Fluoride is becoming more difficult to source due to the Iran war, which has strained global supply chains and has led some local governments to reduce their use of the widely used cavity-fighting agent. Two major water supply systems in Maryland, which serve the Baltimore and D.C. areas, have announced they are temporarily reducing the concentration of fluoride due to this. A Pennsylvania town also halted fluoridation for at least a few weeks. The shortage was caused by supply chain disruptions and higher transportation costs, according to chemical suppliers and trade groups. Israel is one of the major global suppliers of the chemical used in water systems, fluorosilicic acid, and the U.S. is currently the ninth top exporter of fluoride.