Child Research

Solvent Exposure, Sperm Abnormalities, and Birth Defects

Human exposures and human health effects

Birth Defects of the Penis and Testicles Rising in Europe, the U.S. and Japan

SOLVENT EXPOSURE, SPERM ABNORMALITIES, AND BIRTH DEFECTS

Two recent studies, one looking at the relationship between occupational exposure to organic solvents (such as benzene, toluene, and xylene) and sperm quality, and the other studying pregnant women occupationally exposed to organic solvents and resultant birth defects found positive associations. In the male study, men with poorer sperm quality were more likely to have been exposed to the solvents compared to men with normal sperm measures [exposure to pesticides and metals were not related to sperm quality]. For the study with females, exposed women were 13 times more likely to deliver a child with a major birth defect. Tielemans E et al. Occupationally related exposures and reduced semen quality: a case-control study. Fertility and Sterility 1999; 71(4): 690-696. Khattak S et al. Pregnancy outcome following gestational exposure to organic solvents. Journal of the American Medical Association 1999; 281(12): 1106-1109.

http://www.med.harvard.edu/chge/toxics11.html#solvent

Human exposures and human health effects

Reproductive Tract of the Female Adult
There is a higher degree of concern for ovarian toxicity in females, since a woman produces a limited number of ova within a lifetime. In comparison, a normal and healthy male has an unlimited supply of sperm. Lindane, tomoxophan and hexachlor are hormone disruptors that are ovarian toxins. Exposure to ovarian toxins results in death of ova and/or a decrease of ovarian production. Smoking is particularily hazardous to the female reproductive tract. With an increase in a half a package of cigarettes a day, menopause occurs one and a half years earlier. Thus, the fertility of a female is drastically reduced due to the toxins in cigarettes.

Ensenbach U, Nagel R. Toxicity of binary chemical mixtures: effects on reproduction of zebrafish (Brachydanio rerio). Arch Environ ContamToxicol 1997;32(2):204-10.
BIOSIS COPYRIGHT: BIOL ABS. A complete life-cycle test with zebrafish was carried out with different concentrations of the binary mixture 3,4-dichloroaniline and lindane under flow-through conditions. Length and weight of fish of the F1-generation were reduced, even in the lowest test concentration of 2 mug/L 3,4-dichloroaniline and 40 mug/L lindane. The same effects were found in the early life stage test for the F2-generation. In the mixture of 100 mug/L 3,4-dichloroaniline and 40 mug/L lindane, fish which were exposed for their whole life time stopped spawning, irreversibly; the fish population will become extinct. In an additional experiment, fish were exposed to the same xenobiotic concentrations after reaching maturity. In this case, egg production was reduced. Cessation of egg production occurs in a concentration of 200 mug/L 3,4-dichloroaniline and 40 mug/L lindane. Nevertheless, effects on spawning are influenced by duration of exposure and the life stages of exposure.

BIRTH DEFECTS OF THE PENIS AND TESTICLES RISING IN EUROPE, THE U.S., AND JAPAN

Paulozzi LJ. International trends in rates of hypospadias and cryptorchidism. Environmental Health Perspectives 1999; 107 (4): 297-302.

Data from the International Clearinghouse for Birth Defects Monitoring Systems on rates of cryptorchidism and hypospadias reveal trends in the diagnosis of these two defects over the past few decades. Marked increases in the diagnosis of hypospadias occurred in two American birth defects registries, and in Scandinavia and Japan, with some evidence of leveling-off after 1985. Increases in hypospadias were not seen in less affluent nations. Increases in cryptorchidism were only seen in two U.S. systems and in South America. It is not clear if these trends reflect increasing diagnosis and reporting of these male genital defects, or if there is a real increase. Both cryptorchidism and hypospadias reflect disruption of the normal maturation process of the male reproductive tract during a specific period of vulnerability during gestation. Estrogenic or anti-androgenic agents, including some environmental chemicals, can cause these defects in laboratory animals.

http://www.med.harvard.edu/chge/toxics11.html

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