Determination of Particulate Matter Emissions from Cattle Feedlots Using Wind-Trax and the Flux-Gradient Technique

Large commercial cattle feedlots are significant sources of particulate matter (PM) emissions. This research compared WindTrax and the flux-gradient technique in estimating emissions of PM with aerodynamic diameter < 10 μm (PM10) from cattle feedlots. Meteorological conditions were measured and PM10 concentrations were profiled vertically (i.e., 2.0 to 7.62 m) at a large commercial beef cattle feedlot in Kansas from May through September 2011. Results show that between the two methods evaluated, WindTrax was least sensitive to changes in heights and number of heights used in the emission estimation, with calculated PM10 emission rates varying by up to 18% only. On the other hand, PM10 emission rates produced by the flux-gradient technique varied by almost 56% when changing either heights and/or number of heights in emission calculation. Both methods were sensitive to height settings, with their respective PM10 emission rates higher when the lowest height setting (2.0 m) was included. Calculating PM10 emission rates with the 7.62-m height led to lower estimates for the flux-gradient technique but no significant change in estimates was observed for WindTrax. As demonstrated in this study, for the flux-gradient technique, settings for the lowest and highest heights were the most critical in emission estimation;exclusion of other heights in between showed only to 2% to 6% change in calculated PM10 emission rates. In general, the higher PM10 emission rates were obtained with the flux-gradient technique. However, eliminating the lowest height (2.0 m) in the calculation and, at the same time, using a specific set of formulations for the flux-gradient technique made its calculated PM10 emission rates slightly lower (but not significantly different) than those from WindTrax.

Air Quality, Health and Community Action

Air quality is impacting health in many cities in most countries because of particulate pollution, sulfur dioxide, nitrogen dioxide, and ozone. Very small particulates from engine emissions and coal fired electric power plants enter the lungs and pollute the blood of urban residents leading to a burden of disease with more than 3 million premature deaths per year attributed to outdoor air pollution. Welfare losses including premature deaths associated with air pollution were about $5 trillion in 2013. A global transition to electric vehicles, and the generation of electricity without combustion emissions would improve air quality significantly and reduce greenhouse gas emissions. This transition is in progress in many parts of the world with more than 2 million electric vehicles in service in 2017. Electric bus and electric taxi sales are increasing, and many large cities have multiple programs to improve air quality. When health costs are considered, it is very appropriate for communities to take action to improve air quality and health. This work reviews and reports many positive actions that are in progress in larger cities.