Arsenic: An Overview of Applications, Health, and Environmental Concerns and Removal Processes

Abstract

Arsenic is a toxic element and has been responsible for many accidental, occupational, deliberate, and therapeutic poisonings since its discovery in 1250. It occurs in natural waters as the arsenite (As³⁺) and arsenate (As⁵⁺) ions. The solubility of arsenite and arsenate compounds is relatively high so that these ions are readily transported through aqueous routes into the environment. Arsenic can be transferred from soils to crops and accumulates in various food crops and aquatic plants. The fascinating chemistry and toxicity potential make arsenic and its compounds of particular scientific interest and environmental concern. The conventional removal of heavy metals from wastewater, natural waters, and drinking water has only limited effects on arsenic removal. In this review, the main engineering and medical applications, salient health and environmental concerns, novel research on treatment for arsenic poisoning, and removal technologies for arsenic and their derivatives are discussed and enumerated with a view to pursue valuable applied research in order to protect the environment from arsenic toxicity.

KEYWORDS:

• arsenic
• environmental impact
• health
• toxicity
• treatment technologies

ACKNOWLEDGMENTS

The authors wish to express their gratitude to all the researchers whose valuable data, maps, and figures, as reported in their respective publications and reports, have been of considerable significance in adding substance to this review: Sienko and Plane (1974), Schnoor (1996), Gomez-Caminero et al. (2001), Johnston and Heijnen (2001), Frankenberger (2002), Roy and Saha (2002), Langdon et al. (2003), van Geen et al. (2006), Solo-Gabriele et al. (2004), Schwarzenegger et al. (2004), Shih (2005), Gibaud et al. (2006), Fleming (2007), Jones (2007), and Shaikh (2007). Special thanks go to Dr. Alexander van Geen (Doherty Senior Research Scientist and Associate Director of the NIEHS Superfund Basic Research Program at Columbia University, USA) for having been gracious and kind enough to provide us important survey data of arsenic in Bangladesh. The authors are also highly thankful to Md. Nurul Osman, IT Specialist and In-Charge at the National Arsenic Mitigation Information Center (NAMIC), for the valuable arsenic distribution map (Figure 6). They are also grateful to their other colleagues and the anonymous reviewers whose criticisms have benefited the manuscript.

Notes

1. In medicine, specifically cardiology, the QT interval is a measure of the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. The QT interval is dependent on the heart rate in an obvious way (the faster the heart rate, the shorter the QT interval) and has to be adjusted to aid interpretation. Additional information on the QT interval may be obtained in Goldenberg et al. (2006) and Panicker et al. (2006).

2. More details of the levels of arsenic in drinking water for health standards are provided in Section 5 and Table 3.

3. Details of the results of the survey are available at http://www.soesju.org/arsenic/FirstReportEruani.PDF.

4. Agency for Toxic Substances and Disease Registry [ATSDR]. (2000). Case studies in Environmental Medicine; Arsenic toxicity. Retrieved: June 23, 2008. http://www.atsdr.cdc.gov/HEC/CSEM/arsenic/index.html