Parental Occupational Exposure Research Articles

Parental occupations at birth and risk of adult testicular germ cell tumors in offspring: a French nationwide case-control study.

Testicular germ cell tumors (TGCT) are the most frequent cancer in young men in developed countries. Parental occupational exposures during early-life periods are suspected to increase TGCT risk. The objective was to estimate the association between parental occupations at birth and adult TGCT. A case-control study was conducted, including 454 TGCT cases aged 18-45 from 20 French university hospitals, matched to 670 controls based on region and year of birth. Data collected from participants included parental jobs at birth coded according to the International Standard Classification of Occupation-1968 and the French nomenclature of activities-1999. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors. Paternal jobs at birth as service workers (OR = 1.98, CI 1.18-3.30), protective service workers (OR = 2.40, CI 1.20-4.81), transport equipment operators (OR = 1.96, CI 1.14-3.37), specialized farmers (OR = 2.66, CI 1.03-6.90), and maternal jobs as secondary education teachers (OR = 2.27, CI 1.09-4.76) or in secondary education (OR = 2.35, CI 1.13-4.88) were significantly associated with adult TGCT. The risk of seminoma was increased for the above-mentioned paternal jobs and that of non-seminomas for public administration and defence; compulsory social security (OR = 1.99, CI 1.09-3.65); general, economic, and social administration (OR = 3.21, CI 1.23-8.39) for fathers; and secondary education teacher (OR = 4.67, CI 1.87-11.67) and secondary education (OR = 3.50, CI 1.36-9.01) for mothers. Some paternal jobs, such as service workers, transport equipment operators, or specialized farmers, and maternal jobs in secondary education seem to be associated with an increased risk of TGCT with specific features depending on the histological type. These data allow hypotheses to be put forward for further studies as to the involvement of occupational exposures in the risk of developing TGCT, such as exposure to pesticides, solvents, or heavy metals.

Association between parental occupational exposure and the risk of asthma in offspring: A meta-analysis and systematic review.

Previous epidemiological studies have shown inconsistent results regarding the relation between the risk of asthma in offspring and parental occupational exposure. Therefore, we conducted a comprehensive and systematic collection of currently available epidemiological data to quantify the correlation between the 2. Related studies published before March 2023 were identified through searches of the Cochrane Library, Embase, PubMed, and Web of Science databases. The quality of included studies was assessed using the Newcastle-Ottawa Scale, while pooled odds ratios (ORs) with 95% confidence intervals (CIs) were computed using fixed-effect or random-effects models. This systematic review included 10 cohort studies, with a total of 89,571 parent-child pairs included in the quantitative analysis. The results exhibited a substantial association between parental occupational exposure to allergens (OR = 1.11; 95% CI: 1.00, 1.23; P = .051) and irritants (OR = 1.19; 95% CI: 1.07, 1.32; P = .001) and an increased risk of asthma in offspring. This association was also observed in the analysis of wheezing (OR = 1.22; 95% CI: 1.11, 1.35; P < .001 and OR = 1.19; 95% CI: 1.08, 1.32; P = .001). Subgroup analysis demonstrated that maternal occupational exposure to allergens (OR = 1.07; 95% CI: 1.02, 1.12; P = .008) and irritants (OR = 1.13; 95% CI: 1.05, 1.21; P = .001) significantly increased the risk of childhood asthma. Furthermore, parental postnatal occupational exposure to allergens (OR = 1.26; 95% CI: 1.10, 1.46; P = .001) and irritants (OR = 1.26; 95% CI: 1.06, 1.49; P = .009) had a more pronounced impact on childhood asthma. Higher levels of exposure (OR = 1.26; 95% CI: 1.10, 1.46; P = .001 and OR = 1.30; 95% CI: 1.16, 1.47; P < .001) were recognized as significant risk factors for childhood asthma. Parental occupational exposure to allergens and irritants increases the risk of asthma and wheezing in offspring, with maternal exposure, postnatal exposure, and high-dose exposure being the primary risk factors for childhood asthma.

