Environmental Assessment and Blood Lead Levels of Children in Owino Uhuru and Bangladesh Settlements in Kenya

Abstract

Background.Lead exposure is linked to intellectual disability and anemia in children. The United States Centers for Disease Control and Prevention (CDC) recommends biomonitoring of blood lead levels (BLLs) in children with BLL ≥5 μg/dL and chelation therapy for those with BLL ≥45 μg/dL.Objectives.This study aimed to determine blood and environmental lead levels and risk factors associated with elevated BLL among children from Owino Uhuru and Bangladesh settlements in Mombasa County, Kenya.Methods.The present study is a population-based, cross-sectional study of children aged 12–59 months randomly selected from households in two neighboring settlements, Owino Uhuru, which has a lead smelter, and Bangladesh settlement (no smelter). Structured questionnaires were administered to parents and 1–3 ml venous blood drawn from each child was tested for lead using a LeadCare ® II portable analyzer. Environmental samples collected from half of the sampled households were tested for lead using graphite furnace atomic absorption spectroscopy.Results:We enrolled 130 children, 65 from each settlement. Fifty-nine (45%) were males and the median age was 39 months (interquartile range (IQR): 30–52 months). BLLs ranged from 1 μg/dL to 31 μg/dL, with 45 (69%) children from Owino Uhuru and 18 (28%) children from Bangladesh settlement with BLLs >5 μg/dL. For Owino Uhuru, the geometric mean BLL in children was 7.4 μg/dL (geometric standard deviation (GSD); 1.9) compared to 3.7 μg/dL (GSD: 1.9) in Bangladesh settlement (p<0.05). The geometric mean lead concentration of soil samples from Owino Uhuru was 146.5 mg/Kg (GSD: 5.2) and 11.5 mg/Kg (GSD: 3.9) (p<0.001) in Bangladesh settlement. Children who resided <200 m from the lead smelter were more likely to have a BLL ≥5 μg/dL than children residing ≥200 m from the lead smelter (adjusted odds ratio (aOR): 33.6 (95% confidence interval (CI): 7.4–153.3). Males were also more likely than females to have a BLL ≥5 μg/dL (39, 62%) compared to a BLL<5 μg/dL [aOR: 2.4 (95% CI: 1.0–5.5)].Conclusions.Children in Owino Uhuru had significantly higher BLLs compared with children in Bangladesh settlement. Interventions to diminish continued exposure to lead in the settlement should be undertaken. Continued monitoring of levels in children with detectable levels can evaluate whether interventions to reduce exposure are effective.Participant Consent.ObtainedEthics Approval.Scientific approval for the study was obtained from the Ministry of Health, lead poisoning technical working group. Since this investigation was considered a public health response of immediate concern, expedited ethical approval was obtained from the Kenya Medical Research Institute and further approval from the Mombasa County Department of Health Services. The investigation was considered a non-research public health response activity by the CDC.Competing Interests.The authors declare no competing financial interests.

Conflicting Conclusions or Competing Methodologies? Documenting Soil Lead Pollution in Owino Uhuru, Kenya

“…What we do know from assimilating the information in these two papers is that there is a historic lead smelter in Owino Uhuru that likely contributed to the elevated BLLs observed by Etiang et al1 Additionally, we know that levels of lead in soil vary significantly in these communities and it appears it is entering residential dwellings. What still needs to be determined is the precise exposure source and pathway.…”

“…In June 2018, this journal published the work of Etiang et al1 The authors took childhood blood lead level (BLL) measurements (n=130) as well as limited samples of lead in soil (n=8), dust (n=7) and drinking water (n=15) from 130 households. They concluded that, among other activities, “ The high lead level of soil in Owino Uhuru (neighborhood) illustrates the need for coordinated efforts to remediate the environment .”1 They furthermore stated that “ This requires removal of the first several inches of soil and replacing with clean fill, which may necessitate the removal of children from their homes until the environment is confirmed to be safe .”1…”

“…However, these papers, while related, are each distinctly different in their methodologies. Ericson et al conducted extensive community lead in soil profiling, while Etiang et al did not 1,2. Meanwhile, Etiang et al conducted actual testing of children's blood in both the “exposed” and “unexposed” neighborhoods, while Ericson relied on the United States Environmental Protection Agency's “Integrated Exposure, Uptake and Biokinetic Model” to predict children's BLLs 1,2…”

“…Ericson et al further used established lead deposition models in an attempt to predict Etiang et al's observed lead in soil observation, with little success 1,2…”

Assessment of the Presence of Soil Lead Contamination Near a Former Lead Smelter in Mombasa, Kenya

“…Following the closure of the facility in 2015, a study of environmental lead concentrations and community BLLs was carried out jointly by the Kenya Ministry of Health and the CDC. The study found a geometric mean surface soil lead concentration in the community of 146.5 mg/kg (geometric standard deviation (GSD): 5.2) and dust lead loadings in homes of 1.5 μg/ft 2 (GSD: 12.3) 49. These results were significantly below applicable United States Environmental Protection Agency (USEPA) screening levels for residential soil and household dust of 400 mg/kg and 40 μg/ft 2 , respectively 50.…”