Roadside air pollution in a tropical city: physiological and biochemical response from trees

Bulletin of the National Research Centre

Table 3 Ambient air quality of Kumasi Metropolis during the study period

Parameter/sampling sites	CO (ppm)	SO₂ (ppm)	NO₂ (ppm)	VOC (ppm)
Arterial road I	7.96 ± 1.62^b	0.15 ± 0.01^b	0.08 ± 0.00^a	0.12 ± 0.29^a
Arterial road II	6.81 ± 0.16^b	0.21 ± 0.02^b	0.08 ± 0.01^a	0.07 ± 0.02^a
Arterial road III	5.26 ± 0.06^b	0.21 ± 0.01^b	0.10 ± 0.00^a	0.08 ± 0.00^a
Control site	0.85 ± 0.24^a	0.07 ± 0.02^a	0.06 ± 0.01^a	0.01 ± 0.00^a

Mean + SE in the same column with different letters in superscript are significantly different (P < 0.05)