Currently, allowable levels of bromate in drinking water are 10 micrograms per liter. The US EPA and WHO are considering lowering this limit. Under certain conditions, bromate may be formed when drinking water with bromide ion content is ozonated. Technologies exist to prevent or mitigate this formation, but question have been raised as to whether bromate actually poses a human health risk.
The critical question is whether low level exposure to bromate creates a cancer risk. The Ammerican Water Works Association Research Foundation (AWWARF) decided to investigate the health impact of bromate. The research was lead by Dr. Joseph Cotruvo and Dr. Gill Gordon. It was funded by a consortium of water utilities, universities and the International Ozone Association. The project is ongoing, but preliminary results have been reported at meetings in Berlin and Tokyo.
The research looked at exposure to environmentally realistic levels of bromate and the potential for detoxification in the human body prior to the target organ of concern, the kidney. The studies showed that bromate is rapidly broken down in the body after ingestion. Bromate removal occurs in the stomach, liver and in teh blood. The dose response at low broamte doses was found to be sub linear. This implies that the previous risk studies over estimated the bromate cancer risk.
Completion of the research and modeling should show that because the previous studies did not take into account the detoxification of bromate or DNA repair, that the previous risk assessments upon which the current regulations are based over estimate the risk of cancer from low level bromate exposure in drinking water.
The research is ongoing and additional sponsors are being sought to complete the research.