Cavanagh Jo-Anne E, Trought Katherine, Brown Leslie, Duggan Sean
Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
Sci Total Environ. 2009 Sep 1;407(18):5007-18. doi: 10.1016/j.scitotenv.2009.05.020. Epub 2009 Jul 1.
We examined the chemical composition and biological response associated with particulate emissions from the two largest cities in New Zealand, Auckland and Christchurch. The organic and water-soluble fractions were isolated from the particulate matter (PM). The organic fraction was examined for PAH content, direct mutagenicity, CYP1A1 induction, and cytotoxicity and TNF-alpha release in RAW264.7 macrophages. The water-soluble fraction was examined for metal content, and cytotoxicity and TNF-alpha release in RAW264.7 macrophages. Particulate, PAH and water-soluble metal concentrations were all higher in PM collected from Christchurch, being highest in May-July when woodburners for home heating are widely in use. In contrast, PM from Auckland showed the highest concentrations in March, but PAH and metal concentrations were highest in July. We found marked differences in the biological response elicited by ambient air PM: the organic extracts of Christchurch PM(2.5) and PM(10) showed higher mutagenicity and CYP1A1 induction compared with PM(10) from Auckland. In contrast, water-soluble extracts of Auckland PM were more cytotoxic and resulted in greater TNF-alpha release than those from Christchurch PM, although they had a lower metal content. The organic fraction of PM from both cities did not induce any cytokine release, and the organic extract from Auckland samples showed no cytotoxicity; smaller PM mass was available for testing for these samples. Biological responses typically occurred at lower doses of the organic extract, indicating that organic components may be more important in eliciting effects than water-soluble components. Preliminary apportionment of the biological responses to the dominant sources of PM in both cities-woodburners and vehicles-was undertaken. This indicated that for both cities, vehicles have a greater contribution to the direct mutagenic activity of ambient PM than woodsmoke, despite a lower contribution to ambient PM. In contrast, woodsmoke is estimated to have a greater contribution to CYP1A1 induction of ambient PM. The calculated activity forms only a small proportion of the activity observed in extracts of ambient PM from Christchurch, particularly for mutagenicity, and may indicate a significant influence of atmospheric transformation processes on biological response. Only data for mutagenicity and CYP1A1 activity could be used for apportionment as low and/or variable cytotoxicity or TNF-alpha release response were obtained for either the individual source or ambient PM at the doses tested. Further, in the case of the water-soluble extracts from Auckland, additional components are suggested to have a role in the observed activity.
我们研究了新西兰两个最大城市奥克兰和克赖斯特彻奇的颗粒物排放所涉及的化学成分和生物反应。从颗粒物（PM）中分离出有机部分和水溶性部分。检测了有机部分的多环芳烃（PAH）含量、直接致突变性、CYP1A1诱导作用、细胞毒性以及RAW264.7巨噬细胞中肿瘤坏死因子-α（TNF-α）的释放情况。检测了水溶性部分的金属含量、细胞毒性以及RAW264.7巨噬细胞中TNF-α的释放情况。从克赖斯特彻奇采集的PM中，颗粒物、PAH和水溶性金属浓度均较高，在5月至7月最高，此时家庭取暖用的燃木炉广泛使用。相比之下，奥克兰的PM在3月浓度最高，但PAH和金属浓度在7月最高。我们发现环境空气中的PM引发的生物反应存在显著差异：与奥克兰的PM(10)相比，克赖斯特彻奇PM(2.5)和PM(10)的有机提取物显示出更高的致突变性和CYP1A1诱导作用。相反，奥克兰PM的水溶性提取物细胞毒性更强，导致RAW264.7巨噬细胞释放的TNF-α比克赖斯特彻奇PM的更多，尽管其金属含量较低。两个城市PM的有机部分均未诱导任何细胞因子释放，奥克兰样本的有机提取物未显示细胞毒性；这些样本可用于检测的PM质量较小。生物反应通常在较低剂量的有机提取物时出现，这表明有机成分在引发效应方面可能比水溶性成分更重要。对两个城市PM的主要来源——燃木炉和车辆——引发的生物反应进行了初步的源解析。这表明，对于两个城市来说，尽管车辆对环境PM的贡献较低，但对环境PM的直接致突变活性的贡献比木烟更大。相比之下，估计木烟对环境PM的CYP1A1诱导作用贡献更大。计算得出的活性仅占克赖斯特彻奇环境PM提取物中观察到的活性的一小部分，尤其是致突变性方面，这可能表明大气转化过程对生物反应有重大影响。由于在测试剂量下，无论是单个来源还是环境PM，均获得较低和/或变化的细胞毒性或TNF-α释放反应，因此仅能将致突变性和CYP1A1活性数据用于源解析。此外，对于奥克兰的水溶性提取物，建议其他成分在观察到的活性中起作用。
