Paternal Occupational Exposure Research Articles

Musculoskeletal congenital malformations: do paternal occupational exposures play a role?

BackgroundPaternal occupational exposures to potential health hazards are likely to affect congenital malformations through the spermatogenesis cycle.PurposeThe aim of this case–control study was to assess the relationship between the risk of musculoskeletal congenital malformations in offspring and paternal workplace exposure to potential health hazards during the preconception period.MethodThe study comprised 105 patients (cases) with a musculoskeletal congenital malformation(s) and 135 controls matched for age and demographic characteristics. Both parents of each case and control were interviewed in the hospital by a trained physician. They also completed a questionnaire focusing on the preconception period and on the 3-month period immediately before and after the pregnancy conception date, respectively, of the child under study.ResultsThe odds of having a child with a congenital malformation was higher (P < 0.05) if the father was occupationally exposed to pesticides, solvents, or welding fumes during the preconception period.ConclusionControl of workplace exposures and adherence to threshold limit values of these potential health hazards should be adopted to minimize the risk of fathers having offspring with a congenital malformation.

Paternal Occupational Exposure to Endocrine-Disrupting Chemicals as a Risk Factor for Leukaemia in Children: A Case-Control Study from the North of England

Occupations with exposures to a variety of chemicals, including those thought to be potential endocrine disruptors, have been associated with an increased risk of leukaemia in offspring. We investigated whether an association exists between paternal occupations at birth involving such exposures and risk of leukaemia in offspring. Cases (n=958) were matched, on sex and year of birth, to controls from two independent sources, one other cancers, one cancer-free live births. Paternal occupations at birth were classified, using an occupational exposure matrix, as having “very unlikely,” “possible,” or “likely” exposure to six groups of potential endocrine-disrupting chemicals. There was a significantly increased risk of acute nonlymphocytic leukaemia (ANLL) for polychlorinated organic compounds (OR 1.95, 95% CI 1.08–3.54) only in comparison with cancer-free controls, and for phthalates (OR 1.61, 95% CI 1.00–2.61) only with registry controls. A number of other, including inverse, associations were seen, but limited to one control group only. No associations were seen with likely paternal exposure to heavy metals. The associations identified in this study require further investigation, with better exposure and potential confounding (for example maternal variables) information, to evaluate the likelihood of true associations to assess whether they are real or due to chance.

Self-reported parental exposure to pesticide during pregnancy and birth outcomes: the MecoExpo cohort study.

The MecoExpo study was performed in the Picardy region of northern France, in order to investigate the putative relationship between parental exposures to pesticides (as reported by the mother) on one hand and neonatal parameters on the other. The cohort comprised 993 mother-newborn pairs. Each mother completed a questionnaire that probed occupational, domestic, environmental and dietary sources of parental exposure to pesticides during her pregnancy. Multivariate regression analyses were then used to test for associations between the characteristics of parental pesticide exposure during pregnancy and the corresponding birth outcomes. Maternal occupational exposure was associated with an elevated risk of low birth weight (odds ratio (OR) [95% confidence interval]: 4.2 [1.2, 15.4]). Paternal occupational exposure to pesticides was associated with a lower than average gestational age at birth (−0.7 weeks; p = 0.0002) and an elevated risk of prematurity (OR: 3.7 [1.4, 9.7]). Levels of domestic exposure to veterinary antiparasitics and to pesticides for indoor plants were both associated with a low birth weight (−70 g; p = 0.02 and −160 g; p = 0.005, respectively). Babies born to women living in urban areas had a lower birth length and a higher risk of low birth length (−0.4 cm, p = 0.006 and OR: 2.9 [1.5, 5.5], respectively). The present study results mainly demonstrate a negative correlation between fetal development on one hand and parental occupational and domestic exposure to pesticides on the other. Our study highlights the need to perform a global and detailed screening of all potential physiological effects when assessing in utero exposure to pesticides.

