title: Comparative developmental toxicity of new aromatic halogenated DBPs in a chlorinated saline sewage effluent to the marine polychaete Platynereis dumerilii.
abstract: Using seawater for toilet flushing may introduce high levels of bromide and iodide into a city's sewage treatment works, and result in the formation of brominated and iodinated disinfection byproducts (DBPs) during chlorination to disinfect sewage effluents. In a previous study, the authors' group has detected the presence of many brominated DBPs and identified five new aromatic brominated DBPs in chlorinated saline sewage effluents. The presence of brominated DBPs in chlorinated saline effluents may pose adverse implications for marine ecology. In this study, besides the detection and identification of another seven new aromatic halogenated DBPs in a chlorinated saline sewage effluent, their developmental toxicity was evaluated using the marine polychaete Platynereis dumerilii. For comparison, the developmental toxicity of some commonly known halogenated DBPs was also examined. The rank order of the developmental toxicity of 20 halogenated DBPs was 2,5-dibromohydroquinone > 2,6-diiodo-4-nitrophenol ≥ 2,4,6-triiodophenol > 4-bromo-2-chlorophenol ≥ 4-bromophenol > 2,4-dibromophenol ≥ 2,6-dibromo-4-nitrophenol > 2-bromo-4-chlorophenol > 2,6-dichloro-4-nitrophenol > 2,4-dichlorophenol > 2,4,6-tribromophenol > 3,5-dibromo-4-hydroxybenzaldehyde > bromoform ≥ 2,4,6-trichlorophenol > 2,6-dibromophenol > 2,6-dichlorophenol > iodoacetic acid ≥ tribromoacetic acid > bromoacetic acid > chloroacetic acid. On the basis of developmental toxicity data, a quantitative structure-activity relationship (QSAR) was established. The QSAR involved two physical-chemical property descriptors (log P and pKa) and two electronic descriptors (the lowest unoccupied molecular orbital energy and the highest occupied molecular orbital energy) to indicate the transport, biouptake, and biointeraction of these DBPs. It can well predict the developmental toxicity of most of the DBPs tested.
authors.affiliation: Environmental Engineering Program, Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology , Hong Kong SAR, China.
authors.forename: Mengting
authors.initials: M
authors.lastname: Yang
authors.forename: Xiangru
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000085:Acetates / Q000032:analysis / Q000633:toxicity*; D000818:Animals; D001966:Bromine / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry; D004203:Disinfection; D004625:Embryo, Nonmammalian / Q000187:drug effects; D047108:Embryonic Development / Q000187:drug effects; D054879:Halogenation; D010636:Phenols / Q000032:analysis / Q000633:toxicity*; D011077:Polychaeta / Q000187:drug effects* / Q000254:growth & development; D021281:Quantitative Structure-Activity Relationship; D054712:Salinity; D012722:Sewage / Q000009:adverse effects* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification
chemical_list: D000085:Acetates; D010636:Phenols; D012722:Sewage; D014874:Water Pollutants, Chemical; D002713:Chlorine; D001966:Bromine