Exposure to organochlorine compounds at the aerly stages of DDT use for indoor residual spraying in domestic environments in Manhiça, Mozambique.

Manaca, Maria Nélia Joquim

Exposure to organochlorine compounds at the aerly stages of DDT use for indoor residual spraying in domestic environments in Manhiça, Mozambique.

Document Type

Doctoral thesis
Published Version

Author

Manaca, Maria Nélia Joquim

Director

Grimalt Obrador, Joan
Dobaño, Carlota

Publication Date

2011-09-27

Pages

171 p.

Citation

Manaca, M. Exposure to organochlorine compounds at the aerly stages of DDT use for indoor residual spraying in domestic environments in Manhiça, Mozambique.. Universitat Pompeu Fabra; 2011. handle: http://hdl.handle.net/10803/53062

This citation was generated automatically.

Doctoral program

Programa de doctorat en Biomedicina

Abstract

Past and present uses of DDT and pyrethroids have led to their incorporation into humans, mainly through the food chain and sometimes by direct exposure. The present work focuses on establishing the levels of DDT, its analogous compounds (DDE and DDD), and pyrethroids in humans and the human environment in Manhiça, a rural area where they have been used as insecticides for indoor residual spraying (IRS) and insecticide treated nets (ITN) in malaria control programs. Thatch samples from human dwellings, breast milk from pregnant women and cord blood from newborns were analyzed for assessment of the concentration levels of these compounds. The results showed that DDT and its analogues were already present in humans and dwellings before reintroduction of this insecticide for IRS. As consequence of these applications DDT concentrations increased significantly. The higher proportion of 4,4’-DDT than 4,4’-DDE evidenced that the observed amounts were due to recent applications of this insecticide. Concerning pyrethroids, their presence has been identified in both breast milk and human dwellings showing that both agricultural applications and use for ITN may be responsible for their occurrence in humans and human environments of Manhiça.
L’ús en el passat i en temps actuals del DDT i piretroides ha donat lloc a la seva incorporació en els humans, principalment mitjançant la cadena tròfica i a vegades per exposició directa. Aquest treball té com objectiu establir els nivells de DDT i els seus compostos anàlegs (DDE i DDD), i piretroides en humans i l’ambient humà a Manhiça, una àrea rural on aquests s’han utilitzat com insecticides per aplicació interna (indoor residual spraying, IRS) i tractament de xarxes de protección (insecticide treated nets, ITN) en programes de control de la malària. Per a esbrinar els nivells de concentració d’aquests compostos s’analitzaren mostres de palla de cabanes, de llet materna i de sang de cordó de nou nats. Els resultats mostraren que el DDT i els seus compostos anàlegs ja eren presents en humans i cabanes abans de la reintroducció d’aquest insecticida per IRS. L’ús del DDT en aquest programa féu augmentar considerablement les concentracions d’aquest insecticida. La major proporció de 4,4’-DDT que 4,4’-DDE posà de manifest que les quantitats observades corresponien a aplicacions recents d’aquest insecticida. Respecte als piretroides, s’han trobat en mostres de llet materna i cabanes tot mostrant que tant les aplicacions agrícoles com el seu ús en ITN poder esser la causa de la seva presència en els humans i els ambients humans de Manhiça.

Keywords

DDT, Pyrethroids, Indoor Residual Spraying, Malaria Vector Control, Thatch, Umbilical cord, Mozambique, Pulveritzaciò Residual Intradomiciliaria, Control del Vector de la Malària, Llet Materna