Parental occupational exposure to benzene and the risk of childhood cancer: A census-based cohort study

Abstract

Background: Previous studies on occupational exposures in parents and cancer risks in their children support a link between solvents and paints with childhood leukaemia. Few studies have focused specifically on benzene.Objectives: To examine whether parental occupational exposure to benzene is associated with an increased cancer risk in a census-based cohort of children.Methods: From a census-based cohort study in Switzerland, we included children aged <16 years at national censuses (1990, 2000). We retrieved parental occupations reported at census and assessed exposure to benzene using a job exposure matrix. We identified incident cancer cases through record linkage with the Swiss Childhood Cancer Registry. We fitted Cox proportional-hazards models to assess associations between exposures and the following outcomes: any cancer, leukaemia, acute lymphoid leukaemia (ALL), acute myeloid leukaemia (AML), lymphoma, non-Hodgkin lymphoma, CNS tumours, and glioma. We adjusted models for a range of socio-economic, perinatal and environmental factors.Results: Analyses of maternal (paternal) exposure were based on 9.0 (13.2) million person years at risk and included 1004 (1520) diagnoses of cancer, of which 285 (438) had leukaemia, 186 (281) lymphoma, 227 (339) a CNS tumour. Maternal exposure was associated with an increased risk of childhood leukaemia (hazard ratio 1.73, 95% CI 1.12-2.67) and ALL (1.88, 1.16-3.04). We found little evidence of an association for other outcomes or for paternal exposure. Adjusting for potential confounders did not materially affect the results.Conclusions: This nationwide cohort study suggests an increased risk of leukaemia among children whose mothers were exposed to benzene at work. Highlights: A job exposure matrix was used to assess occupational benzene exposure in parents  A higher risk of leukaemia was observed in offspring of exposed mothers  In utero exposure is a plausible explanation for this finding

Temporal trends in incidence of childhood cancer in Switzerland, 1985-2014

“…Other potential risk factors include genetic causes, higher birth weight and parental age, increased infections, exposure to pesticides and traffic-related air pollution, as well as parental exposure to benzene. 47-49 However, the results of this study do not allow us to draw conclusions about specific risk factors that may have contributed to the overall increasing incidence of cancer in general, and specifically of leukaemia and CNS tumours.…”

Temporal trends in incidence of childhood cancer in Switzerland, 1985–2014

“…Other potential risk factors include genetic causes, higher birth weight and parental age, increased infections, exposure to pesticides and traffic-related air pollution, as well as parental exposure to benzene. [47][48][49] However, the results of this study do not allow us to draw conclusions about specific risk factors that may have contributed to the overall increasing incidence of cancer in general, and specifically of leukaemia and CNS tumours.…”

A spatial analysis of childhood cancer and industrial air pollution in a metropolitan area of Colombia

“…As also for the permanent transit of this type of automotive in this area, due to the loading and unloading of merchandise in the industrial sources that are in this industrial agglomerate. Likewise, in this area of industrial agglomerate the exhibition may not be related to air emissions but to the occupational exposure of parents who live near the workplace; there are several authors who have found a relationship between childhood cancer and maternal or paternal occupation [40] [41] [42] [43] [44].…”