Schreinemachers Dina M
National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
Environ Health Perspect. 2006 Feb;114(2):186-93. doi: 10.1289/ehp.8352.
In this ecologic study I examined ischemic heart disease (IHD) and diabetes mortality in rural agricultural counties of Minnesota, Montana, North Dakota, and South Dakota, in association with environmental exposure to chlorophenoxy herbicides, using wheat acreage as a surrogate exposure. I collected data on agricultural land use and 1979-1998 mortality from the U.S. Department of Agriculture and the Centers for Disease Control and Prevention websites, respectively. Counties were grouped based on percentage of land area dedicated to wheat farming. Poisson relative risks (RR) and 95% confidence intervals (CIs), comparing high- and medium- with low-wheat counties, were obtained for IHD, the subcategories acute myocardial infarction (AMI) and coronary atherosclerosis (CAS), and diabetes, adjusting for sex, age, mortality cohort, and poverty index. Mortality from IHD was modestly increased (RR = 1.08; 95% CI, 1.04-1.12). Analyses of its two major forms were more revealing. Compared with low-wheat counties, mortality in high-wheat counties from AMI increased (RR = 1.20; 95% CI, 1.14-1.26), and mortality from CAS decreased (RR = 0.89; 95% CI, 0.83-0.96). Mortality from AMI was more pronounced for those < 65 years of age (RR = 1.31; 95% CI 1.22-1.39). Mortality from type 2 diabetes increased (RR = 1.16; 95% CI, 1.08-1.24). These results suggest that the underlying cause of mortality from AMI and type 2 diabetes increased and the underlying cause of mortality from CAS decreased in counties where a large proportion of the land area is dedicated to spring and durum wheat farming. Firm conclusions on causal inference cannot be reached until more definitive studies have been conducted.
在这项生态学研究中，我以小麦种植面积作为替代暴露指标，考察了明尼苏达州、蒙大拿州、北达科他州和南达科他州农村农业县的缺血性心脏病（IHD）和糖尿病死亡率，以及与氯苯氧基除草剂环境暴露之间的关联。我分别从美国农业部和疾病控制与预防中心网站收集了农业土地利用数据和1979 - 1998年的死亡率数据。根据用于小麦种植的土地面积百分比对各县进行分组。针对IHD、其亚类急性心肌梗死（AMI）和冠状动脉粥样硬化（CAS）以及糖尿病，在调整性别、年龄、死亡率队列和贫困指数后，得出高小麦种植县和中小麦种植县与低小麦种植县相比的泊松相对风险（RR）和95%置信区间（CI）。IHD死亡率略有增加（RR = 1.08；95% CI，1.04 - 1.12）。对其两种主要形式的分析更具启发性。与低小麦种植县相比，高小麦种植县的AMI死亡率增加（RR = 1.20；95% CI，1.14 - 1.26），而CAS死亡率降低（RR = 0.89；95% CI，0.83 - 0.96）。65岁以下人群的AMI死亡率更为显著（RR = 1.31；95% CI 1.22 - 1.39）。2型糖尿病死亡率增加（RR = 1.16；95% CI，1.08 - 1.24）。这些结果表明，在大部分土地面积用于春小麦和硬质小麦种植的县，AMI和2型糖尿病死亡率的潜在原因增加，而CAS死亡率的潜在原因减少。在进行更多确定性研究之前，无法得出关于因果推断的确切结论。
