Department of Epidemiology, University of North Carolina at Chapel Hill (UNC-Chapel Hill), Chapel Hill, North Carolina, USA.
Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Environ Health Perspect. 2022 Jun;130(6):67002. doi: 10.1289/EHP10335. Epub 2022 Jun 1.
No safe level of lead in blood has been identified. Blood lead testing is required for children on Medicaid, but it is at the discretion of providers and parents for others. Elevated blood lead levels (EBLLs) cannot be identified in children who are not tested.
The aims of this research were to identify determinants of lead testing and EBLLs among North Carolina children and estimate the number of additional children with EBLLs among those not tested.
We linked geocoded North Carolina birth certificates from 2011-2016 to 2010 U.S. Census data and North Carolina blood lead test results from 2011-2018. We estimated the probability of being screened for lead and created inverse probability (IP) of testing weights. We evaluated the risk of an EBLL of at of age, conditional on characteristics at birth, using generalized linear models and then applied IP weights to account for missing blood lead results among unscreened children. We estimated the number of additional children with EBLLs of all North Carolina children using the IP-weighted population and bootstrapping to produce 95% credible intervals (CrI).
Mothers of the 63.5% of children (402,002 of 633,159) linked to a blood lead test result were disproportionately young, Hispanic, Black, American Indian, or on Medicaid. In full models, maternal age [; 95% confidence interval (CI): 1.13, 1.20] or smoking (1.14; 95% CI: 1.12, 1.17); proximity to a major roadway (1.10; 95% CI: 1.05, 1.15); proximity to a lead-releasing Toxics Release Inventory site (1.08; 95% CI: 1.03, 1.14) or a National Emissions Inventory site (1.11; 95% CI: 1.07, 1.14); and living in neighborhoods with more housing built before 1950 (1.10; 95% CI: 1.05, 1.14) or before 1940 (1.18; 95% CI: 1.11, 1.25) or more vacant housing (1.14; 95% CI: 1.11, 1.17) were associated with an increased risk of EBLL, whereas overlap with a public water service system was associated with a decreased risk of EBLL (0.85; 95% CI: 0.83, 0.87). Children of Black mothers were no more likely than children of White mothers to have EBLLs (0.98; 95% CI: 0.96, 1.01). Complete blood lead screening in 2011-2018 may have identified an additional 17,543 (95% CrI: 17,462, 17,650) children with EBLLs .
Our results indicate that current North Carolina lead screening strategies fail to identify over 30% (17,543 of 57,398) of children with subclinical lead poisoning and that accounting for characteristics at birth alters the conclusions about racial disparities in children's EBLLs. https://doi.org/10.1289/EHP10335.
目前尚未确定血液中铅含量的安全标准。接受医疗补助的儿童必须进行血铅检测，但其他儿童的血铅检测则由提供者和家长自行决定。未接受检测的儿童无法发现血铅水平升高（EBLL）。
本研究旨在确定北卡罗来纳州儿童血铅检测的决定因素和 EBLL 发生率，并估计在未接受检测的儿童中，EBLL 儿童的数量。
我们将 2011 年至 2016 年北卡罗来纳州出生证明与 2010 年美国人口普查数据和 2011 年至 2018 年北卡罗来纳州血铅检测结果进行了链接。我们估计了血铅检测的概率，并创建了逆概率（IP）检测权重。我们使用广义线性模型评估了特定年龄时 EBLL 的风险，条件是出生时的特征，并使用 IP 权重来纠正未接受血铅检测的儿童的缺失结果。我们使用 IP 加权人口数据来估计所有北卡罗来纳州儿童的 EBLL 数量，并通过自举法生成 95%置信区间（CrI）。
与血铅检测结果相关联的儿童（633,159 名中的 63.5%，402,002 名）的母亲普遍年轻、西班牙裔、黑人、美国印第安人或享受医疗补助。在全模型中，母亲年龄[1.13，1.20]或吸烟[1.14；95%置信区间（CI）：1.12，1.17]；靠近主要道路[1.10；95% CI：1.05，1.15]；靠近铅释放有毒物质排放清单站点[1.08；95% CI：1.03，1.14]或国家排放清单站点[1.11；95% CI：1.07，1.14]；居住在 1950 年以前（1.10；95% CI：1.05，1.14）或 1940 年以前（1.18；95% CI：1.11，1.25）建造的房屋较多的社区[1.10；95% CI：1.05，1.14]或有更多闲置房屋[1.14；95% CI：1.11，1.17]与 EBLL 风险增加相关，而与公共供水系统重叠则与 EBLL 风险降低相关（0.85；95% CI：0.83，0.87）。黑人母亲的孩子与白人母亲的孩子相比，EBLL 的可能性并没有更高（0.98；95% CI：0.96，1.01）。2011 年至 2018 年全面血铅筛查可能发现了另外 17,543 名（95% CrI：17,462，17,650）患有亚临床铅中毒的儿童。
我们的结果表明，北卡罗来纳州目前的铅筛查策略未能识别出超过 30%（17,543 名中的 17,543 名，57,398 名）患有亚临床铅中毒的儿童，并且考虑出生时的特征会改变关于儿童 EBLL 种族差异的结论。
