Air quality assessment in urban areas of Gipuzkoa (Spain).

Objectives: To evaluate the air quality to which a population of 90,000 inhabitants in the province of Gipuzkoa (Basque Country, Spain) is exposed. The population resides in a periurban environment, where industrial activity (11 iron and steel foundries) is scattered among residential areas.

Methods: Throughout 2006 and 2007, levels of particulate matter less than 2.5mm in diameter (PM(2.5)) were quantified and levels of trace elements in PM(2.5) fraction [cadmium (Cd), arsenic (As), manganese (Mn), copper (Cu), chromium (Cr), nickel (Ni), iron (Fe), lead (Pb), mercury (Hg) and zinc (Zn)] were analyzed. The samples were gathered in seven sampling sites using three high-volume Digitel DAH 80 samplers. Annual and seasonal variability were evaluated for the various contaminants in each valley and PM(10) and PM(2.5) samples were also gathered at the same site for a month, with the goal of analyzing the composition of trace elements in each particle size. Finally, the results were compared with those obtained from the same study area by the Basque Government Air Quality Network equipment.

Results: The observed PM(2.5) concentrations (12.2-28.9 microg/m(3)) were similar to those described in urban environments in large European cities, while mean trace element concentrations were significantly higher. The Mn levels observed in all three valleys indicated the influence of the steel and metal industries on air quality.

Conclusion: The finding that levels of particulate matter and trace elements in the study area were similar to or higher than those found in metropolitan areas has implications for the evaluation of health risks in populations far from large population centers.