Assessment of blood levels of heavy metals including lead and manganese in healthy children living in the Katanga settlement of Kampala, Uganda

Abstract

BackgroundExposure to environmental heavy metals is common among African children. Although many of these metals are known neurotoxicants, to date, monitoring of this exposure is limited, even in countries such as Uganda that are undergoing rapid industrialization. An assessment of the burden and potential causes of metal exposure is a critical first step in gauging the public health burden of metal exposure and in guiding its elimination.MethodsIn May 2016, we enrolled 100 children between the ages of 6 and 59 months living in the Katanga urban settlement of Kampala, Uganda. We measured whole blood concentrations of antimony, arsenic, barium, cadmium, cesium, chromium, cobalt, copper, lead, manganese, nickel, selenium, and zinc. Applying reference cutoffs, we identified metals whose prevalence of elevated blood concentrations was > 10%. We also administered an environmental questionnaire to each child’s caregiver to assess potential exposures, including source of drinking water, cooking location and fuel, materials used for roof, walls, and floor, and proximity to potential pollution sources such as main roads, garbage landfills, and fuel stations. We compared log-transformed blood metal concentrations by exposure category, using t-test for dichotomous comparisons and ANOVA for comparisons of three categories, using Tukeys test to adjust for multiple comparisons.ResultsThe prevalence of high blood levels was elevated for six of the metals: antimony (99%), copper (12%), cadmium (17%), cobalt (19.2%), lead (97%), and manganese (36.4%). Higher blood manganese was significantly associated with having cement walls (p = 0.04) or floors (p = 0.04). Cadmium was greater among children who attended school (< 0.01), and cobalt was higher among children who lived near a garbage landfill (p = 0.01).ConclusionsHeavy metal exposure is prevalent in the Katanga settlement and may limit neurodevelopment of children living there. Future studies are needed to definitively identify the sources of exposure and to correct potential nutritional deficiencies that may worsen metal absorption.Electronic supplementary materialThe online version of this article (10.1186/s12889-018-5589-0) contains supplementary material, which is available to authorized users.

Blood Lead Influences the Anemia Status of Malaria-Infected Children in Katanga Kampala Uganda

“…The BLL cut off point recommended by CDC is 5µg/dL [20]. Of the 198 children recruited in this study, 80.3 % had BLL with a mean level (9.3 µg/dL) slightly lower than those reported by [6] depositions from the atmosphere, household wastes, and from manure and fertilizer applications [23,26].…”

“…Although, malaria infections remain the key cause of the high prevalence of anemia, there are maybe other neglected cofounders like Lead poisoning resulting from contaminated air, soils, water sources, urban-grown foodstuffs and Leaded paints [2,6,7,8]. Because both lead pollution and malaria geographically overlap, and produce similar hematological outcomes their co-existence in this area may affect the child's health [28].…”

Piloting a Developmental Screening Tool Adapted for East African Children

“…As previously described [ 29 ], we recently conducted a cross-sectional study of blood levels of heavy metals in 100 children aged 6–59 months living in the Katanga urban settlement of Kampala. Briefly, we mapped the Katanga area with a Global Positioning System (GPS).…”

“…To begin to answer these questions, we implemented an adapted developmental screening tool to determine if known neurodevelopmental risk factors, specifically lead exposure and undernutriton as assessed by nutritional stunting, are associated with delayed developmental milestones. We piloted the screening tool as part of a larger survey on environmental heavy metal exposure among children living in the Katanga urban settlement [ 29 ]. We hypothesized that elevated blood lead levels and growth stunting would be positively associated with delayed developmental outcomes for chronological age.…”

Blood Lead Alters The Anemia Status of Malaria Infected Children in Katanga Kampala Uganda.

“…There are reports of elevated lead levels in water sources, soils, foodstuffs and air around Kampala city [3]. According to the study done by [4], Plasmodium malaria accounts for up to 40% of all outpatient visits, 25% of all hospital admissions, and 14% of all hospital deaths [4,5] despite the government efforts to curb its transmission [7]. 53% of the children in this area especially those under the age of 5 years have been reported to be anemic [3,5] and this could be due to high malaria prevalence in this area.…”