Submitted to: National Groundwater AFO/CAFO Conference
Publication Type: Abstract Only
Publication Acceptance Date: April 10, 2001
Publication Date: July 1, 2001
Technical Abstract: Laying chickens can excrete 17B-estradiol and testosterone at 500 and 250 ng/g dry manure/day, respectively. Since estradiol has a 100-fold greater affinity for the estrogen receptor than do man-made estrogenic substances of current environmental concern, e.g., alkylphenol ethoxylates, we decided to investigate their fate in composted manure. Chicken layer manure (commercial source) was mixed as follows: manure (3.3 parts), old hay (2), straw (2), partially decomposed leaves (4), and starter compost (2) to achieve a C:N ratio of 30:1. The mixture was adjusted to ~50% moisture and composted in windrows (23 x 2 x 1.75 m); four windrows were constructed. All windrows were turned weekly using a compost turner that brings the outer portions of the piles into the self- heated core zone. Composting involved the peak heating and curing phases. Temperature and O2 were monitored to ensure aerobic, thermophilic conditions. At each sampling time, subsamples (3) were blended with dry ice; extracted with ultra-pure water, and prepared for quantitative enzyme immunoassay of 17B-estradiol and testosterone. The 17B-estradiol steadily declined from 42.4 ppb (or 45.7 ppb, mixture described above amended with 1 part clay) to 34.2 ppb (or 27.6) during the first three weeks. Testosterone levels declined from 95.2 ppb (or 109) initially to 53.1 ppb (or 78.9). Data suggest composting reduces concentrations of these potent endocrine disrupting hormones at concentrated animal operation facilities.