U.S. Environmental Protection Agency (EPA), Office of Research and Development (ORD), Research Triangle Park, North Carolina, NC, USA.
LinTech Global, Inc., Boston, MA, USA.
J Expo Sci Environ Epidemiol. 2024 Jul;34(4):718-726. doi: 10.1038/s41370-024-00666-x. Epub 2024 Apr 4.
Lead is a persistent, ubiquitous pollutant whose historical sources have been largely addressed through regulation and voluntary actions. The United States (U.S.) has achieved significant decreases in children's blood lead levels (BLL) over the past 40 years; however, there is no known safe level of Pb exposure. Some communities continue to be disproportionately impacted by exposure to Pb, including Black children and families living in older homes.
To identify Ohio (OH) census tracts with children exposed to Pb and evaluate potential exposure determinants.
We obtained individual children's blood Pb data from 2005-2018 in OH. The percent of children with elevated BLL (EBLL) was calculated for OH census tracts using three blood Pb reference values (3.5, 5, and 10 µg/dL). Getis-Ord Gi* geospatial hotspot or top 20th percentile methodologies were then applied to identify "hotspots." Findings across multiple time periods and blood Pb reference values were evaluated and compared with existing Pb exposure indices and models.
Consistency was observed across different blood Pb reference values, with the main hotspots identified at 3.5 µg/dL, also identified at 5 and 10 µg/dL. Substantial gains in public health were demonstrated, with the biggest decreases in the number of census tracts with EBLL observed between 2008-2010 and 2011-2013. Across OH, 355 census tracts (of 2850) were identified as hotspots across 17 locations, with the majority in the most populated cites. Generally, old housing and sociodemographic factors were indicators of these EBLL hotspots. A smaller number of hotspots were not associated with these exposure determinants. Variables of race, income, and education level were all strong predictors of hotspots.
The Getis-Ord Gi* geospatial hotspot analysis can inform local investigations into potential Pb exposures for children living in OH. The successful application of a generalizable childhood blood Pb methodology at the census tract scale provides results that are more readily actionable. The moderate agreement of the measured blood Pb results with public Pb indices provide confidence that these indices can be used in the absence of available blood Pb surveillance data. While not a replacement for universal blood Pb testing, a consistent approach can be applied to identify areas where Pb exposure may be problematic.
铅是一种持久、普遍存在的污染物，其历史污染源主要通过法规和自愿行动加以解决。美国在过去 40 年中大幅降低了儿童血铅水平；然而，目前尚不清楚接触铅的安全水平。一些社区仍然受到铅暴露的不成比例的影响，包括黑人和居住在老旧房屋中的家庭。
确定俄亥俄州（OH）有儿童接触铅的普查区，并评估潜在的暴露决定因素。
我们从 2005 年至 2018 年获得了 OH 个体儿童的血铅数据。使用三种血铅参考值（3.5、5 和 10μg/dL）计算 OH 普查区的儿童血铅升高率（EBLL）。然后应用 Getis-Ord Gi* 空间热点或前 20%分位数方法来识别“热点”。评估和比较了多个时间周期和血铅参考值的结果，并与现有的铅暴露指数和模型进行了比较。
不同血铅参考值之间存在一致性，在 3.5μg/dL 处确定的主要热点也在 5μg/dL 和 10μg/dL 处确定。公共卫生取得了显著进展，在 2008-2010 年至 2011-2013 年期间，观察到 EBLL 普查区数量减少最多。在整个 OH，在 17 个地点发现了 355 个普查区（2850 个）是热点，其中大部分位于人口最多的城市。一般来说，老旧房屋和社会人口因素是这些 EBLL 热点的指标。一小部分热点与这些暴露决定因素无关。种族、收入和教育水平等变量都是热点的强预测因素。
Getis-Ord Gi* 空间热点分析可以为居住在俄亥俄州的儿童的潜在铅暴露提供当地调查依据。在普查区规模上成功应用可推广的儿童血铅方法，可以提供更易于操作的结果。血铅测量结果与公共铅指数的中度一致性，使我们有信心在没有可用血铅监测数据的情况下使用这些指数。虽然不能替代普遍的血铅检测，但可以应用一致的方法来确定可能存在铅暴露问题的区域。
