Arsenic pollution in West Bengal at a glance

1. Arsenic in food chain and ground water & its
mitigation options with particular emphasis in
West Bengal
Aritra Saha
And
Dr. Pabitra Kr. Mani
DEPARTMENT OF AGRICULTURAL CHEMISTRY AND SOIL SCIENCE
FACULTY OF AGRICULTURE
BIDHAN CHANDRA KRISHI VISWAVIDYALAYA

2. Arsenic contamination
Worst calamity in the world

3. An overview
• 1st reported in our country- 1983(Garai et al.)
• Most acute arsenic contaminated site of World- Ganga-
Brahmaputra-Meghna basin(> 4000 µg/L, Rahman et al.
2006)
• Area under As contaminated zone in W.B.- 88750 km2
including 79 blocks of different districts.
• Area under Highly As contaminated zone in W.B- 38,861
km2 (Nadia, Murshidabad, N & S 24 pargana, Kolkata)
(Chakraborti et al., 2009)

4. (Source: National Institute of Hydrology, Roorkee)

5. As- toxic metalloid
Mostly present in sedimentary rocks (Shales, Carbonates,
Sandstones). (Sanyal, 2014)
• Atomic no. 33
• copper(II) acetoarsenite, calcium arsenate, and lead
hydrogen arsenate- herbicides, insecticides
• Orpiment (As2S3) and realgar (As4S4)- paint production
• Held by solid phases within the sediments, especially iron
oxides(FeOOH), organic matter and sulphides.
• Crustal abundance- 2 ppm (Sanyal, 2014)
• Coal mining- 2000 ppm (Sanyal, 2014)

6. As con. in natural water
other than g. water
Source As(µg/L)
Rainwater and snow <0.002-0.59
Rivers 0.20-264
Lakes 0.38-1.00
Sea water 0.15-6.00
Ponds(WB) 4-70
Canals(WB) 40-150
Source: welch et al., (1988) & ICAR(2003)

7. Periodic Table of the Elements
As is a Group VA element (like N and P)

8. Guideline value
• WHO (1993) permissible limit for drinking purpose- 0.01
mg/L
• National standard for MAC- 0.05 mg/L ( WHO, 1971)
• Proposal by WHO in 2001- 0.001 mg/L
• PMTDI inorganic As- 0.002 mg/kg of body wt.(JECFA,
1983)
• PTWI inorganic As- 0.015 mg/kg of body wt.(FAO/WHO,
1989)

9. Extent of contamination in West Bengal
State Coverage Level of
contaminatio
n
citation
West Bengal 12 districts( Murshidabad, Maldah,
Nadia, N & S 24 parganas, Burdwan,
Howrah, Hooghly, Kolkata,
Coochbehar, N. Dinajpur & S.
Dinajpur), 111 blocks.
50-3700 µg/L http://www.soesju.
org/arsenic/wb.ht
m
Source: Sanyal (2014)

10. Arsenic cycle in the environment

11. Chemistry & behaviour
In ground water:
• At pH 6-8 : H2AsVO4
- and HAsVO4
2 (oxidized env. Eh =
0.2-0.5 V)
• H3AsIIIO3 (reduced condition. Eh = 0-0.1 V)
(Saddiq et. al, 1997)

12. Chemistry & behaviour
In Soil: Arsenite and arsenate (inorganic)
MMA acid , DMA acid, TMA acid (org.form)
(on reduction) (anoxic cond.)
Di/trimethyl arsine(AsH3)
Flooded cond. (Eh= 0-0.1 V, pH 6-8)
 As acid sp. And arsenite oxyanions- H3AsO3
0, H2AsO4
-, HAsO4
2-, AsO4
3-
(Rochette et al., 1998; Sanyal, 1999).
Aerobic cond.
 Under aerobic (oxidizing) conditions AsV predominates- As acid sp. and arsenate
oxyanions (H3AsO4
0, H2AsO4
-, HAsO4
2-, AsO4
3-) (Fitz and Wenzel, 2002;
Takahashi et al., 2004).

