Obie Ashford is the national leader for animal husbandry with the Natural Resource Conservation Service in Beltsville, Md.

Q In some areas, livestock manure and odor have moved into the public health arena. What are the issues or perceptions that link these?
A Livestock manure has emerged over the past few years as a major political, as well as environmental, issue. The nationwide move to greater concentrations of livestock in a given area has triggered individuals and surrounding communities to present manure-related complaints. Officials that collect those reports generally indicate that the main health complaints involve eyes, nose and throat irritation; drowsiness; and headaches.

However, all of the reported odor symptoms are not associated with livestock operations. There are a variety of air-borne compounds that can trigger those same health symptoms.

Q Which issue is of most concern?
A Odor is the most controversial nuisance problem associated with animal feeding operations. Complaints regarding odor generally come from downwind neighbors and from manure land application activities. Odors consist of gases, such as hydrogen sulfide, methane, ammonia and organic compounds that are produced during manure decomposition. Some are known to be harmful in large amounts. The main effect that odor has on humans appears to be annoyance or nuisance.

Q Why has the public health side of this issue come to the forefront lately?
A Public perception of the impacts that concentrated livestock feeding operations may have on the environment is based, in part, on the Pfiesteria outbreaks along the Mid-Atlantic and urban water supplies contaminated by pathogens, Cryptosporidium.

Two issues of growing concern are 1) perception of nonpoint-source pollution of the nation's waters from animal feeding operations and 2) the inadequacy of traditional land-based manure nutrient management opportunities as livestock and poultry numbers have surpassed the carrying capacity of the land in some geographic areas.

Q What research is being done to determine the facts and potential impact of livestock manure on public health?
A Odor and pathogen management will require an understanding of effective manure management systems. Research is underway to better match diets to the animal's nutritional requirements to increase digestibility and availability in feed, thereby reducing nutrient excretions in manure.

Technology such as the Phosphorus Index is being developed as a site vulnerability assessment tool when animal manure is applied to the land. Constructed wetlands, adding aluminum sulfate to poultry litter and converting manure to value-added products are some of the techniques being implemented to minimize the potential adverse soil, water and public health concerns.

Q Are there any unique concerns related to manure from swine operations?
A The main concern is proper nutrient management using a systems approach involving: manure collection, handling, storage, and treatment; land application; alternative uses of manure; or transport off-site.

Q Is this issue a regional or national concern?
A It appears to be a national concern with specific regional geographic areas of generating more concern.

Q What actions and/or regulations, if any, might evolve from this issue? And how will those measures affect pork producers?
A The public is demanding more effective and efficient control of water, air and human health impacts from all kinds of agricultural production processes.

National policy attention has reached a peak over the last few years, as symbolized by the release of the USDA/Environmental Protection Agency's Unified National Strategy on Animal Feeding Operations. The section related to pork production is scheduled for implementation in the new year.

At the state level, 34 states have passed, voted on or at least debated policies in the last five years that would directly or indirectly affect control of livestock manure. Numerous counties and local governments have passed their own ordinances related to the matter.

The whole issue of manure management will continue to evolve and impact producers.