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

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.