Long-term exposure to mould/damp stains and mouldy odour increases low birth weight

摘要

Background: Low birth weight (LBW), as a major concern in public health, is now increasing worldwide, but its main indoor environmental factors remain unclear.Objective: We examined whether LBW including term-LBW (T-LBW) and preterm-LBW (P-LBW) was associated with maternal exposure to indoor environmental factors, with a purpose to identify the key indoor environmental factor(s) contributing to LBW.Methods: A nationwide retrospective cohort study of 30,735 pre-schoolers in six Chinese cities was performed from 2010 to 2012. One questionnaire survey was conducted to collect information on the pre-schoolers' birth outcomes and their maternal exposure of indoor environmental factors including new furniture, house redecoration, cooking fuels, mould/damp stains, and mouldy odour during pregnancy. Maternal exposure of trafficrelated air pollutant (NO2), industrial pollutant (SO2), and inhalable particulate matter (PM10), as well as meteorological parameters, was estimated in pregnancy. Associations of LBW, T-LBW and P-LBW with indoor environmental factors were evaluated by two-level (city-child) logistic regression models with an odds ratio (OR) and 95 confidence interval (CI).Results: We found that P-LBW (1.0) and T-LBW (1.4) prevalence were respectively associated with persistent mould/damp stains and mouldy odour exposure in utero, ORs = 1.81 (95 CI: 1.01-3.24) and 1.49 (95 CI: 1.01-2.21). Exposure to high temperature and PM2.5 in pregnancy significantly enhanced the effect of persistent mould/damp stains and/or mouldy odour on P-LBW and LBW, ORs (95 CI) = 2.92 (1.40-6.07) and 1.78 (1.00-3.15) with significant interaction p values of 0.067 and 0.094 respectively. Sensitivity analysis suggested that raising cats and dogs significantly increased LBW risk of persistent mould/damp stains and mouldy odour exposure.