Exposure to Strontium through Drinking Water used in the Preparation of Foods
Citation:
Melnyk, L., M. Donohue, M. Pham, AND J. Donohue. Exposure to Strontium through Drinking Water used in the Preparation of Foods. ISES-ISEE 2018, Ottawa, CANADA, August 26 - 30, 2018.
Impact/Purpose:
Presentation at the 2018 ISES-ISEE Annual Meeting
Description:
Strontium (Sr) is a natural element, ubiquitous in the environment and known to occur in water, food, air, and soils. Strontium is present in media as a salt or an ionized divalent cation. The Sr ion (dissociated) is toxicokinetically important because this form is easily absorbed into systemic circulation when inhaled as particulates or ingested with water or foods. Identifying all routes of exposure to Sr is important for determining the relative source contribution (RSC) used when deriving a regulatory or advisory value applicable to local public drinking water sources. The RSC analysis is conducted to compare the estimated Sr exposure expected in the general population from drinking water to exposure from intake of Sr in other media, including food. The EPA’s Office of Water has an interest in the RSC of Sr because some systems are finding levels exceeding 60 mg/L. The impact of not only drinking water containing high levels of Sr directly, but also using the water for food preparation, is important to accurately determine an appropriate RSC. Research to determine the amount of Sr transferred from contaminated drinking water to individual foods during preparation was conducted. Strontium transferred to broccoli, lentils, and spaghetti at all levels tested (1.5, 10, and 50 mg/L) as evidenced by the residual Sr in the pour-off water following food preparation (33 – 64%). The data from the cooking study support the hypothesis that cooking of foods with water containing Sr adds to the total dietary Sr and should be considered as part of the food in the dietary component of the RSC analysis. An accurate RSC analysis will support a more comprehensive understanding of the contribution of the local water to dietary intakes because of food preparation practices. This project demonstrates the linkage between research, policy, and decision making when developing health-based guidelines applicable to contaminants present in tap water from public systems.
