Seasonal change of PCDDs/PCDFs/DL-PCBs in the water of Ayase River, Japan: Pollution sources and their contributions to TEQ

► The water samples of Ayase River were collected once per month for a year. ► The dioxin TEQ of the water was higher during the irrigation period. ► The source apportionment on TEQ was performed by using indicative congeners. ► The main TEQ contributors in the irrigation period were impurities of h...

Full description

Saved in:
Bibliographic Details
Published in:Chemosphere (Oxford) 2011-09, Vol.85 (2), p.188-194
Main Authors: Minomo, Kotaro, Ohtsuka, Nobutoshi, Hosono, Shigeo, Nojiri, Kiyoshi, Kawamura, Kiyoshi
Format: Article
Language:English
Subjects:
Applied sciences
Benzofurans - analysis
Chlornitrofen
Congeners
Continental surface waters
Dibenzofurans, Polychlorinated
Dioxins
Dioxins - analysis
Earth sciences
Earth, ocean, space
Engineering and environment geology. Geothermics
Equivalence
Exact sciences and technology
Formulations
Fresh Water - chemistry
Freshwater
Herbicides
Herbicides - analysis
Indicative congener
Irrigation
Japan
Natural water pollution
Paddy field
Pentachlorophenol
Pentachlorophenol - analysis
Phenyl Ethers - analysis
Pollution
Pollution abatement
Pollution, environment geology
Polychlorinated Biphenyls - analysis
Polychlorinated Dibenzodioxins - analogs & derivatives
Rivers
Source apportionment
Water Pollutants, Chemical - analysis
Water Pollution
Water treatment and pollution
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:► The water samples of Ayase River were collected once per month for a year. ► The dioxin TEQ of the water was higher during the irrigation period. ► The source apportionment on TEQ was performed by using indicative congeners. ► The main TEQ contributors in the irrigation period were impurities of herbicides. ► The herbicides-originated dioxins ran off from paddy fields and polluted the river. In Japan, Ayase River is one of the most polluted rivers by PCDDs, PCDFs and dioxin-like PCBs, which are referred to as dioxins in this paper. The water samples of the river were collected once per month for a year, and dioxins were analyzed to examine the dioxin sources and their contributions to toxic equivalent (TEQ). The WHO-2006 TEQs ranged from 0.26 to 7.0 pg-TEQ L −1 and the average was 2.7 pg-TEQ L −1; eight of 12 samples exceeded the environmental quality standard in Japan (1.0 pg-TEQ L −1). The TEQ value was high during the irrigation period from May to August. The most part of the dioxins in the river water existed in suspended solids (SS) and it seemed that the river received water with highly-dioxin-contaminated SS in the irrigation period. The homologue profiles of the water samples suggested that the dioxins were influenced by pentachlorophenol (PCP) and chlornitrofen (CNP) formulations which were widely used as herbicides for the paddy fields in Japan. According to TEQ apportionment estimated by using indicative congeners, the TEQ was mainly contributed by PCP. Moreover, it was also shown that the TEQ contributions of PCP and CNP formulations increased along with the increase of the total TEQ and the TEQ contribution was dominated by these herbicides during the irrigation period. Therefore, it was concluded that the herbicides-originated dioxins run off from the paddy fields into the river during the irrigation period and increased the dioxins level in the river water. The result from the principal component analysis was consistent with these conclusions.
ISSN:0045-6535
1879-1298
DOI:10.1016/j.chemosphere.2011.06.033