Atmospheric vapour phase and particulate phase mercury in a coastal desert climate

Abstract

Vapour (T-Hg_v) and particulate (T-Hg_p) mercury were measured in the lower atmosphere at a ground station in Kuwait Bay. The concentration of T-Hg_v 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-Hg_v values over Kuwait Bay are higher than the global range (1–3 ng m⁻³). Car exhausts contributed to the increase of T-Hg_v during the rush hours. However the contribution of T-Hg_v from air crossing Kuwait Bay exceeds that T-Hg_v 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-Hg_p varied from 0.00–0.22 ng m⁻³ with a mean of 0.03 ± 0.03 ng m⁻³ (n = 175). The T-Hg_p/T-Hg_v% ratio varied from 0–11.1 (n = 171) with a mean of 1.0 ± 1.5%. Meteorological parameters influence the T-Hg_v and T-Hg_p concentrations with dust storms having a major impact on T-Hg_p concentrations.