Public Health Implications of Bromate in Botled Water 01

IntroductionBottled water containing bromate up to two-and-a-half times the level considered safe by the US Food and Drug Administration has been detected and removed from shelves in some supermarkets in the US. It is believed that long term exposure to bromate may increase the risk of cancer in susceptible individuals. These include women of child bearing age, young children, pregnant, immunocompromised persons and aged individuals. How is bromate formed in bottled water?Bromide is a normal constituent of bottled water. Depending on the source of water the level of bromide may fluctuate,

that is, will be higher or lower depending on where it is found. Bromate is formed when bromide ions and ozone react together. The level of bromate that may form in water depends on the concentration of bromide in the source water, the amount of ozone contact time, and a variety of water chemistry factors including pH, organic material, hardness and alkalinity.Ozone is often used as a disinfectant for mineral water and the presence of bromide and ozone in bottled water makes this combination a public health concern. Ozonation is one aspect of a multi-barrier approach used to help ensure the safety and quality of bottled water products. Ozonation is often preferred over chlorination to disinfect water because it does not leave a residual taste, color or odor in the water. While chlorination is primarily used for disinfection in public water systems in the U.S., a number of U.S. public water systems use ozone.

Ozonation has been used extensively for disinfection of public water utilities in Europe and the USA for many years.What are the health effects?There is very little or no actual convincing evidence to suggest that exposure to bromate in drinking water presents a health risk to humans. Despite the lack of sufficient studies to detect any adverse health effect in humans, animal studies prove differently. Potassium bromate when administered in drinking water to rats induced a dose-related increase in cancerous as well as non cancerous kidney cell tumors, thyroid and peritoneal mesotheliomas. Bromate gave largely negative results in bacterial mutagenicity tests, whereas positive results were obtained for clastogenic effects and DNA damage in all in vivo tests to date. Bromate has therefore been classified as probably carcinogenic to humans because of sufficient evidence in animals, but little or insufficient data in humans. Cancer risks have been estimated on the basis of renal cell tumors from two bioassays: one conducted in male and female F344 rats, and a second conducted at a lower range of doses in the same laboratory on males only.