2,2-bis(4-Chlorophenyl)Acetic Acid (DDA), a Water-Soluble Urine Biomarker of DDT Metabolism in Humans

Abstract

DDT metabolism in humans yields DDA as the principal urinary metabolite and potential exposure biomarker. A method for DDA analysis in human urine was developed using pentafluorobenzyl bromide and diisopropylethyl amine. Dried hexane extracts were reacted for 1 hour at room temperature. The stable DDA-pentafluorobenzyl-ester derivative was analyzed by gas chromatography-electron capture detector (GC-ECD) and confirmed by gas chromatography-mass spectrometry (GC-MS) in selective ion monitoring mode. The limit of detection for DDA was 0.1 microg/L urine by GC-ECD and 2 microg/L urine by GC-MS, with a relative standard deviation of 12%. Urine specimens from DDT applicators in Swaziland and South Africa were analyzed to evaluate the method. The mean DDA levels during the spray season and post season were 59 and 11 microg/L, respectively. These results must be interpreted cautiously because different groups of workers provided urine specimens in each case. The DDA urinalysis may be a feasible monitoring strategy for low-level occupational and residential DDT exposure assessment in antimalaria campaigns.

Association between Lung Function in Adults and Plasma DDT and DDE Levels: Results from the Canadian Health Measures Survey

“…DDT can naturally break down into DDE [1,1-bis-(4-chlorophenyl)-2,2-dichloroethene] and DDD [1,1-dichloro-2,2-bis( p -chlorophenyl)ethane] through photolysis and microbial biodegradation [ Agency for Toxic Substances and Disease Registry (ATSDR) 2002 ]. In humans, DDT can be either oxidized or reduced by cytochrome P450 enzymes (CYP450) to form DDE or DDD ( Chen et al 2009 ). DDE can further undergo epoxidation and phase 2 metabolism, and DDD can be further oxidized to DDA [2,2-bis(4-chlorophenyl)acetic acid] ( Chen et al 2009 ).…”

Exposure and health risk assessment of applicators to DDT during indoor residual spraying in malaria vector control program

“…Based on the 0.4% recovery/excretion, 99.6% of this total absorbed dose (75.298 mg/kg bw) remains in the body of the applicators. It was also noted that the excretion of DDA in urine was reduced during post application time (Chen et al, 2009). This shows that high amount of DDT remains in the body of applicators resulting in unacceptable health risk level.…”

“…This indicates how much the exposure can be during spraying of 15 houses per day for 36 days of spraying programme. For example, in an experimental study done on volunteers by Chen et al (2009), at lower dosage, 0.4% of the administered DDT dose was recovered as DDA from urine. The calculated 75 th percentile total absorbed dose at 1.8% dermal absorption rate during spraying of 36 days is 75.6 mg/kg bw at steady state.…”

“…Data on the systemic concentration of DDT and its metabolites in men and women from studies done in South Africa and in other countries suggest that IRS can result in high DDT exposure in humans (Eskenazi et al, 2009;Chen et al, 2009). Consequently, the applicators of IRS might be experiencing or may experience in the future the health risks of DDT (Aneck-Hahn et al, 2007;Rignell-Hydbom et al, 2009;Van den Berg, 2009).…”

Occurrences and fate of DDT principal isomers/metabolites, DDA, and o,p'-DDD enantiomers in fish, sediment and water at a DDT-impacted superfund site

“…Nevertheless, DDA may be important: for example, it has been shown to leach more readily than other congeners into groundwater wells that are sources of drinking water (Dunnbier et al, 1997). In addition, it may serve as a water-soluble urine biomarker of DDT metabolism in humans and DDA urinalysis may serve as a monitoring strategy for low-level DDT exposure (Chen et al, 2009).…”