Traffic-Related Atmospheric Pollutants Levels during Pregnancy and Offspring’s Term Birth Weight: A Study Relying on a Land-Use Regression Exposure Model

International audienceBACKGROUND: Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education. RESULTS: Exposure was defined for 1,016 births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29). CONCLUSION: Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in term birth weight. Traffic-related air pollutants may have adverse effects on birth weight

Health risks of early swimming pool attendance

Swimming pool attendance and exposure to chlorination by-products showed adverse health effects on children. We assessed whether early swimming pool attendance, especially baby swimming, is related to higher rates of early infections and to the development of allergic diseases. In 2003-2005, 2192 children were analysed for the 6-year follow-up of a prospective birth cohort study. Data on early swimming pool attendance, other lifestyle factors and medical history were collected by parental-administered questionnaire. Bivariate and multivariate logistic regression analyses were used to evaluate associations. Babies who did not participate in baby swimming had lower rates of infection in the 1st year of life (i) diarrhoea: OR 0.68 CI 95% 0.54-0.85; (ii) otitis media: OR 0.81 CI 95% 0.62-1.05; (iii) airway infections: OR 0.85 CI 95% 0.67-1.09. No clear association could be found between late or non-swimmers and atopic dermatitis or hay fever until the age of 6 years, while higher rates of asthma were found (OR 2.15 95% CI 1.16-3.99), however, potentially due to reverse causation. The study indicates that, in terms of infections, baby swimming might not be as harmless as commonly thought. Further evidence is needed to make conclusions if the current regulations on chlorine in Germany might not protect swimming pool attendees from an increased risk of gastrointestinal infections. In terms of developing atopic diseases there is no verifiable detrimental effect of early swimming