Kitchen Characteristics and Practices Associated with Increased PM2.5 Concentration Levels in Zimbabwean Rural Households.

Household air pollution (HAP) from biomass fuels significantly contributes to cardio-respiratory morbidity and premature mortality globally. Particulate matter (PM), one of the pollutants generated, remains the most accurate indicator of household air pollution. Determining indoor air concentration levels and factors influencing these levels at the household level is of prime importance, as it objectively guides efforts to reduce household air pollution. This paper describes household factors associated with increased PM2.5 levels in Zimbabwean rural household kitchens. Our HAP and lung health in women study enrolled 790 women in rural and urban households in Zimbabwe between March 2018 and December 2019. Here, we report data from 148 rural households using solid fuel as the primary source of fuel for cooking and heating and where indoor air samples were collected. Data on kitchen characteristics and practices were collected cross-sectionally using an indoor walk-through survey and a modified interviewer-administered questionnaire. An Air metrics miniVol Sampler was utilized to collect PM2.5 samples from the 148 kitchens over a 24 h period. To identify the kitchen features and practices that would likely influence PM2.5 concentration levels, we applied a multiple linear regression model. The measured PM2.5 ranged from 1.35 µg/m3 to 1940 µg/m3 (IQR: 52.1-472). The PM2.5 concentration levels in traditional kitchens significantly varied from the townhouse type kitchens, with the median for each kitchen being 291.7 µg/m3 (IQR: 97.2-472.2) and 1.35 µg/m3 (IQR: 1.3-97.2), respectively. The use of wood mixed with other forms of biomass was found to have a statistically significant association (p < 0.001) with increased levels of PM2.5 concentration. In addition, cooking indoors was strongly associated with higher PM2.5 concentrations (p = 0.012). Presence of smoke deposits on walls and roofs of the kitchens was significantly associated with increased PM2.5 concentration levels (p = 0.044). The study found that kitchen type, energy type, cooking place, and smoke deposits were significant predictors of increased PM2.5 concentrations in the rural households. Concentrations of PM2.5 were high as compared to WHO recommended exposure limits for PM2.5. Our findings highlight the importance of addressing kitchen characteristics and practices associated with elevated PM2.5 concentrations in settings where resources are limited and switching to cleaner fuels may not be an immediate feasible option.

Analysis of the Mercury Distribution in Blood as a Potential Tool for Exposure Assessment - Results from Two Artisanal and Small-Scale Gold Mining Areas in Zimbabwe.

People in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to high levels of mercury (Hg). Hg analyses in urine and whole blood are the gold standard of biomonitoring, although this may not provide sufficient information about the source of exposure, e.g., due to the use of Hg for gold extraction or due to nutrition. To evaluate, whether the pharmacokinetic properties of individual Hg species may be useful for exposure assessment, we determined the Hg levels in different blood components from 199 participants. Therefore, whole blood was centrifuged on-site to yield erythrocytes and plasma. Globin was isolated from the erythrocytes by precipitation with ethyl acetate. Albumin was isolated from plasma by gradual precipitation with saturated ammonium sulfate solution. Hg levels in all samples were determined by using a direct Hg analyzer. Median Hg levels for whole blood, erythrocytes, and plasma were 2.7, 3.7, and 1.3 µg/l, respectively. In globin and albumin, median Hg levels were 10.3 and 7.9 µg/kg, respectively. The distribution of Hg was strongly correlated with whole blood Hg levels (p < 0.01) and the time between the last use of Hg and the date of the participation (p < 0.01). The results suggest that the distribution of Hg in blood is substantially affected by the extent and the frequency of the exposure to elemental Hg. Therefore, the analysis of Hg in erythrocytes and plasma may be a valuable tool for Hg exposure assessment in ASGM areas.

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

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.

Health-related quality of life (EQ-5D + C) among people living in artisanal and small-scale gold mining areas in Zimbabwe: a cross-sectional study.

BACKGROUND: In Zimbabwe, an estimated 500,000 people work in the sector of artisanal and small-scale gold mining (ASGM). Two million Zimbabweans are dependent on this sector. Using mercury is common to extract gold from ore. Long term exposure to mercury can cause various adverse health conditions including chronic mercury intoxication. The influence of these adverse health effects on the health-related quality of life (HRQoL) is still unknown. The aim of this study is to assess the HRQoL of people who identify themselves as miners, and to analyze potential influencing factors, such as age, years of working with mercury and health conditions caused by mercury exposure. METHODS: This cross-sectional study assessed the HRQoL using the standardized EQ-5D + C (3 L) questionnaire and collected human specimens (blood, urine) of people living and possibly working in ASGM areas in Zimbabwe. Factors such as age, years of working with mercury and adverse health conditions possibly caused by mercury exposure were analyzed with regards to their influence on the HRQoL. RESULTS: The 207 participants (82% male, mean age 38 years) reported 40 different health states. Of the study participants 42.5% reported to be in complete good health while 57.5% reported being unwell in different ways. Nine participants (4.3%) were identified with chronic mercury intoxication, whereas 92 participants (33.3%) had mercury levels above the "Alert" threshold in at least one specimen. Having chronic mercury intoxication has a significant negative influence on the HRQoL, when taking into account age, gender and years of working with mercury. Cognitive problems were the most reported in the questionnaire, however, the association between this domain separately and the HRQoL was not verified. CONCLUSION: This study shows that adverse health effects caused by chronic exposure to mercury, have a negative influence on the HRQoL among people living in ASGM areas.

Artisanal and small-scale gold mining: A cross-sectional assessment of occupational mercury exposure and exposure risk factors in Kadoma and Shurugwi, Zimbabwe.

In artisanal and small-scale gold mining (ASGM) the toxic metal mercury is used for gold extraction. The objective of this cross-sectional study was to assess mercury concentrations in urine and blood and mercury-related symptoms of participants identifying themselves as miners from Kadoma and Shurugwi, Zimbabwe. Moreover, we aimed to explore possible risk factors influencing mercury body burden. In 2019, urine and blood samples of 207 participants were collected and analyzed for mercury using atomic absorption spectroscopy. All participants answered questions regarding their exposure risks. The median urine mercury value was 4.75 µg/L with a maximum of 612 µg/L. Median mercury concentration in creatinine corrected urine values was 3.98 µg/g with a maximum value of 478 µg/g. The median blood mercury value was 2.70 µg/L with a maximum of 167 µg/L. Correlations between exposure risks factors such as the lack of retort use and elevated mercury values were demonstrated. ASGM is very common in Zimbabwe. Thus, mercury exposure is a major occupational health risk for miners. Moreover, this study emphasizes the impact of exposure risk factors on the mercury body burden.