Artisanal and Small Scale Gold Mining (ASGM) contributes as the biggest source of mercury (Hg) emission in Southeast Asian countries including Indonesia. Rice paddies are the most impacted agriculture area caused by Hg emission from ASGM sewage water. It may pose to health risk effect to humans due to the consumption of the rice as the staple food. This study was aimed to evaluate the Hg accumulation in rice and health effect to residents in Lebaksitu ASGM area by analysis of total mercury (THg) and methylmercury (MeHg) in hair. Two villages were selected in this study, Hg hotspot village (Lebak-1) and low Hg exposure village (Lebak-2). The THg concentration in rice ranged from 9.1-115 µg/kg with an average of 32.2 µg/kg. MeHg concentration in rice constituted 14.7-81.8% of the THg. Rice in Lebak-1 had higher THg and MeHg concentrations than those in Lebak-2. The mean THg and MeHg concentration in hair were 3.2 mg/kg and 1.78 mg/kg, respectively. Residents in Lebak-1 had significantly higher THg and MeHg in hair than those collected from Lebak-2. The MeHg ratio to THg in hair varied widely ranged from 15.68-92.43%. There was a significant correlation between high intake of MeHg from rice and the accumulation of MeHg in the hair. It was concluded that rice is the potential source of MeHg exposure to humans through daily consumption in rice consumer countries.

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Food consumption remains the commonest pathway through which humans ingest higher levels of mercury (Hg). Long-term exposure to Hg through Hg-contaminated food may result in acute or chronic Hg toxicity. Incessant discharge of Hg waste from ASGM facilities into nearby farms contaminates food crops. Ingestion of such food crops by residents may lead to detrimental human health effects. The human health risks upon exposure to total mercury (THg) and methylmercury (MeHg) in farmland soils and plantains from farms sited near ASGM facilities were studied in four communities around Obuasi, Ghana. The human health risk assessment was evaluated using hazard quotient (HQ), estimated average daily intake ( e AvDI), hazard index (HI) and Hg elimination and retention kinetics. Tweapease, Nyamebekyere and Ahansonyewodea had HQ, e AvDI and HI for THg of plantains for both adults and children below the recommended USEPA limit of 1, 3 Â 10 À4 mg/kg/day and 1, respectively. Odumase had HQ, e AvDI and HI for THg of plantains for both adults and children, higher than the guideline values. This meant that only Odumase may cause non-carcinogenic human health effects upon repeated exposure. The HQ, e AvDI and HI values of MeHg for all the study areas were far below guideline values, hence may not pose any non-carcinogenic human health risks to residents even upon repeated exposure. Retention and elimination kinetics of Hg also showed that only plantains from Odumase may pose significant non-carcinogenic human health risks to residents because the final amount of inorganic mercury exceeded the extrapolated USEPA guideline value of 0.393 μg/kg/year.

In recent years, paraoxybenzoic acid esters (parabens) have been used in pharmaceuticals, cosmetics, and food additives. Parabens have been reported to have a weak estrogenic effect in in vitro test systems, and it is presumed that the longer the alkyl chain of the paraben, the greater its endocrine-disrupting and reproductive function effects. However, the effects of parabens on human health are still unclear. In this study, we evaluated the effects of six parabens (methyl p-hydroxybenzoate [MP], ethyl p-hydroxybenzoate [EP], propyl p-hydroxybenzoate [PP], isopropyl p-hydroxybenzoate [IPP], butyl p-hydroxybenzoate [BP], and isobutyl p-hydroxybenzoate [IBP]) on the reproductive function of the model organism Caenorhabditis elegans. We used 25, 50, and 100 µg/mL solutions of parabens in 0.1% dimethyl sulfoxide (DMSO). Bioassays (growth and maturation effect tests and reproduction effect tests) were performed on L1 larvae of wild-type C. elegans. In the growth effects test, all parabens were observed to have no effect. In the maturation effects test, there was a significant decrease in maturity at each concentration of five of the six parabens, with the exception being MP. In the reproduction effects test, a significant decrease in the number of lifetime offspring was observed at each concentration of five of the six parabens, with the exception being EP. This decrease was remarkable with PP, which has been reported to adversely affect reproductive function in rats. It is necessary to continue to focus on the estrogen-like action of parabens, including PP, and perform genetic analyses, such as RNA sequencing.

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