Determination of radon concentration and heavy metals (Ni, Pb, Cd, As, Cr) in drinking and irrigated water sampled from Kulim, Malaysia

Background: The presence of heavy metals and radon in water are considered as a potential threat to public health. Modern day industrialization has led to increase pollutants in ecosystem whilst the main source of public radiation exposure, especially exposure from radon, is caused by portable water. This study aimed to estimate the health risk related to radon concentration and heavy metals in drinking and irrigated water. Materials and Methods: Water samples, from different sources, were collected from Kulim, Malaysia and analyzed for radon and heavy metals using RAD7 and Atomic Absorption Spectrometry. Results: Results showed that the maximum average value of radon concentration (16.06 +/- 1.7) Bq/l was found in well water used for drinking and irrigation. Minimum average value of radon concentration (2.65 +/- 0.33) Bq/l was found in tap water used for drinking purpose. From the measured radon concentrations, age dependent associated annual effective doses and contribution of radon in drinking water to indoor air was calculated which were found below the lower limit of recommended action level. Metal concentrations were found higher in stream and lake waters used for irrigation, compared to well and tap waters. The average daily intake of drinking water and health risk indices were found higher for infants and lower for children and adults. Conclusion: Radon concentrations in well, stream and lake waters were found higher than EPA recommended level and lower than WHO action level while the annual effective doses and level of heavy metals in water reported in this study were found lower than recommended levels.