资源环境科技发展态势分析平台

We report atmospheric benzene measurements in the main metropolitan and industrial areas across Spain from 2014 to 2017 period. We have used hourly benzene levels measured at air-quality stations influenced by urban and industrial environments. Annual mean levels ranged between 0.3 and 2.4 mu g(-3) with an hourly maximum values of 112 mu g m(-3) in Tarragona. Industrial stations can reach concentrations of one order of magnitude greater than urban sites. Higher annual averages are also reported in the industrial stations (maximum similar to 3.5 mu g m(-3) in Aviles). When the monthly pattern is taken into account, the industrial sites also presented higher values than urban sites; urban stations show higher monthly values always in winter, ranging between < 0.5 mu g m(-3) and similar to 3 mu g m(-3). Three different features were observed in industrial stations according to their monthly pattern. A different diurnal pattern was also found in urban stations compared with the industrial sites. Applying a criterion, four exceedance events were selected as representatives of the behaviour of industrial and traffic stations. These events were analysed in detail along with the weather conditions, using ERAS reanalysis data from ECMWF (European Centre for Medium Range Weather Forecasts). The benzene events occurred under weather conditions governed by high pressure systems. In these cases, the accumulation of benzene in the lower atmosphere was favoured by both the lower wind speed and height of the ABL, which would lead to minor horizontal and vertical dispersion.