A national study on the residential impact of biological aerosols from the land application of biosolids

Abstract

Aims: The purpose of this study was to evaluate the community risk of infection from bioaerosols to residents living near biosolids land application sites. Methods and Results: Approximately 350 aerosol samples from 10 sites located throughout the USA were collected via the use of six SKC BiosamplersÒ. Downwind aerosol samples from biosolids loading, unloading, land application and background operations were collected from all sites. All samples were analysed for the presence of HPC bacteria, total coliform bacteria, Escherichia coli, Clostridium perfringens, coliphage, enteroviruses, hepatitis A virus and norovirus. Total coliforms, E. coli, C. perfringens and coliphage were not detected with great frequency from any sites, however, biosolids loading operations resulted in the largest concentrations of these aerosolized microbial indicators. Microbial risk analyses were conducted on loading and land application operations and their subsequent residential exposures determined. Conclusions: The greatest annual risks of infection occurred during loading operations, and resulted in a 4 · 10 )4 chance of infection from inhalation of coxsackievirus A21. Land application of biosolids resulted in risks that were <2 · 10 )4 from inhalation of coxsackievirus A21. Overall bioaerosol exposure from biosolids operations poses little community risk based on this study. Significance and Impact of the Study: This study evaluated the overall incidence of aerosolized microorganisms from the land application of biosolids and subsequently determined that microbial risks of infection were low for residents close to biosolids application sites.

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

“…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. While there is very little pathogen-specific information, laboratory and field studies have shown that viability of airborne microorganisms generally decreases with increases in temperature and solar radiation or decreases in relative humidity.…”

“…Some recently published risk analyses addressing biosolids land application scenarios have utilized this approach. 4,61,71 Similar to the approach used in this paper, QMRA has been used to understand human health effects from exposures to biosolids and related pathogens released during land application. 26,71,74 Regardless of the context in which these exposures were being assessed, there is much uncertainty associated with inhalation of airborne pathogens and their ability to cause infection after subsequent ingestion.…”

Systems for Detection and Identification of Biological Aerosols (Review Paper)

“…It includes linear and point sources. The linear source is represented by mobile equipment (aircraft or spraying car) although in this case based on to the intensity and wind direction, inversion, atmospheric pressure, characteristics of the agent itself it can involve a large area 4,5 . The point source of contamination is typically immobile stationary equipment (nebulizer), which produces aerosols only around its area of placement.…”

“…There are several studies focused on military aspects as well as articles in specialized journals which provide comprehensive overview of various systems and devices for detection and identification of biological agents [2][3][4][5] . Furthermore, limited information about each of the detection systems are available from company literature, web pages and promotional items.…”

“…The comparison of the individual systems for attributes such a sensitivity, selectivity and resistance are not described anywhere. Only sometimes can be found articles describing experiments from field trials4, land applications of biosolids 5 or describing natural sources of aerosols.…”