13. Chemistry & behaviour
In Rhizosphere:
Micro-organisms oxidized rhizosphere
Precipitation of FeOOH
(Fe plaques on root of wetland crops)
( Meharg et al. 2004)

14. Uptake in plants
• AsV- high affinity PO4
- upatke system (Meharg, 2004)
• AsIII- aquaporins (water channels of roots) (Meharg,
2003)
• MMA & DMA –rice (but rate is slow than inorg. Form)
(Abedin et al. 2002c)
*Mechanism of uptake of org. As – UNCLEAR
*Prediction of As uptake- Impossible

15. Translocation & accumulation
• Roots to shoot- limited(except hyperaccumulators)
• Org As- readiliy translocated but uptake is lower
than inorg. Sp. (Carbonell et al., 1998)
• Pot expt. Of rice( irrigated with As contaminated
water)- root>straw>husk>grain. (Abedin et al.,
2002a)

16. Metabolism in plant
• AsV reduction AsIII (causing oxidative stress)
Anti-oxidants
(Detoxification) (Hartley,2002)
• Exposure to As III induces no such type of
mechanism
• 70% of As in rice straw- AsV (Abedin et al., 2002b)
• AsV in plant- exposed to AsIII ( oxidation of AsIII
takes place) (Schmidt et al. 2004)

17. Sources of As in Ground water
Two hypotheses: Geogenic origin
1.Oxidation of pyrite(FeS2) & solubilisation of As
FeS2 + 2H2O + 502 = FeSO4 + 2H2SO4
As liberated in aquifers
(Mandal et. al, 1996)
2. Reduction of As rich FeOOH in anoxic(depleted dissolved O2)
g.water (due to microbial oxidation of sedimentary organic matter,
paddy cultivation, high WT)
(Bhattacharya et. al., 1997)

18. Sources of As in food chain
Irrigation with As contaminated ground water
Soil
(major sink in Agro-ecosystem)
Crop
Human Livestock Human

19. As in food-chain
As in Soil
(mg/kg)
As in Rice As in
Vegetables
(mg/kg)
Reference
11.35 0.245 <0.0004-0.693 Roychowdhury et
al.(2002)
7.0-38.0 0.30 NA Norra et al.( 2005)
1.34-14.09 0.16-0.58 NA Bhattacharya et al.(2009)
5.70-9.71 0.334-0.451 0.030-0.654 Bhattacharya et al. (2010)
NA 0.156-0.194 0.069-0.78 Samal et al. (2011)
NA 0.01-0.64 0.03-0.35 Halder et al. (2012)

20. Several findings
 Rice (due to flooded cond. Where mobile As III presents in soil
water)- Takahashi et al.(2004)
 As TF is more in rice (0.8)>wheat(0.1)- Xu et al. (2008)
 root, shoot and leaf tissue of rice- inorganic AsIII and AsV
 rice grain- DMA (85 to 94%) and As III (Smith et al.,2008, Liu et
al.,2006).
 Shoot root > root shoot (Bhattacharya et al. 2009)
 Accumulation in boro rice> Aman rice (Bhattacharya et al.
2010b)
 As level in daily consumption of rice- 0.08 mg/kg (Williams et al.
2006)

21. Several findings
 More in tuberous vegetables > leafy vegetables
 Aurum(0.11- 3.49 ppm) Kalmi sak (0.09- 2.03ppm)
(Samal et al. 2011)
 Chilli- 0.114 ppm oil seed- 0.339 ppm – 0.373 ppm
(Biswas et al. 2012)
 Pulses- pea(1.3 ppm) & Mung bean (0.314 ppm)
(Biswas et al. 2012)
 90% of daily intake of As in farm animals of Nadia
district- Feed< drinking water. (Sanyal, 1999)

22. Clinical ill effects
• Melanosis
• Leucomelanosis
• Keratosis
• Hyperkeratosis
• Skin cancer
• Oedema
• Nausea
• Anorexia
• Chronic lung disease
• Black foot disease

23. Mitigation options
• Using Surface water Sources.
• Exploring and harnessing alternative arsenic free
aquifer, if available.
• Removal of Arsenic from ground water using
Arsenic treatment plants/filters.
• Rain Water harvesting.

