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Se presentan algunos conceptos básicos relativos a la contaminación atmosférica. Aunque, desde un punto de vista sanitario, nuestro interés se centra en los efectos que producen los contaminantes sobre la salud de la población, es importante conocer cuáles son los principales contaminantes, sus fuentes emisoras, sus características fisicoquímicas, los métodos de captación y análisis que utilizan las estaciones de control de la contaminación atmosférica, los límites establecidos por la legislación vigente y las recomendaciones de la Organización Mundial de la Salud respecto a los niveles de inmisión. Este trabajo repasa estos conceptos en relación con los contaminantes que se han analizado en el Estudio Multicéntrico Español de Contaminación Atmosférica y Mortalidad (EMECAM): partículas, dióxido de azufre (SO2), dióxido de nitrógeno (NO2), monóxido de carbono (CO) y ozono (O3). Para ello se han utilizado las publicaciones más recientes en la materia, incluyendo parte de lo que va a ser en un futuro inmediato el eje de actuación frente a la contaminación atmosférica: el nuevo conjunto de directivas de la Unión Europea (algunas en fase de propuesta) y las recomendaciones últimas (aún sin publicar) de la Organización Mundial de la Salud. Por último, se plantea el amplio abanico de aspectos que incumben a la Salud Pública en el campo de la contaminación atmosférica, a pesar de que la vigilancia y control dependen administrativamente de las autoridades ambientales.

Average ranges of particulate matter (PM10 and PM2.5) concentrations and chemical composition in Spain show significant variations across the country, with current PM10 levels at several industrial and traffic hotspots exceeding recommended pollution limits. Such variations and exceedances are linked to patterns of anthropogenic and natural PM emissions, climate, and reactivity/stability of particulate species. PM10 and PM2.5 concentrations reach 14–22μgPM10 m−3 and 8–12μgPM2.5 m−3 at most rural/regional background sites, 25–30μgPM10 m−3 and 15–20μgPM2.5 m−3 at suburban sites, 30–46μgPM10 m−3 and 20–30μgPM2.5 m−3 at urban background and industrial sites, and 46–50μgPM10 m−3 and 30–35μgPM2.5 m−3 at heavy traffic hotpots. Spatial distributions show sulphate and carbon particle levels reach maxima in industrialised areas and large cities (where traffic emissions are higher), and nitrate levels increase from the Atlantic to the Mediterranean (independent of the regional NO x emissions). African dust outbreaks have an influence on the number of exceedances of the daily limit value, but its additional load on the mean annual PM10 levels is only highly significant in Southern Iberia and Canary and Balearic islands. The marine aerosol contribution is near one order of magnitude higher in the Canaries compared to the other regions. Important temporal influences include PM intrusion events from Africa (more abundant in February–March and spring–summer), regional-scale pollution episodes, and weekday versus weekend activity. Higher summer insolation enhances (NH4)2SO4 but depletes particulate NO3 − (as a consequence of the thermal instability of ammonium nitrate in summer) and Cl− (due to HCl volatilisation resulting from the interaction of gaseous HNO3 with the marine NaCl), as well as generally increasing dry dust resuspension under a semi-arid climate. Average trace metal concentrations rise with the highest levels at industrial and traffic hotspots sites, in some cases (Ti, Cr, Mn, Cu, Zn, As, Sn, W, and Pb) exceeding rural background levels by over an order of magnitude. [Copyright &y& Elsevier]

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.

Prenatal and early life exposure to environmental agents, including dietary exposure, is associated with child health and human development and predisposes to late adult effects. Children are more vulnerable than adults to chemical, physical and biological hazards in air, water and soil, because they are still growing and their immune system and detoxification mechanisms are not fully developed. The physical, social and intellectual development of children from conception to the end of adolescence requires a protected environment that is also protective of their health. Following WHO and European Union recommendations, the Cooperative Environment and Childhood Research Network was funded by the Spanish Ministry of Health to study effects of environment and diet on foetal and early childhood development in different geographical areas of Spain. This network integrates different multidisciplinary research groups and is comprised of six cohorts--three pre-existing and three de novo--which will prospectively follow up 3600 pregnant women from start of pregnancy until the children are 4-6-year old.

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.

Samples were simultaneously taken of precipitation and atmospheric aerosol in two (rural and urban) stations, during 1986 and 1987, in which sulphates, nitrates and chlorides were analyzed by ionic chromatography. The wet deposition of the S and N composites were greater in the urban than in the rural area, and opposite was true for the chlorides. Regarding the aerosols, the average biennial concentrations of the anions studied were greater urban than in the rural area. Based on the figures obtained for the precipitation and the atmospheric aerosols, the washout ratios of each anion and the non-marine sulphates were determined. Both stations that the sulphates as a whole and the non-marine sulphates had very similar washout ratios while those of nitrates were greater in the rural area. The potential regressions between the rates at which they were washed away and the volume of precipitations reveal excellent correlation coefficients.