「至目前為止，我們並沒有很好的證據顯示戴奧辛是否會影響人類的生殖系統，」古普塔醫生（Dr. Amit Gupta）說。他是德州大學西南醫學中心的泌尿科醫生，以及這份研究報告的主要作者。「現在我們知道戴奧辛與人類前列腺有關，這讓我們懷疑戴奧辛或許會減緩人類前列腺的生長，如同我們在動物身上看到的情形。」
德州大學西南醫學中心的泌尿科主任，也是這項研究的作者羅耳波（Dr. Claus Roehrborn）說：「我們知道戴奧辛會造成人體許多內分泌失調。這項研究間接顯示前列腺肥大是一種內分泌失調。」
A toxic chemical contained in the herbicide Agent Orange affects male reproductive health by limiting the growth of the prostate gland and lowering testosterone levels, researchers have found in a study of more than 2,000 Vietnam War Air Force veterans.Published in the November issue of the journal "Environmental Health Perspectives," the study indicates that exposure to TCDD, the most toxic of the dioxin family of chemicals contained in Agent Orange, may disturb the male endocrine and reproductive systems in several ways.
"Until now, we did not have very good evidence whether or not dioxins affect the human reproductive system," said Dr. Amit Gupta, an urologist at the University of Texas Southwestern Medical Center and the study's lead author. "Now we know that there is a link between dioxins and the human prostate leading us to speculate that dioxins might be decreasing the growth of the prostate in humans like they do in animals," he said.
Agent Orange is an herbicide that was developed for military use in Vietnam to deny cover and concealment to enemies of the United States and its allies.
The researchers found that veterans exposed to dioxin had lower incidence rates of benign prostate hyperplasia, BPH, a disease that is caused by an enlargement of the prostate. Patients must strain to pass urine and they urinate frequently. BPH can lead to complications such as an inability to urinate and urinary tract infection.
Although the study found fewer incidences of disease, Dr. Gupta cautioned that the finding should not be interpreted as a positive result. "It may be construed that a decrease in the risk of BPH is not a harmful effect, but the larger picture is that dioxins are affecting the normal growth and development of the reproductive system," he said.
Dr. Claus Roehrborn, professor and chairman of urology at UT Southwestern and a study author, said, "We know that dioxin causes many endocrine disturbances in the human body. The study indirectly proves that BPH is an endocrine disorder."
The study was based on data from the Air Force Health Study, an epidemiologic study of more than 2,000 Air Force veterans who were responsible for spraying herbicides, including Agent Orange, during the Vietnam War. The veterans were interviewed and underwent physical examinations and lab tests during six examination cycles. The first cycle was conducted in 1982, so the veterans were followed for more than 20 years.
"We found that the risk of developing BPH decreased with increasing exposure to dioxins in the comparison group," said Dr. Arnold Schecter, professor of environmental sciences at the UT School of Public Health Regional Campus at Dallas and a study author. The study shows that higher dioxin exposure is associated with decreased testosterone levels, Dr. Gupta said."It is known that lower testosterone levels are associated with decreased sexual function, decreased muscle mass and strength, infertility, increased fatigue, depression and reduced bone density," Dr. Gupta said. "However, we could not conclude from this study that dioxin exposure did lead to any of these adverse affects in the veterans in the study."