Program and Abstracts: The Seventeenth Conference of the International Society for Environmental Epidemiology (ISEE): Abstracts
Hypospadias and cryptorchidism are relatively common male urogenital anomalies, but seem to be on the increase in some populations (Paulozzi 1999). Early exposure to endocrine disrupting chemicals in the environment appear to be at least partly responsible (Sharpe and Skakkebaek 1993; Toppari et al. 1996). This suggestion is supported by higher rates of urogenital anomalies, including cryptorchidism, in studies of sons exposed in utero to diethylstilbestrol, a potent estrogenic chemical (Cosgrove et al. 1977; Gill et al. 1979). p,p′-Dichlorodiphenyldichloroethylene (DDE), the persistent metabolite of p,p′-dichlorodiphenyl-trichloroethane (DDT), acts both as an androgen receptor antagonist and inhibitor of testosterone (Danzo 1997; Kelce et al. 1995). Adverse reproductive system effects associated with in utero DDT or DDE exposure in male animals include, amongst others, abnormal development of ovarian tissue (Fry and Toone 1981), reduced penis size (Guillette and Guillette 1996), hypospadias (Gray et al. 2001) and cryptorchidism (Facemire et al. 1995; Gray et al. 2001).
This study addresses the hypothesis that neonates in a high-risk malaria area have high DDE levels and an increased prevalence of urogenital birth defects.
A cross-sectional study was conducted among 45 pregnant women admitted to the labour ward at Tshilidzini Hospital, a public hospital 3 km outside the DDT- sprayed area in Limpopo Province. The population is an economically and ethnically homogenous remote rural population. Maternal and cord blood samples were collected for DDT and metabolite measurements. From May to November 2004, two trained professional nurses screened 2086 neonates for congenital anomalies. Anomalies were coded as definite only if confirmed by a paediatrician or a Genetics Nursing Specialist.
The maternal (n=42) mean, median and range for p,pDDE were 24.75, 3.19, 0.14 to 419.91 μg/g lipid respectively. In neonates (n=45) these values were 5.2, 1.14 and 0.03–29.82 μg/g lipid. In 2010 newborns (96.35%) no external urogenital birth defects were observed. However, in 76 (3.65%) babies abnormalities were found, of which ambiguous genitalia in 18 (0.86%) newborns raised particular concern.
The concordant high prevalence of urogenital birth defects and the DDE concentrations in cord blood in neonates from a DDT-sprayed area should be regarded as a matter of extreme international concern.