Biomonitoring of arsenic, cadmium and lead in two artisanal and small-scale gold mining areas in Zimbabwe

Abstract

People living and working in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to elemental mercury (Hg), which is used for gold extraction. However, additional exposure to other toxic metals such as arsenic (As), cadmium (Cd) and lead (Pb) may result from mining-related activities and could be ingested via dust, water or food. In these areas, only limited biomonitoring data is available for toxic metals other than Hg. In particular, data about the exposure to As, Cd and Pb is unavailable for the Zimbabwean population. Therefore, we conducted a cross-sectional study in two ASGM areas in Zimbabwe to evaluate the internal exposure to these metals. In total, urine and blood samples from 207 people that identified themselves as miners were collected and analysed for As and Cd in urine as well as Pb in blood by GF-AAS. Median levels (interquartile ranges in μg/l) of As and Pb were 9.7 μg/l (4.0, 18.5) and 19.7 μg/l (12.5, 34.5), respectively. The 25th percentile and the median for Cd were below the limit of detection (0.5 μg/l); the 75th percentile was at 0.9 μg/l. The results were compared to reference values found for the general population in the USA and Germany, and a significant number of participants exceeded these values (As, 33 %; Cd, 27 %; Pb, 32 %), indicating a relevant exposure to toxic metals. Although not representative for the Zimbabwean population, our results demonstrate that the exposure to toxic metals is relevant for the public health in Zimbabwe and requires further investigation.

Human Health Risk Assessment due to Heavy Metals in Ground and Surface Water and Association of Diseases With Drinking Water Sources: A Study From Maharashtra, India

“…The mean value of As in the urine sample was 42.04 µg/L, with a range of 10.00 to 82.00 µg/L. The result in the present study for urinary As levels were higher than the studies from mining areas in Zimbabwe 41 and Guatemala. 42 Urinary As levels in Michigan urban anglers were found lower than the present study.…”

Potential Health Effects of Heavy Metals and Carcinogenic Health Risk Estimation of Pb and Cd Contaminated Eggs from a Closed Gold Mine Area in Northern Thailand

“…People living and working in both artisanal and gold-mining areas are frequently exposed to Hg, which is used for gold extraction. It is estimated that about 15 million miners are affected globally [ 56 ]. Additionally, exposure to other toxic metals such as arsenic (As), Pb, Cd, and Mn may occur through mining-related activities and could be ingested via air, sediment, water, or food contamination [ 57 , 58 ].…”

“…Mining activities such as excavation, crushing, and milling may result in the increased liberation of these toxic metals. Although the gold metal is collected at the end of the mining process, metals may end up in the tailing dumps at mining locations, thus presenting an exposure hazard for people living and working in these mining areas [ 56 ]. Santos et al (2020) found that surface-sediment samples collected in an area under the influence of gold mining were polluted (moderately to seriously) [ 59 ].…”

Biomonitoring of lead in blood of children living in a former mining area in Lower Saxony, Germany

“…Soil from all parts of the study area still exceeds the German precautionary value of 70 mg lead per kg soil (Landkreis Goslar 2017 ). Other similarly polluted regions show comparable lead levels in their population (Schoof et al 2016 ; Rakete et al 2022 ). Other studies, for example, in Kabwe (Zambia), which has lead levels in soil ranging from 139 to 62,142 mg/kg, children’s lead blood values were approximately 30 times as high as the ones measured in the present study (Bose-O'Reilly et al 2018 ).…”