A summary of ammonia emission factors and quality criteria for commercial poultry production in North America

Efforts to quantify emissions of ammonia to the atmosphere from poultry housing in North America have been underway for the past two decades. In order to accurately estimate emissions from facilities in each poultry sector, emission factors used to derive the average must be of sufficiently high quality. However, it has become evident that current methods are inadequate and emission factors do not accurately reflect North American poultry production. Using an initial screening, based on measurement methods for ammonia and ventilation rates as well as study duration, a collection of studies have been identified that report the highest quality emission factors currently available. Each study was rated for data quality and then an average emission factor was developed for each sector of poultry production and rated based its ability to represent that sector. The laying hen sector, using deep pit manure storage, received a C (average) emission factor quality rating, which is the highest of all the poultry sectors evaluated. Laying hen with manure belts, broiler chicken, and turkey sectors received quality ratings considered to be below average or poor. This study highlights the need for additional research that needs to be conducted in order to accurately quantify ammonia releases from housing in most poultry sectors in North America.