School of the Environment, Yale University, New Haven, CT, USA.
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
Environ Res. 2021 Apr;195:110862. doi: 10.1016/j.envres.2021.110862. Epub 2021 Feb 11.
Several studies have reported environmental disparities regarding exposure to concentrated animal feeding operations (CAFOs). Public health implications of environmental justice from the intensive livestock industry are of great concern in North Carolina (NC), USA, a state with a large number and extensive history of CAFOs.
We examined disparities by exposure to CAFOs using several environmental justice metrics and considering potentially vulnerable subpopulations.
We obtained data on permitted animal facilities from NC Department of Environmental Quality (DEQ). Using ZIP code level variables from the 2010 Census, we evaluated environmental disparities by eight environmental justice metrics (i.e., percentage of Non-Hispanic White, Non-Hispanic Black, or Hispanic; percentage living below the poverty level; median household income; percentage with education less than high school diploma; racial residential isolation (RI) for Non-Hispanic Black; and educational residential isolation (ERI) for population without college degree). We applied two approaches to assign CAFOs exposure for each ZIP code: (1) a count method based on the number of CAFOs within ZIP code; and (2) a buffer method based on the area-weighted number of CAFOs using a 15 km buffer.
Spatial distributions of CAFOs exposure generally showed similar patterns between the two exposure methods. However, some ZIP codes had different estimated CAFOs exposure for the different approaches, with higher exposure when using the buffer method. Our findings indicate that CAFOs are located disproportionately in communities with higher percentage of minorities and in low-income communities. Distributions of environmental justice metrics generally showed similar patterns for both exposure methods, however starker disparities were observed using a buffer method.
Our findings of the disproportionate location of CAFOs provide evidence of environmental disparities with respect to race and socioeconomic status in NC and have implications for future studies of environmental and health impacts of CAFOs.
多项研究报告了集中式动物饲养场（CAFOs）暴露方面的环境差异。美国北卡罗来纳州（NC）拥有大量且历史悠久的 CAFO，密集型畜牧业对环境正义的公共卫生影响引起了极大关注。
我们使用多种环境正义指标并考虑潜在的弱势群体，研究了 CAFO 暴露方面的差异。
我们从 NC 环境质量部（DEQ）获得了有关许可动物设施的数据。利用 2010 年人口普查的邮政编码级别变量，我们根据八项环境正义指标（即，非西班牙裔白人、非西班牙裔黑人或西班牙裔的百分比；生活在贫困线以下的百分比；家庭中位数收入；未完成高中学业的百分比；非西班牙裔黑人的种族居住隔离（RI）；以及无大学学位人口的教育居住隔离（ERI））评估环境差异。我们应用两种方法为每个邮政编码分配 CAFO 暴露：（1）基于邮政编码内 CAFO 数量的计数方法；（2）基于使用 15 公里缓冲区的加权 CAFO 数量的缓冲区方法。
CAFO 暴露的空间分布通常在两种暴露方法之间显示出相似的模式。然而，一些邮政编码由于不同的方法而具有不同的估计 CAFO 暴露，使用缓冲区方法时暴露更高。我们的研究结果表明，CAFO 不成比例地分布在少数民族比例较高和低收入社区中。环境正义指标的分布对于两种暴露方法通常显示出相似的模式，但使用缓冲区方法观察到更明显的差异。
我们发现 CAFO 的位置不成比例，这为 NC 种族和社会经济地位方面的环境差异提供了证据，并对未来 CAFO 环境和健康影响的研究具有影响。