24. Scientific technologies followed in removal of As from
Ground water -
• Coagulation/ Co-precipitation(with Fe/Al salts)
• Adsorption(with Fe hydroxides & activated alumina)
• Sedimentation
• Ion exchange expensive
• Membrane/ Reverse osmosis
• Biological Treatment (Oxidation)

25. Various ARPs
Name Activity type Media used
RPM technology Adsorbant Activated alumina
WSI technology Ion exchange Bucket of resin
Pal trockner technology Adsorbant AdsorpAS
Oxide India technology Adsorbant Activated alumina
Apyron technology Adsorbant Activated alumina
School Of fundamental
research
Adsorption Al-silicate+Ferric
hydroxide
AIIH & PH model Oxdn.+coagulation+flocc
ulation+filtration
Chlorinated agent+Ferric
alum
PHE dept., Govt. of WB
model
Adsorption Red hematite+quartz+
sand activated alumina
Source : Technology Brochure on arsenic mitigation programme (by AIIHPH& SFR)

26. Phytoremediation
Hyperaccumulator plants
(phytoextraction, phytostabilization)
As in above ground parts
e.g. Pteris vittata (Brake fern), P. longifolia, P. umbrosa
Pteris genera – most efficient (Raskin, 2000)
 Water hyacinth (Eichhornia crassipes)– 170- 340 µg As/dry wt.
(Low & Lee, 1990)
 Pointed gourd (Trichosanthes dioica)
(panda & Das, 2001)
 Hydrilla (Hydrilla verticillata)
(Lee et al., 1991)
 Elephant foot yam, green gram
(ICAR, 2001)

27. Microbial remediation
Micro-organism- AsV (e- acceptor) or AsIII (e- donor)
(Joshi et al. 2009)
As tranforming genera- Pseudomonas, Rhizobium,
Acinetobacter and Microbacterium
(Paul et al., 2014)

28. Mitigation from Food chain
• Use of surface water (pond water) for irrigation-
Safer altenative ( Giri et al., 2011).
• Use of rainwater collected in harvesting structure
may be used. (Planning commission, 2007)

29. Mitigation from Food chain
Imposition of intermittent ponding during 16 to 40 DAT
reduced the As content of straw, husked grain and
unhusked grain respectively by 22, 33 and 36% with
insignificant reduction in grain yield.(Sarkar et al., 2012)
Table 3. Impact of deficit irrigation on arsenic load in soil and different parts of
rice as well as yield of rice grain (As content of irrigation water 0.163 mg L-1)
Irrigation
regimes
As added,
mg m-2 soil
Total As, mg Kg-1 Grain
yield, Mg
ha-1
Soil Straw Husked
Grain
Unhuske
d grain
CP 171.6 18.74 4.20 0.56 0.26 4.69
IP 143.0 18.16 3.42 0.42 0.19 4.43
SAT 125.84 17.75 3.96 0.53 0.21 3.92
AER 115.83 16.22 3.51 0.46 0.19 3.65
CD (p = 0.05) 1.98 0.13 0.08 0.04 0.03 0.65

30. Mitigation from Food chain
Recycling of crop residues, incorporation of organic manures to
improve the soil organic matter stock and hence arsenic retention
in the arsenic-affected soil. (Giri et al.)
Fig: Role of organics on percent share of As species in straw and grain of boro
rice. (Sarkar et al., 2012)

