title: Occurrence, distribution, and trends of volatile organic compounds in urban rivers and their estuaries in Osaka, Japan, 1993-2006.
abstract: Fifty-five volatile organic compounds (VOCs) in 738 water samples collected from 33 monitoring sites in the rivers of highly industrialized urban area in Osaka, Japan, 1993-2006 were analyzed. VOCs could be classified into three groups by the detection frequency and levels of mean concentrations detected. Firstly, for 30 compounds, almost all data were non detection or were around the detection limits. Secondly, for 11 compounds, higher values were occasionally observed at some sites. Thirdly, VOCs were ubiquitously found at relatively high or high levels. Spatial distributions of mean concentrations of the most ubiquitous VOCs throughout 13 years have shown exponentially decreasing trends towards the downstream direction of the rivers. Time series of mean concentrations of all sites of five solvents have shown monotonically downward trends. In contrast, three disinfection by-products and six gasoline compounds were not decreasing.
authors.affiliation: Osaka City Institute of Public Health and Environmental Sciences, 8-34 Tojo-cho, Tennoji-ku, Osaka, 543-0026, Japan, ko-yamamoto@city.osaka.lg.jp.
authors.forename: Kohji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D004784:Environmental Monitoring; D063366:Estuaries; D007564:Japan; D045483:Rivers / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D055549:Volatile Organic Compounds; D014874:Water Pollutants, Chemical