Possible endocrine disruption in molluscs from the Limpopo Province / Ignatius Michael Viljoen

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dc.contributor.author Viljoen, Ignatius Michael en_US
dc.date.accessioned 2011-08-26T12:24:37Z
dc.date.available 2011-08-26T12:24:37Z
dc.date.issued 2010 en_US
dc.identifier.uri http://hdl.handle.net/10394/4510
dc.description Thesis (M.Sc (Environmental Science))--North-West University, Potchefstroom Campus, 2011.
dc.description.abstract With parts of SA in a malaria endemic area, a preventative way of fighting malaria is with the use of pesticides such as 1,1,1–Trichloro–2,2–bis(pclorophenyl) ethane, also known as DDT. DDT is listed under the persistent organic pollutants (POPs) and considered an endocrine disruptive compound (EDC) under the Stockholm Convention. SA registered an exemption to use DDT as means to fight malaria. DDT and its isomers are, however, known EDCs. Combined with their ability to persist in the environment while not being target specific motivates further studies into possible detrimental effects. The present study aimed to establish if ED was present by comparing the male reproductive organs from snails from an area currently sprayed with DDT (for malaria control) to an area not sprayed with DDT in the Limpopo Province. A possible endpoint (the penis sheath/preputium length ratio or PSPLR) was identified for the freshwater snail Bulinus tropicus. B. tropicus and sediment samples were collected from DDT–sprayed and nonsprayed areas located close together. The snails were dissected and various morphometric parameters measured. Sediments from the sites where the snails were collected were analysed for DDT using GC–MS. Statistical analysis showed significant differences in PSPLR (and therefore possible ED) between snails from the two areas. The difference in PSPLR values was mainly due to a relatively shorter preputium for the snails from the DDT–sprayed area. Even though the sediment samples showed that DDT was present in most of the DDT–sprayed sites and not in the non–DDT sprayed sites, causality of the possible ED could not be established from this field study. This study indicated the possibility of using the PSPLR as endpoint for ED. Recommendations are made for further development of the PSPLR and B. tropicus as biological indicators for endocrine disruption, but causality must first be established. en_US
dc.publisher North-West University
dc.subject Persistent organic pollutants en_US
dc.subject Mollusc en_US
dc.subject Endocrine disruption en_US
dc.subject Endocrine system en_US
dc.subject DDT en_US
dc.subject Limpopo Province en_US
dc.subject Morphometrics en_US
dc.subject Penis sheath en_US
dc.subject Preputium en_US
dc.subject Malaria control en_US
dc.subject Persisterende organiese besoedelstowwe en_US
dc.subject Slak en_US
dc.subject Endokriene versteuring en_US
dc.subject Endokriene stelsel en_US
dc.subject Limpopo Provinsie en_US
dc.subject Morfometriese afmetings en_US
dc.subject Penis skede en_US
dc.subject Malaria beheer en_US
dc.title Possible endocrine disruption in molluscs from the Limpopo Province / Ignatius Michael Viljoen en_US
dc.type Thesis en_US
dc.description.thesistype Masters en_US

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