title: Cesium-137 in the Goiânia waterways during and after the radiological accident.
abstract: The main contamination areas in Goiânia were exposed soil surfaces, and with the first rainfalls, 137Cs quickly reached the Meia-Ponte River, the main local waterway. Regular measurements of bottom sediment, surface water, and fish were begun 3 wk after the accident. In the first survey, 137Cs was detectable in sediments up to 12 km downstream from the accident area. Maximum 137Cs concentrations found in sediments of the Meia-Ponte River were 1.3 kBq kg-1 dry weight and 200 Bq kg-1 fresh weight for fish. Cesium-137 was always less than 10 Bq L-1 in surface waters plus suspended particulates, even in the most contaminated creeks. Because it was the beginning of the rainy season, downstream sediment transport was enhanced. This resulted in a decrease of 137Cs concentrations in sediments of the urban area by a factor of approximately 20, 5 wk after the accident. The main sedimentation area for suspended sediments in this portion of the river is the Rochedo Reservoir, which is 80 km downstream from the accident area. In a survey performed 10 mo after the accident, 137Cs concentrations in the reservoir were up to 14 Bq kg-1 for fish, 1 Bq kg-1 for aquatic plants, and 100 Bq kg-1 dry weight for bottom sediments.
authors.affiliation: Instituto de Radioproteção e Dosimetria/CNEN, Rio de Janeiro, Brazil.
authors.forename: J M
authors.initials: JM
authors.lastname: Godoy
authors.forename: J R
authors.initials: JR
authors.lastname: Guimarães
authors.forename: J C
authors.initials: JC
authors.lastname: Pereira
authors.forename: M A
authors.initials: MA
authors.lastname: do Rio
mesh_terms: D000059:Accidents; D000818:Animals; D001938:Brazil; D002588:Cesium Radioisotopes; D005399:Fishes; D005507:Food Contamination, Radioactive / Q000032:analysis; D011867:Radioisotope Teletherapy / Q000295:instrumentation; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D014875:Water Pollutants, Radioactive