Parental Pesticide Exposure and Childhood Brain Cancer: A Systematic Review and Meta-Analysis Confirming the IARC/WHO Monographs on Some Organophosphate Insecticides and Herbicides

Background: Brain tumors are the second most common neoplasm in the pediatric age. Pesticides may play an etiologic role, but literature results are conflicting. This review provides a systematic overview, meta-analysis, and IARC/WHO consideration of data on parental exposure to pesticides and childhood brain tumors. Methods: We searched PubMed, SCOPUS, and Google Scholar for literature (1 January 1966–31 December 2020) that assessed childhood brain tumors and parental exposure to pesticides. We undertook a meta-analysis addressing prenatal exposure, exposure after birth, occupational exposure, and residential exposure. A total of 130 case-control investigations involving 43,598 individuals (18,198 cases and 25,400 controls) were included. Results: Prenatal exposure is associated with childhood brain tumors (odds ratio, OR = 1.32; 95% CI: 1.17–1.49; I2 = 41.1%). The same occurs after birth exposure (OR = 1.22; 95% CI: 1.03–1.45, I2 = 72.3%) and residential exposure to pesticides (OR = 1.31; 95% CI: 1.11–1.54, I2 = 67.2%). Parental occupational exposure is only marginally associated with CBT (OR = 1.17, 95% CI: 0.99–1.38, I2 = 67.0%). Conclusions: There is an association between CBT and parental pesticides exposure before childbirth, after birth, and residential exposure. It is in line with the IARC Monograph evaluating the carcinogenicity of diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.

Parental occupational exposure and congenital heart diseases in a Hungarian case–control study

Purpose Our study aimed to explore the effect of parental occupational exposure to endocrine disrupting chemicals (EDCs) on the development of congenital heart diseases (CHDs) in the offspring, and to compare job-exposure matrix (JEM)-assessed and self-reported occupational exposures with each other. Methods Live-born infants born in 2007–2008 were selected from the population-based Hungarian Case–Control Surveillance of Congenital Abnormalities Study. 577 cases with any CHDs were compared to 1731 matched controls. Parental periconceptional occupational exposure to EDCs was assessed by a JEM and by questionnaire-based self-reporting of parents. Multivariate conditional logistic regression analyses were conducted to explore associations between parental occupational exposure to EDCs and the entire spectrum of CHDs and by CHD subtypes in the offspring. Kappa statistics were also performed to determine the consistency among JEM-assessed and self-reported occupational exposure of parents. Results JEM-assessed paternal exposure to polychlorinated organic substances, phthalates, biphenolic compounds, and solvents were significantly associated with the entire spectrum of CHDs. Ventricular septal defects were significantly associated with paternal self-reported exposure to pesticides, while atrial septal defects were significantly associated to paternal JEM-assessed phthalate exposure. Paternal solvent exposure was significantly associated with atrial septal defects and right ventricle outflow tract obstructions. JEM-assessed and self-reported exposures to pesticides, heavy metals, and solvents exhibited poor agreement for mothers and slight agreement for fathers. Conclusion Even though parental occupational exposure to EDCs seems to have a minor impact on the occurrence of CHDs, the results of biological and environmental monitoring should be taken into consideration as well.

Parental occupational exposure pre- and post-conception and development of asthma in offspring

Background While direct effects of occupational exposures on an individual’s respiratory health are evident, a new paradigm is emerging on the possible effects of pre-conception occupational exposure on respiratory health in offspring. We aimed to study the association between parental occupational exposure starting before conception and asthma in their offspring (at 0–15 years of age). Methods We studied 3985 offspring participating in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Their mothers or fathers (n = 2931) previously participated in the European Community Respiratory Health Survey (ECRHS). Information was obtained from questionnaires on parental job history pre- and post-conception which was linked to an asthma-specific job-exposure matrix (JEM). We assessed the association between parental occupational exposure and offspring asthma, applying logistic regression models, clustered by family and adjusted for study centre, offspring sex, parental characteristics (age, asthma onset, place of upbringing, smoking) and grandparents’ level of education. Results Parental occupational exposure to microorganisms, pesticides, allergens or reactive chemicals pre-conception or both pre- and post-conception was not related to offspring asthma; in general, subgroup analyses confirmed this result. However, maternal exposure both pre- and post-conception to allergens and reactive chemicals was associated with increased odds for early-onset asthma in offspring (0–3 years of age); odds ratio 1.70 (95% CI: 1.02–2.84) and 1.65 (95% CI: 0.98–2.77), respectively. Conclusions This study did not find evidence that parental occupational exposure, defined by an asthma JEM before conception only or during pre- and post-conception vs non-exposed, was associated with offspring asthma.

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring: findings from the Childhood Leukaemia International Consortium (CLIC)

ObjectivesPreviously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium.MethodsWe pooled 11 case–control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses.ResultsORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses.ConclusionsIn this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia.

Parental occupational exposure to benzene and the risk of childhood and adolescent acute lymphoblastic leukaemia: a population-based study

ObjectivesOnly a small number of studies have reported on the association of parental occupational exposure to benzene and risk of childhood and adolescent leukaemias. We examined associations with acute lymphoblastic leukaemia (ALL) in this population-based study in Denmark.MethodsBenzene was largely banned from Danish workplaces after 1975, thus this case-control study focused on the immediately prior years. Paediatric cancer cases (<age 20) were ascertained from the Danish Cancer Registry among children born 1968–1974, and controls were selected from population records. Paternal occupation within the 3 months preconception and maternal pregnancy occupation were identified from nationwide pension fund records. Blinded, we assigned benzene exposure using a job-exposure matrix that had been developed for the Danish population. Risk for ALL was estimated using conditional logistic regression. In an exploratory analysis, we also examined other cancers with at least five case parents exposed.ResultsWe identified 217 employed case fathers and 169 employed case mothers, of which 22 (10.1%) and 11 (6.5%), respectively, were exposed to benzene (vs 6.7% and 2.9% of control fathers and mothers). Most exposed parents worked as machine or engine mechanics, or in the shoe industry. Maternal occupational exposure to benzene in pregnancy was related to increased risk of ALL in offspring (adjusted OR=2.28, 95% CI 1.17 to 4.41), while paternal preconceptional benzene exposure was not as strongly associated (adjusted OR=1.40, 95% CI 0.88 to 2.22).ConclusionsOur study supports an increased risk for ALL with parental occupational benzene exposure.