PSIV-26 Development of a Controlled Exposure Particulate and Oxidative Radical Mask for Causality Experiments Investigating Smoke Exposure on Livestock Animals

Abstract

Abstract Understanding and mapping the specific effects of smoke inhalation on cattle performance provides strategic insights for producers and policy makers to better prepare or adjust when faced with sporadic or even seasonal reductions in air quality. As of now, no current studies have attempted to investigate the effects of seasonal fires on performance and health adequately in livestock while addressing obvious confounding effects, controlling exposure, and examining fuel for differential oxidative radicals and particulate smoke. Herein, we propose the design of the first cost-effective controlled system for investigating smoke, particulate matter, and varied oxidative radicals through a pre-mixing chamber. The mask main body is constructed from 8” nominal diameter schedule 40 PVC pipe. The endcap was designed in an online CAD software to provide an interface for standard 2 ⅞” bulkhead fittings and was produced via additive manufacturing (3D printing). A silicone SCUBA neck seal was used to line the face orifice and is the component that directly contacts the animal’s nose and mouth. A neoprene rubber sheet and an insulation hose were used as padding under the silicone seal to help maintain an airtight connection and animal comfort when the mask is worn. Bulkhead fittings used provide 1 ½” female national pipe thread connection to allow for modular connection of inlet and outlet hoses, check valves for airflow isolation, filters, or any number of connections can be made via these gasket sealed fittings, making this platform extremely adaptable. In its shown configuration, 3D printed adapters were made to attach 4” suction hose to 2” socket union joints for quick connect/disconnect functionality. An inlet and outlet gas/smoke flow regulator are attached to a mixing chamber where particulate and chemical composition sensors are utilized to deliver the desired composition of smoke delivered to the animals. Negative pressure fans and pumps regulate the flow to the animals and are utilized for exposure of smoke in time-specific intervals. An additional fully 3D printed version enables the mask design to be lower in weight through regulation of the density of the internal matrix, and after an initial investment in the equipment also represents a cost-efficient approach to generating multiple masks. Understanding the effects of particulate and reactive oxidative molecules on livestock health and performance requires the study of a controlled exposure, the system presented herein represents a viable and cheap alternative for bettering a mechanistic model and understanding of the effects of smoke on animal health and performance. Ultimately, the proposed mask paired with currently available sensors permit for the controlled exposure of smoke particulate with different chemical compositions for accurate evaluation of prolonged exposure effects on livestock.