Arsenic’s notoriety is most predominant in groundwater systems as toxic metalloid. The greatest mass poisoning in human history was reportedly due to the
drinking of arsenic contaminated groundwater in millions of people (Dey et al.
2017). Various anthropogenic activities have further accelerated arsenic contamination, especially in the South East Asia region. It was estimated that more than six
million people in West Bengal, India (Dey et al. 2016; Anyanwu and Ugwu 2010)
and 46 million people in Bangladesh are at a risk of arsenic poisoning due to
drinking water (Dey et al. 2016; Bachate and L Cavalca 2009). Arsenic contamination in groundwater is at an alarming situation in Indian states of West Bengal,
Chhattisgarh, Bihar, Telangana and Uttar Pradesh.
Removing the contaminating heavy metals through (micro)biological means is
widely accepted as the most efficient, cost effective, and eco- and health-friendly
(Ekperusi and Aigbodion 2015; Ayangbenro and Babalola 2017). The capacity
of microbes to remove heavy metals and metalloids is dependent on the suitability
of the abiotic factors, such as, temperature, pH, physical and chemical properties of
soil, and moisture (Verma and Jaiswal 2016). The chapter deliberates on the
chemical and biological remediation of arsenic from contaminated soils, and the
phytological/microbial mechanisms involved in heavy metals decontamination.
8.2 Sources of Arsenic Contamination
Arsenic in the environment (air, soil, water, and sediment) originates from both
natural (geogenic) and anthropogenic sources (Satyapal et al. 2018; Fig. 8.1). The
key origin points of arsenic flow from the natural geogenic sources include volcanic
eruptions, weathering, fossil fuels, minerals, parent/sedimentary rock bearing arsenic
(Mohapatra et al. 2017a). Various anthropogenic activities like agriculture, mining,
smelting, refining, electroplating, coal combustion, painting and chemical
manufacturing have added to the arsenic release to the environment (Mohapatra
et al. 2017a; Dey et al. 2016; Akhtar et al. 2013). Manufacturing of agricultural
chemicals (e.g. pesticides, herbicides, fertilisers, wood preservatives, etc.), dying
materials and medical products, are other major sources of arsenic contamination
(Mohapatra et al. 2017a; Vishnoi and Singh 2014).
8.3 Arsenic Toxicity
Presence of Arsenic in the environment beyond the permissible limit of 0.01 mg/l
can generate multiple acute and chronic health disorders (Dey et al. 2016). As
III
compound such as arsenic trioxide, sodium arsenite and arsenic trichloride could
cause neurotoxicity of both the peripheral and the central nervous system (Adeniji
2004). On the other hand, As
V inorganic forms such as arsenic pentoxide, arsenic
acid and Arsenates could also affect the enzyme activity of human metabolism
(Klaassen and Watkins III 2003). Trivalent or pentavalent organoarsenic, specially
8 Arsenic Contamination: Sources, Chemistry and Remediation Strategies
221
drinking of arsenic contaminated groundwater in millions of people (Dey et al.
2017). Various anthropogenic activities have further accelerated arsenic contamination, especially in the South East Asia region. It was estimated that more than six
million people in West Bengal, India (Dey et al. 2016; Anyanwu and Ugwu 2010)
and 46 million people in Bangladesh are at a risk of arsenic poisoning due to
drinking water (Dey et al. 2016; Bachate and L Cavalca 2009). Arsenic contamination in groundwater is at an alarming situation in Indian states of West Bengal,
Chhattisgarh, Bihar, Telangana and Uttar Pradesh.
Removing the contaminating heavy metals through (micro)biological means is
widely accepted as the most efficient, cost effective, and eco- and health-friendly
(Ekperusi and Aigbodion 2015; Ayangbenro and Babalola 2017). The capacity
of microbes to remove heavy metals and metalloids is dependent on the suitability
of the abiotic factors, such as, temperature, pH, physical and chemical properties of
soil, and moisture (Verma and Jaiswal 2016). The chapter deliberates on the
chemical and biological remediation of arsenic from contaminated soils, and the
phytological/microbial mechanisms involved in heavy metals decontamination.
8.2 Sources of Arsenic Contamination
Arsenic in the environment (air, soil, water, and sediment) originates from both
natural (geogenic) and anthropogenic sources (Satyapal et al. 2018; Fig. 8.1). The
key origin points of arsenic flow from the natural geogenic sources include volcanic
eruptions, weathering, fossil fuels, minerals, parent/sedimentary rock bearing arsenic
(Mohapatra et al. 2017a). Various anthropogenic activities like agriculture, mining,
smelting, refining, electroplating, coal combustion, painting and chemical
manufacturing have added to the arsenic release to the environment (Mohapatra
et al. 2017a; Dey et al. 2016; Akhtar et al. 2013). Manufacturing of agricultural
chemicals (e.g. pesticides, herbicides, fertilisers, wood preservatives, etc.), dying
materials and medical products, are other major sources of arsenic contamination
(Mohapatra et al. 2017a; Vishnoi and Singh 2014).
8.3 Arsenic Toxicity
Presence of Arsenic in the environment beyond the permissible limit of 0.01 mg/l
can generate multiple acute and chronic health disorders (Dey et al. 2016). As
III
compound such as arsenic trioxide, sodium arsenite and arsenic trichloride could
cause neurotoxicity of both the peripheral and the central nervous system (Adeniji
2004). On the other hand, As
V inorganic forms such as arsenic pentoxide, arsenic
acid and Arsenates could also affect the enzyme activity of human metabolism
(Klaassen and Watkins III 2003). Trivalent or pentavalent organoarsenic, specially
8 Arsenic Contamination: Sources, Chemistry and Remediation Strategies
221