Residential proximity to vines and risk of childhood embryonal tumours in France - GEOCAP case-control study, 2006–2013

BackgroundExposure to pesticides has been suggested as a potential risk factor for childhood embryonal tumour. The existing literature has mainly focused on parental occupational exposure and domestic use of pesticides, and is very limited for residential exposures to agricultural pesticides. The study aimed to test the hypothesis of an increased risk of embryonal tumour in children living close to viticultural plots, likely to be subject to frequent pesticide applications. MethodsThe study is part of the French national registry-based GEOCAP program. We included 2761 cases of neuroblastoma, retinoblastoma, Wilms tumour and rhabdomyosarcoma diagnosed before the age of 15 years in the 2006–2013 period, and 40,196 controls representative of the same age population during this period. Indicators of proximity to vines, the presence of vines and viticulture density within 1000 m of the geocoded addresses of residence, were evaluated combining three sources of data on agricultural land use in a geographic information system. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regressions and carried out several sensitivity analyses to test the stability of the results. ResultsApproximately 10% of the controls lived within 1000 m of vines, with regional variations ranging from <1% to 38%. We observed a 5% increase in the risk of neuroblastoma for a 10% increase in viticulture density (OR = 1.05, 95% CI: 0.98–1.13), with a regional heterogeneity. The indicators of proximity to vines were not associated with the other non-CNS embryonal tumours. ConclusionThe study showed a slight increase in the risk of neuroblastoma in children living close to vines, suggesting that residential exposure to agricultural pesticides may be involved in the occurrence of these tumours.

Pediatric leukemia and maternal occupational exposure to anticancer drugs: the Japan Environment and Children’s Study

AbstractOccupational exposure to medical agents and ionizing radiation has been suggested as a possible risk factor for childhood cancer. However, the relationship between such exposure and pediatric malignant neoplasms has not yet been comprehensively studied. This cohort study aimed to investigate the association between parental occupational exposure to hazardous medical agents or ionizing radiation and the risk of childhood cancer in offspring. Data from a large birth cohort in Japan, which included 104 062 fetuses, were analyzed. The primary outcome was the development of leukemia or brain tumors diagnosed by community physicians during the first 3 years after birth. Exposure factors were medical agents, including anticancer agents, ionizing radiation, and anesthetics, handled by mothers during pregnancy or by fathers for 3 months before conception. The incidence of leukemia, but not of brain tumors, was higher in mothers exposed to anticancer drugs. Multivariable regression analysis showed that maternal exposure to anticancer drugs was associated with an increased risk of leukemia in offspring older than 1 year (adjusted relative risk, 7.99 [95% confidence interval, 1.98-32.3]). Detailed information obtained from medical certificates of patients with identified leukemia revealed no infant leukemia but acute lymphoblastic leukemias in the exposed group. Our findings suggest that maternal occupational exposure to anticancer drugs may be a potential risk factor for acute lymphoblastic leukemia in offspring older than 1 year. Effective prevention methods may be necessary to prevent maternal exposure to anticancer drugs and to reduce the risk of childhood malignant neoplasms.

Parental occupational exposure to metals and risk of cancer in the offspring: A register-based case-control study from Sweden