31. Mitigation from Food chain
Application of Vermicompost & FYM.
(Benik and Bhebaruah 2004).
Fig: Per cent reduction in grain arsenic content in rice (genotype Shatabdi)
through organic amendments. (Sarkar et al. 2012)

32. Mitigation from Food chain
• Incorporation of inorganic amendments especially
micronutrients like Zn, Fe, Si etc.
• Efficiency order- FeSO4 > ZnSO4 > CaSiO3 -
regardless of growth stages of plant. (Giri et al.,
2011).
• Application of silica (Bogdan and Schank,2008)

33. Mitigation from Food chain
Suitable Rice Varieties- khitish, Satabdi, Lalswarna
As content of important rice genotypes of Nadia district
Variety As mg kg-1
ROOT STRAW GRAIN
Nayanmoni 7.37 - 9.71 1.20 – 2.35 0.46 – 0.93
Gs-3 7.52 – 11.64 1.79 – 1.93 0.47 -0.68
Satabdi 7.26 – 9.52 1.22 – 1.64 0.43 – 0.61
Naraminikit 6.21 – 8.92 1.12 – 1.94 0.33 – 0.61
Khitish 6.49 – 8.42 1.02 – 1.65 0.38 -0.51
Lal swarna 6.94 – 9.36 1.18 – 2.30 0.22 – 0.48
(Sarkar et al.2012)

34. Mitigation from Food
chain
Selection of appropriate site for rice cultivation
(Sarkar et al. 2012)
As load and grain yield of rice in different topo-sequences
Land
situation
Total amount of
irrigation, mm
As content mg kg-1 Grain
yield
Mg ha-1
Straw Grain
Med-up land
1400
2.91 0.67 4.05
Medium land
950
2.63 0.51 5.13
Low land
500
2.01 0.36 5.56
CD (P=0.05) 0.24 0.12 0.41

35. Govt. Initiatives
Tapping of arsenic free
deep aquifers for
drinking water supply (3rd
aquifers or beyond) as
found uncontaminated.
Water supply schemes-
surface waters and
ground water after
treatment.
Development and
application of Arsenic
removal filters with Hand
Pumps on tubewells with
sludge disposal
arrangement.
Change of cropping
pattern resulting lesser
consumption of
ground water.
Epidemiological,
clinical and
therapeutic studies.
Study on effects of
Arsenic toxicity on
animals.
Study on impact of
Arsenic laden ground
water, on food chain.
Setting up of modern
laboratories to test samples of
water on this parameter, of
District and State levels.

36. Conclusion

37. References
• Abedin M.J., Cressner M.S., Meharg A.A., Feldmann J. & Cotter-Howells J.
Arsenic accumulation and metabolism in rice (Oryza sativa L.). Environ Sci
Technol, 2002b; 36: 962-968.
• Abedin M.J., Cotter-Howells J. & Meharg A.A. Arsenic uptake and
accumulation in rice (Oriza sativa L.) irrigated with contaminated water. Plant
Soil, 2002a; 240: 311-319.
• Bhattacharya P., Samal A.C., Majumdar J., Santra S.C. Uptake of arsenic in rice
plant varieties cultivated with arsenic rich groundwater. Environment Asia,
2010b; 3(2): 34-37.
• Biswas A., Samal A.C., Santra S.C. Arsenic in relation to protein content of rice
and vegetables. Research Journal of Agricultural Science 2012; 3(1): 80-83.
.

38. References
• Benik P., Bejbaruah R. Effect of vermicompost on rice (Oryza sativa) yield
and soil-fertility status of rainfed humid sub-tropics. Indian Journal of
Agriculture Sciences, 2004; 74(9): 488-491
• Bhattacharya P., Samal A.C., Majumdar J., Santra S.C. Transfer of Arsenic
from Groundwater and Paddy Soil to Rice Plant (Oryza sativa L.): A micro
Level Study in West Bengal, India, World Journal of Agricultural Sciences,
2009; 5(4): 425-431.
• Bhattacharya P., Samal A.C., Majumdar J., Santra S.C. Arsenic
contamination in rice, wheat, pulses, and vegetables: A study in an arsenic
affected area of West Bengal, India. Water, Air and Soil Pollution, 2010a;
213(1-4): 3-13