0306 Parental occupational exposure to ionising radiation and selected birth defects in the US

ObjectivesResults of previous studies of occupational exposure to ionising radiation (IR) and birth defects are inconsistent. Our objective was to assess the association between maternal and paternal occupational exposure to...

Revisiting an old challenging issue: do paternal and maternal occupational exposures to ionizing radiation affect the gender of the offspring?

Revisiting an old challenging issue: do paternal and maternal occupational exposures to ionizing radiation affect the gender of the offspring?

Exposure to household painting and floor treatments, and parental occupational paint exposure and risk of childhood brain tumors: results from an Australian case–control study

Childhood brain tumors (CBT) are the leading cause of cancer death in children, yet their etiology remains largely unknown. This study investigated whether household exposure to paints and floor treatments and parental occupational painting were associated with CBT risk in a population-based case-control study conducted between 2005 and 2010. Cases were identified through all ten Australian pediatric oncology centers, and controls via nationwide random-digit dialing, frequency matched to cases on age, sex, and state of residence. Data were obtained from parents in mailed questionnaires and telephone interviews. Information on domestic painting and floor treatments, and parental occupational exposure to paint, in key periods relating to the index pregnancy and childhood was obtained for 306 cases and 950 controls. Data were analyzed using unconditional logistic regression, adjusting for frequency matching variables and potential confounders. Overall, we found little evidence that parental, fetal, or childhood exposure to home painting or floor treatments was associated with risk of CBT. There was, though, some evidence of a positive association between childhood exposure to indoor painting and risk of high-grade glioma [odds ratio (OR) 3.31, 95 % confidence interval (CI) 1.29, 8.52] based on very small numbers. The OR for the association between CBT and paternal occupational exposure to paint any time before the pregnancy was 1.32 (95 % CI 0.90, 1.92), which is consistent with the results of other studies. Overall, we found little evidence of associations between household exposure to paint and the risk of CBT in any of the time periods investigated.

Risk factors for non‐syndromic oral clefts: a matched case–control study in Hubei Province, China

To explore the risk factors for CL/P in Hubei Province, China. A hospital-based, matched case-control study was conducted. One hundred and eight cases with CL/P were matched by age and sex with 108 normal controls. Their parents were retrospectively interviewed using a questionnaire. Univariate and multivariate analyses were used to calculate the relative risk by odds ratio and 95% confidence interval. Univariate analysis identified ten factors as significantly related to CL/P (P < 0.05). Multivariate conditional logistic regression models showed that five of these factors were significantly associated with CL/P. Paternal occupational exposure (OR = 13.08, 95% CI: 2.35-72.86), first-trimester maternal illness (OR = 36.67, 95% CI: 5.37-250.36), first-trimester maternal bad mood (OR = 8.69, 95% CI: 1.35-55.84), first-trimester maternal diet of eggs or milk (≥5 meals per week, OR = 6.72, 95% CI: 1.23-36.69), and first-trimester maternal sexual activity (OR = 5.98, CI 95%:1.14-31.49) were risk factors for CL/P. In our study, we identified that paternal occupational exposure, first-trimester maternal illness, first-trimester maternal bad mood, first-trimester maternal diet of eggs or milk (≥5 meals per week), and first-trimester maternal sexual activities were significantly associated with increased CL/P.

Case-control study of paternal occupation and social class with risk of childhood central nervous system tumours in Great Britain, 1962-2006.

