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March 2008

Laboratory Measures Cumulative Effect of Chemicals on Male Reproductive Systems

Common household chemicals and widespread pollutants are changing male reproductive health and impacting sexual function, development and cancer rates of today's generations and possibly their offspring, according to more than 15 years of research by a Colorado State University expert.

Dr. Rao VeeramachaneniDr. Rao Veeramachaneni, a Professor in the Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, has found that chemicals including insecticides; pesticides; common pollutants in ground water; and chemicals in plastics, make-up and nail polish are on a growing list of culprits causing developmental abnormalities such as hypospadias and cryptorchidism, impaired sperm quality and impotence. Reproductive health can be compromised if males are exposed at various times in life spanning from in utero up to adulthood.

Dr. Veeramachaneni's findings span the globe and cross species lines, including humans, horses, and frogs. His research, coupled with the collective findings of other experts in the field, indicates a strong link between pollutants and reproductive health.

"Exposure to these chemicals, particularly during certain windows of time during fetal development, in newborns or as adolescents, can do permanent damage," said Dr. Veeramachaneni. "It's been a difficult task to trace the impact of these chemicals because an exposure as a fetus may not be manifested until that fetus becomes an adult. Once exposed, many males develop a condition for life. But when we look at the big picture -- at trends over time -- research shows lasting effects of chemicals since their popularity after World War II."

Some of these chemicals can survive in the environment for 30 to 40 years, and the chances for exposure are high because the chemicals have permeated our world. For example, the EPA says that about one-third of the nation's lakes and one quarter of its rivers are polluted. There is also evidence that exposure today to some of these chemicals can affect the reproductive health of this generation as well as the future health of offspring of those exposed. 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. One study looking at sperm counts globally from 1940 - when chemicals first began to be widely produced - to the 1990s, indicates a 1.15 percent per year decline in sperm counts. These declines may be linked to chemical exposure.

These chemicals affect the body through several channels. They attach to receptors in the body that help hormones carry out their functions and either block actual hormones from attaching or mimic the expression of the real hormones, causing confusion in the male body. In addition, some interfere with the body's natural production of hormones.

A pattern emerges when comparing the explosion of the world's use of chemicals, including pesticides and herbicides, and the steadily increasing incidence of testicular cancer, reproductive system abnormalities and impotence.