BackgroundCancer risks in the offspring of mothers and fathers exposed to metals are unknown. We estimated the relative risks of childhood cancer, overall and by type, associated with parental occupational exposure to arsenic, cadmium, chromium, nickel, and lead. MethodsWe conducted a nested case-control study (1960–2015) of children born in Sweden aged 0–19 years diagnosed with cancer (National Cancer Register) matched 25:1 to controls on birth year and sex. We obtained parental occupational data around their birth from censuses and a nationwide register and identified exposure to each metal (yes/no, or higher/lower/no exposure) using the Swedish job-exposure matrix (SWEJEM). Adjusted odds ratios (OR) and 95% confidence intervals (CIs) were estimated separately for maternal and paternal exposures using conditional logistic regression. ResultsWe compared 9653 cases to 1,72,194 controls in maternal and 12,521 cases to 2,74,434 controls in paternal analyses, respectively. We found a 38% increased risk of cancer associated with maternal occupational exposure to arsenic (OR 1.38 [95% CI 1.06, 1.82]), likely driven by higher risks for lymphoma (OR 1.52 [0.73, 3.15]), central nervous system (CNS) (OR 1.49 [0.88, 2.54]) and other solid malignancies (OR 1.74 [1.14, 2.65]). There were also indications of higher risks of lymphoma in children of mothers exposed to nickel and iron, and of CNS tumours due to chromium exposure. No associations were observed from paternal occupational exposure to any of the metals. ConclusionsWe found evidence of increased risks of cancer in children of mothers but not fathers occupationally exposed to arsenic and potentially other metals.

Parental occupational exposure to solvents and risk of developing testicular germ cell tumors among sons: a French nationwide case-control study (TESTIS study).

The etiology of testicular germ cell tumors (TGCT) is suspected to be related to prenatal environmental risk factors. Some solvents have potential endocrine disrupting or carcinogenic properties and may disrupt male genital development in utero. The aim of this study was to examine the association between parental occupational exposure to solvents and TGCT risk among their offspring. A French nationwide case-control study, TESTIS included 454 TGCT cases and 670 controls frequency-matched on region and 5-year age strata. Participants were interviewed via telephone and provided information on parental occupations at birth. Job-exposure matrices (JEM) developed in the French Matgéné program were used to assign exposure to five petroleum-based solvents, five solvents or groups of oxygenated solvents, and five chlorinated solvents. Odds ratios (OR) for TGCT and 95% confidence intervals (CI) were estimated using conditional logistic regression, adjusting for TGCT risk factors. Occupational exposure to at least one solvent during the year of their son's birth was 41% among fathers and 21% among mothers. Paternal exposure to at least one solvent showed OR 0.89 (95% CI 0.68-1.15). Exposure to perchloroethylene (OR 1.41, 95% CI 0.55-3.61), methylene chloride (OR 1.13, 95% CI 0.54-2.34) and diesel/kerosene/fuel oil (OR 1.17, 95% CI 0.80-1.73) disclosed OR >1 but with low precision. Our results suggest a possible modest increase in non-seminoma risk for sons whose fathers were highly exposed to trichloroethylene (OR 1.44, 95% CI 0.79-2.63). Maternal exposure to at least one solvent showed OR 0.90 (95% CI 0.65-1.24). When stratifying by birth year, men born in the 1970s experienced an increased TGCT risk following maternal exposure to fuels and petroleum-based solvents (OR 2.74, 95% CI 1.11-6.76). Overall, no solid association was found between parental occupational exposure to solvents and TGCT risk. The association found with maternal occupational exposure to fuels and petroleum solvents among older men needs further investigation.

The association between maternal nutrient intake during pregnancy and the risk of sporadic unilateral retinoblastoma among offspring

Previous studies have associated maternal diet during pregnancy with the development of sporadic unilateral retinoblastoma (RB), but few studies have focused on the role of individual nutrients. The aim of this study is to investigate the association between maternal nutrient intake during pregnancy and the development of sporadic unilateral RB in the offspring.A modified food frequency questionnaire, with additional questions on supplement use, was completed via a phone interview. Cases were recruited from hospitals and controls were comprised of friends and relatives of the patient without a history of cancer. Overall, 168 sporadic unilateral RB cases and 145 controls were included in case-control study. We performed logistic regression to estimate odds ratios (ORs) and 95 % confidence intervals (CI), adjusting for child’s age, child’s sex, parental race/ethnicity, maternal education, total calorie intake during pregnancy, maternal age at birth, maternal smoking during pregnancy, pre-pregnancy body mass index, maternal weight gain during pregnancy, paternal age at birth, and maternal multivitamin use in the year before pregnancy.In the adjusted model, the interquartile (IQR) increase in vitamin A intake, which was measured in retinol activity equivalent (RAE; OR: 0.64, 95 % CI: 0.46–0.90), and vitamin D intake (OR: 0.62, 95 % CI: 0.42–0.91) significantly reduced the risk of sporadic unilateral RB.These findings suggest that a higher intake of vitamins A and D can be a protective factor for sporadic unilateral RB. Further analyses in consideration of multi-exposures such as parental occupational exposures are warranted to discover the complex etiology of sporadic unilateral RB. In addition, the role of nutritional epigenetics for how maternal nutrient intake influences the risk of sporadic unilateral RB in the offspring still needs to be explored.

