Mercury contamination-what we have learned since Minamata

Abstract

Atmospheric cycling of mercury and other pollutants has become a major concern as industrialized countries have eliminated point discharges, sometimes by relocating the industries to underdeveloped and developing countries where point sources have become problems. Such circumventions may be to no avail in the long run as pollution continues to elevate levels of methylmercury in fish in waterways that are remote from direct contamination as well as where the source can be readily identified. Much has been learned about the cycling of mercury in the environment since human disabilities and deaths at Minamata, Japan, initially drew attention to the problem of methylmercury poisoning from the consumption of contaminated seafood in the 1950s. In that instance, methylmercury produced industrially concentrated to toxic levels in fish. As this manufacturing process was not used outside Japan, concern did not become immediate in other developed nations until the 1960s when it was established that mercury was not only biomethylated by microorganisms but also biomagnified through the food chain. Point sources to the waterways may have been eliminated too late to return the levels in fish to background because of the geochemical cycling of mercury through the environment. Despite decreases in domestic, industrial and agricultural point source releases over the last two decades, large quantities from non-point sources such as fossil fuel combustion, smelters, and incinerators are still being released. Much of this mercury is transported from the atmosphere to aquatic ecosystems and stored in sediments until it is again released to the water and atmosphere.

Exposure Assessment of Mercury and Its Compounds by Dispersion Modeling: A Case Study in the Sea of Japan Coastal Area

“…32 In the coal combustion power industries, the capacity in MW and coal combustion rate has been used as a basis of calculations of atmospheric mercury emission. In the sector of iron works, total production is 69.5 x 10 6 MT and total atmospheric mercury emission is 5.7 MT, in the sector of cement plants, total production is 79 x 10 6 MT and total atmospheric mercury emission is 35 MT, in the sector of chemical plants, total production is 9057 MT and total atmospheric mercury emission is 0.03 MT in Japan. 33 To calculate atmospheric mercury emission from each point source of iron works, cement plants, and chemical complexes, the yearly production capacity and yearly mercury emission from each sector has been considered as a basis of calculation by using simple unitary methods.…”

“…Notwithstanding, the bioaccumulation of methyl mercury via the food chain, especially through fish, concentrates the mercury and poses serious toxicity hazards in the biosphere. 2 For that reason, natural and anthropogenic emissions of mercury in the environment, 3 its transportation and fate, 4,5 and its adverse effect on human health and the ecosystem 6 have all attracted great attention as aspects of a major environmental problem. Stack emissions from coal-combustion power industry include both vapor and particle-bound phases.…”

A human-health risk assessment of dietary methylmercury exposure in Fort Albany First Nation

“…Organisms can be exposed to the contaminant through ingestion, respiration and absorption from the water (D'Itri, 1991). Due to its lipophilic nature, it can bioaccumulate in an organism, and due to its long half-life, it is also difficult to metabolize and eliminate (D'Itri, 1991).…”

Tolerance of High Inorganic Mercury of <i>Perna viridis</i>: Laboratory Studies of Its Accumulation, Depuration and Distribution

“…Based on his suggestion, P. viridis could play a role in the Hg retention mechanism of coastal waters. Since inorganic Hg could be biologically converted into methyl-Hg by factors such as microbial activity and the concentration of bioavailable Hg in the marine environment (D'itri, 1991;Ullrich et al, 2001), these fecal materials together with the organic nutrients would become the source of Hg contamination for the primary producers in the coastal waters. The experimental treatment with inorganic Hg in dissolved solution does not, however, provide a satisfactory analogy for the field samples.…”