Using Isomeric and Metabolic Ratios of DDT To Identify the Sources and Fate of DDT in Chinese Agricultural Topsoil.
Environ Sci Technol
; 52(4): 1990-1996, 2018 02 20.
Article
em En
| MEDLINE
| ID: mdl-29345919
ABSTRACT
The metabolic ratio of (p,p'-DDE + p,p'-DDD)/p,p'-DDT or p,p'-DDE/p,p'-DDT has been used previously to estimate the approximate half-life of p,p'-DDT, with a relatively unclear concept of "old" and "new" sources of p,p'-DDT and without paying attention to the influence by dicofol-type DDT contributed from the more recent usage of dicofol. Based on the isomeric ratio of o,p'-DDT/p,p'-DDT to distinguish the sources of DDT, this study used the corrected metabolic ratio of (p,p'-DDE + p,p'-DDD)/p,p'-DDT to estimate a more accurate half-life of p,p'-DDT using a model-based approach. This indicates the average half-life of p,p'-DDT in Chinese topsoils was 14.2 ± 0.9 years with dicofol-type DDT input considered. In deeper soil, the half-life was >30 years and the metabolic pathway of p,p'-DDT was significantly different with topsoil's. Further analysis on the fraction of DDT from technical DDT suggested that a region that had been sprayed with technical DDT was likely to have been sprayed with dicofol as well, but the monitoring residues of DDT in topsoil mainly derive from historical use of technical DDT.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Monitoramento Ambiental
/
DDT
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article