Role of nitrous acid in the association between nitrogen dioxide and asthma symptoms: effect of nitrous acid exposure on specific airway resistance in guinea pigs

Environmental Sciences Europe

Table 1 Concentrations of nitrogen oxides in each camber

Group	HONO (ppm)	NO₂ (ppm)	NO (ppm)
Experiment 1
Group C	0.005	0.044 ± 0.063	0.027 ± 0.062
Group M	0.775	0.174 ± 0.291	1.032 ± 0.495
Group H	4.179	1.374 ± 1.175	3.997 ± 1.626
Experiment 2
Group C	0.030	− 0.011 ± 0.0 35^a	0.094 ± 0.131
Group M	0.542	0.000 ± 0.042	0.721 ± 0.219
Group H	2.670	0.385 ± 0.212	2.639 ± 0.569
Average^b
Group C	0.018 ± 0.013	0.017 ± 0.028	0.061 ± 0.0335
Group M	0.659 ± 0.117	0.087 ± 0.087	0.877 ± 0.156
Group H	3.425 ± 0.755	0.880 ± 0.495	3.318 ± 0.679

^aNegative value due to inadequate of calibration of the NOx analyzer
^bData are presented as the mean value ± SD based on the average value of 2 experiments