<mark>Saline contamination of drinking water has been documented and the risk is increasing with climate change in Bangladesh (Talukder, 2016; Rasheed et al., 2016; Khan et al., 2008; Vineis et al., 2011) and it also contributes to internal migration risks (Rakib et al., 2019). A</mark> rsenic (Nickson et al., 1998), salinity (Khan et al. 2011; 2008), and fecal pathogens (Naser et al., 2019a) are major groundwater contaminants in Bangladesh. Essential macro-minerals influence many biological and enzymatic mechanisms in fetuses and infants that can in turn influence neonatal and infant mortality (Abrams, 2007). Groundwater in Bangladesh is predominantly CaHCO3 type but in the coastal region where water is mostly saline, groundwater is primarily Na-Ca-Mg-HCO3-Cl type (Brammer, 1996). Sediments from different rivers have different chemical compositions. For example, the River Ganges derived sediments have higher calcium-magnesium carbonate contents than the sediments of the Rivers Brahmaputra and Meghna (Brammer, 1996). The concentration of many of these macro-minerals in drinking water is determined by the chemical properties of rocks and sediments through which groundwater percolates and interacts (Hudson, 2010). Small-scale variations exist in groundwater chemicals within a short geographical distance in Bangladesh due to high variability in surface geology and sediment types (Naser et al., 2018). Studies suggest that bioavailability of essential minerals from drinking water is very high (WHO, 2009), and some population in coastal Bangladesh can get up to 50% of their daily calcium and magnesium requirement by drinking 2 L of groundwater (Hoque and Butler, 2015). Groundwater is the primary source of drinking water in rural Bangladesh, and minerals and chemicals in groundwater have important public health implications (Dhar et al., 2008; Smith et al., 2000).

The general diet in Bangladesh is low in calcium content (Bromage et al., 2016), and globally, magnesium concentration in the general diet is declining (Kumssa et al., 2016). Hence, drinking water may contribute an appreciable proportion of daily calcium and magnesium intake among the Bangladeshi population, and drinking fresh or low mineral water can contribute to a deficiency of these essential minerals which can have detrimental health effects. <mark>Ur Rahman et al. (2017) found that regarding salinity the average values of total dissolved solids (TDS), electrical conductivity (EC) and Chloride concentration (Cl−) were found to be 4044.12 mg/L, 7186.7 μS/cm, and 3143.6 mg/L respectively in Shyamnagar and 2313.60 mg/L, 4390.3 μS/cm, and 1402.1 mg/L respectively in Tala. The result of community perception reveals that the local population is aware of the safe water scarcity. There is a perception that salinity is the main reason. Similar results were found regarding community perceptions by Abedin et al. (2014). Meanwhile, salt in diet is also a major issue in the country (Sakomoto, 2017).</mark> <mark>Health consequences of salinity were also documented for coastal Bangladesh ranging from hypertension to poor maternal health. Salinity increased the risk of gestational hypertension particularly in the coastal areas (Shammi et al., 2019; Talukder et al., 2016; Scheelbeek et al., 2016; Khan et al., 2014). In general, salinity adversely affected maternal health in Bangladesh (Khan et al., 2011) and is particularly</mark> 5