Comparison of Ammonia Emissions from Poultry Houses Based on Diurnal Integration vs. Daily Means of Gas Concentration and Building Ventilation Rate
Quantification of aerial emissions from animal feeding operations (AFOs) requires the knowledge of both concentration of the constituent of interest and the ventilation rate (VR) through the emitting source. Daily emissions can be and are normally determined from diurnal integration of frequent measurements, referred to as the diurnal integration method (DIM), but is resource intensive. Alternatively, daily emission may be more economically estimated from daily means of concentration and VR, referred to as diurnal means method (DMM). In this study, DMM was compared with DIM in determining daily ammonia (NH3) emissions from mechanically ventilated laying-hen, turkey and broiler houses under U.S. production conditions. Results show that deviations in daily NH3 emissions between DMM and DIM methods ranged from as small as < 3% (e.g., for medium age turkey under both cold and warm weather conditions) to as high as 98% (e.g., broiler houses in summer). Deviations were related with coefficient of variation (CV) of VR or NH3 concentration, although prediction of the deviation using CV of VR and/or NH3 concentration alone will likely not produce reliable results. The study suggests that caution must be taken when using DMM to estimate daily NH3 emissions from poultry houses under typical US production conditions.
EFFECTS OF MEASUREMENT INTERVALS ON ESTIMATION OF AMMONIA EMISSIONS FROM LAYER HOUSES
Continuous quantification of aerial emissions from animal feeding operations over an extended time period is 
labor and resource intensive. Strategically reducing measurement time to achieve comparable emission results is thus highly 
desirable. This article delineates the effects of measurement intervals on estimation of annual mean and maximum daily 
ammonia emission rate (ER) of high-rise (HR) and manure-belt (MB) layer houses. The full dataset consisted of 318 daily 
ER values of four HR houses from weekly 48 h continuous measurement and 112 daily ER values of two MB houses from 
bi-weekly 48 h continuous measurements over one-year period. Each full dataset was sampled to yield subsets of daily ER 
at different intervals, i.e., one week (HR houses only), two weeks, one month, two months, or three months. The corresponding 
estimates of annual ammonia ER from the subsets were computed and compared with that of the full dataset. The results 
indicate that the annual mean daily ER values derived from the subsets progressively deviated from that of the full dataset 
by 3% to 37% for the HR houses and by 6% to 41% for the MB houses. The augmented measurement intervals (i.e., greater 
than bi-weekly for the HR houses and greater than monthly for the MB houses) led to considerable underestimation of the 
daily maximum ER values, and thus are not recommended when daily maximum emission values are to be assessed.
Accumulation of Bone-Seeking Radionuclides in Liver Metastasis from Colon Carcinoma
Fifteen colon cancer patients with metastasis to the liver were examined by both liver and bone scans. Seven of these showed accumulation of bone seeking radionuclides in the liver at the site of a defect in the scan. Such accumulation was found in two diphosphonate, in one pyrophosphate and in six 18F scans. To our knowledge, this is the first series to report localization of 18F in intrahepatic metastasis from colon cancer. The precise mechanism for this non-skeletal accumulation is unknown.