Common chemicals can cause reproductive abnormalities

Common household chemicals and widespread pollutants can cause developmental abnormalities, increase cancer rates, and affect reproductive health in men, says Rao Veeramachaneni, CSU biomedical sciences professor, who reported his findings after 15 years of research.

Insecticides, pesticides, ground water pollutants, chemicals in plastics, make-up, and nail polish cause such developmental abnormalities in males as hypospadias (a birth defect of the urethra) and cryptorchidism (undescended testicles), says Veeramachaneni. These birth defects now affect almost one in 100 males born, a marked twofold increase in the last 25 to 30 years, according to the Centers for Disease Control and Prevention.

Lasting damage

The chemicals also impair sperm quality, contribute to impotence, and compromise reproductive health in males, the research found. Sperm counts have decreased from the 1940s, when chemicals were first widely produced, to the 1990s, a decline of 1.15 percent per year, according to the research.

Some chemicals can survive in the environment for 30 to 40 years. "Exposure to these chemicals, particularly during certain windows of time during fetal development in newborns or as adolescents, can do permanent damage," says Veeramachaneni.

The incidence of testicular cancer in young men 15 to 35 years old has increased three- to four-fold over the past 50 years, particularly in the Western world.

Humans to horses to frogs

Phthalates — chemical compounds used in cosmetics, upholstery, pharmaceuticals, and medical tubing and also present in drinking water and air — have been found in the urine, blood, and breast milk (which can readily be passed on to an infant) of people who have been exposed.

The research findings cross species lines. Veeramachaneni's lab found that exposing tadpoles to dibutyl phthalate drastically slows their growth and reproductive development. At varying doses, tadpoles lagged weeks behind non-exposed frogs in developing legs and entering adulthood. More significant, frogs exposed to the chemicals had mating calls that were weaker and shorter (the larynx was significantly underdeveloped), ultimately affecting their ability to reproduce.

DDT and other pesticides and herbicides have been linked to testicular cancer in humans and animals. Veeramachaneni found cases of testicular cancer in wildlife in Africa, potentially tied to the increasing renewed use of DDT to fight malaria-carrying mosquitoes. His research showed that DDT causes precancerous and cancerous lesions in the testes of infertile domestic horses and wild deer.

Erectile dysfunction, reported in one-third of the U.S. male population, is also linked to chemicals in the environment. Vinclozolin, a fungicide commonly used in agriculture, can contaminate food and water supplies. In laboratory tests, some male offspring of animals exposed to vinclozolin during pregnancy displayed a complete lack of interest in females.