BOARD-INVITED REVIEW: Fate and transport of bioaerosols associated with livestock operations and manures

Abstract

Airborne microorganisms and microbial by-products from intensive livestock and manure management systems are a potential health risk to workers and individuals in nearby communities. This report presents information on zoonotic pathogens in animal wastes and the generation, fate, and transport of bioaerosols associated with animal feeding operations and land applied manures. Though many bioaerosol studies have been conducted at animal production facilities, few have investigated the transport of bioaerosols during the land application of animal manures. As communities in rural areas converge with land application sites, concerns over bioaerosol exposure will certainly increase. Although most studies at animal operations and wastewater spray irrigation sites suggest a decreased risk of bioaerosol exposure with increasing distance from the source, many challenges remain in evaluating the health effects of aerosolized pathogens and allergens in outdoor environments. To improve our ability to understand the off-site transport and diffusion of human and livestock diseases, various dispersion models have been utilized. Most studies investigating the transport of bioaerosols during land application events have used a modified Gaussian plume model. Because of the disparity among collection and analytical techniques utilized in outdoor studies, it is often difficult to evaluate health effects associated with aerosolized pathogens and allergens. Invaluable improvements in assessing the health effects from intensive livestock practices could be made if standardized bioaerosol collection and analytical techniques, as well as the use of specific target microorganisms, were adopted.

Estimation of Infectious Risks in Residential Populations Exposed to Airborne Pathogens During Center Pivot Irrigation of Dairy Wastewaters

“…Regardless of the bioaerosol source such as animal feeding operations, composting facilities, municipal treatment plants, and biosolids (sewage sludge), manure, and wastewater land application sites, the general trend is that airborne microorganism concentrations have been shown to decrease with increasing distance from the source. 60 A decrease in bioaerosol concentration with distance is associated with a decrease in infectious risks from pathogens as determined by the results from this QMRA, which is also supported by risk assessments that considered aerosol generation and transport during land application of biosolids. 26,34,61 Dilution clearly plays a key role in reducing airborne microorganism concentrations, but meteorological factors such as temperature, solar radiation, and humidity can affect the viability of microorganisms during their dispersion.…”

Characteristics of Microbial Aerosols Released from Chicken and Swine Feces

“…For example, the temperature and RH of air statistically significantly affect the generation of bioaerosols within different indoor environments. 1,5,23 Biological particulates from solid and relatively dry surfaces can be released as individual cells or with other particles 5 ; therefore, factors that affect the disassociation of bioaerosols from a matrix, such as air current (wind speed), may also be important. However, only common values of environmental parameters (30°C, 65% RH, ACH of 1 hr Ϫ1 , and an airflow of 0.01 m/sec) were set in this exploratory study.…”

“…[1][2][3][4] These contaminants include toxic gases (such as ammonia [NH 3 ] and hydrogen sulfide [H 2 S]), inorganic particulates (such as soil dusts), nonviable organic particles (such as feed/feces droplets and feathers/dandruff), and viable particulates (such as bacteria and fungi) and their byproducts (such as fragments and endotoxins), which are sometimes referred to as "bioaerosols." 4 -9 High animal densities are typical of modern largescale poultry and swine production, and they increase the load of airborne contaminants.…”

Microbiological Air Rating in a Variety of Objects During Treatment of the Post-Slaughter Poultry Wastes Part I. Escherichia Coli

“…The concentration and type of microorganisms in the air depends on various factors such as the type of buildings system, number of animals, type of ventilation system, and other conditions including temperature, humidity, gas concentrations, light, or dust concentration (Green et al, 2009). Air pollution, including biological one, which is generated during the breeding of livestock and poultry, like in the case of these analyzed objects, can have a significant impact on the increase of this type of pollution and health effects on workers and service stuff (Donham et al,1989, Dungan, 2010.…”

“…The air pollutants, that are generated during animal and poultry breeding, adversely affect the sense and health of employees and stuff (Donham et al,1989, Dungan, 2010. Microorganisms can also be transmitted from this type of objects over long distances and affect the residents of nearby habitats (Cox & Wathes,1995 Escherichia coli is a gram-negative bacteria, motile, facultative anaerobic, classified into the family of Enterobacteriaceae (Buxton and Fraser, 1977).…”