Enstrom James E
University of California, Los Angeles and Scientific Integrity Institute, Los Angeles, CA, USA.
Dose Response. 2017 Mar 28;15(1):1559325817693345. doi: 10.1177/1559325817693345. eCollection 2017 Jan-Mar.
In 1997 the US Environmental Protection Agency (EPA) established the National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM), largely because of its positive relationship to total mortality in the 1982 American Cancer Society Cancer Prevention Study (CPS II) cohort. Subsequently, EPA has used this relationship as the primary justification for many costly regulations, most recently the Clean Power Plan. An independent analysis of the CPS II data was conducted in order to test the validity of this relationship.
The original CPS II questionnaire data, including 1982 to 1988 mortality follow-up, were analyzed using Cox proportional hazards regression. Results were obtained for 292 277 participants in 85 counties with 1979-1983 EPA Inhalable Particulate Network PM measurements, as well as for 212 370 participants in the 50 counties used in the original 1995 analysis.
The 1982 to 1988 relative risk (RR) of death from all causes and 95% confidence interval adjusted for age, sex, race, education, and smoking status was 1.023 (0.997-1.049) for a 10 µg/m increase in PM in 85 counties and 1.025 (0.990-1.061) in the 50 original counties. The fully adjusted RR was null in the western and eastern portions of the United States, including in areas with somewhat higher PM levels, particularly 5 Ohio Valley states and California.
No significant relationship between PM and total mortality in the CPS II cohort was found when the best available PM data were used. The original 1995 analysis found a positive relationship by selective use of CPS II and PM data. This independent analysis of underlying data raises serious doubts about the CPS II epidemiologic evidence supporting the PM NAAQS. These findings provide strong justification for further independent analysis of the CPS II data.
1997年，美国环境保护局（EPA）制定了细颗粒物（PM）的国家环境空气质量标准（NAAQS），这主要是因为在1982年美国癌症协会癌症预防研究（CPS II）队列中，它与总死亡率呈正相关。随后，EPA将这种关系作为许多昂贵法规的主要依据，最近的一项是《清洁电力计划》。为了检验这种关系的有效性，对CPS II数据进行了独立分析。
使用Cox比例风险回归分析了原始的CPS II问卷数据，包括1982年至1988年的死亡率随访情况。获得了85个县中292277名参与者的结果，这些县在1979 - 1983年有EPA可吸入颗粒物网络的PM测量数据，以及原始1995年分析中使用的50个县中212370名参与者的结果。
在85个县中，PM每增加10微克/立方米，1982年至1988年全因死亡的相对风险（RR）及经年龄、性别、种族、教育程度和吸烟状况调整后的95%置信区间为1.023（0.997 - 1.049），在最初的50个县中为1.025（0.990 - 1.061）。在美国西部和东部地区，包括PM水平略高的地区，特别是俄亥俄河谷5个州和加利福尼亚州，完全调整后的RR为零。
当使用现有最佳的PM数据时，未发现CPS II队列中PM与总死亡率之间存在显著关系。1995年的原始分析通过选择性使用CPS II和PM数据发现了正相关关系。对基础数据的这项独立分析对支持PM NAAQS的CPS II流行病学证据提出了严重质疑。这些发现为进一步独立分析CPS II数据提供了有力依据。
