Navistar, Inc., Chicago, IL, USA.
J Air Waste Manag Assoc. 2011 Sep;61(9):894-913. doi: 10.1080/10473289.2011.599277.
Diesel exhaust (DE) characteristic of pre-1988 engines is classified as a "probable" human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC), and the U.S. Environmental Protection Agency has classified DE as "likely to be carcinogenic to humans." These classifications were based on the large body of health effect studies conducted on DE over the past 30 or so years. However, increasingly stringent U.S. emissions standards (1988-2010) for particulate matter (PM) and nitrogen oxides (NOx) in diesel exhaust have helped stimulate major technological advances in diesel engine technology and diesel fuel/lubricant composition, resulting in the emergence of what has been termed New Technology Diesel Exhaust, or NTDE. NTDE is defined as DE from post-2006 and older retrofit diesel engines that incorporate a variety of technological advancements, including electronic controls, ultra-low-sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters (DPFs). As discussed in a prior review (T. W. Hesterberg et al.; Environ. Sci. Technol. 2008, 42, 6437-6445), numerous emissions characterization studies have demonstrated marked differences in regulated and unregulated emissions between NTDE and "traditional diesel exhaust" (TDE) from pre-1988 diesel engines. Now there exist even more data demonstrating significant chemical and physical distinctions between the diesel exhaust particulate (DEP) in NTDE versus DEP from pre-2007 diesel technology, and its greater resemblance to particulate emissions from compressed natural gas (CNG) or gasoline engines. Furthermore, preliminary toxicological data suggest that the changes to the physical and chemical composition of NTDE lead to differences in biological responses between NTDE versus TDE exposure. Ongoing studies are expected to address some of the remaining data gaps in the understanding of possible NTDE health effects, but there is now sufficient evidence to conclude that health effects studies of pre-2007 DE likely have little relevance in assessing the potential health risks of NTDE exposures.
柴油机排气（DE）的特点是在 1988 年之前的发动机被国际癌症研究机构（IARC）归类为“可能”的人类致癌物（2A 组），美国环境保护署已将 DE 归类为“可能对人类致癌”。这些分类是基于过去 30 年左右对 DE 进行的大量健康影响研究。然而，美国对柴油机排气中颗粒物（PM）和氮氧化物（NOx）的排放标准越来越严格（1988-2010 年），这有助于刺激柴油机技术和柴油机燃料/润滑油成分的重大技术进步，从而出现了所谓的新技术柴油机排气，或 NTDE。NTDE 被定义为来自 2006 年后和旧的 retrofit 柴油机的 DE，这些柴油机采用了多种技术进步，包括电子控制、超低硫柴油燃料、氧化催化剂和壁流式柴油机微粒过滤器（DPF）。正如之前的一篇评论中所讨论的（T.W.Hesterberg 等人；环境科学与技术 2008，42，6437-6445），许多排放特征研究表明，NTDE 和 1988 年前的柴油机的“传统柴油机排气”（TDE）之间在受控和非受控排放方面存在显著差异。现在有更多的数据表明，NTDE 中的柴油机排气颗粒物（DEP）与 2007 年前的柴油机技术相比，在化学和物理性质上存在显著差异，并且与压缩天然气（CNG）或汽油发动机的颗粒物排放更为相似。此外，初步毒理学数据表明，NTDE 的物理和化学组成的变化导致 NTDE 与 TDE 暴露之间的生物学反应存在差异。正在进行的研究预计将解决对 NTDE 健康影响的理解中一些剩余的数据差距，但现在有足够的证据得出结论，对 2007 年前的 DE 进行健康影响研究对于评估 NTDE 暴露的潜在健康风险意义不大。