Parental occupational exposure to chemicals and risk of breast cancer in female offspring

ObjectivesParental exposure to chemicals at work has been hypothesized to be a potential predisposing factor for breast cancer in next generations. The objective of the present nationwide nested case-control study was to contribute with evidence to this area. MethodsWomen with primary breast cancer were identified using the Danish Cancer Registry and they were required to have information on either maternal or paternal employment history, which resulted in the inclusion of 5587 cases. For each case, 20 female cancer free controls were matched on year of birth using the Danish Civil Registration System. Employment history was linked to job exposure matrices to assess specific occupational chemical exposures. ResultsFor maternal exposures, we observed an association between ever exposure to diesel exhaust (OR = 1.13, 95% CI: 1.01–1.27) and exposure to bitumen fumes in the perinatal period (OR = 1.51, 95% CI: 1.00–2.26) and breast cancer in female offspring. Highest cumulative exposure to benzo(a)pyrene, diesel exhaust, gasoline and bitumen fumes was further indicated to increase the risk. Results further indicated a stronger association between diesel exhaust (OR = 1.23, 95% CI: 1.01–1.50) and benzo(a)pyrene exposure (OR = 1.23, 95% CI: 0.96–1.57) and estrogen receptor negative tumors than tumors with ER expression, while bitumen fumes seemed to elevate the risk of both hormonal subtypes. For paternal exposures, the main results did not indicate any associations with breast cancer in female offspring. ConclusionsOur study suggests an elevated breast cancer risk in daughters of women occupational exposed to some occupational pollutants, including diesel exhaust, benzo(a)pyrene and bitumen fumes. These findings need to be confirmed in future large-scale studies before any firm conclusions can be reached.

Parental occupational exposure to solvents and autism spectrum disorder: An exploratory look at gene-environment interactions

Parental occupational exposure to solvents and autism spectrum disorder: An exploratory look at gene-environment interactions

Relationship between parental exposure to radiofrequency electromagnetic fields and primarily hematopoietic neoplasms (lymphoma, leukemia) and tumors in the central nervous system in children: a systematic review.

Low-frequency electromagnetic fields have grown exponentially in recent years due to technological development and modernization. The World Health Organization (WHO)/International Agency for Research on Cancer (IARC) has classified radiofrequency electromagnetic fields (RF-EMFs) as possibly carcinogenic to humans (Group 2B), and recent studies have investigated the association between exposure to electromagnetic fields in parents and possible health effects in children, especially the development of tumours of the central nervous system (CNS). The objective of this systematic review was to collate all evidence on the relationship between parental occupational exposure to electromagnetic fields and the development of CNS cancer in children and to evaluate this association. This review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Embase, and Web of Science were searched from January 1990 to April 2021. The search was conducted using the following search string: "occupational" AND "child" AND "electromagnetic" AND "cancer". Seventeen articles met our inclusion criteria: 13 case-control studies, two cohort studies, and 2 meta-analyses. Most of the studies showed several methodological weaknesses that limited their results. Due to a lack of consistency regarding the outcome as well as the heterogeneity in the reviewed studies, the body of evidence for the effects of parental exposure to electromagnetic fields is not clear. Methodological heterogeneity in the way that studies were conducted could be responsible for the lack of consistency in the findings. Overall, the body of evidence allows no conclusion on the relationship between parental exposure to electromagnetic fields and the occurrence of CNS tumours in children.

