McCarthy Michael C, Hafner Hilary R, Montzka Stephen A
Sonoma Technology Inc, Petaluma, CA, USA.
J Air Waste Manag Assoc. 2006 Jan;56(1):3-11. doi: 10.1080/10473289.2006.10464436.
The U.S. Clean Air Act identifies 188 hazardous air pollutants (HAPs), or "air toxics," associated with adverse human health effects. Of these air toxics, 18 were targeted as the most important in a 10-City Pilot Study conducted in 2001 and 2002 as part of the National Air Toxics Trend Sites Program. In the present analysis, measurements available from monitoring networks in North America were used to estimate boundary layer background concentrations and trends of these 18 HAPs. The background concentrations reported in this study are as much as 85% lower than those reported in recent studies of HAP concentrations. Background concentrations of some volatile organic compounds were analyzed for trends at the 95% confidence level; only carbon tetrachloride (CCI4) and tetrachloroethylene decreased significantly in recent years. Remote background concentrations were compared with the one-in-a-million (i.e., 10(6)) cancer benchmarks to determine the possible causes of health risk in rural and remote areas; benzene, chloroform, formaldehyde, and chromium (Cr) fine particulate were higher than cancer benchmark values. In addition, remote background concentrations were found to contribute between 5% and 99% of median urban concentrations.
美国《清洁空气法》确定了188种与对人体健康产生不利影响相关的有害空气污染物（HAPs），即“空气毒物”。在这些空气毒物中，有18种被确定为2001年和2002年开展的一项10个城市试点研究中最为重要的污染物，该研究是国家空气毒物趋势监测点计划的一部分。在本分析中，利用北美监测网络提供的测量数据来估算这18种有害空气污染物的边界层背景浓度和趋势。本研究报告的背景浓度比近期关于有害空气污染物浓度的研究报告的浓度低多达85%。对部分挥发性有机化合物的背景浓度进行了95%置信水平的趋势分析；近年来只有四氯化碳（CCI4）和四氯乙烯显著下降。将偏远地区的背景浓度与百万分之一（即10⁻⁶）的癌症基准进行比较，以确定农村和偏远地区健康风险的可能原因；苯、氯仿、甲醛和铬（Cr）细颗粒物高于癌症基准值。此外，发现偏远地区的背景浓度占城市中位数浓度的5%至99%。
