A study revealed that toxic 'Forever Chemicals', known as perfluoroalkyl substances (PFAS), have been found in drinking water samples worldwide. Bottled water from various countries showed varying levels of PFAS. Perfluorooctanoic acid and perfluorooctane sulfonate were detected in over 99% of samples of bottled water sourced from 15 countries. PFAS are known to cause adverse health effects.