Temporal distribution of air quality related to meteorology and road traffic in Madrid

The impact of climatology-air temperature, precipitation and wind speed-and road traffic-volume, vehicle speed and percentage of heavy-duty vehicles (HDVs)-on air quality in Madrid was studied by estimating the effect for each explanatory variable using generalized linear regression models controlling for monthly variations, days of week and parameter levels. Every 1 m/s increase in wind speed produced a decrease in PM10 concentrations by 10.3 % (95 % CI 12.6-8.6) for all weekdays and by 12.4 % (95 % CI 14.9-9.8) for working days (up to the cut-off of 2.4 m/s). Increases of PM10 concentrations due to air temperature (7.2 % (95 % CI 6.2-8.3)) and traffic volume (3.3 % (95 % CI 2.9-3.8)) were observed at every 10 degrees C and 1 million vehicle-km increases for all weekdays; oppositely, slight decreases of PM10 concentrations due to percentage of HDVs (3.2 % (95 % CI 2.7-3.7)) and vehicle speed (0.7 % (95 % CI 0.6-0.8)) were observed at every 1 % and 1 km/h increases. Stronger effects of climatology on air quality than traffic parameters were found.