Establishment of estimation method for manure-borne steroid estrogens

Because of the wide existence and serious endocrine disturbing for humans and animals, the steroid estrogen hormones have been focused more and more in recent years. Steroidal estrogen hormones such as 17β-estradiol and estrone are particular concerns because there is evidence that low nanogram per liter concentrations of them in water can adversely affect the reproductive biology of fish and other aquatic vertebrate species. The animal manure is one of the main sources of steroid estrogens to the environment. Based on the literatures review, the study established the basical models to estimate the excretion of 17β-estradiol and estrone from five types of animals including pig, dairy cattle, beef cattle, layer and broiler. We tried to assess the yearly excretion of steroid estrogens from farm animals in China and compare the difference of excretion rates between five types of animal feces and urine. On the basis of current studies on the estrogens, the tendency for the future research in this field was discussed and suggested.