The
consumption of fish is by far the most significant source of ingestion-related mercury exposure in humans and animals, although plants and livestock also contain mercury due to
bioconcentration of mercury from seawater, freshwater, marine and lacustrine sediments, soils, and atmosphere, and due to
biomagnification by ingesting other mercury-containing organisms.[SUP]
[6][/SUP] Exposure to mercury can occur from breathing contaminated air,[SUP]
[7][/SUP] from eating foods that have acquired mercury residues during processing,[SUP]
[8][/SUP] from exposure to mercury vapor in mercury
amalgam dental restorations,[SUP]
[9][/SUP] and from improper use or disposal of mercury and mercury-containing objects, for example, after spills of elemental mercury or improper disposal of
fluorescent lamps.[SUP]
[10]
[/SUP]
Consumption of whale and dolphin meat, as is the practice in
Japan, is a source of high levels of mercury poisoning. Tetsuya Endo, a professor at the Health Sciences
University of Hokkaido, has tested
whale meat purchased in the whaling town of
Taiji and found mercury levels more than 20 times the acceptable Japanese standard.[SUP]
[11]
[/SUP]
Human-generated sources, such as coal-burning power plants [SUP]
[12][/SUP] emit about half of atmospheric mercury, with natural sources such as
volcanoes responsible for the remainder. An estimated two-thirds of human-generated mercury comes from stationary combustion, mostly of
coal. Other important human-generated sources include
gold production,
nonferrous metal production,
cement production,
waste disposal, human
crematoria,
caustic soda production,
pig iron and
steel production, mercury production (mostly for batteries), and biomass burning.[SUP]
[13]
[/SUP]
Small independent gold-mining operation workers are at higher risk of mercury poisoning because of crude processing methods. Such is the danger for the
galamsey in Ghana and similar workers known as
orpailleurs in neighboring
francophone countries. While no official government estimates of the labor force have been made, observers believe 20,000-50,000 work as galamseys in Ghana, a figure including many women, who work as porters. Similar problems have been reported amongst the gold miners of Indonesia.[SUP]
[14]
[/SUP]
Mercury and many of its chemical compounds, especially
organomercury compounds, can also be readily absorbed through direct contact with bare, or in some cases (such as
methylmercury) insufficiently protected, skin. Mercury and its compounds are commonly used in chemical laboratories, hospitals, dental clinics, and facilities involved in the production of items such as fluorescent light bulbs, batteries, and explosives.[SUP]
[15][/SUP]