Background:Paternal occupational exposures have been proposed as a risk factor for childhood central nervous system (CNS) tumours. This study investigates possible associations between paternal occupational exposure and childhood CNS tumours in Great Britain.Methods:The National Registry of Childhood Tumours provided all cases of childhood CNS tumours born and diagnosed in Great Britain from 1962 to 2006. Controls without cancer were matched on sex, period of birth and birth registration sub-district. Fathers' occupations were assigned to one or more of 33 exposure groups. A measure of social class was also derived from father's occupation at the time of the child's birth.Results:Of 11 119 cases of CNS tumours, 5 722 (51%) were astrocytomas or other gliomas, 2 286 (21%) were embryonal and 985 (9%) were ependymomas. There was an increased risk for CNS tumours overall with exposure to animals, odds ratio (OR) 1.40 (95% confidence intervals (CIs) 1.01, 1.94) and, after adjustment for occupational social class (OSC), with exposure to lead, OR 1.18 (1.01, 1.39). Exposure to metal-working oil mists was associated with reduced risk of CNS tumours, both before and after adjustment for OSC, OR 0.87 (0.75, 0.99).Risk of ependymomas was raised for exposure to solvents, OR 1.73 (1.02,2.92). For astrocytomas and other gliomas, risk was raised with high social contact, although this was only statistically significant before adjustment for OSC, OR 1.15 (1.01,1.31). Exposure to paints and metals appeared to reduce the risk of astrocytomas and embryonal tumours, respectively. However, as these results were the result of a number of statistical tests, it is possible they were generated by chance.Higher social class was a risk factor for all CNS tumours, OR 0.97 (0.95, 0.99). This was driven by increased risk for higher social classes within the major subtype astrocytoma, OR 0.95 (0.91, 0.98).Conclusion:Our results provide little evidence that paternal occupation is a significant risk factor for childhood CNS tumours, either overall or for specific subtypes. However, these analyses suggest that OSC of the father may be associated with risk of some childhood CNS cancers.

Exposure to pesticides and the risk of childhood brain tumors

Previous research has suggested positive associations between parental or childhood exposure to pesticides and risk of childhood brain tumors (CBT). This Australian case-control study of CBT investigated whether exposures to pesticides before pregnancy, during pregnancy and during childhood, were associated with an increased risk. Cases were recruited from 10 pediatric oncology centers, and controls by random-digit dialing, frequency matched on age, sex, and State of residence. Exposure data were collected by written questionnaires and telephone interviews. Data were analyzed by unconditional logistic regression. The odds ratios (ORs) for professional pest control treatments in the home in the year before the index pregnancy, during the pregnancy, and after the child's birth were 1.54 (95% confidence interval (CI): 1.07, 2.22), 1.52 (95% CI: 0.99, 2.34) and 1.04 (95% CI: 0.75, 1.43), respectively. ORs for treatments exclusively before pregnancy and during pregnancy were 1.90 (95% CI: 1.08, 3.36) and 1.02 (95% CI: 0.35, 3.00), respectively. The OR for the father being home during the treatment was 1.79 (95% CI: 0.85, 3.80). The OR for paternal occupational exposure in the year before the child's conception was 1.36 (95% CI: 0.66, 2.80). ORs for prenatal home pesticide exposure were elevated for low- and high-grade gliomas; effect estimates for other CBT subtypes varied and lacked precision. These results suggest that preconception pesticide exposure, and possibly exposure during pregnancy, is associated with an increased CBT risk. It may be advisable for both parents to avoid pesticide exposure during this time.

A case-control study of paternal occupational exposures and the risk of childhood sporadic bilateral retinoblastoma

BackgroundThe risk factors for sporadic (ie, non-familial) retinoblastoma remain largely unknown.ObjectivesWe examined the relationship between paternal occupational exposures from jobs held 10 years and 1 year prior to conception and...

Use of Birth Certificates to Examine Maternal Occupational Exposures and Autism Spectrum Disorders in Offspring

