Why Lithium Toxicological Reference Values Are Needed for the General Population and Workers?

Lithium industry can generate a risk of airborne transport of substances, followed by a significant risk of deposition on soils and in water. It raises concerns about chronic low-dose exposure in the general population and occupational exposure among workers. Lithium exposure induces chronic toxicities on kidney, thyroid, heart, and effects on phosphate-calcium metabolism, reproduction and development. Current toxicological knowledge is largely derived from clinical data in patients under lithium treatment, but there is a critical lack of information on health effects associated with environmental exposure levels and on occupational exposures. The establishment of human biomonitoring guidance values (HBM-GVs) allows to aggregate all exposure routes for risk characterization related to real-life exposure. In 2026, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) together with the European Partnership for the Assessment of Risks from Chemicals (PARC) derived HBM-GVs in serum/plasma of 0.035 mg Li⁺.L^-1 for the general population and 0.10 mg Li⁺.L^-1 for workers, based on adverse effects observed at the minimum therapeutic lithium serum/plasma level of 0.5 mmol.L^-1. ANSES also established a long-term oral toxicological reference value of 0.02 mg Li⁺.kg bw^-1.day^-1. These values apply to lithium as element and all its inorganic compounds. These guidance values will allow the implementation of management measures.