Presented as a Term Paper during my M.Sc. 4th Semester

1. Groundwater Arsenic Pollution in
West Bengal Gangetic Basin,
India
Presented by: Ankita Datta
Semester IV Student
Ecology & Environmental Biology
Department of Zoology
The University of Burdwan
Roll No. BUR ZOO 2019/007

2. Introduction
● Has become a global matter of concern since the last 3-4
decades
● “The largest poisoning of a population in history” (WHO,
2000)
● Permissible limit in drinking water: 0.01 mg/L or 10 μg/L
(WHO, 2004)

3. Scenario in West Bengal
● People started to switch from surface water to
groundwater during 60s
● “Boro” season introduced, solely dependable on
groundwater irrigation
● First arsenic poisoning reported in West Bengal in 1983
(Garai et al., 1984)

4. ● 88 blocks of 8 districts are
arsenic-polluted
● 50 blocks have patients with
arsenic-borne illnesses
● Worst affected 5 districts
lying by the east of
Bhagirathi-Hooghly
○ Malda
○ Murshidabad
○ Nadia
○ North 24 Parganas
○ South 24 Parganas
Malda
Murshidabad
Nadia
N24P
S24P
Pu. Bardhaman
Hooghly
Howrah

5. What is arsenic?

6. Chemistry

7. Biogeochemistry of arsenic
● High arsenic concentrations (<10 μg/L) mainly in Holocene
aquifers (McArthur et al. 2004, Adhikari et al., 2017) rather
than older Pleistocene aquifers.
● Holocene sediments with arsenic concentrations on average 2.0
mg/kg (Datta and Subramanian, 1997; Chakraborti et al., 2001;
Swartz et al., 2004)
● Reduction of iron hydroxides leads to releasing of As absorbed
within it (Nickson et al, 2000)
● Arsenopyrite (FeAsS)- most common mineral found in anaerobic
environments of the aquifers (Oremland et al, 2003)

8. Why arsenic is a matter of concern?

9. Toxicity due to arsenic
● Acute toxicity
● Chronic toxicity

10. Effects on skin
A. Keratosis on palm B. Leucomelanosis C. Mees’ line
A B C
A-B. Chakraborti, D., Rahman, M. M., Chatterjee, A., Das, D., Das, B., Nayak, B., ... & Kar, P. B. (2016). Fate of over 480 million inhabitants living in arsenic
and fluoride endemic Indian districts: Magnitude, health, socio-economic effects and mitigation approaches. Journal of Trace Elements in Medicine and
Biology, 38, 33-45.
C. https://en.wikipedia.org/wiki/Mees%27_lines#/media/File:Mees'_lines.jpg

11. Effect on other organs/systems
System Effects
Cardiovascular Blackfoot disease
Nervous Peripheral neuropathy, encephalopathy
Hepatic
Hepatomegaly, cirrhosis, altered heme
metabolism
Hematological Bone marrow depression
Endocrine Diabetes
Renal
Proximal tubule degeneration, papillary and
cortical necrosis
Taken from Hughes, 2002

12. Malignancy
● Classified as a Group-1 carcinogen (International Agency
for Research on Cancer, IARC)
● Due to daily exposure of arsenic more than 300 µg/L
(Smith et al., 1992, 2002, 2006)
● More serious cancer in internal organs (Chakraborti et al.,
2018)

13. What does arsenic do to human
body?

14. Metabolism of arsenic
Taken from Ramasamy et al., 2015

15. Oxidative stress
● Arsenic produces more ROS
● H3AsO3+H2O+O2 H3AsO4+H2O2 (Valko et al., 2005)
● Bind to the -SH groups of glutathione
● Krebs cycle inhibited

16. Epigenetic changes
1. Alteration in DNA methylation
a. Methylation patterns in the promoter of p16 and DAPK influence the
formation of skin-lesions (Banerjee et al., 2013)
b. Lack of AS3MT- arsenic-borne basal cell carcinoma (Engstrom et
al., 2015)

17. Epigenetic changes (Contd.)
2. DNA excision repair inhibited by arsenic
● Cytotoxic effects of the arsenicals: DMA (III)> MMA (III)> Arsenite> MMA
(V)> DMA (V) (Dopp et al., 2010)
● Multiple-arsenic-species exposure- a stronger inhibition in BER and NER
(Ebert et al., 2011)

18. What can we do?

19. Primary prevention
1. Basic mitigation
○ Well-switching
○ Deep groundwater
○ Dug well
○ Surface water
○ Rainwater harvesting
2. Advanced Mitigation (Details: next slide)

20. Advanced Mitigation
Physico-chemical Biological
Phytoremediation
Microbial
remediation
Both from
Water and
Soil
From Soil
From Water
● Oxidation-
Filtration
● Coagulation-
Flocculation
● RO
● Adsorption
● Chemical
Immobilization
● Chemical
Mobilization
● Nano-
composite
● Nano-
cellulose
● Bioaccumulation-
Biosorption
● Microbial redox
reaction
● Biovolatilization
● Phytoextraction
● Phytostabilization
● Rhizofiltration
● Phytovolatilization

21. How to get rid of arsenic from the body?
Chelation therapy is most commonly used
● British anti-lewisite (BAL)
● Dimercaptosuccinic acid (DMSA)
● 2,3-dimercapto-1-propanesulfonic acid (DMPS)
● Monoisoamyl DMSA (MiADMSA)

22. How to prevent from getting affected?
● Drink water with low arsenic concentration and using
arsenic-contaminated water for other uses
● Well-nourishing food, balanced nutritious supplement
● Educating people

23. Conclusion
● No evidence yet found about evolutionary resistance
against arsenic
● Beneficial use of abundant arsenic- a matter of future
research

24. Thank you
Supervisor: Dr. Sanjoy Podder
Prof. Dr. Anandamay Barik
Dr. Asif Hossain
My parents, brother and friends