Livestock flood the environment with estrogen

摘要

On the basis of sampling for estro-genic compounds at 8 dairy and 11 swine waste storage facilities, researchers concluded that farm animals in the United States flood the environment with these hormones, according to data published in this issue of ES&T (pp 3567-3573). Previous studies have found that these compounds feminize male fish. The problem arises from the sheer numbers of farm animals; the authors estimate that the United States' 10 million cows and 43 million swine excrete a daily mix of 10-30 kilograms (kg) of 17-β-estra-diol and 20-80 kg of estrone; 17-α-estradiol was found mainly on dairy farms. "Our best estimate is that the amount of estrogen coming out of pigs and cows is over an order of magnitude higher than what the human population puts out," says study author Raj Raman, associate professor of biosystems engineering and environmental science at the University of Tennessee.