Abstract
Due to global climate change and anthropogenic activities, many low-lying coastal communities experience high sodium in drinking water as a result of saltwater intrusion, an emerging environmental health problem in many coastal regions. Drinking saline water is associated with higher sodium intake and hypertension. Exposure to higher ambient temperatures is common in many regions affected by saltwater intrusion, particularly in tropical and subtropical regions. Little attention has been given to the role of ambient temperature in the epidemiological association between drinking saline water and population blood pressure. We argue that high ambient temperatures increase water salinity and influence communities' sodium intake, urinary sodium excretion, and blood pressure. Hence, we hypothesize that ambient temperature is a potential confounder for the relationship between drinking saline water and population blood pressure. Testing the hypothesis requires a detailed measurement of urinary, blood, and sweat biomarkers (e.g., sodium), the population's blood pressure, and their drinking water’s salinity. An increasing number of coastal regions and islands will face the dual burden of high ambient heat exposure and saltwater intrusion in the future. Future studies are needed to determine the association between drinking saline water and blood pressure after adjusting for ambient temperature in saltwater intrusion-affected regions.