Vinitketkumnuen Usanee, Kalayanamitra Kittiwan, Chewonarin Teera, Kamens Richard
Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Thailand.
Mutat Res. 2002 Aug 26;519(1-2):121-31. doi: 10.1016/s1383-5718(02)00130-4.
Daily levels of particulate matter (PM) in the ambient air (PM 2.5 and PM 10) were measured in a northern city of Thailand (Chiang Mai) from March 1998 to October 1999. Twenty-four-hour air particulate matter samples were collected each day with Airmetric Minivol portable air samplers. Monthly averages of PM 2.5 from four stations in Chiang Mai varied from 15.39 to 138.31microg/m(3) and 27.29 to 173.40 microg/m(3) for PM 10. The PM 2.5 annual average was 58.48 mg/m(3) and PM 10, 86.38 microg/m(3). Daily PM 2.5 (24h values) during the winter months in Chiang Mai frequently exceeded 200-300 microg/m(3). The maximum concentrations of PM 2.5 (24h average) in Chiang Mai air from December 1998 to April 1999 were 2.8-, 3.5-, 4.2-, 6.5- and 3.2-fold higher than the US Environmental Protection Agency (US EPA), PM 2.5, 24h standard of 65 microg/m(3). From May to October, the mean 24h levels of PM 2.5 and PM 10 were at acceptable levels. The data shows that during the winter season (December to March), levels of PM 2.5 and PM 10 in the Chiang Mai atmosphere are very high, and there may be significant health implications associated with these high concentrations. During the summer season, the fine particles were generally within the acceptable levels. To our knowledge, these are the first measurements of PM 2.5 to be reported for the city of Chiang Mai and they indicate considerable ambient fine particle exposures to the Chiang Mai population. In addition, dichloromethane extracts of airborne particulate matter PM 2.5 or PM 10 collected in the months of winter in the city of Chiang Mai were mutagenic to Salmonella typhimurium strain TA100 without metabolic activation. The mutagenicity appeared to track particle concentrations and increased in the presence of S9 mix.
1998年3月至1999年10月期间，在泰国北部城市清迈对环境空气中的颗粒物（PM）（PM2.5和PM10）每日水平进行了测量。每天使用Airmetric Minivol便携式空气采样器收集24小时空气颗粒物样本。清迈四个站点的PM2.5月平均值在15.39至138.31微克/立方米之间，PM10在27.29至173.40微克/立方米之间。PM2.5的年平均值为58.48毫克/立方米，PM10为86.38微克/立方米。清迈冬季月份的每日PM2.5（24小时值）经常超过200 - 300微克/立方米。1998年12月至1999年4月清迈空气中PM2.5的最大浓度（24小时平均值）比美国环境保护局（US EPA）的PM2.5 24小时标准65微克/立方米分别高出2.8倍、3.5倍、4.2倍、6.5倍和3.2倍。从5月到10月，PM2.5和PM10的24小时平均水平处于可接受水平。数据表明，在冬季（12月至3月），清迈大气中的PM2.5和PM10水平非常高，这些高浓度可能对健康有重大影响。在夏季，细颗粒物通常处于可接受水平。据我们所知，这些是清迈市首次报告的PM2.5测量值，它们表明清迈人群暴露于相当多的环境细颗粒物中。此外，在清迈市冬季月份收集的空气传播颗粒物PM2.5或PM10的二氯甲烷提取物对鼠伤寒沙门氏菌TA100菌株具有致突变性，且无需代谢激活。致突变性似乎与颗粒物浓度相关，并在存在S9混合液时增加。
