The Distribution of Mercury, Arsenic, and Antimony in Sediments of Kagoshima Bay

Abstract

Mercury, arsenic, and antimony were determined in marine sediments collected from Kagoshima Bay, and their distribution was investigated. The contents of mercury, arsenic, and antimony in surface sediments were higher than those in the marine sediments of the open ocean. The average contents of mercury, arsenic, and antimony in surface sediments in the northern part of the bay were higher than in the southern part. The high-temperature sediments (about 200 °C) in the vicinity of a sea bottom fumarole, located at a depth of about 200 m in the northern part of the bay, showed abnormal concentrations of mercury, arsenic, and antimony derived from the fumarole gas; the contents of these components decreased sharply with an increase in the distance from the fumarole. A high degree of positive correlation was found among the contents of the three components (mercury, arsenic, and antimony) over the northern part of the bay. In contrast, no such correlation was observed in the southern part of the bay. This is in accord with the fact that volcanic activity is more vigorous in the northern than in the southern part of the bay.

The contents and chemical forms of mercury in sediments from Kagoshima Bay, in comparison with Minamata Bay and Yatsushiro Sea, southwestern Japan.

“…3 (110°C Figure 3 shows the total mercury contents in the surface sediments collected from Kagoshima Bay in our previous work (Sakamoto, 1985b). These results were obtained by on board survey at sea level in the period of September, 1976to October, 1979(Sakamoto, 1985b. Higher contents of total mercury were found in the present study (Table 1).…”

“…More than 80% of the mercury is in the form of HgS. This suggests that the fu marolic gases including mercury and hydrogen sulfide have directly deposited in the sediments in an anoxic condition (Kamada et al, 1977;Sakamoto, 1985b;Sakamoto, 1992).…”

“…Mercury-polluted fish was also found at the Northern Kagoshima Bay in November, 1973 (Environmental Agency of the Government and 97 H. S Kagoshima Prefecture, 1975). The university and research organizations of Kagoshima Prefecture checked in detail water quality (Kamada et al, 1976;Sakamoto, 1985a), fish (Kagoshima Pre fecture, 1977), shellfish (Fisheries Lab., 1978), fumarolic gases (Ossaka et al, 1977) and sedi ments (Kamada et al, 1977;Sakamoto, 1985b;Sakamoto et al, 1990) …”

Arsenic in fumarolic gases of Vulcano(Aeolian Islands, Italy) from 1978 to 1993: Geochemical evidence from multivariate analysis.

“…Indeed, soils containing 1400 ppm of As in the region of Osorezon volcano (Harako, 1986) and 464 ppm in Sakurajima vol cano zone (Sakamoto, 1985) were reported, as well as up to 50 ppm in some geothermal areas (Ballantyne and Moore, 1988) and about 20 ppm for thermal waters around Lassen Volcanic Na tional Park (Thompson, 1985). Recent studies have confirmed that volcanoes are the main natural source of arsenic in the atmosphere (Nriagu and Pacyna, 1988;Nriagu, 1989) and arsine has been hypothesised as the most important volatile com pound responsible for As mobilisation in gaseous phase at Vulcano Island (Brondi and Dall'Aglio, 1991).…”

A currently forming petroleum associated with hydrothermal mineralization in a submarine caldera, Kagoshima Bay, Japan.

“…Gypsum, carbonate, native sulfur, barite and kaolinite are the dominant hydrothermal minerals, and other ore minerals are also reported such as pyrrhotite, stibnite, realgar, orpiment and As-S amorphous particles. Base metals, mercury, arsenic, and anti mony also concentrate in the sediment around the caldera (Sakamoto et al, 1997;Sakamoto, 1985). These mineral compositions are comparable with chimney and hydrothermal deposits at the Izena Caldera in the Okinawa Trough (Aoki and Nakamura, 1989), and can be classified as a Kuroko-type sulfide ores.…”