The continuing rise in the prevalence of autism spectrum disorders has led to heightened interest in the role of nongenetic factors, including exogenous exposures, but little research has been conducted. To explore a possible role in autism etiology, we used data available from our prior studies to examine potential occupational exposures, as these may occur at higher levels than environmental exposures. Parental occupation was obtained from birth certificates for 284 children with autism and 659 controls, born in 1994 in the San Francisco Bay Area. Self-reported occupation and industry were coded into eight exposure/chemical groups based on potential neurotoxicity or reprotoxicity by a board-certified physician in occupational medicine and an industrial hygienist blinded to case-control status. Mothers of autistic children were twice as likely to work in occupations considered exposed (14.4%) as mothers of controls (7.2%) (adjusted odds ratio [AOR] 2.3 [95% confidence interval {CI} 1.3-4.2]). The exposure categories of the greatest frequency among case mothers were exhaust and combustion products (AOR = 12.0 [95% CI 1.4-104.6]) and disinfectants (AOR = 4.0 [95% CI 1.4-12.0]). Paternal occupational exposure was not associated with autism, potentially consistent with a direct in-utero exposure effect. There are several limitations of this hypothesis-generating study, including lack of detail on workplace and job duties, leading to possible misclassification and low proportion exposed. However, this misclassification would not be biased by case-control status and is unlikely to explain the associations we did find, suggesting that further research on exogenous exposures may yield useful etiologic clues.

Case–control study of paternal occupation and childhood leukaemia in Great Britain, 1962–2006

Background:Paternal occupational exposures have been proposed as a risk factor for childhood leukaemia. This study investigates possible associations between paternal occupational exposure and childhood leukaemia in Great Britain.Methods:The National Registry of Childhood Tumours provided all cases of childhood leukaemia born and diagnosed in Great Britain between 1962 and 2006. Controls were matched on sex, period of birth and birth registration subdistrict. Fathers’ occupations were assigned to 1 or more of 33 exposure groups. Social class was derived from father’s occupation at the time of the child’s birth.Results:A total of 16 764 cases of childhood leukaemia were ascertained. One exposure group, paternal social contact, was associated with total childhood leukaemia (odds ratio 1.14, 1.05–1.23); this association remained significant when adjusted for social class. The subtypes lymphoid leukaemia (LL) and acute myeloid leukaemia showed increased risk with paternal exposure to social contact before adjustment for social class. Risk of other leukaemias was significantly increased by exposure to electromagnetic fields, persisting after adjustment for social class. For total leukaemia, the risks for exposure to lead and exhaust fumes were significantly <1. Occupationally derived social class was associated with risk of LL, with the risk being increased in the higher social classes.Conclusion:Our results showed some support for a positive association between childhood leukaemia risk and paternal occupation involving social contact. Additionally, LL risk increased with higher paternal occupational social class.

Paternal Occupational Exposures and the Risk of Childhood Sporadic Bilateral Retinoblastoma

Paternal Occupational Exposures and the Risk of Childhood Sporadic Bilateral Retinoblastoma

The ‘take home’ burden of workplace sensitizers: Flour contamination in bakers' families

BackgroundExposure to flour/flour constituents is a leading cause of occupational asthma. Paternal occupational exposure to flour has been associated with increased likelihood of childhood asthma, raising the possibility of para-occupational exposure whereby family members are exposed to sensitizers ‘taken home’ on contaminated skin/clothing. ObjectiveTo establish whether workplace contamination of skin/clothing with wheat flour allergen (WFA) and fungal α-amylase (FAA) is associated with increased levels of these allergens in bakers' homes. MethodsBakeries in north-east Scotland were invited to participate. Control subjects were recruited from University of Aberdeen staff and students. Exposure assessment was carried out in bakeries, bakers' cars and the homes of bakers and controls using surface wipe and vacuum sampling; samples were analyzed for total protein, FAA and WFA. Results164 wipe samples and 49 vacuum samples were collected from 38 bakers (from 5 bakeries) and 10 controls.Compared to non-bakers, bakers had higher median levels of WFA and FAA in house vacuum samples; the difference was statistically significant for WFA/total protein (515.8×10−6 vs. 163.7×10−6, p=0.031), FAA/total protein ratios (1.45×10−6 vs. 0.04×10−6, p<0.001) and FAA loading (median 1.2pg/cm2 vs. 0.1pg/cm2, p<0.001) with workplace exposure–home contamination relationships between bakers with higher and lower workplace contamination.We found positive correlations between WFA contamination of the bakers' foreheads and cars (rs0.57, p=0.028), foreheads and houses (rs0.46, p=0.025), shoes and houses (rs0.45, p=0.029); and between FAA contamination of shoes and houses (rs0.46, p=0.023), and cars and houses (rs0.70, p=0.008). There was no evidence of bakers using work-sourced flour for domestic baking. ConclusionsThis work demonstrates pathways for ‘take home’ exposure of occupationally sourced flour. Taken with our previous work, showing that bakers' children are more likely to have asthma, this supports the need for further investigation to establish whether ‘take home’ of occupationally sourced flour is widespread with health consequences.

