Table 9. Concentration (ppm) of hydrogen sulfide (H2S), ammonia (NH3), and carbon dioxide (CO2) in 9 pig farms

Gases 1 2 3 4 5 6 7 8 9 Mean SD
H2S 1.23 0.00 0.75 0.27 0.16 0.74 0.45 0.00 0.13 0.41 0.42
NH3 41.67 9.60 57.60 11.83 3.69 59.07 11.30 7.50 68.17 30.05 26.21
CO2 1,400 2,686.24 5583.75 955.00 1,014.13 4,766.67 4,040.00 2,816.67 3,243.33 2,945.09 1,648.04