39. References
• Carbonell A.A., Aarabi M.A., DeLaune R.D., Gambrell R.P. & Patrick Jr W.H. Arsenic in
wetland vegetation: Availability, phytotoxicity, uptake and effects on plant growth and
nutrition. Sci Tot Environ, 1998; 217: 189-199.
• Chakraborti D., Das B., Rahman M.M., Chowdhury U.K., Biswas B., Goswami A.B., Nyak
B., Pal A., Sengupta M.K., Ahmed S., Hossain A., Basu G., Roychowdhury T., Das D. Status
of Groundwater arsenic contamination in the state of West Bengal, India: A 20-year study
report. Molecular Nutrition and Food Research, 2009; 53(5): 542-551.
• Fitz W.J. & Wenzel W.W. Arsenic transformations in the soil-rhizosphere-plant system:
fundamentals and potential application to phytoremediation. J. Biotechnol, 2002; 99: 259-
278.
• Garai R., Chakraborti A.K., Dey S.B., Saha K.C. Chronic arsenic poisoning from tubewell
water. Journal of Indian Medical Associations, 1984; 82: 34-42.
• Giri P., Bhattacharya K., Sinha B., Roy N. R. Mitigation options of arsenic uptake by rice
plant in arsenic endemic area. Oryza 2011; 48(2): 127-131

40. References
• Hartley-Whitaker J., Ainsworth G., Vooijs R., Ten Bookum W.M., Schat H. &
Meharg A.A.. Phytochelatins are involved in differential arsenate tolerance in
Holcus lanatus. Plant Physiol, 2001; 126: 299-306.
• Halder D., Bhowmick S., Biswas A., Chatterjee D., Nriagu J., Guha Mazumder D.
Risk of Arsenic Exposure from Drinking Water and Dietary Components:
Implications for Risk Management in Rural Bengal, Environ. Sci. Technol 2012;
dx.doi.org/10.1021/es303522s.
• ICAR. (2001) Final Report: Status, causes and impacts of arsenic contamination in
groundwater in parts of West Bengal vis-à-vis management of agricultural systems.
[Ad-hoc scheme executed (1998-2001) by BCKV (Nodal Centre); NBSS & LUP
Regional Centre, Kolkata; NDRI, Kalyani; GSI, Govt. of India, Kolkata; CSSRI,
Regional Research Station, Canning Town; SWID, Govt. of West Bengal, Kolkata;
Principal Investigator – Sanyal, S.K.].

41. References
• Joshi D.N., Flora S.J.S., Kalia K. Bacillus sp. strain DJ-1, potent arsenic
hypertolerant bacterium isolated from the industrial effluentof India. J.
Hazard Mater, 2009;166:1500–1505
• Lee, C. K., Low, K. S. and Hew, N. S. Accumulation of arsenic by aquatic
plants. Sci. Total Environ. 1991; 103: 215-227.
• Liu W.J., Zhu Y.G., Hu Y., Williams P.H., Gault A.G., Meharg A.A.,
Charnock J.M., Smith F.A. Arsenic sequestration in iron plaque, its
accumulation and speciation in mature rice plants (Oryza sativa L.).
Environmental Science and Technology, 2006; 40: 5730–5736.
• Norra S., Berner Z.A., Agarwala P., Wagner F., Chandrasekharam D.,
Stüben D. Impact of irrigation with arsenic rich groundwater on soil and
crops: a geochemical case study in West Bengal delta plain, India. Applied
Geochemistry, 2005; 20:1890-1906

