Atmospheric vapour phase and particulate phase mercury in a coastal desert climate
Abstract
Vapour (T-Hgv) and particulate (T-Hgp) mercury were measured in the lower atmosphere at a ground station in Kuwait Bay. The concentration of T-Hgv varied from 0–86 ng m−3 with a mean of 3.8 ± 5.5 ng m−3 (n = 13 326). About 40% of the measured T-Hgv values over Kuwait Bay are higher than the global range (1–3 ng m−3). Car exhausts contributed to the increase of T-Hgv during the rush hours. However the contribution of T-Hgv from air crossing Kuwait Bay exceeds that T-Hgv produced by traffic probably because of the effects of the substantial load of industrially-derived mercury in the sediments of this shallow region. Thermal inversions have a major impact on the levels during the evening hours. The concentration of T-Hgp varied from 0.00–0.22 ng m−3 with a mean of 0.03 ± 0.03 ng m−3 (n = 175). The T-Hgp/T-Hgv% ratio varied from 0–11.1 (n = 171) with a mean of 1.0 ± 1.5%. Meteorological parameters influence the T-Hgv and T-Hgp concentrations with dust storms having a major impact on T-Hgp concentrations.