Blood Lead Levels Among Afghan Children in the United States, 2014-2016

We conducted a cross-sectional analysis of blood lead test results during immigration-related DMEs of children <17 years old screened in 9 United States sites (7 states, 1 county, and 1 university-affiliated clinic) between January 1, 2014, and December 31, 2016. Participating sites reported quantitative blood lead screening results from venous specimens (preferred), capillary, or unknown specimens. BLLs ≥5 μg/dL were considered elevated. We compared BLL ≥5 μg/dL prevalence between Afghan and non-Afghan children receiving DMEs and assessed prevalence by age, sex, days from US arrival to DME, lead specimen type (capillary, venous, or unknown), DME year, nationality, country of last residence, anemia (hemoglobin of ≤10 g/dL), and stunting (<-2 standard deviations from the median height-for-age Z-score for the reference population).

We included independent variables significantly associated with BLL ≥5 μg/dL (P < .05) in bivariate analysis to calculate prevalence ratios and 95% confidence intervals using generalized estimating equations adjusted for age with repeated subjects to account for site-level clustering. All analyses were conducted using SAS software, version 9.4 (SAS Institute Inc, Cary, NC). This project was reviewed in accordance with Centers for Disease Control and Prevention’s institutional review policies and procedures and was determined to be nonresearch program evaluation.

Nine sites provided lead screening results for 30 435 children, including 4130 Afghans. Prevalence of BLLs ≥5 μg/dL among Afghan children was 32.0%, 3 times higher than non-Afghan children (9.2%, adjusted prevalence ratio [aPR] = 3.1, P < .0001) (Table 1) and was associated with having been examined in April through September, stunting, and country of last residence. Most (98.4%) Afghan children were screened within 90 days of US arrival.

Among Afghan children only, the highest prevalence of BLLs ≥5 μg/dL occurred among children ≤2 years old; 47% of these children had BLLs ≥5 μg/dL and 17% had a BLL ≥10 µg/dL (Table 2). Approximately 8.8% of Afghans were stunted; stunting was significantly associated with BLLs ≥5 μg/dL (37.8% of children with stunting compared with 29.6% of children without, P = .0013). This association remained after adjusting for age (aPR 1.2, P < .0001). After age adjustment, children screened in April through September were significantly more likely to have BLLs ≥5 μg/dL compared with children screened in October through March (aPR 1.2, P = .0007; not shown), and prevalence of BLLs ≥5 μg/dL among Afghan children last residing in Pakistan was higher compared with children coming from Afghanistan (aPR 1.8, P < .0001; not shown).

Children resettled from Afghanistan had a higher prevalence of BLLs ≥5 μg/dL compared with non-Afghan children screened shortly after United States resettlement and to all United States children (3.8% in 2016).⁶  Current Centers for Disease Control and Prevention guidance recommends that clinicians caring for Afghan arrivals screen for lead and potential sources of lead exposures (eg, use of surma/ kajal—eye cosmetics commonly used in Afghan children^7,8 ) in children ≤16 years of age and in pregnant or lactating people.⁹  Clinicians should also promptly evaluate and manage the nutritional status of Afghan children. Afghans may not arrive through immigration channels that connect them to the domestic medical examination including blood lead screening. State-based refugee health and lead programs, clinicians treating Afghans, and resettlement agencies supporting Afghans should work with families to ensure lead screening is conducted for all recently arrived Afghan children.

aPR

adjusted prevalence ratio

BLL

blood lead level

DME

domestic medical examination