High levels of salinity in drinking water are emerging as a significant health concern for people living in Bangladesh’s coastal areas, according to preliminary findings from an ICDDR,B study.

Researchers found widespread saline drinking-water sources in communities surveyed in Koyra Upazila of Khulna and Assasuni Upazila of Satkhira.

The study assessed water sources across 172 villages covering 71 community clinic catchment areas in the two coastal upazilas.

A total of 6,703 drinking-water sources were surveyed.

Researchers found that 55.3 percent of the surveyed water sources in Koyra were saline, compared with 23.3 percent in Assasuni.

The preliminary findings were presented at a seminar titled "Drinking water salinity and impact on health: Bangladesh evidence and policy recommendations" at the ICDDR,B headquarters in Dhaka.

Dr Aliya Naheed, senior scientist at ICDDR,B, presented the findings.

She said drinking-water salinity should no longer be considered only an environmental issue because increased sodium exposure could contribute to high blood pressure and related cardiovascular and kidney diseases.

Women could also face additional health risks during pregnancy, she said.

Researchers assessed 15,471 adults aged 40 years and above for their risk of cardiovascular disease and stroke.

Of those assessed, 21.6 percent were found to have a moderate-to-high risk of developing cardiovascular disease or stroke within the next 10 years.

According to the preliminary findings, that level of risk is at least 10 times higher than the national-level risk.

The research forms part of the Bangladesh programme of the NIHR Global Health Research Centre for Non-Communicable Diseases and Environmental Change.

Researchers have also designed an integrated water and primary healthcare package aimed at addressing high blood pressure associated with saline drinking water in coastal communities.

The findings have broader implications for Bangladesh as climate change and extreme weather increase pressure on freshwater supplies in vulnerable coastal regions.

Paolo Vineis, professor at Imperial College London, called for the development of health-based water salinity guidelines to help reduce blood-pressure-related risks.

Imperial College London professor Adrian Butler highlighted the need for higher polder embankments and rapid cleanup following storm surges to reduce long-term salinisation.

ICDDR,B executive director Dr Tahmeed Ahmed said more evidence was needed on climate adaptation and its relationship with health in Bangladesh.

He said ICDDR,B was working to address research gaps by testing approaches that bring together safe drinking water, primary healthcare and community participation.

Sheikh Momena Moni, additional secretary at the Ministry of Health and Family Welfare, said that if saline drinking water is contributing to hypertension and other health problems, preventive measures cannot remain limited to the health sector alone.

The preliminary findings underline the connection between safe drinking water, climate adaptation and prevention of non-communicable diseases in Bangladesh’s coastal communities.