Cheng Wong

About 17 million people are at risk of gastrointestinal problems from excessive sulfate levels in groundwater, according to the Hong Kong University of Science and Technology.

This alarming health finding was revealed by the world's first high-resolution global groundwater sulfate distribution map, developed by the university's School of Engineering.

Sulfate damages water quality and triggers the release of heavy metals from pipeline corrosion.

Consuming groundwater with high sulfate levels can lead to diarrhea and dehydration, presenting increased risks for infants, seniors and other at-risk groups.

"With climate change and urbanization intensifying, sulfate exceedance is expected to worsen, further jeopardizing global water quality and availability," said PhD student Xiao Chengyu, who first authored the study.

The research team analyzed over 17,000 sulfate concentration measurements and global geospatial datasets to create a 1-km resolution map, highlighting sulfate hot spots and identifying key contributing factors.

The team discovered that around 194 million people are exposed to water with sulfate concentrations over 250 mg/L - a World Health Organization-recommended level indicating that water may taste unpleasant - and about 17 million people live in areas with sulfate levels exceeding 500 mg/L.

The map also underscored the need for region-specific sulfate mitigation strategies by showing that natural geological conditions contribute in some areas, while anthropogenic factors like industrial discharge are more significant in others.

The study, conducted alongside Princeton University, the City University of Hong Kong and the Beijing Institute of Technology, emphasized the urgent need to incorporate sulfate into global water safety management practices.

cheng.wong@singtaonewscorp.com

The HKUST team, from left, Zhang Zi, Chen Guanghao and Xiao Chengyu.

HKUST team pinpoints global groundwater gastro threats