title: Serum DDT and DDE levels in Singapore general population.
abstract: A simple and fast method was used to determine 1,1'-(2,2,2-trichloroethylene)-bis(4-chlorobenzene) (DDT) and 1,1'-(2,2-dichloroethylidene)-bis(4-chlorobenzene) (DDE) in blood serum. Serum samples pre-treated with formic acid were extracted with n-hexane and determined by gas chromatography (GC-ECD), using PTE-5 capillary column. Detection limits for DDT and DDE were 0.5 ppb. Recovery with a fortified pooled sample at 1 ppb level was 107.0% for DDT and 106.0% for DDE. At 10 ppb level, the recoveries for DDT and DDE were 96.1% and 92.7%, respectively. Eighty-nine random blood samples collected from volunteers were analyzed. The geometric mean (GM) serum level of DDT was 1.9 ppb (0.2-8.9 ppb) and that of DDE was 10.8 ppb (1.5-88.1 ppb). There was a positive correlation between DDE and DDT level (r = 0.33, P < 0.01). The serum DDE level was positively correlated with age (r = 0.49, P < 0.01) and DDT x Age (r = 0.62, P < 0.01). No correlation was observed between DDT and age. These results suggest that DDE, a metabolite of DDT, is cumulative in the body. Therefore blood DDE could be used as a cumulative exposure marker for DDT, whereas blood DDT may be used to reflect its recent exposure.
authors.affiliation: Department of Community, Occupational and Family Medicine, Faculty of Medicine, National University of Singapore, Singapore.
authors.forename: X W
authors.initials: XW
authors.lastname: Luo
authors.forename: S C
authors.initials: SC
authors.lastname: Foo
authors.forename: H Y
authors.initials: HY
authors.lastname: Ong
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002849:Chromatography, Gas; D003634:DDT / Q000097:blood* / Q000493:pharmacokinetics; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood* / Q000493:pharmacokinetics; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D007306:Insecticides / Q000097:blood* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D012846:Singapore
chemical_list: D007306:Insecticides; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT