Article courtesy of Sohel Parvez | July 23, 2015 | The Daily Star | Shared as educational material
Fifty-five percent of urban households surveyed across the country use water that contains risky levels of hazardous bacteria E. coli at source, according to the findings of Bangladesh Bureau of Statistics (BBS).
Though Bangladesh has set a parameter that no E. coli should be found in a 100-millilitre sample of drinking water, the bacteria has been found from 1 to more than 100 colony forming units (cfu) per 100-ml sample of water, says the BBS.
This is the first time that the BBS, with support from Unicef, compiled data on E. coli contamination of water after testing water samples at Icddr,b.
The BBS has found that the bacterial contamination of water in urban areas is much higher than the national level where 41.7 percent of households use water with medium (1 to 10 cfu per 100-ml sample of water) to very high level (more than 100 cfu) of E. coli.
In urban areas, 18 percent of households use water that has very high level of E. coli.
Analysts say consumption of E. coli-contaminated water can cause diarrhoea and other water-borne diseases. And the bacterial contamination at source happens mainly because of leakages in water pipes.
The statistical agency recently published the findings of its Multiple Indicator Cluster Survey 2012-13. It carried out the survey based on data from 51,895 households in 64 districts from December 2012 to April 2013.
Water samples were collected from 2,543 of the households and were tested for E. coli, said the BBS.
Talking to The Daily Star, Ruhul Amin Miah, professor of microbiology and immunology at Bangabandhu Sheikh Mujib Medical University, said, “Water has to be boiled or filtered for purification. As middle class and upper middle income groups usually do this, they are less likely to be affected.
“But poor and low income people, who don’t have the scope for boiling water or the ability to afford filters, are more likely to be affected.”
The latest BBS findings come at a time when arsenic contamination of water remains a threat to public health, mainly for people in rural areas where tube wells are the main source of drinking water.
In contrast, E. coli contamination of water emerges as a health risk for urban people who get water mainly from public utility agencies.
The BBS has found that 92 percent water of dug wells is contaminated with E. coli, followed by surface water (84.8 percent), piped water (78.5 percent) and tube well water (37.7 percent).
Analysts say since the number of dug wells is negligible in urban areas, piped water is the main source of E. coli-contaminated water there.
“If water gets contaminated at source, the supplier has to take the responsibility. E. coli contamination can also take place at households because of poor hygiene,” said Khairul Islam, country representative of UK-based WaterAid Bangladesh.
The BBS says 61.7 percent of households consume water that contains risky level of E. coli, indicating contamination also occurs between the points of collection and use.
Khairul said E. coli contamination of piped water might happen for the absence of required pressure in pipelines.
“Contamination may occur through leakages in pipes. Dirt and filth may enter pipes at the time of water logging,” said the country chief of WaterAid that campaigns for safe water, sanitation and hygiene.
Unclean reservoirs and use of dirty jugs and bottles at households may also lead to such contamination.
The number of child deaths from diarrhoea has dropped but the morbidity rate is yet to come down. “This is mainly because of consumption of unsafe water and also poor hygiene,” he said.
Shofiqul Alam, water, sanitation and hygiene specialist at Unicef Bangladesh, said leakage in distribution lines was one of the main reasons for E. coli contamination of piped water in urban areas. It also occurs at the points of water collection and transportation in low-income areas, especially in slums.
The problem can be solved by fixing leakages and replacing old pipes, he said.
Sirajul Islam, emeritus scientist at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), said E. coli was considered an indicator bacterium.
The presence of this bacterium in water indicates that other pathogenic bacteria and viruses, responsible for diseases like cholera, typhoid, dysentery and jaundice, may also be found in that contaminated water.
If a person consumes it, he might contract those diseases, said Sirajul.
On E. coli contamination of water, Akram Al Hossain, additional secretary (water supply) at the Local Government Division responsible for supply of safe water, said the LGD asked the Water Supply and Sewerage Authority and the Department of Public Health Engineering to submit reports based on the BBS findings.
He said they would comment on the issue after getting the reports.
“We supply pure drinking water. But there could be problems because of leakage in pipes and also illegal connections.”
Akram said Dhaka Wasa was replacing old water pipes with the Asian Development Bank’s finance. Once it is done, there will be no scope for having illegal connections.
Residents of the capital would be able to drink water from taps by 2019, he said.