Development of Land Use Regression Models for Particle Composition in Twenty Study Areas in Europe

Land Use Regression (LUR) models have been used to describe and model spatial variability of annual mean concentrations of traffic related pollutants such as nitrogen dioxide (NO2), nitrogen oxides (NOx) and particulate matter (PM). No models have yet been published of elemental composition. As part of the ESCAPE project, we measured the elemental composition in both the PM10 and PM2.5 fraction sizes at 20 sites in each of 20 study areas across Europe. LUR models for eight a priori selected elements (copper (Cu), iron (Fe), potassium (K), nickel (Ni), sulfur (S), silicon (Si), vanadium (V), and zinc (Zn)) were developed. Good models were developed for Cu, Fe, and Zn in both fractions (PM10 and PM2.5) explaining on average between 67 and 79% of the concentration variance (R(2)) with a large variability between areas. Traffic variables were the dominant predictors, reflecting nontailpipe emissions. Models for V and S in the PM10 and PM2.5 fractions and Si, Ni, and K in the PM10 fraction performed moderately with R(2) ranging from 50 to 61%. Si, NI, and K models for PM2.5 performed poorest with R(2) under 50%. The LUR models are used to estimate exposures to elemental composition in the health studies involved in ESCAPE

Ambient air pollution and low birthweight: a European cohort study (ESCAPE)

Background Ambient air pollution has been associated with restricted fetal growth, which is linked with adverse respiratory health in childhood. We assessed the effect of maternal exposure to low concentrations of ambient air pollution on birthweight. Methods We pooled data from 14 population-based mother-child cohort studies in 12 European countries. Overall, the study population included 74 178 women who had singleton deliveries between Feb 11, 1994, and June 2, 2011, and for whom information about infant birthweight, gestational age, and sex was available. The primary outcome of interest was low birthweight at term (weight <2500 g at birth after 37 weeks of gestation). Mean concentrations of particulate matter with an aerodynamic diameter of less than 2.5 mu m (PM2.5), less than 10 mu m (PM10), and between 2.5 mu m and 10 mu m during pregnancy were estimated at maternal home addresses with temporally adjusted land-use regression models, as was PM2.5 absorbance and concentrations of nitrogen dioxide (NO 2) and nitrogen oxides. We also investigated traffic density on the nearest road and total traffic load. We calculated pooled effect estimates with random-effects models. Findings A 5 mu g/m(3) increase in concentration of PM2.5 during pregnancy was associated with an increased risk of low birthweight at term (adjusted odds ratio [OR] 1.18, 95% CI 1.06-1.33). An increased risk was also recorded for pregnancy concentrations lower than the present European Union annual PM2.5 limit of 25 mu g/m(3) (OR for 5 mu g/m(3) increase in participants exposed to concentrations of less than 20 mu g/m(3) 1.41, 95% CI 1.20-1.65). PM10 (OR for 10 mu g/m(3) increase 1.16, 95% CI 1.00-1.35), NO2 (OR for 10 mu g/m(3) increase 1.09, 1.00-1.19), and traffic density on nearest street (OR for increase of 5000 vehicles per day 1.06, 1.01-1.11) were also associated with increased risk of low birthweight at term. The population attributable risk estimated for a reduction in PM2.5 concentration to 10 mu g/m(3) during pregnancy corresponded to a decrease of 22% (95% CI 8-33%) in cases of low birthweight at term. Interpretation Exposure to ambient air pollutants and traffic during pregnancy is associated with restricted fetal growth. A substantial proportion of cases of low birthweight at term could be prevented in Europe if urban air pollution was reduced