal insecticide and fungicide exposures and spina bifida (aOR, 1.5; 95% CI, 0.8-2.8), however, nearly all other aORs were close to unity. Overall, there was little evidence paternal occupational pesticide exposure was associated with spina bifida. However, the small numbers make it difficult to precisely evaluate the role of pesticide classes, individually and in combination. Birth Defects Research (Part A) 106:963-971, 2016. © 2016 Wiley Periodicals, Inc.

Risk of Central Nervous System Tumors in Children Related to Parental Occupational Pesticide Exposures in three European Case-Control Studies.

The aim of this study was to assess the risk of childhood central nervous system (CNS) tumors associated with parental occupational pesticide exposure. We pooled three population-based case-control studies from France, Germany, and the United Kingdom. Cases were children below 15 years of age with CNS tumors; controls were matched by gender and age. A general population job-exposure matrix assessed parental occupational pesticide exposure. Logistic regressions estimated odds ratios (ORs) and 95% confidence intervals (CIs). The study included 1361 cases and 5498 controls. Prevalence of maternal occupational pesticide exposure during pregnancy was low and no association with childhood CNS tumors was detected (OR 0.76, 95% CI: 0.41 to 1.41). Around conception, OR for childhood CNS tumors associated with paternal occupational pesticide exposure was 0.71 (95% CI: 0.53 to 0.95). Our results do not suggest a role of parental occupational pesticide exposure in the etiology of childhood CNS tumors.

Parental Occupational Pesticide Exposure and Childhood Acute Lymphoblastic Leukemia

Parental Occupational Pesticide Exposure and Childhood Acute Lymphoblastic LeukemiaAbstract Number:2286 Robert Gunier*, Alice Kang, Katharine Hammond, Suzanne Lea, Patricia Quinlan, Kyndaron Reinier, Monique Does, and Catherine Metayer Robert Gunier* University of California, Berkeley, United States, E-mail Address: [email protected] Search for more papers by this author , Alice Kang University of California, Berkeley, United States, E-mail Address: [email protected] Search for more papers by this author , Katharine Hammond University of California, Berkeley, United States, E-mail Address: [email protected] Search for more papers by this author , Suzanne Lea East Carolina University, United States, E-mail Address: [email protected] Search for more papers by this author , Patricia Quinlan University of California, San Francisco Search for more papers by this author , Kyndaron Reinier Cedars-Sinai, United States Search for more papers by this author , Monique Does University of California, Berkeley, United States Search for more papers by this author , and Catherine Metayer University of California, Berkeley, United States Search for more papers by this author AbstractBackground: Most studies investigating the association between parental occupational pesticide exposure and childhood acute lymphoblastic leukemia (ALL) have relied on job titles.Methods: Children diagnosed with ALL (n=669) and age-, sex, race-matched controls (n=1,021) were enrolled in the California Childhood Leukemia Study (2000-2008). We assessed parental pre- and postnatal occupational pesticide exposure using job-title (JT) and corresponding occupational codes from the United States Bureau of Labor Statistics, as well as detailed task-based job modules (JM) and corresponding expert rating. We used unconditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for parental occupational pesticide exposure adjusting for child’s sex, age, ethnicity, and household income.Results: The overall specificity of occupational pesticide exposure using JT compared to JM was 94-95% and the sensitivity was 70-77% in both cases and controls. The use of JT to assess paternal postnatal occupational pesticide exposure and risk of ALL resulted in an OR=0.9 (95% CI: 0.6, 1.2); in contrast, the use of JM resulted in ORs equal to 1.5 (95% CI = 1.0, 2.2) and 1.7 (95% CI: 1.1, 2.5) for pre- and postnatal exposure, respectively. Risk of ALL was only elevated in children diagnosed at four years of age or younger, with an OR=2.2 (95% CI: 1.3, 3.9) for postnatal paternal exposure. Maternal occupational pesticide exposure was not associated with ALL during the prenatal or postnatal period. Risk estimates were nearly identical among Hispanic and non-Hispanic children, and were very similar using conditional logistic regression.Conclusions: We observed an increased risk of childhood ALL with paternal occupational pesticide exposure assessed using task-based JM, but not JT. In this study, the use of JT instead of JM resulted in exposure misclassification and underscores the importance of improved exposure assessment.

A systematic review and meta-analysis of childhood leukemia and parental occupational pesticide exposure.

ObjectivesWe conducted a systematic review and meta-analysis of childhood leukemia and parental occupational pesticide exposure.Data sourcesSearches of MEDLINE (1950–2009) and other electronic databases yielded 31 included studies.Data extractionTwo authors independently abstracted data and assessed the quality of each study.Data synthesisRandom effects models were used to obtain summary odds ratios (ORs) and 95% confidence intervals (CIs). There was no overall association between childhood leukemia and any paternal occupational pesticide exposure (OR = 1.09; 95% CI, 0.88–1.34); there were slightly elevated risks in subgroups of studies with low total-quality scores (OR = 1.39; 95% CI, 0.99–1.95), ill-defined exposure time windows (OR = 1.36; 95% CI, 1.00–1.85), and exposure information collected after offspring leukemia diagnosis (OR = 1.34; 95% CI, 1.05–1.70). Childhood leukemia was associated with prenatal maternal occupational pesticide exposure (OR = 2.09; 95% CI, 1.51–2.88); this association was slightly stronger for studies with high exposure-measurement-quality scores (OR = 2.45; 95% CI, 1.68–3.58), higher confounder control scores (OR = 2.38; 95% CI, 1.56–3.62), and farm-related exposures (OR = 2.44; 95% CI, 1.53–3.89). Childhood leukemia risk was also elevated for prenatal maternal occupational exposure to insecticides (OR = 2.72; 95% CI, 1.47–5.04) and herbicides (OR = 3.62; 95% CI, 1.28–10.3).ConclusionsChildhood leukemia was associated with prenatal maternal occupational pesticide exposure in analyses of all studies combined and in several subgroups. Associations with paternal occupational pesticide exposure were weaker and less consistent. Research needs include improved pesticide exposure indices, continued follow-up of existing cohorts, genetic susceptibility assessment, and basic research on childhood leukemia initiation and progression.

Potential parental exposure to pesticides and limb reduction defects.

The goal of the study was to examine the effects of the potential pesticide exposure of parents on the risk of limb reduction defects in their offspring. A case-referent study was conducted utilizing New York State Congenital Malformation Register data. Persons with limb reduction defects and referents were compared in terms of parental occupations and residence counties. Parental occupations and industries reported on birth certificates were qualitatively rated by industrial hygienists to estimate potential pesticide (list four groups) exposures. Residential exposures were estimated from agricultural census data according to county of residence. Neither parental exposure to pesticides [odds ratio (OR) 0.9, 95% confidence interval (95% CI) 0.6-1.4] nor farming occupation (OR 1.1, 95% CI 0.5-2.7) had an effect on the risk of total limb reduction defects. Those persons with limb reduction defects who had additional defects showed weak but consistent elevated risks in relation to parental occupational pesticide exposure. However, isolated cases of limb reduction defects were negatively related to these exposures. Residence in a farming or high pesticide use county was not associated with any type of limb reduction defect. Cases of limb reduction defect with additional malformations appear to be associated with parental occupational pesticide exposure. Improving exposure classifications and subdividing the limb reduction defects by types in the analyses are suggested for future research.