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There is a growing concern about the possible adverse effects of exposure to air pollution on health during pregnancy. Therefore, a priority of the INMA (environment and childhood) study was to estimate personal exposure to traffic-related air pollution. In the cohort from Valencia (n=855), ambient levels of NO(2) were measured at 93 sampling sites spread over the study area during four different sampling periods of 7 days each. Multiple regression models were used to map ambient NO(2) over the area. Geographical data and predictions from kriging obtained by the "let one out" procedure were used as predictors. Individual exposure was assigned as 1) the estimated ambient NO(2) level at the home address and 2) the average of estimated ambient NO(2) levels at home and work addresses, weighted by the time spent in each environment. Estimations were temporally customized using the NO(2) levels registered daily by the regional Air Pollution Monitoring Network. The entire pregnancy and each trimester were taken as exposure windows. The model for the mean levels of NO(2) during the sampling periods explained 81% of the variation in NO(2) levels. Relative percent differences between the two models of personal exposure assignment were less than 9% for more than 90% of the participants; however the rest of them showed marked differences. Personal exposure estimates were slightly higher in the second model. In both cases, exposure during the whole pregnancy was strongly correlated with exposure in the second trimester. Considering periods shorter than the entire pregnancy will provide us the opportunity to identify specific windows of susceptibility.

This paper summarises the results of a series of studies on the interpretation of time series of levels of total suspended particles (TSP) and particulate matter (PM, <10 microm) in six regions of Spain in the period 1996-2000. In addition to the local pollution events, high PM10 episodes are recorded during African dust outbreaks, regional atmospheric recirculation events (mainly in spring to autumn), and to a lesser extent, under the influence of European and Mediterranean long range transported air masses. The lowest PM10 levels are usually recorded under Atlantic air mass advective conditions. All these regional and large-scale processes account for the relatively high PM10 levels recorded in regional background stations in Spain. Thus, the PM10 levels recorded at EMEP (Cooperative Program for Monitoring and Evaluation of the Long Range Transmission of Air Pollutants in Europe) regional background stations between March 2001 and March 2002 are very close to the annual limit value proposed for 2010 by the EU Air Quality Directive 1999/30/CE. Chemical data obtained for the different monitoring stations during 2001 show a high mineral load in PM10 for most of the study sites in Spain. Furthermore, a high marine aerosol load is evidenced in the Canary Islands. These mineral and marine loads are lower when considering PM2.5, but a relatively high proportion (8-21%) of mineral dust is still present.