Table 4 Indoor air quality in select photocopier centers in Coimbatore
Air quality parameters | Background levels (n = 5) | Mean levels (n = 5) | Indoor air quality | Reference levels (NAAQS, 2009) |
|---|---|---|---|---|
Carbon monoxide (CO) (mg/m3) | <1.2 | <1.2 | <1.2 | 2.0 |
Nitrogen dioxide (NO2) (μg/m3) | 8.0 ± 2.6 | 8.4 ± 3.8 | 9.1 | 80 |
Ozone (O3) (μg/m3) | <9.8 | <9.8 | <9.8 | 100 |
Fine particulate matter (PM2.5) (μg/m3) | 128.1 ± 21.4 | 168.2 ± 34.6 | 78.5 | 60 |
Particulate matter (PM10) (μg/m3) | 241.7 ± 44.2 | 376.4 ± 63.8 | 106.7 | 100 |
Sulphur dioxide (SO2) (μg/m3) | 3.5 ± 1.5 | 4.7 ± 2.3 | 5.1 | 80 |
Lead (Pb) (μg/m3) | <0.1 | <0.1 | <0.1 | 1.0 |
Arsenic (As) (ng/m3) | <0.1 | <0.1 | <0.1 | 6.0 |
Nickel (Ni) (ng/m3) | <0.1 | <0.1 | <0.1 | 20 |
Ammonia (NH3) (μg/m3) | 2.3 | 2.5 | 2.7 | 400 |
Benzene (C6H6) (μg/m3) | <1.0 | <1.0 | <1.0 | 5.0 |
Benzo(a)pyrene (BaP) (ng/m3) | <1.0 | <1.0 | <1.0 | 1.0 |