Effects of Paternal Occupation Exposure to Formaldehyde on Reproductive Outcomes

To investigate whether paternal occupational exposure to formaldehyde (FA) affects the reproductive outcomes. Data were collected from 302 male workers occupationally exposed to FA and 305 referent controls through interview questionnaires. Formaldehyde exposure level was measured and calculated for every subject. Different reproductive outcomes were compared for two groups by logistic regression analyses. A significant increased risk of prolonged time to pregnancy (P = 0.034; odds ratio, 2.828; 95% confidence interval, 1.081 to 7.406) and significant elevated risk of spontaneous abortion (P = 0.021; odds ratio, 1.916; 95% confidence interval, 1.103 to 3.329) were observed in wives of male workers occupationally exposed to FA after correction for confounding factors. Moreover, reproductive toxicity due to FA exposure is dose dependent. This epidemiological study adds some evidence for the hypothesis that paternal FA occupation exposure has adverse effects on reproductive outcomes.

Congenital heart defects and parental occupational exposure to chemicals

Congenital heart defects (CHDs) are the most common major malformations in newborns. In this study we examined the associations between the occurrence of CHDs in children and periconceptional occupational parental exposures to chemicals. In an age-matched case-control study with standardized data collection at c. 15 months after birth, 424 mothers and 421 fathers of a child with CHD and 480 mothers and 477 fathers of a non-malformed child, filled out questionnaires on periconceptional general and job characteristics. A job exposure matrix, which links the information on job title and a description of work tasks to an expert judgement on exposure to chemicals in the workplace, was used. The overall prevalence of occupational exposure to chemicals was 5.0 in cases and 6.2% in controls for mothers [odds ratio (OR) adjusted = 0.92; 95% confidence interval (CI): 0.26-3.25], while 22.3 and 15.9% for fathers, respectively (OR adjusted = 1.23; 95% CI: 0.39-3.91). No association of maternal occupational exposure to chemicals with risk of CHDs was found. Paternal exposure to phthalates was associated with a higher incidence of CHDs in general (OR adjusted = 2.08; 95% CI: 1.27-3.40). Paternal exposure to phthalates was associated with perimembranous ventricular septal defect (OR adjusted = 2.84; 95% CI: 1.37-5.92), to polychlorinated compounds with atrioventricular septal defect (OR adjusted = 4.22; 95% CI: 1.23-14.42) and to alkylphenolic compounds with coarctation of the aorta (OR adjusted = 3.85; 95% CI: 1.17-12.67). Periconceptional paternal (but not maternal) occupational exposure to certain chemicals is associated with an increased risk of CHDs in children. The results, however, must be interpreted cautiously as exposure probabilities are a crude measure of exposure.

Case-control study of paternal occupation and risk of childhood cancer in Great Britain, 1962–2006

ObjectivesPaternal exposure to carcinogens has been proposed as a risk factor for childhood cancer. Previous epidemiological studies, complicated by weak exposure assessments and limited case numbers, have reported mixed results,...

