影响中国近地面g -HCH浓度和沉积量的贡献源评估

采用CanMETOP模型,模拟了2005年欧洲(去除前苏联所占区域)、印度、中国和前苏联4个主要的g-HCH土壤残留区域的g-HCH通过挥发、大气传输和沉积对中国环境的影响.结果表明,中国东部和西部地区近地面的年均浓度分别为10~100pg/m3和1~10pg/m3.中国本地源对东中部和东北部的浓度贡献在90%以上,对东南部地区的贡献为30%~80%,印度源对该地区的贡献为10%~30%;印度源对西部的近地面浓度贡献在50%以上;欧洲源和前苏联源主要影响西北地区,贡献比例均在10%左右.中国本地源对东北区域的总沉积贡献最大(75%),西北区域和南部区域的总沉积均以印度源贡献为主,贡献比例分别为63%和67%.整个中国,年总沉积量为691t,贡献比例依次为印度源(55.1%),中国源(31.6%),欧洲源(3.6%),前苏联源(2.5%).

Sources of g-HCH in Chinese air at near-surface level and deposited to Chinese soil.

CanMETOP model was employed to assess the contributions to g-HCH in Chinese air and soil from four major g-HCH residual regions, including India, the former Soviet Union (FSU), Europe (excluding the FSU),and China itself in 2005. Modeled annual average air concentrations of g-HCH at 1.5 m height above ground surface ranged for 10~100 pg/m3 in eastern region, and 1~10 pg/m3 in western region of China. The former was mainly due to Chinese source (30%~80%), while the major of the later was attributable to Indian source (> 50%). The European and FSU sources both mostly contributed to the Chinese northwestern region (10%). The contributions of deposition in China were also different in different area. Chinese source dominated the deposition of g-HCH in the northeastern area (75%), while Indian source made the largest contribution in northwestern (63%) and southern (67%) areas of China. For whole China, annual total deposition of g-HCH in 2005 was 691 t, among which, 55.1% was from India, 31.6% was from China, 3.6% was from Europe, and 2.5% was from the FSU.