The purpose of this study is to test the following hypotheses: (1) if air quality control strategy can be directly evaluated by measuring respiratory responses in swine building environments. Twenty naA?ve human subjects (subjects were between 18 and 35 years old and had never been exposed to an enclosed swine environment before) were exposed to two different air qualities, a treatment and a control, in a swine building. The treatment room was sprinkled with crude canola oil, which reduced the dust, ammonia and hydrogen sulfide by 93%, 30% and 27%, respectively, compared with the control. Each subject spent five hours in each room. They were scheduled to do a bicycle exercise that was intended to simulate the barn workersa