Alteration of oral microbiome composition in children living with pesticide-exposed farm workers.

Our prior work shows that azinphos-methyl pesticide exposure is associated with altered oral microbiomes in exposed farmworkers. Here we extend this analysis to show the same association pattern is also evident in their children. Oral buccal swab samples were analyzed at two time points, the apple thinning season in spring-summer 2005 for 78 children and 101 adults and the non-spray season in winter 2006 for 62 children and 82 adults. The pesticide exposure for the children were defined by the farmworker occupation of the cohabitating household adult and the blood azinphos-methyl detection of the cohabitating adult. Oral buccal swab 16S rRNA sequencing determined taxonomic microbiota proportional composition from concurrent samples from both adults and children. Analysis of the identified bacteria showed significant proportional changes for 12 of 23 common oral microbiome genera in association with azinphos-methyl detection and farmworker occupation. The most common significantly altered genera had reductions in the abundance of Streptococcus, suggesting an anti-microbial effect of the pesticide. Principal component analysis of the microbiome identified two primary clusters, with association of principal component 1 to azinphos-methyl blood detection and farmworker occupational status of the household. The children's buccal microbiota composition clustered with their household adult in ∼95% of the households. Household adult farmworker occupation and household pesticide exposure is associated with significant alterations in their children's oral microbiome composition. This suggests that parental occupational exposure and pesticide take-home exposure pathways elicit alteration of their children's microbiomes.

Preconception origins of asthma, allergies and lung function: The influence of previous generations on the respiratory health of our children.

Emerging research suggests that exposures occurring years before conception are important determinants of the health of future offspring and subsequent generations. Environmental exposures of both the father and mother, or exposure to disease processes such as obesity or infections, may influence germline cells and thereby cause a cascade of health outcomes in multiple subsequent generations. There is now increasing evidence that respiratory health is influenced by parental exposures that occur long before conception. The strongest evidence relates adolescent tobacco smoking and overweight in future fathers to increased asthma and lower lung function in their offspring, supported by evidence on parental preconception occupational exposures and air pollution. Although this literature is still sparse, the epidemiological analyses reveal strong effects that are consistent across studies with different designs and methodologies. The results are strengthened by mechanistic research from animal models and (scarce) human studies that have identified molecular mechanisms that can explain the epidemiological findings, suggesting transfer of epigenetic signals through germline cells, with susceptibility windows in utero (both male and female line) and prepuberty (male line). The concept that our lifestyles and behaviours may influence the health of our future children represents a new paradigm. This raises concerns for future health in decades to come with respect to harmful exposures but may also open for radical rethinking of preventive strategies that may improve health in multiple generations, reverse the imprint of our parents and forefathers, and underpin strategies that can break the vicious circle of propagation of health inequalities across generations.

Consequences of parental preconceptional irradiation: Endocrine-metabolic pathology in offspring

