Arsenic Problem in Bangladesh

1. Arsenic Problem in Bangladesh
Presented by
Md. Mahmudul Hasan Chy.
Agricultural Water Management Engineering
University of Debrecen

2. Contents
● Introduction on Groundwater
● What is Arsenic?
● Arsenic Situation in Bangladesh
● Presence of Arsenic and when it was detected
● Health issues related with Arsenic
● Social Problems by Arsenic
● Action taken to address the problem
● Impacts
● Arsenic in Agriculture
● Suggestions
● Conclusions

3. Groundwater:
Groundwater is the water found beneath Earth’s surface that soaks into cracks and crevices in soil and
rock. When water infiltrates earth’s surface it becomes part of the groundwater.
Water from rainfall can hit Earth’s surface and do a number of things:
 Slowly soak into the ground: Infiltration
 Change to a gas: Evaporation
 Flow across Earth’s surface: Runoff
There are 3 layers:
Zone of aeration: layer of rock and soil above the water table where pores in rock and soil are NOT filled
with water.
Water Table: The upper limit to the zone of saturation (like the surface of pool water). The water table
follows the shape of the land.
Zone of saturation: Layer of rock and soil pores are completely filled with water (saturated)
Groundwater

4. What is Arsenic?
• 33rd element in Periodic Table.
• Inorganic toxically metal pollutant.
• Highest priority contaminant on the
priority list of hazardous substances.
• Known as poison and human
carcinogen.

5. Arsenic Situation in Bangladesh
 Prior to arsenic contamination 98% (approx) population had access to safe drinking water.
After contamination it was reduced to nearly 72%. After intervention it is back to around 80%.
 Drinking contaminated water for a long time may cause arsenicosis.
 Arsenicosis is reversible if detected at an early stage.
 How and what triggered the release of arsenic in the ground water still not conclusive.
 Some scientists argue that oxidation of arsenic pyrites have caused contaminates while
others opine that oxihydroxide reduction is responsible.
 Shallow aquifers (≤ 50 M deep) are mostly affected. Deep aquifers are generally free from
arsenic. Dhaka deep aquifers have not shown presence of arsenic.
 Arsenic contamination is not caused by tube wells or by irrigation or by application of fertilizer.
 WHO Arsenic limit is <10 μg/L; in Bangladesh it is <50 μg/L.

8. Presence of Arsenic and when it was detected
 Exists naturally in the Arsenic rich bed rock of the river system.
 First Detected in Bangladesh in 1993.
 In West Bengal of India, it was detected in mid-seventies. Aquifers of other countries in
the region are also contaminated with arsenic.
 How and what triggered the release of arsenic in the ground water still not conclusive.
 Some scientists argue that oxidation of arsenic pyrites have caused contamination while
others opine that oxi-hydroxide reduction is responsible.
 Shallow aquifers (≤ 50 M deep) are mostly affected. Deep aquifers are generally free
from arsenic. Dhaka deep aquifers have not shown presence of arsenic.
 Arsenic contamination is not caused by tube wells or by irrigation or by application of
fertilizer.

9. Health issues related with Arsenic
 Nearly 40,000 people showing symptoms of arsenic contamination or Arsenicosis
 Cause acute and chronic toxicity.
 Liver and kidney damage.
 Skin disease such as keratosis (hardening palm and sole), melanosis (hyperpigmentation),
blackening of skin.
 Irritation to skin and mucous membrane.
 Irreversible circulatory insufficiency.
 Arsenicosis by drinking arsenic contaminated water which can lead to very painful death.
 There is no known cure to arsenic poisoning.
 WHO estimates 100,000 cases of skin lesions in the country.

11. Social Problems
• Arsenicosis patients suffer from enormous social stigma.
• People believe it as contagious or curse.
• Children with Arsenicosis are not allowed to play with other children.
• Impact on Women is worse. Single women finds it almost impossible to get married
and if acquired after marriage they have risk of divorce. Women are also less likely
to receive early diagnosis and treatment.
• Patients have difficulties in getting jobs thus causing loss of livelihood.

12. Action taken to address the problem
• National wide survey to screen arsenic affected tube-wells especially in arsenic
prone areas carried out between 2000-2003.
• Development and implementation of National Arsenic Communication Strategy
and awareness program.
• Contaminated tube wells painted red and the others painted green (≤ 50 ppb)
• Installation of new arsenic free water points. This includes arsenic free tube wells,
dug wells and treated surface water from available sources. Sono Filter in Use.
• Introduction and use of commercial arsenic removal filters.

14. Impacts
• Awareness of arsenic poisoning has improved dramatically.
• Presently 80% of the population are aware that arsenic is a problem, up from single digit
in the late 1990s.
• 70% households are taking some action to avoid arsenic contaminated water.
• Screening has allowed people to share safe tube wells and identify depth where arsenic is
less prevalent.
• More than 100,000 safe water sources have been installed in arsenic effected areas
between 2000 and 2005.
• Rain water is harvested and used for drinking as well as cooking purposes.
• Surface water which is arsenic free is being increasingly used for domestic purposes.
• Arsenicosis patients are also reporting fewer social problem as awareness increases.

15. Arsenic in Agriculture
• Evidence suggest that high levels of arsenic in irrigation water could degrade soils,
reduce yield and find its way in to the food chain.
• People may be exposed to arsenic not only through drinking water, but indirectly through
food crops irrigated by contaminated ground water.
• Of the 4 million ha of land under irrigation about 2.4 million ha are irrigated by shallow
tube wells. Approx 95% extracted ground water used for irrigation especially in dry
season. The STW water is likely to contain arsenic.
• Arsenic levels of rice in Bangladesh is as high as 1.8 ppm compared to 0.05 ppm in
Europe and USA.
• In Leafy vegetable like spinach, cabbage etc it can be 200% higher than that of rice.

16. Suggestions
 Use pesticides and fertilizers with care.
 Keep chemicals and waste safe from rain.
 Conduct household hazardous wastes collection.

17. Conclusions
 Arsenic contamination is not peculiar to Bangladesh alone. This is a
global problem.
 The great difference is the degree and velocity of this environmental
disaster in Bangladesh for the number of people at risk is higher than
other countries.
 Prevention and awareness are the best way to reduce groundwater
pollution.
 High arsenic concentration is present mostly in shallow groundwater

18. Any Question?

19. Köszönöm!