Geo-referenced multimedia environmental fate model (G-CIEMS): model formulation and comparison to the generic model and monitoring approaches.
A spatially resolved and geo-referenced dynamic multimedia environmental fate model, G-CIEMS (Grid-Catchment Integrated Environmental Modeling System) was developed on a geographical information system (GIS). The case study for Japan based on the air grid cells of 5 x 5 km resolution and catchments with an average area of 9.3 km2, which corresponds to about 40,000 air grid cells and 38,000 river segments/catchment polygons, were performed for dioxins, benzene, 1,3-butadiene, and di-(2-ethyhexyl)phthalate. The averaged concentration of the model and monitoring output were within a factor of 2-3 for all the media. Outputs from G-CIEMS and the generic model were essentially comparable when identical parameters were employed, whereas the G-CIEMS model gave explicit information of distribution of chemicals in the environment. Exposure-weighted averaged concentrations (EWAC) in air were calculated to estimate the exposure ofthe population, based on the results of generic, G-CIEMS, and monitoring approaches. The G-CIEMS approach showed significantly better agreement with the monitoring-derived EWAC than the generic model approach. Implication for the use of a geo-referenced modeling approach in the risk assessment scheme is discussed as a generic-spatial approach, which can be used to provide more accurate exposure estimation with distribution information, using generally available data sources for a wide range of chemicals.
Suzuki
Noriyuki
N
National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan. nsuzuki@nies.go.jp
Murasawa
Kaori
K
Sakurai
Takeo
T
Nansai
Keisuke
K
Matsuhashi
Keisuke
K
Moriguchi
Yuichi
Y
Tanabe
Kiyoshi
K
Nakasugi
Osami
O
Morita
Masatoshi
M
D001554:Benzene / Q000032:analysis; D002070:Butadienes / Q000032:analysis; D004147:Dioxins / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D007564:Japan; D008954:Models, Biological; D019212:Multimedia; D010795:Phthalic Acids / Q000032:analysis; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry
D002070:Butadienes; D004147:Dioxins; D010795:Phthalic Acids; C032279:phthalic acid; D001554:Benzene; C031763:1,3-butadiene