Arsenic is not a rare element; according to the World Health Organization (WHO), it is the 20th most common element in the earth’s crust. Natural (volcanic) or anthropogenic (industrial) activities release arsenic into the environment. Anthropogenic sources include mining, metallurgical processes (such as smelting of nonferrous metals), and energy production (burning of fossil fuels). These activities are major contributors to arsenic contamination in air, water, and soil, primarily in the form of arsenic trioxide. Additionally, the historical use of arsenic-containing pesticides in agriculture has led to land and food contamination. Arsenic has also been used in preserving timber and during glass manufacturing. Recently, arsenic trioxide has been used in the treatment of acute promyelocytic leukemia. Due to its wide industrial applications and presence in the environment, arsenic has contaminated various environmental compartments. Among inorganic arsenic compounds, arsenic sulfides, such as iron, manganese, silver, lead, copper, nickel, and antimony sulfides, are common. Arsenopyrite is the most prevalent arsenic-bearing mineral. Arsenic occurrence in the earth’s crust averages around 5 mg kg−1, but it can be even higher in sulfide deposits. Sedimentary iron and manganese ores deposits may occasionally contain arsenic levels of up to 2900 mg kg−1. Groundwater arsenic levels have an average of about 1–2 μg L−1; however, in areas impacted by volcanic rock or sulfide minerals, it can exceed 3 mg L−1. Sediment arsenic levels range from 5 to 3000 mg kg−1, with higher concentrations found at contaminated sites. Background arsenic in soil typically falls within the range of 1–40 mg kg−1. Arsenic in percent concentrations can be found in soil associated with sulfide minerals and anthropogenic waste materials. Arsenic contamination in Latin America has been reported for over a century, with 70% of the continent’s countries facing some arsenic contamination issues. Using the 10 μg L−1 limit for As in drinking water, it is estimated that about 14 million people (including Brazilian citizens) have drinking water exceeding this limit.
Author(s) Details:
Young-Cheol Chang,
Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, Muroran Institute of Technology, 27-1 Mizumoto, Muroran 050-8585, Japan.
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