Adams Kate, Greenbaum Daniel S, Shaikh Rashid, van Erp Annemoon M, Russell Armistead G
a Health Effects Institute , Boston , MA , USA.
J Air Waste Manag Assoc. 2015 May;65(5):544-58. doi: 10.1080/10962247.2014.1001884.
Exposure to particulate matter (PM) is associated with adverse health outcomes. There has long been a question as to whether some components of the PM mixture are of greater public health concern than others so that the sources that emit the more toxic components could be controlled. In this paper, we describe the National Particle Component Toxicity (NPACT) initiative, a comprehensive research program that combined epidemiologic and toxicologic approaches to evaluate this critical question, partly relying on information from a national network of air quality monitors that provided data on speciated PM2.5 (PM with an aerodynamic diameter<2.5 μm) starting in 2000. We also consider the results of the NPACT program in the context of selected research on PM components and health in order to assess the current state of the field. Overall, the ambitious NPACT research program found associations of secondary sulfate and, to a somewhat lesser extent, traffic sources with health effects. Although this and other research has linked a variety of health effects to multiple groups of PM components and sources of PM, the collective evidence has not yet isolated factors or sources that would be closely and unequivocally more strongly related to specific health outcomes. If greater success is to be achieved in isolating the effects of pollutants from mobile and other major sources, either as individual components or as a mixture, more advanced approaches and additional measurements will be needed so that exposure at the individual or population level can be assessed more accurately. Enhanced understanding of exposure and health effects is needed before it can be concluded that regulations targeting specific sources or components of PM2.5 will protect public health more effectively than continuing to follow the current practices of targeting PM2.5 mass as a whole.
This paper describes a comprehensive epidemiologic and toxicologic research program to evaluate whether some components and sources of PM may be more toxic than others. This question is important for regulatory agencies in setting air quality standards to protect people's health. The results show that PM from coal and oil combustion and from traffic sources was associated with adverse health outcomes, but other components and sources could not definitively be ruled out. Thus, given current knowledge, the current practice of setting air quality standards for PM mass as a whole likely remains an effective approach to protecting public health.
接触颗粒物（PM）与不良健康后果相关。长期以来，一直存在一个问题，即PM混合物的某些成分是否比其他成分更值得公众健康关注，以便可以控制排放毒性更大成分的来源。在本文中，我们描述了国家颗粒物成分毒性（NPACT）倡议，这是一个综合研究项目，它结合了流行病学和毒理学方法来评估这个关键问题，部分依赖于一个国家空气质量监测网络提供的信息，该网络从2000年开始提供关于特定PM2.5（空气动力学直径<2.5μm的颗粒物）的数据。我们还在关于PM成分与健康的选定研究背景下考虑NPACT项目的结果，以便评估该领域的当前状态。总体而言，雄心勃勃的NPACT研究项目发现二次硫酸盐以及在一定程度上交通源与健康影响之间存在关联。尽管这项研究和其他研究已将多种健康影响与多组PM成分和PM来源联系起来，但总体证据尚未分离出与特定健康结果密切且明确更强烈相关的因素或来源。如果要在分离来自移动源和其他主要源的污染物的影响方面取得更大成功，无论是作为单个成分还是作为混合物，都将需要更先进的方法和额外的测量，以便能够更准确地评估个体或人群水平的暴露情况。在得出针对PM2.5的特定来源或成分的法规比继续遵循当前将PM2.5总量作为目标的做法更能有效保护公众健康的结论之前，需要加强对暴露和健康影响的理解。
本文描述了一个综合的流行病学和毒理学研究项目，以评估PM的某些成分和来源是否可能比其他成分毒性更大。这个问题对于监管机构制定空气质量标准以保护人们的健康很重要。结果表明，来自煤炭和石油燃烧以及交通源的PM与不良健康后果相关，但其他成分和来源不能被明确排除。因此，根据目前的知识，目前将PM总量作为空气质量标准的做法可能仍然是保护公众健康的有效方法。
