Seasonal Variations of Total Gaseous Mercury at a French Coastal Mediterranean Site

10.4209/aaqr.2015.04.0219

Nicolas Marusczak；Sabine Castelle；Benoist de Vogüé；Joël Knoery；Daniel Cossa

Total gaseous mercury ； Coastal Mediterranean site ； Anthropogenic and local sources ； Seasonal and daily variations

Aerosol and Air Quality Research

16卷1期（2016 / 01 / 01）

46 - 60

英文

Total gaseous mercury (TGM) was continuously measured in 2009 and 2012, at a coastal site on the Mediterranean Sea (La Seyne-sur-Mer, France). Air temperature, humidity, wind speed and direction, and chemical parameters (O_3, CO, NO_x and PM_(10)) were also measured as tracers of atmospheric pollution. Average TGM concentrations did not differ between the two years, 2.20 ± 0.54 and 2.16 ± 0.60 ng m^(–3) for 2009 and 2012 respectively. Diurnal variations of TGM were observed for both years and linked to local industrial or urban activities. Furthermore, a clear seasonal trend was observed, with TGM minima in summer and maxima in winter. This seasonality is common to several air pollutants, like the result of the variation in the dispersion of pollutants in the boundary layer and higher photochemical activity in summer. The highest TGM concentrations (＞ 3 ng m^(–3)) were associated with air masses originating over urban and industrial areas of the Rhône Valley and local/regional anthropogenic sources. The influence of polluted air masses from these local/regional sources was confirmed by the significantly positive correlations between TGM and CO, NO_x and PM_(10). We demonstrate that polluted air masses from nearby urban and industrial regions are an important source of TGM to Mediterranean coastal areas, rather than volatilization from the sea surface.