Epidemiological studies of late effects of preconceptional (prior to conception) radiation exposure are necessary in order to understand the risks of tumor and non-tumor pathology in next generations. Research of possible relation between parental preconceptional exposure and development of endocrine and metabolic disorders in the offspring is one of the topical issues of radiation hygiene. The objective of the study: comparative analysis of endocrine and metabolic pathology in children of the individuals exposed to long term preconceptional external gamma-radiation at the Mayak Production Association – at the first atomic industry facility on Russia. Materials and methods: A retrospective research was performed based on the Ozyorsk Children’s Health Registry. Ozyorsk – the city where Mayak Production Association is the enterprise forming the city. Analysis of endocrine and metabolic disorders was performed for 13880 children of 1949-1973 years of birth who were born and resided in Ozyorsk; parents of 9321 children of this number had accumulated doses of prolonged external gamma-radiation exposure at the production facility prior to conception. A comparative analysis of the structure and incidence of “Endocrine, nutritional and metabolic diseases” and nosological forms of this class of pathology was performed. Characteristic features of parental preconceptional exposure were analyzed in relation to thyroid pathology in children. Relative risk of endocrine and metabolic disorders among the children of exposed and unexposed parents was calculated for the whole disease class and for certain nosologies. Results: A significant predominance of thyroid diseases, particularly, iodine deficiencies, was detected at an earlier age among the offspring of Mayak Production Association workers compared to the control group; these cases were mostly related to low dose parental preconceptional exposure. Thyroid cancer was further detected in 0.16% (15/9321) of the studied cohort of the offspring of exposed parents with average manifestation age of 42.6. Relative risk of thyroid diseases was significantly higher among the exposed parents’ offspring compared to the controls: 2.0 among boys (95% confidence interval 1.38-2.9), 1.59 among girls (1.25-2.02) and in the group as a whole – 1.64 (1.34- 2.01). Relative risk of thyroid diseases related to iodine deficiency among the offspring of Mayak Production Association personnel was almost twice higher than the in the control group: 1.92 (1.3-2.84) among boys, 1.68 (1.29-2.2) among girls, 1.7 (1.36-2.12) in the whole group. Discussion and conclusion: A statistically significant overweight of non-tumor thyroid pathology in the offspring of Mayak Production Association personnel cannot be explained through external reasons taking into account similar climate and geographic conditions, possible technogenic exposure and the same unified medical survey of the followed children. We cannot exclude increased sensibility if thyroid tissue to iodine deficiency and its predisposition to hypertrophy and hyperplasia among the offspring of individuals exposed to long term occupational contact with ionizing radiation sources; that should be taken into account in the course of medical monitoring of these patients. Further research of transgenerational effects in the offspring of personnel of radiation hazardous production facilities are needed for complete understanding of the role of parental occupational exposure in health risks for further generations.

Environmental Risk Factors for Pediatric Acute Leukemia: Methodology and Early Findings.

Acute leukemia is the most common type of malignancy in children, and no major environmental risk factors have been identified relating to its pathogenesis. This study has been conducted with the aim for identifying risk factors associated with this disease. This study was conducted in 2016-2020 among children aged <15 years residing in Isfahan Province, Iran. Children with newly diagnosed Acute lymphoblastic leukemia, including Acute myeloid leukemia (ALL and AML) were considered a case group. The control group was selected among children hospitalized in orthopedic and surgery wards in the same region. Demographic data, parental occupational exposures and educational level, maternal obstetric history, type of feeding during infancy and parental smoking habits, exposure to pesticides, and hydrocarbons besides dietary habits (using a food frequency questionnaire) were evaluated. Overall, 497 children (195 cases and 302 controls) completed the survey. In the initial analysis, there was no significant difference between case and control groups about type of milk feeding (P = 0.34) or parental age (P = 0.56); however, an association between mothers' education and increased risk for ALL was observed (P = 0.02). The results of this study can be helpful in better understanding the environmental risk factors involved in the incidence of acute leukemia. Future publications based on the analysis of the database created in the present study can lead to recognizing these factors. In addition, evaluating the effect of these factors on treatment outcomes is an important step in reducing the burden of the disease.

Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life

Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life. We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs. In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested. Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children.

Residential proximity to croplands at birth and childhood leukaemia

BackgroundDomestic and parental occupational pesticide exposures are suspected of involvement in the occurrence of childhood acute leukaemia (AL), but the role of exposure to agricultural activities is little known. In a previous ecological study conducted in France, we observed an increase in acute lymphoblastic leukaemia (ALL) incidence rate with increasing viticulture density in the municipalities of residence at diagnosis.ObjectivesThis study aimed to test the hypothesis that residential proximity to croplands at birth increases the risk of childhood AL, with a particular focus on vineyards.MethodsWe identified all the primary AL cases diagnosed before the age of 15 years in the cohorts of children born in the French municipalities between 1990 and 2015. We estimated crop densities in each municipality of residence at birth using agricultural census data, for ten crop types. Variations in standardized incidence ratios (SIR) were evaluated with Poisson regression models, for all AL, ALL and acute myeloid leukaemia (AML), separately.ResultsAmong the 19,809,700 children born and residing in mainland France at birth in 1990–2015, 8,747 AL cases (7,236 ALL and 1,335 AML) were diagnosed over the period. We did not evidence any statistically significant positive association between total crop density or any specific crop density in the municipality of residence at birth and all AL, ALL or AML. Interestingly, we observed a higher ALL incidence rate in the municipalities with the highest viticulture densities (SIR = 1.25 95%CI [1.01–1.54]). Adjusting for the main potential confounders did not change the results.ConclusionOur study does not support the hypothesis that residential proximity to croplands, particularly vineyards, around birth plays a role in childhood leukaemia. The slightly higher ALL incidence rate in children born in the municipalities with the highest viticulture densities may reflect the previously-observed association at diagnosis.