42. References
• Paul D., Poddar S., Sar P. Characterization of arsenite-oxidizing bacteria
isolated from arsenic-contaminated groundwater of West Bengal. Journal
of Environmental Science and Health, Part A, 2014; 49:1481–1492.
• Panda S., Das N.C. Impact of cultivation of pointed gourd (Trichosanthes
dioica) on mobilization of arsenic in surface soil and water – A report.
Proc. Intl. Conf. On Changing Environmental Scenario of India and
Adjacent Countries since Independence, Calcutta, December 29, 2000 –
January 01, 2001, p. 107.
• Roychowdhury T., Uchino T., Tokunaga H., Ando M. Survey of arsenic in
food composites from an arsenic-affected area of West Bengal, India. Food
Chem. Toxicol. 2002; 40(11): 1611-21.

43. References
• Rahman M., Vahter M., Wahed M.A., Sohel N., Yunus M., Streatfield P.K.,
El Arifeen S., Bhuiya A., Zaman K., Chowdhury A.M., Ekstrom E.C.,
Persson L.A. Prevalence of arsenic exposure and skin lesions. A population
based survey in Matlab, Bangladesh. J. Epidemiol. Community Health,
2006; 60: 242–248
• Raskin I., Ensley B.D. (Ed.). Phytoremediation of toxic metals: using
plants to clean up the environment, John Wiley and Sons, N. York, 2000, p.
303.
• Samal A.C., Kar S., Bhattacharya P., Santra S.C. Human exposure to
arsenic through foodstuffs cultivated using arsenic contaminated
groundwater in areas of West Bengal, India. Journal of Environmental
Science and Health - Part A: Toxic/Hazardous Substances and
Environmental Engineering, 2011; 46(11): 1259-1265.

44. References
• Sanyal, S. K. (1999) Chemodynamics of geogenic contaminants in the soil environment-Arsenic.
Proc. Second Intl. Conf. on Contaminants in the Soil Environment in the Australasia-Pacific Region,
New Delhi, December 12-17, 1999. Abstracts, p. 389-390. Indian Network for Soil Contamination
Research, New Delhi, India and Soil Contamination Research in Asia and the Pacific, Adelaide,
Australia.
• Sanyal, S.K. (2014). Arsenic contamination in ground water: an environmental issue. Journal of
Crop and Weed, 10(1): 1-12.
• Sarkar S., Bhattacharya K., Bhattacharya S., Mondal S., Kole S.C., Kundu C.K., Patra P.K.,
Mukherjee A., Mukhopadhyay D. (2012). Comprehensive overview of mitigation options on arsenic
entry in food-chain. Proceedings of the International workshop on Arsenic in Food Chain: Cause,
Effect and Mitigation, 20th February, 2012, Kolkata, India, DNGM Research Foundation, Kolkata,
p. 2012 pp. 99-109.
• Schmidt A.C., Mattusch J., Reisser W. & Wennrich R. Uptake and accumulation behaviour of
angiosperms irrigated with solutions of different arsenic species. Chemosphere, 2004; 56: 305-313.
• Smith E, Juhasz AL, Weber J, Naidu R. Arsenic uptake and speciation in rice plants grown under
greenhouse conditions with arsenic contaminated irrigation water. Science of the Total Environment,
2008; 392, 277–283

45. References
• Takahashi Y., Minamikawa R., Hattori K.H., Kurishima K., Kihou N. &
Yuita K. Arsenic behavior in paddy fields during the cycle of flooded and
non-flooded periods. Environ Sci Technol, 2004; 8:1038-1044.
• WHO (1971). International Standards for drinking Water, Third edition.
• WHO (1993). Guidelines for drinking-water quality, 2nd Ed. Vol. 1.
• WHO (2001). Environmental Health Criteria 224: Arsenic and Arsenic
compounds. WHO, 2001. Geneva.
• Xu X.Y., McGrath S.P., Meharg A.A., Zhao F.J., Growing rice aerobically
markedly decreases arsenic accumulation. Environ. Sci. Technol., 2008; 42:
5574-5579.

46. THANK YOU