Paternal occupational exposure to pesticides and risk of neuroblastoma among children: a meta-analysis

Epidemiological data relating paternal pesticide exposure in occupational settings with higher risk of neuroblastoma are inconsistent. Since most studies included a small number of cases, lack of power is a potential reason for observed inconsistencies. We conducted a meta-analysis of published studies that investigated the association of paternal occupational pesticide exposure with childhood neuroblastoma. We identified published studies up to October 2009 on paternal pesticide exposure and neuroblastoma using online databases and extracted relative risk estimates for the association. Summary relative risk estimates were calculated using the fixed effects inverse variance weighting method. To account for heterogeneity, we used Shore-corrected confidence intervals and the random effects method. Subgroup analyses were conducted according to study design, location, and exposure ascertainment method. The meta-analysis included seven case-control and two cohort studies with a combined total of 1,426 cases. Overall, between-study heterogeneity was low (p=0.46), and the fixed effects, random effects, and Shore-adjusted confidence intervals were similar. The summary risk ratio was 1.07 (95% CI 0.79-1.46, two-sided p value=0.65). Results of the subgroup meta-analyses were robustly null. Findings from current published studies do not support an association between paternal occupational pesticide exposure and childhood neuroblastoma.

Occupational exposure to endocrine disruptors and time to pregnancy among couples in a large birth cohort study: the Generation R Study

To study the influence of occupational exposure to endocrine disruptors (EDs) on time to pregnancy (TTP). Cross-sectional analysis within a prospective, population-based cohort study. Medical center. Mothers and fathers who filled out a questionnaire during mid-pregnancy (response 77% and 82% of enrollment, respectively) were selected if the pregnancy was planned and either parent performed paid employment. In total, 2,774 mothers and 2,728 partners were included in the statistical analyses. None. Self-reported TTP (months). There was no correlation between maternal and paternal exposure, because κ values for agreement for all exposure categories ranged from 0.03 to 0.13. Paternal occupational exposure to heavy metals (hazard ratio of pregnancy 0.83; 95% confidence interval 0.71-0.97) and overall exposure to EDs (hazard ratio 0.85; 95% confidence interval 0.75-0.96) was statistically significantly associated with an increased TTP. Maternal occupational exposure to all categories of EDs showed prolonged TTP, but the decreased hazard ratios were not statistically significant. This birth cohort study provides indications for adverse effects of parental occupational exposure to EDs on TTP.

Parental occupational exposure to endocrine disrupting chemicals and male genital malformations: A study in the danish national birth cohort study

BackgroundSex hormones closely regulate development of the male genital organs during fetal life. The hypothesis that xenobiotics may disrupt endogenous hormonal signalling has received considerable scientific attention, but human evidence is scarce.ObjectivesWe analyse occurrence of hypospadias and cryptorchidism according to maternal and paternal occupational exposure to possible endocrine disrupting chemicals.MethodsWe conducted a follow-up study of 45,341 male singleton deliveries in the Danish National Birth Cohort during 1997-2009. Information on work during pregnancy was obtained by telephone interviews around gestational week 16. Parents' job titles were classified according to DISCO-88. A job exposure matrix for endocrine disrupting chemicals (EDCs) was implemented to assess occupational exposures. The Medical Birth and National Hospital Register provided data on congenital anomalies diagnosed at birth or during follow-up, which ended in 2009. Crude and adjusted hazard ratios (HR) were obtained from Cox regression models.ResultsAmong all pregnancies, 6.3% were classified as possibly or probably exposed to EDCs. The most prevalent occupations conferring possible exposure were cleaners, laboratory technicians, hairdressers and agricultural workers (58% of all potentially exposed). The final cumulative incidence of cryptorchidism in boys was 2.2% (1002 cases), and of hypospadias 0.6% (262 cases). The occurrence of hypospadias increased when mothers were probably [HRa = 1.8 (95% CI 1.0-2.6)] or possibly exposed to one or more EDCs [HRa = 2.6 (95% CI 1.8-3.4). Possible paternal exposure to heavy metals increased the risk of hypospadias [HRa 2.2 (95% CI: 1.0-3.4)] and cryptorchidism [HRa 1.9 (95% CI: 1.1-2.7)]. None of the exposure groups reached statistical significance.ConclusionThe study provides some but limited evidence that occupational exposure to possible endocrine disrupting chemicals during pregnancy increases the risk of hypospadias.