Health risks associated with heavy metal exposure in geophagic products (Emumbwa) consumed during pregnancy

Abstract

Geophagic products (Emumbwa) consumed by some pregnant women in Uganda may be a source of heavy metal poisoning. However, there is paucity of information regarding the composition, safety and consumption patterns of these products. This study aimed to assess the levels of heavy metals; lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), copper (Cu), chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn), and the health risks due to Pb, As, Cr and Ni in geophagic products consumed by pregnant women in Kampala city and the surrounding areas. A total of 60 geophagic clay samples obtained from five markets in Kampala city, were analyzed for the 10 elements using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Geophagic products consumption patterns of 280 pregnant women (18 to 60 years of age) were determined using a set of pre-tested questionnaires. Means were separated by two-way analysis of variance (ANOVA) using XLSTAT, version 2020. Health risk assessment was done using Chi square statistics of the Microsoft Excel in built @risk software (Version 8.1, USA). Iron had the highest concentration (1500 to 22900 mg/kg) followed by Mn (0.68 to 8.99 mg/kg), Zn (0.48 to 2.44 mg/kg), Cr (0.51 to 1.57 mg/kg), Cu (0.14 to 1.20 mg/kg), Pb (0.29 to 0.66 mg/kg), Ni (0.08 to 0.39 mg/kg) and Cd (0.02 to 0.06 mg/kg). Mercury and As were not detected in any of the samples of Emumbwa analyzed. Most respondents were 35 to 54 yrs and had body weight between 60 and 80 kg. The majority (83.81%) earned less than one million Uganda shillings per month. The mean clay ingestion rate was 17.08±7.32 g per day. According to this study findings, both consumers and the total population are at a risk of developing chronic kidney disease, combined adenomas and carcinomas and post implantation fetal loss due to lead, chromium and nickel exposure. While geophagia can contribute significantly towards the intakes of useful elements such as Fe, Cu and Zn, the practice poses potential health risks to the consumers due to Pb, Mn, Cd, Ni and Cr poisoning. Sensitization of the population by health workers about the potential health risks of heavy metals in geophagic products is recommended. Key words: Heavy metal, Emumbwa, geophagia, health risk, risk assessment, consumption pattern.