Distribution of total mercury and methylmercury around the small-scale gold mining area along the Cikaniki River, Bogor, Indonesia

Abstract

This study investigates the distribution of total mercury (T-Hg) and methylmercury (MeHg) in the soil and water around the artisanal and small-scale gold mining (ASGM) area along the Cikaniki River, West Java, Indonesia. The concentration of T-Hg and MeHg in the forest soil ranged from 0.07 to 16.7 mg kg and from <0.07 to 2.0 μg kg, respectively, whereas it ranged from 0.40 to 24.9 mg kg and from <0.07 to 56.3 μg kg, respectively, in the paddy field soil. In the vertical variation of the T-Hg of forest soil, the highest values were observed at the soil surface, and these values were found to decrease with increasing depth. A similar variation was observed for MeHg and total organic carbon content (TOC), and a linear relationship was observed between them. Mercury deposited on the soil surface can be trapped and retained by organic matter and subjected to methylation. The slope of the line obtained for the T-Hg vs. TOC plot became larger near the ASGM villages, implying a higher rate of mercury deposition in these areas. In contrast, the plots of MeHg vs. TOC fell along the same trend line regardless of the distance from the ASGM village. Organic carbon content may be a predominant factor in controlling MeHg formation in forest soils. The T-Hg concentration in the river water ranged from 0.40 to 9.6 μg L. River water used for irrigation can prove to be a source of mercury for the paddy fields. The concentrations of Hg and Hg in river water showed similar variations as that observed for the T-Hg concentration. The highest Hg concentration of 3.2 μg L can be attributed to the waste inflow from work sites. The presence of Hg in river water can become a source of mercury present in the atmosphere along the river. MeHg concentration in the river water was found to be 0.004-0.14% of T-Hg concentration, which was considerably lower than the concentrations of other Hg species. However, MeHg comprised approximately 0.2% of the T-Hg in paddy field soil. Mercury deposited from the atmosphere and the river water can be subjected to methylation. Paddy fields are very important ecosystems; therefore, the effect of MeHg on these ecosystems and human beings should be further investigated.

Biometric Condition of Seurukan Fish (Osteochillus Vittatus Valenciennes, 1842) Exposed to Mercury in Krueng Sabee River Aceh Jaya Indonesia

“…Most mercury enters the water body via anthropogenic activities, mainly industrial waste and illegal gold mining (Purnawan et al, 2017;Juhaeti et al, 2017). There are several rivers in Indonesia that have been reported to be contaminated with mercury including the Kuantan River, Riau (Yulis, 2018), the Banyuasin River, South Sumatra (Suteja et al, 2019), the Banyumas River, Central Java (Budianta et al, 2019) and the Cikaniki River, Bogor (Tomiyasu et al, 2017).…”

Illegal gold mining in Indonesia: structure and causes

“…Moreover, the weak regulatory regime is worsened by inconsistent lawenforcement regarding, e.g. illegal Mercury distribution and use (Ismawati, 2014;Tomiyasu et al, 2017), environmental abuse and pollution (Nainggolan, 2015;Nopriadi, 2016;Resosudarmo et al, 2009) and IGM operations (Nainggolan, 2015;Nopriadi, 2016). After observing these problems for many years, Labonne (2014, p. 1) concluded that governments and investors have little interest in supporting ASM, and that "ASM's primary concerns are sidelined by the agenda of other stakeholders" who have access to power.…”

Indigeneous Streptomyces spp. isolated from Cyperus rotundus rhizosphere indicate high mercuric reductase activity as a pontential bioremediation agent

“…Indonesian artisanal and small-scale gold mining activities (ASGM) have been found in the islands of Borneo (Kalimantan), Buru, Sulawesi, Java and operations extending to the islands of Lombok and Sumbawa (Krisnayanti et al 2012;Male et al 2013;Tomiyasu et al 2016). In the ASGM, gold is recovered by miners through a two-stage process of whole-ore amalgamation and cyanidation.…”