Study of Parental Occupational Exposures to Solvents and Risk of Autism Spectrum Disorder in Offspring

BACKGROUND AND AIM: Solvents can accumulate in fat and later metabolize during pregnancy. Additionally, these toxicants could lead to germline mutations. We investigated associations between multiple parental occupational solvent exposures and odds of autism spectrum disorder (ASD) diagnosis in offspring. METHODS: Using population-based data from the Danish National Patient Registry, we identified a subset of ASD cases from 1982 to 2016 and 1:100 sex and birth-year matched controls obtained from the Central Population Register. We determined parental occupation history from age 16 years through 6 months post-childbirth from the Danish Pension Fund and estimated cumulative benzene, methylcyclohexane, toluene, trichloroethylene, perchloroethylene, and 1,1,1-trichloroethane exposure for mothers and fathers based on job exposure matrices (JEMs). Conditional logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for exposures one year prior to conception and during pregnancy. RESULTS: In analysis of data from 1898 people with ASD and 141,702 without ASD, there were no observed associations between maternal solvent exposures during pregnancy and risk of ASD in offspring. However, analysis for maternal benzene exposure one year prior to conception revealed higher adjusted odds for those with any exposure (aOR=1.55; 95% CI 1.02, 2.37). Additionally, although there were no significant associations between paternal solvent exposures during pregnancy and ASD risk, there were significantly increased odds of ASD in offspring whose fathers were exposed to benzene (aOR=3.07; 95% CI 1.72, 5.46) and toluene (aOR=1.66; 95% CI 1.05, 2.62) one year before conception. CONCLUSIONS: Although previous studies have suggested parental solvent exposure during pregnancy can contribute to pathogenesis of ASD, our findings suggest that risk may be increased through exposures prior to conception. However, unavoidable non-differential misclassification from the use of JEMs may have masked truly increased risk during pregnancy.

Parental occupational exposure to combustion products, metals, silica and asbestos and risk of childhood leukaemia: Findings from the Childhood Cancer and Leukaemia International Consortium (CLIC).

Parental occupational exposures around conception (father) or during pregnancy (mother) have been hypothesized as potential predisposing factors for childhood leukaemia. We investigated parental exposure to several known occupational carcinogens and childhood leukaemia risk. We conducted a pooled analysis using case-control data from four European countries (3362 childhood leukemia cases and 6268 controls). Parental occupational exposures to polycyclic aromatic hydrocarbons (PAH), diesel engine exhaust (DEE), chromium, nickel, crystalline silica, and asbestos were assessed by a general population job-exposure matrix. We estimated odd ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models for all childhood leukaemia combined, by leukaemia type (ALL and AML) and by ALL subtype (B-lineage and T-lineage). We found an association between high paternal occupational exposure to crystalline silica and childhood ALL (OR 2.20, CI 1.60–3.01) with increasing trend from no exposure to high exposure (P = <0.001), and also for AML (OR 2.03, CI 1.04–3.97; P for trend = 0.008). ORs were similar for B- and T-lineage ALL. For ALL, ORs were also slightly elevated with wide confidence intervals for high paternal occupational exposure to chromium (OR 1.23, CI 0.77–1.96), and DEE (OR 1.21, CI 0.82–1.77). No associations were observed for paternal exposures to nickel, PAH and asbestos. For maternal occupational exposure we found several slightly elevated odds ratios but mostly with very wide confidence intervals due to low numbers of exposed mothers. This is a first study suggesting an association between fathers’ occupational exposure to crystalline silica and an increased risk of childhood leukaemia in their offspring. As this association was driven by certain occupations (field crop farmers and miners) where other potentially relevant exposures like pesticides and radon may also occur, more research is needed to confirm our findings of an association with crystalline silica, and if so, mechanistic studies to understand the pathways.

