Trong hai thập kỷ qua, số lượng gia súc, gia cầm các trang trại ở Hoa Kỳ đã giảm khoảng một nửa, trong khi số lượng các đơn vị động vật lớn lên đã tăng khoảng 10% .1 Sự thay đổi này đối với ít hơn nhưng ngày càng lớn hơn các trang trại công nghiệp hóa, gọi là "giới hạn" hoặc "hoạt động thức ăn chăn nuôi tập trung" (CAFOs), đã dẫn đến sự gia tăng đồng thời sử dụng dược phẩm và phân bón tạo ra cho mỗi đơn vị diện tích đất. Trong thời gian tuổi thọ của họ, khoảng 60 đến. | 6 Sorption and Degradation of Selected Pharmaceuticals in Soil and Manure Nadia Carmosini and Linda S. Lee Contents Assessing Contaminant Fate and Transport in Soil Sorption by Degradation in Manure and Sorption by Soil and Degradation in Manure and Conclusion. 160 INTRODUCTION Over the past two decades the number of livestock and poultry farms in the United States has decreased by approximately half while the number of animal units being raised has increased by about 10 .1 This shift toward fewer but increasingly larger industrialized farms termed confined or concentrated animal feeding operations CAFOs has resulted in concomitant increases in pharmaceutical use and manure generated per unit land area. During their lifespan roughly 60 to 80 of commercial livestock are treated with antibiotics as therapeutic prophylactic or growth promoting agents 2 and much of the ingested dose is excreted unchanged or as active Hormones are also used for growth promotion and reproductive control. In addition hormones and their metabolites are produced and excreted naturally with more than 50 tons of reproductive hormones being released annually by farm animals in the United As a result the 130 billion pounds of manure produced every year represent an expansive source of pharmaceutical contamination. CAFOs typically store animal wastes in an outdoor lagoon underground pit or litter storage facility. For example approximately 23 of swine operations in 139 2008 by Taylor Francis Group LLC 140 Fate of Pharmaceuticals in the Environment and in Water Treatment Systems the United States use lagoons 57 use below-ground pits and the remaining 20 employ other storage techniques such as manure Lagoons and pits contain liquid sludge and solids that are periodically pumped out and injected or .
