H1: Research Roundup Biological Hazards

The pork industry plays a major role in the US agricultural economy. The US ranks as the third-largest pork-producing country and was the leading exporter of pork and pork products in 2024. Over the last three decades, this industry has undergone major changes, with farms becoming larger and pigs increasingly raised indoors under controlled environments. These enclosed barns often contain elevated concentrations of airborne contaminants, raising the risk of workers' exposure to airborne hazards such as carbon dioxide, ammonia,, hydrogen sulfide , particulate matter, and biological agents generated from animal waste, feed, and barn activities. Long-term exposure to these hazards has been linked to chronic bronchitis, and reduced lung function.

Despite extensive research, there is no consensus on how ventilation rate, housing design, seasonality, or stocking density affect worker exposure. Two review studies reported inconsistent results regarding ventilation mode, barn type, season, temperature, humidity and animal factors on PM and H2S exposure. Moreover, although higher Staphylococcus aureus concentrations were associated with lower ventilation rates, broader determinants of biological exposures remain understudied.

This presentation summarizes findings from a study in grow-to-finish swine barns in the US Midwest, evaluating the role of farm size, ventilation rate, season, temperature, humidity, and pig-level data on worker exposures. 

Germicidal ultraviolet radiation (GUV) was commonly used in the past to inactivate viruses, and kill bacteria, mould spores and other microorganisms, typically in hospital settings. This technology has been reintroduced as a control measure to prevent the transmission of SARS CoV 2 in high-risk indoor settings. An evaluation was conducted of GUV devices to be used to disinfect the surfaces of trays used to contain passengers' personal items during security screening at airport departures. These trays can reasonably be described as "high-touch surfaces". The re-evaluation of this technology included a desktop review of the research available on the efficacy of UVC radiation (region of the UV spectrum from about 200 to 280 nm in wavelength) and its ability to inhibit SARS CoV 2; review of the available testing equipment and procedures to confirm/test surface power levels, UVC emissions/leaks from equipment, ozone, etc.; and hazard review and risk assessment of five selected UVC devices that were commercially available.

Following the desktop review, two devices were chosen for further assessment of performance and risk. Test objectives included leakage testing, specifically the possibility of worker exposure to UVC caused by reflection or scattering of UVC from adjacent surfaces within the device; and dosimetry to assess whether the device was operating at the expected dose rate. For systems that may not adequately filter UV below 250 nm, air monitoring for ozone was conducted.