Abstract: One of the most important characterizations of social health is existence the availability of safe drinking water. Since, one of the sources of water contamination is nuclear contamination from radon gas so in this research radon 222 concentration levels in water supplies in the Toyserkan (a region located in the West of Iran) is investigated. For measuring radon gas in water wells and springs Lucas chamber method is used. Review the results of these measurements that taken from 15th place show that only five sites have radon concentrations above the limit dose. To reduce radon concentration, it is better to keep water in open pools in contact with air before the water is delivered to users.