Fluoride occurrence in groundwater systems at global scale and status of defluoridation – State of the art

Co-occurrence, possible origin, and health-risk assessment of arsenic and fluoride in drinking water sources in Mexico: Geographical data visualization

“…The highest exposures have been reported for India (West Bengal), Bangladesh, Nepal, Pakistan, China, Taiwan, Japan, Cambodia, Vietnam, Australia, Hungary, and Romania. In the Americas, As is mainly found in the arid and semi-arid regions of the United States, Mexico, Bolivia, Nicaragua, El Salvador, Peru, Chile, and Argentina (Chakraborti et al, 2016;Kimambo et al, 2019;Kumar et al, 2016;Shakoor et al, 2017). Exposure to F in drinking water has been reported in >25 countries.…”

“…Exposure to F in drinking water has been reported in >25 countries. An estimated 200 million people rely on water sources with F above the WHO limit of 1500 μg/L, (Kimambo et al, 2019).…”

“…Asian countries with high ground-and surface water F concentrations include India, China, Korea, Thailand, Sri Lanka, Indonesia, Yemen, Pakistan, Iraq, Turkey, Syria, Jordan, Palestine, Bangladesh, Iran, and Saudi Arabia (Biglari et al, 2016;Kimambo et al, 2019;Mumtaz et al, 2015). Though the origin of As and F in drinking water is mostly geological, there is some evidence that prolonged droughts increase the concentration of these contaminants (Ali et al, 2019;Dehbandi et al, 2019;Podgorski et al, 2018;Reyes-Gómez et al, 2015).…”

“…This volcanism relates to the subduction and detachment of the Farallon Plate, which also resulted in the development of grabens and half-grabens to the east. Volcanic emissions, volcanic ash and volcanic glass from other sites (e.g., the Andes mountains, Mount Etna, the (Bhattacharya et al, 2016;Ferrari et al, 2002) have been shown to contain large amounts of As and F (Alvarez and Carol, 2019;Kimambo et al, 2019;Mukherjee et al, 2014). Attempts to pinpoint geologic sources of As and F in Mexico include work by (Armienta and Segovia, 2008;Carrillo-Rivera et al, 2002;Reyes-Gómez et al, 2015).…”

“…Safe and readily available drinking water is an essential requirement for public health that concerns every country in the world (World Health Organization (WHO) and the United Nations Children's Fund (UNICEF), 2017). Arsenic (As) and fluoride (F) are contaminants present in many drinking water sources worldwide, and pose one of the greatest inorganic threats to public health (Kimambo et al, 2019). These elements, which generally occur naturally, are most often found in groundwater and therefore disproportionately affect countries that rely heavily on groundwater for irrigation and drinking.…”