Bulk atmospheric deposition of persistent toxic substances (PTS) along environmental gradients in Brazil.
Environ Sci Pollut Res Int
; 20(4): 2046-53, 2013 Apr.
Article
em En
| MEDLINE
| ID: mdl-22828922
Bulk atmospheric deposition measurements for selected persistent toxic substances (PTS) were performed along environment gradients (urban-suburban-rural-background sites) in Brazil. The aim with this work is to investigate the fate of PTS and their emissions in South America, particularly along environment transects. Bulk sampler systems (polyurethane foams, 1 × 1 m(2)) were fixed along environment gradients (urban-suburban-rural-background) over summer and winter periods (2005-2007) at sites of different climate zones of Brazil. Organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) were analyzed by gas chromatography coupled to electron capture detector (Shimadzu 2010, 20i GC-ECD). Urban sites reported the highest deposition rates for all PTS, ranging from tens to thousands of pictograms per square meter per day. Basically, there were no obvious seasonal differences in deposition rate concentrations for PTS along the urban-suburban-rural-background gradient. Dichlorodiphenyltrichloroethane (DDT) and its metabolites were the OCs most frequently detected at relatively high deposition rate levels (>1,000 pg m(-2) day(-1)). Other legacy and current-use pesticides such as hexachlorocyclohexanes, endosulfans, hexachlorcyclobenzine, dieldrin, aldrin, metoxichlor, and chlodanes were also detected at lower deposition rate levels (10-100 pg m(-2) day(-1)). PCBs were detected at extremely high deposition rate levels (1,000-10,000 pg m(-2) day(-1)) with highest contributions from the tetra-PCBs (PCB-52, PCB-44, PCB-66, PCB-81, and PCB-77) and penta-PCB congeners (PCB-101, PCB-105, PCB-114, PCB-118, and PCB-126). The greatest deposition rate concentrations for total PCBs were mainly detected at urban sites in connection with high population densities. The observed high deposition rate concentrations for PCBs and DDTs at urban sites are probably associated with old PTS stocks emissions. For PCBs in particular, the high levels are strongly associated with local population densities, highlighting the effect of local/regional urban sources on these target PTS. These results are important to show that even though the use of PTS is regulated, the deposition of selected PTS is still impacted by local and regional emissions in Brazil and may be related to the historical and continued emissions from old PTS stocks.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Resíduos de Praguicidas
/
Monitoramento Ambiental
/
Bifenilos Policlorados
/
Poluentes Atmosféricos
/
Poluição do Ar
/
Meio Ambiente
/
Hidrocarbonetos Clorados
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Environ Sci Pollut Res Int
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Alemanha