Exposure to traffic noise and risk for febrile seizure : a cohort study

Traffic noise stresses and disturbs sleep, which are mechanisms that may affect risk of febrile seizures. We aimed to investigate whether road traffic noise increased risk for febrile seizures in children. In a population of 57,282 children from the Danish National Birth Cohort we identified 2,175 children diagnosed with incident febrile seizure before 6 years of age. Residential address history from conception to 6 years of age was found in national registers, and road traffic noise (Lden) and air pollution (NO2) were modeled for all addresses. Analyses were done using Cox proportional hazard model. An interquartile range increase in childhood road traffic noise exposure (9.5 dB) was associated with an incidence rate ratio (IRR) of 1.11 (1.04-1.19) higher risk of febrile seizures after adjustment for gender, maternal lifestyle and socioeconomic status. After further adjustment for air pollution, the IRR was 1.08 (1.00-1.16). In these mutually adjusted models air pollution also seemed associated with febrile seizures (IRR: 1.03 (0.99-1.06)). In conclusion, road traffic noise increased risk of febrile seizures in children, both before and after air pollution adjustment.