of As is also increasing in groundwater due to the geochemical and physical
conditions of aquifers and the water–rock interactions for the mobilization and
accumulation of As in water. The order of As minerals dissolution in groundwater
observed
in
the
series
of
arsenics
>arsenolite>orpiment>realgar>arsenopyrite>tennantite (Islam et al. 2013). The
present chapter summarizes the possible sources of As contamination in groundwater and presents an overview of strategies for mitigation of As toxicity and to reduce
the As level in drinking water and groundwater.
5.2 Global Arsenic Contamination of Groundwater
Contamination of As in groundwater and drinking water is a public health issue and
adversely affects millions of people globally. This leads to a marked increase in
cancer risk (Chakraborti et al. 2017). The International Agency for Research on
Cancer (IARC) and the US Environmental Protection Agency (EPA) declared As
and its compounds as class 1 human carcinogen (WHO 2004). The Agency of Toxic
Substances and Disease Registry (ATSDR) marked As at number 1 position among
20 top hazardous substances. The Joint FAO/WHO Expert Committee on Food
Additives (JECFA) analyzed the impact of As on human health and reported
exceeded concentration of As (50–100 μg/L) in drinking water of many regions of
the world (WHO 2019). Across the world, highly As-contaminated areas have been
reported mainly in large deltas, e.g., Bengal delta (Chakraborti et al. 2010) and along
river basins (Table 5.1) such as Duero Cenozoic Basin in Spain, Danube river basin
in Hungry, Zenne river basin in Belgium Hetao river basin in Mongolia, Tulare Lake
in the USA, and Paraiba do Sul delta in Brazil (Gómez et al. 2006; Nriagu et al.
2007; Khan and Ho 2011; Cutler et al. 2013; Mirlean et al. 2014). For technical and
financial support in many states, a large number of National Rural Drinking Water
Programmes (NRDWP) have been sponsored by the government (Ministry of
Drinking Water and Sanitation) for safe drinking water. Up to 67% of fund was
provided under NRDWP with priority to As- and fluoride-contaminated areas to
tackle water quality problems. Advances have been made to the reduction of As
exposure, e.g., by removal of As from drinking water and by providing residents
with other resource of drinking water.
5.3 Sources of As and Its Impact on Human Health
Several geogenic and anthropogenic activities are being reported for increased As
pollution in groundwater. Himalayan mountains and Shillong plateau are considered
as main sources of As contamination in Gangetic river basin and delta sediments.
Additionally, the Gondwana coal region, Bihar mica belt, the pyrite-bearing region
in Vindhyan range, Sone river valley gold belt, and sulfide regions of eastern
5 Arsenic Contamination of Groundwater and Its Mitigation Strategies
109
conditions of aquifers and the water–rock interactions for the mobilization and
accumulation of As in water. The order of As minerals dissolution in groundwater
observed
in
the
series
of
arsenics
>arsenolite>orpiment>realgar>arsenopyrite>tennantite (Islam et al. 2013). The
present chapter summarizes the possible sources of As contamination in groundwater and presents an overview of strategies for mitigation of As toxicity and to reduce
the As level in drinking water and groundwater.
5.2 Global Arsenic Contamination of Groundwater
Contamination of As in groundwater and drinking water is a public health issue and
adversely affects millions of people globally. This leads to a marked increase in
cancer risk (Chakraborti et al. 2017). The International Agency for Research on
Cancer (IARC) and the US Environmental Protection Agency (EPA) declared As
and its compounds as class 1 human carcinogen (WHO 2004). The Agency of Toxic
Substances and Disease Registry (ATSDR) marked As at number 1 position among
20 top hazardous substances. The Joint FAO/WHO Expert Committee on Food
Additives (JECFA) analyzed the impact of As on human health and reported
exceeded concentration of As (50–100 μg/L) in drinking water of many regions of
the world (WHO 2019). Across the world, highly As-contaminated areas have been
reported mainly in large deltas, e.g., Bengal delta (Chakraborti et al. 2010) and along
river basins (Table 5.1) such as Duero Cenozoic Basin in Spain, Danube river basin
in Hungry, Zenne river basin in Belgium Hetao river basin in Mongolia, Tulare Lake
in the USA, and Paraiba do Sul delta in Brazil (Gómez et al. 2006; Nriagu et al.
2007; Khan and Ho 2011; Cutler et al. 2013; Mirlean et al. 2014). For technical and
financial support in many states, a large number of National Rural Drinking Water
Programmes (NRDWP) have been sponsored by the government (Ministry of
Drinking Water and Sanitation) for safe drinking water. Up to 67% of fund was
provided under NRDWP with priority to As- and fluoride-contaminated areas to
tackle water quality problems. Advances have been made to the reduction of As
exposure, e.g., by removal of As from drinking water and by providing residents
with other resource of drinking water.
5.3 Sources of As and Its Impact on Human Health
Several geogenic and anthropogenic activities are being reported for increased As
pollution in groundwater. Himalayan mountains and Shillong plateau are considered
as main sources of As contamination in Gangetic river basin and delta sediments.
Additionally, the Gondwana coal region, Bihar mica belt, the pyrite-bearing region
in Vindhyan range, Sone river valley gold belt, and sulfide regions of eastern
5 Arsenic Contamination of Groundwater and Its Mitigation Strategies
109