Air Quality and Human Health Risk Assessment in the Residential Areas at the Proximity of the Nkolfoulou Landfill in Yaoundé Metropolis, Cameroon
Table 3
Concentration of odourless gases at the monitoring sites (n1 = 12; n2 = 192).
Site code
CO (mg/m3)
O3 (μg/m3)
NO2 (μg/m3)
Range of hourly mean
Daily mean
Range of hourly mean
Daily mean
Range of hourly mean
Daily mean
Min
Max
Min
Max
Min
Max
RA0
ND
0.30
0.05
ND
10.51
1.32
ND
ND
NC
RA1
ND
1.00
0.27
ND
40.01
5.73
ND
ND
NC
RA2
ND
4.58
0.92
ND
58.90
10.63
ND
75.26
35.92
RA3
ND
8.02
1.48
ND
39.41
6.54
ND
94.07
49.60
RA4
ND
1.55
0.42
ND
58.90
6.54
ND
ND
NC
RA5
ND
4.01
0.46
ND
137.42
26.18
ND
ND
NC
RA6
ND
7.44
1.07
ND
38.94
5.73
ND
ND
NC
RA7
ND
1.86
0.36
ND
39.26
8.18
ND
ND
NC
RA8
ND
0.64
0.13
ND
78.53
6.54
ND
ND
NC
RA9
ND
1.37
0.05
ND
19.63
5.89
ND
ND
NC
RA10
ND
2.40
0.04
ND
58.90
19.63
ND
ND
NC
RA = residential area; ND = not detected; NC = not calculated because not detected; n1 = number of measurements per hour; n2 = number of measurements per day (24 hours).