Distribution of total mercury and methylmercury around the small-scale gold mining area along the Cikaniki River, Bogor, Indonesia.
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-1and from <0.07 to 2.0 μg kg-1, respectively, whereas it ranged from 0.40 to 24.9 mg kg-1and from <0.07 to 56.3 μg kg-1, 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-1. River water used for irrigation can prove to be a source of mercury for the paddy fields. The concentrations of Hg0and Hg2+in river water showed similar variations as that observed for the T-Hg concentration. The highest Hg0concentration of 3.2 μg L-1can be attributed to the waste inflow from work sites. The presence of Hg0in 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.
Graduate School of Science and Engineering, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan. tomy@sci.kagoshima-u.ac.jp.|Environmental Safety Center, Kagoshima University, 1-21-35 Korimoto, Kagoshima, 890-0065, Japan. tomy@sci.kagoshima-u.ac.jp.
Takashi
http://orcid.org/0000-0002-0557-7736
T
Tomiyasu
Graduate School of Science and Engineering, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan.
Hitoshi
H
Kodamatani
Environmental Safety Center, Kagoshima University, 1-21-35 Korimoto, Kagoshima, 890-0065, Japan.
Yuriko Kono
YK
Hamada
National Institute for Minamata Disease, Minamata, Kumamoto, 867-0008, Japan.
Akito
A
Matsuyama
Graduate School of Science and Engineering, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan.
Ryusuke
R
Imura
National Institute for Minamata Disease, Minamata, Kumamoto, 867-0008, Japan.
Yoko
Y
Taniguchi
Research Center for Biology, Indonesian Institute of Sciences, Raya Jakarta, Bogor Km.46 Cibinong, Bogor, JL, 16911, Indonesia.
Nuril
N
Hidayati
Research Center for Biology, Indonesian Institute of Sciences, Raya Jakarta, Bogor Km.46 Cibinong, Bogor, JL, 16911, Indonesia.
Joeni Setijo
JS
Rahajoe
D001272:Atmosphere; D017753:Ecosystem; D004784:Environmental Monitoring; D065928:Forests; D005618:Fresh Water; D006046:Gold; D006801:Humans; D007214:Indonesia; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D008906:Mining; D045483:Rivers; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis
D008767:Methylmercury Compounds; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D006046:Gold; D008628:Mercury
Mercury pollution; Methylmercury; River water; Small-scale gold mining; Soil; Toc