Background: Benzene is a common air-pollutant; it is haematotoxic and an established human carcinogen. Its association with acute myeloid leukaemia is well documented in adults but data on children are scarce. To our knowledge, no cohort studies have investigated potential associations between benzene exposure and childhood cancer in children.

Objective: To examine whether 1) residence in the proximity of petrol stations, motor vehicle service stations or major roads, and 2) parental profession-related exposure to benzene are associated with a higher risk of cancer, particularly leukaemia, in children and adolescents.

Methods: The study includes all children born between January 1985 and December 2008, aged 0-15 years at diagnosis of cancer or leukaemia and resident in Switzerland (N=5300). Data on these children were obtained from the Swiss National Cohort (SNC), a long-term, census-based cohort that includes all Swiss inhabitants. Diagnosed cases of cancer were identified from the SCCR. Geocoded places of residence were used to assess proximity to petrol stations, motor vehicle service stations and major roads. We considered place of residence at birth and at diagnosis separately. Data on parental occupation during the 1990 and 2000 censuses were obtained from the SNC. Using a job exposure matrix we identified children whose parents were exposed to benzene at work. The data were analysed using Poisson regression and Cox proportional hazard models, adjusting for a range of potential confounders including socio-economic status, background ionizing radiation and birth weight.

Rational and Significance: Traffic-related pollution, including benzene, and its effects on health are a major public health problem because a substantial proportion of the population is exposed. This unique, large-scale study will help clarify whether traffic-related air pollution and exposure to benzene in particular, contribute to the incidence of childhood cancer in the general population.

Current status of project: Analyses have been completed and results are currently being written up and submitted for publication.

Study team: Spycher BD, Kuehni CE. Institute of Social and Preventive Medicine, University of Bern.

Funding: Swiss Federal Office of Public Health (BAG 10.002946)

Contact: Ben Spycher (, Claudia Kuehni (

© ISPM - University of Bern 2016