Risk of Cancer in Children of Parents Occupationally Exposed to Hydrocarbon Solvents and Engine Exhaust Fumes: A Register-Based Nested Case–Control Study from Sweden (1960–2015)

Background:It remains unclear whether parental occupational exposure to hydrocarbon solvents (HCS) or engine exhaust fumes (EEF) is associated with higher risks of cancer in the offspring.Objectives:Our aim was to estimate relative risks of childhood cancers associated with maternal or paternal exposure to aliphatic/alicyclic, aromatic, or chlorinated HCS or gasoline/diesel EEF.Methods:We conducted a case–control study in which individuals old, born 1960–2014, were identified from the Swedish National Cancer Register (1960–2015) at first cancer diagnosis and matched to population controls (1 case:25 controls) on birth year and sex. Maternal and paternal occupation around the child’s birth was retrieved for 9,653 cases and 172,194 controls and 12,521 cases and 274,434 controls, respectively, using information from six censuses and a nationwide register. Using the Swedish job-exposure matrix (SWEJEM), we assessed exposure to HCS and EEF (any or higher/lower). Odds ratios (ORs) and 95% confidence intervals (CIs) of 15 childhood cancer subtypes were estimated using conditional logistic regression models adjusted for several confounders.Results:Maternal exposure to aromatic HCS was associated with non-Hodgkin lymphoma (; 95% CI: 1.05, 2.58), aliphatic/alicyclic HCS with germ cell tumors (; 95% CI: 0.89, 2.59), and gasoline/diesel EEF with astrocytoma (; 95% CI: 1.04, 1.88), myeloid leukemia (; 95% CI: 0.84, 2.81), lymphomas (; 95% CI: 0.85, 3.02 for Hodgkin; ; 95% CI: 0.71, 2.91 for non-Hodgkin), and epithelial tumors (; 95% CI: 0.93, 2.44). Paternal exposure to gasoline EEF was associated with Hodgkin lymphoma (; 95% CI: 1.01, 1.44) and soft tissue sarcomas (; 95% CI: 1.00, 1.48). No notable difference was observed between higher and lower exposure.Discussion:Our findings suggest that occupational exposure to HCS or EEF, especially in the mother, may increase the risk of some childhood cancers. They add to the growing literature on adverse effects from HCS and EEF in the child, but replication of these associations in other populations is warranted. https://doi.org/10.1289/EHP11035

Parental Occupational Exposure and Neurodevelopmental Disorders in Offspring: a Systematic Review and Meta-analysis.

Parental occupational exposures might be associated with neurodevelopmental disorders (NDDs) in offspring. We aimed to conduct a systematic review and meta-analysis to summarize and synthesize the current literature and to estimate the pooled magnitude of the underlying association(s) between parental occupational exposures and subsequent risk of NDDs. In the meta-analysis of 20 included studies, significant associations were found between parental occupational exposure to pesticides or solvents and the risk of attention deficit hyperactivity disorder in offspring. Prenatal occupational exposure to pesticides was significantly associated with motor development or cognition disorders in children. Furthermore, some evidence showed that metals might have a role in the development of autism spectrum disorders. Further studies need to identify the level of parental occupational exposures that can be significantly associated with NDDs. Moreover, utilizing standardized outcome and exposure scales is recommended to incorporate paternal, maternal, and parental as well as both prenatal and postnatal exposure in future studies.