Microbial in-situ mitigation of arsenic contamination in plants and soils - In-Situ Remediation of Arsenic-Contaminated Sites - page 112

CHAPTER 6

Microbial in-situ mitigation of arsenic contamination
in plants and soils

Nandita Singh, Pankaj Kumar Srivastava, Rudra Deo Tripathi,
Shubhi Srivastava & Aradhana Vaish

6.1 BASICS OF ARSENIC BIOREMEDIATION

Arsenic (As) is present in the environment and poses threat to humans worldwide, mostly through
food, water, and air. Excessive use of As-based pesticides and indiscriminate disposal of domestic
(biosolids) and industrial (timber, tannery, paints, electroplating, etc.) wastes, as well as min-
ing activities, have resulted in widespread anthropogenic As contamination of soils and water
( Table 6.1 ). However, the presence of geogenic As in groundwater, a main source of drinking and
irrigation water in many countries primarily in South Asia, has drawn much attention of the sci-
entific community. Worldwide, more than 100 million people are exposed to excessive amounts
of As in water. Arsenic is thus a geogenic contaminant-driving from natural sources, which is
dissolved in groundwater and surface water through redox dissolution.
As causes multiple negative effects on human health. The US Environmental Protection Agency
(USEPA) has classified inorganic As (i-As) as a known human carcinogen. Chronic exposure to
As can cause cancer (Eguchi et al ., 1997). More than 70 million people are affected by As in
India and Bangladesh alone (WHO, 2008). As contamination in the groundwater of West Bengal,
India was first reported in the late 1980s (Bhattacharya et al ., 1997; Chakraborti et al ., 2004). As
contamination has also been reported in groundwater from other states in India. Scores of people
from India (Chakraborti et al ., 2002; Chatterjee et al ., 1995), Bangladesh (Smith et al ., 2000),
China (Wang and Lazarides, 1984), Vietnam (Berg et al ., 2001), Taiwan (Lu, 1990), Chile (Smith
et al ., 1998), Argentina (Hopenhayn-Rich et al ., 1998), and Mexico (Del Razo et al ., 1990) are

Table 6.1. Sources of arsenic in soils and aquatic environments.

Concentration [mg kg − 1 ] Source Reference

Coal 180 Wood (1996)

2-825 Adriano et al . (1980)

Ores 2000 Tempel et al . (1977)

500-9300 Hutchinson et al . (1982)

Fly ash 2-6300 Page et al . (1979)

7000 Roussel et al . (2000)

Poultry manure 91.8 Abedin et al . (2002)

Rice straw 11.9-21.0 Ross et al . (1991)

Sewage sludge 2000 Walsh (1977)

Lead arsenate and other arsenical pesticides 100 Davenport and Peryea (1991)

240 Aurelius (1988)

Waste disposal 3-350 Stilwell and Gorny (1997)

Wood preservative (chromated copper arsenate) 550 Cooper and Ung (1997)

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