Sperm chromatin integrity in DDT-exposed young men living in a malaria area in the Limpopo Province, South Africa

BACKGROUNDThere is mounting evidence that deteriorated semen quality may be associated with increased serum concentration of 1,1,1-trichloro-2,2- bis(chlorodiphenyl)ethane (DDT) and its metabolites. The problem is exacerbated in situations where DDT is the only resource available to control malaria mosquitoes and DDT metabolite plasma concentration can reach 1000-fold the level found in other populations. There are limited and contradictory epidemiological data on whether DDT/dichlorodiphenyl-dichloroethylene (DDE) can also damage sperm DNA. Therefore, there is a need to investigate the possible adverse effects on human sperm genetic integrity in a sufficiently large study population with adequate exposure contrasts, especially in the high exposure range.METHODSWe conducted a cross-sectional study, recruiting 209 young males from three communities in an endemic malaria area where DDT is sprayed annually. Blood plasma p,p′-DDT and its metabolite p,p′-DDE levels were measured and expressed as lipid adjusted p,p′-DDT and p,p′-DDE values. The sperm chromatin structure assay and Aniline Blue test were used to assess sperm DNA/chromatin integrity.RESULTSThe lipid adjusted p,p′-DDT mean (±SD) and median concentrations were 109.2 (±106.6) and 83.9 g/g, respectively; and the lipid adjusted p,p′-DDE mean (±SD) and median concentrations were 246.2 (±218.5) and 177.8 g/g, respectively. The results point to a weak association between DDT/DDE plasma concentration and the incidence of sperm with chromatin defects.CONCLUSIONSThe results suggest that non-occupational environmental DDT exposure may have a negative impact on sperm chromatin integrity in young South African males.