Bromine and water quality – Selected aspects and future perspectives

Bromine is a microelement present in waters, both in inorganic and in a wide range of organic compounds, though at lower concentrations. Typically, concentrations of organobromine compounds in waters are several orders of magnitude lower than of bromides. Two issues are addressed in the paper: the influence of bromides on the quality of treated waters and organobromines as contaminants of natural waters. Bromide presence in treated water gives rise to formation of potentially mutagenic disinfection by-products (DBPs). Registered amounts of DBPs in potable waters, exceeding the admissible levels, and the published data on DBPs in waters used for leisure and recreation activities, clearly indicate the health risk. Major sources are identified and registered concentrations of EDB, DBCB, methyl bromide, bromacil and PBDEs in the aquatic environment are summarized. The effects of bromide on DBPs formation and numerous examples of organobromine contamination of the aquatic environment indicate that the presence of bromides and organobromine compounds in the aquatic environment will have to be given more consideration, for several reasons. Firstly, larger amounts of bromide are present in saline and contaminated waters and the proportion of such waters being handled is increasing. Similarly, the processes of water purification, treatment and disinfection are now playing a major role. Secondly, emissions from manufacturing of bromine-containing materials growing, due to, inter alia, intensive development of the electronic industry and the plastic manufacturing sector. Thirdly, bromine compounds are also used as medicine ingredients. There is now a growing awareness of the presence of pharmaceuticals in the aquatic environment. Fourth, low bromide concentrations in hypergene zones may be modified in the future, partly because of the climate changes, which may give rise to difficulties with water treatment systems.Water quality standards having relevance to water used for consumption are based only on the best-known (most widespread) DBPs. However new more restrictive legal regulations relating to the use of bromine compounds have been put in place prohibiting the use of certain bromine-based substances or restricting their amount in finished products. In the light of current legislation, the monitoring of water contamination with potentially toxic, mutagenic and endocrine-disrupting organobromine compounds is still unsatisfactory because newly discovered compounds are not included and certain factors governing the exposure to those substances are still left out.The effects of bromine (bromide and organobromine compounds) on water quality have been investigated by researchers from several fields of expertise. The water management authorities ought to make use of the available research data and identify the problems which need to be addressed directly and those which may emerge in the future.