Characterization, health risks, ozone and secondary organic aerosol formation, and odor-causing analysis of gaseous pollutants from pig houses

The environmental quality of the outdoor, as well as the health of people and animals, might be impacted by the total volatile organic compounds (TVOC), NH, and HS from pig houses. The amount of study on the features of VOC and smell emission from pig fattening process locations is rather limited, and the assessment of the primary odor-causing compounds and health hazards is unclear; inadequate investigation has been done for the generation of ozone and secondary organic aerosols. In this study, a portable odor meter was employed to measure odor levels and analyze the sources of odor at four different locations within the pigsty. Specific VOCs were collected using a Suma tank to determine the magnitude of odor, assess the formation of SOA and OFP, and evaluate associated health risks. Furthermore, online monitoring sensors were utilized to detect fluctuations in TVOC, HS, and NH concentrations. Results showed that TVOC emissions outside the house were prominent in November and January, while inside the house, they were concentrated in December, with a maximum of 60,000 μg·m, with an overall decreasing trend. HS emissions were low, almost zero, and NH emissions showed a stable trend throughout the season, with a peak of 29.3 μg·m in mid-January. A total of 36 VOCs were detected, with the highest concentrations of acetaldehyde and undecane at 34.5 and 34.8 μg·m, respectively, and the main odor-causing substances were acetaldehyde, NH, and HS; OFP contributed most to acetaldehyde and SOA contributed most to aromatic hydrocarbons and alkanes. This research endeavor establishes a scientifically grounded framework for mitigating malodors and determining an optimal treatment methodology.