Curbing arsenic and iron contamination in ground water  

One in nine people in the world does not have access to safe water. The case is worse in respect of children. One in five deaths of under-5 children is caused by water borne diseases. In the developing countries, 80 per cent of the diseases are associated with limited access to safe water and proper sanitation facilities. The situation is similar in Bangladesh as well.

Though Bangladesh is trying hard to access improved water sources for its people, there is still a long way to go. Regarding the quality of drinking water, Bangladesh ranked 86th among 142 countries. It was found that both surface and ground water sources of drinking water are polluted with coliforms, harmful metals and pesticides (Arefin and Mallik, 2017). Two out of five households still drink water from contaminated water sources (UNICEF, 2016). Over 7,000 children under five years of age die annually from poor water, sanitation and hygiene practices in Bangladesh (WaterAid, 2015).

Ground water can be polluted in different ways. Presence of natural and human-induced chemicals is the main reason. Bangladesh has been facing the threat of arsenic contamination since 1993 when arsenic was first detected in tube well water.

The acceptable rate of arsenic in water is 0.01 (milligram/liter). However, for Bangladesh the range is 0.05 milligram/liter (source: WHO), but survey revealed that 27 per cent tube wells in Bangladesh were contaminated with higher level of arsenic presence -- above 0.05. Currently, extreme arsenic presence has been found in 61 districts of Bangladesh. The rate of contamination varies from 1.0 to 90 per cent, the average rate being 29 per cent according to the Department of Public Health and Engineering.

Use of arsenic contaminated water for cooking and drinking usually affects lungs, skin, kidney and liver. Also, association between high inorganic arsenic exposure and spontaneous abortion, stillbirth and low birth weight was found in the research (Milton et al, 2017). A study reveals that in 15 per cent villages of Bangladesh, 80 per cent of the shallow tube wells contaminated with arsenic were used for household activities like cooking and drinking (Ahmed et al, 2018). Thus, thousands of people are highly vulnerable to serious health hazards.

Iron contamination in ground water is another cause of water pollution in Bangladesh. For iron, the acceptable range is 0.30 (mili-grams per litre). Consuming excessive iron may create fatigue, weight loss, joint pain and eventually may affect liver, heart and lead to pancreatic damage and diabetes.

Limited access to safe water impacts women more adversely in comparison to men as two thirds of the households rely on women for collecting water where there is no water source at home. A survey found that 89.6 per cent women in Bangladesh are responsible for collecting water for their households as against only 4.6 per cent males doing the job (UNICEF, 2013).

In such a backdrop, World Vision Bangladesh and World Vision Japan undertook "Community Based WASH Improvement Project" at Gowainghat upazila in Sylhet district from 2016 to 2019. It was found that in Gowainghat upazila, 38 per cent of households drink water from unprotected sources which were contaminated by arsenic and iron. 16.1 per cent of the under-5 children were found to have symptoms of diarrhoea (Baseline, 2016).

One of the initiatives under the project was to install 245 tube-wells. However, most of the wells were contaminated by arsenic and iron. To overcome these challenge, a low cost community driven solution was inevitable. To do that, a total 60 people from two villages (Labu and Punnanagar where iron level was high) were trained to develop Arsenic Iron Removal Plant at their homes. Mostly women took the lead role in this initiative. Due to low cost and user friendly technology, the people themselves built the filter with their own money (amounting to 400/4.8 USD). After using the filter, arsenic and iron level lessened from 7.5-15mg to 0.5-1 mg and from 13 mg to .5 mg respectively in these two villages. Even, the change in the colour of water was so prominent that people from adjacent villages also started to replicate the practice.

Few more initiatives were taken under the project in nearby villages to curb arsenic and iron contamination of ground water. 

According to research conducted by WHO, investment of $1.0 in water and sanitation brings economic return of $3.0 to $34. Thus, innovative initiatives like community-driven Arsenic Iron Removal Plant should be promoted for ensuring safe access to water for all.

Bipasha Dutta is National Coordinator (Research and Innovation), World Vision Bangladesh.

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