Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China Xuewu Fu a,b , Xinbin Feng a, * , Wanze Zhu c , Wei Zheng a,b , Shaofeng Wang a,b , Julia Y. Lu d a State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, PR China b Graduate University of the Chinese Academy Sciences, Beijing 100049, PR China c Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, PR China d Department of Chemistry and Biology, Ryerson University, Toronto, Ont., Canada M5B 2K3 Available online 1 January 2008 Abstract Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m À3 , which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m À3 ) while the minimum mean concentration was observed in winter (4.0 pg m À3 ). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 pg m À3 and had a clear seasonal variation: winter (74.1 pg m À3 ), autumn (22.5 pg m À3 ), spring (15.3 pg m À3 ) and summer (10.8 pg m À3 ), listed in decreasing order. The annual wet deposition was 9.1 lgm À2 and wet deposition in the rainy season (May–October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distin- guishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxi- dation processes and diurnal changes in meteorology play an important role in RGM generation. Ó 2007 Elsevier Ltd. All rights reserved. 1. Introduction Mercury is a highly toxic environmental pollu- tant that can cause great harm to the environment and human health (Schroeder and Munthe, 1998). Since the industrial revolution, Hg released from human activities has significantly increased and it has been estimated that the average Hg concentra- tion in the troposphere has increased by a factor of 3 (Fitzgerald, 1995). Due to its volatility, Hg can be transported over a long distance via the atmosphere to remote areas once emitted from sources. Elevated Hg concentrations in the air can cause contamination of remote areas via 0883-2927/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.apgeochem.2007.12.018 * Corresponding author. Fax: +86 851 5891609. E-mail address: fengxinbin@vip.skleg.cn (X. Feng). Available online at www.sciencedirect.com Applied Geochemistry 23 (2008) 408–418 www.elsevier.com/locate/apgeochem Applied Geochemistry