Sequential variation of atmospheric mercury in Tokai-mura, seaside area of eastern central Japan

Osawa, Takahito  ; Ueno, Takashi ; Fu, F.*

Concentrations of gaseous elemental mercury (GEM) were continuously measured from Oct. 2005 to Aug. 2006 in Tokai-mura, a small city on the Pacific side of central Japan. The concentration of atmospheric mercury in summer and autumn is higher than in winter and spring, and an 11-month average of one-hour measurements is 3.78 ng/m (n=7551). Our results showed that changes in the GEM level in Tokai-mura are largely determined by temperature and relative humidity, but are independent of wind speed and direction. Two contrary patterns were observed in the daily-cycle of GEM concentrations: the most frequent pattern of lower concentrations at noon and a pattern of higher concentrations at noon, which was only observed in November. Our results showed that two nearby potential anthropogenic sources of mercury, a coal-fired power plant and incineration facility, have only little effect on the gaseous elemental mercury (GEM) in Tokai-mura based on only GEM measurements.