Background
Methods and materials
Study design and study area
Sample size and sampling procedures
Air sampling procedures
Data analysis
Results
Bacterial load
Name of School | Number of classrooms | Mean | Standard deviation | Minimum | Maximum | Median |
---|---|---|---|---|---|---|
Morning bacterial load | ||||||
School 1 | 5 | 702.00 | 316.44 | 390 | 1183 | 741 |
School 2 | 7 | 1131.00 | 515.87 | 559 | 2145 | 1066 |
School 3 | 3 | 450.67 | 314.52 | 208 | 806 | 338 |
School 4 | 8 | 5843.50 | 1973.45 | 3588 | 8528 | 5356 |
School 5 | 7 | 5588.14 | 2167.85 | 3341 | 9100 | 4420 |
School 6 | 8 | 3284.13 | 1185.78 | 2067 | 5668 | 3321.5 |
School 7 | 7 | 748.43 | 179.95 | 585 | 1105 | 767 |
School 8 | 6 | 2331.33 | 801.49 | 1430 | 3666 | 2158 |
Total | 51 | 2826.35 | 2408.76 | 208 | 9100 | 2093 |
Afternoon bacterial load | ||||||
School 1 | 5 | 1510.60 | 1267.53 | 728 | 3757 | 1001 |
School 2 | 7 | 5404.29 | 2320.31 | 2301 | 8502 | 5460 |
School 3 | 3 | 507.00 | 144.76 | 351 | 637 | 533 |
School 4 | 8 | 5073.25 | 2517.63 | 2600 | 9984 | 4082 |
School 5 | 7 | 7740.57 | 7228.03 | 2340 | 23,504 | 5304 |
School 6 | 8 | 1158.63 | 709.06 | 260 | 2652 | 994.5 |
School 7 | 7 | 4561.57 | 2031.61 | 819 | 7332 | 4332 |
School 8 | 6 | 7895.33 | 1403.10 | 5720 | 9880 | 7943 |
Total | 51 | 4514.63 | 3918.20 | 260 | 23,504 | 3939 |
Analysis of Variance | |||||
---|---|---|---|---|---|
Source variation | Sum of Square | Degree of freedom | Mean Square | F | Sig. |
Between groups | 189,395,110 | 7 | 27,056,444.3 | 7.67 | < 0.001 |
Within groups | 151,708,969 | 43 | 3,528,115.56 | ||
Total | 341,104,079 | 50 | 6,822,081.58 |
Physical parameters of indoor air environments
Variables | Mean | Standard Deviation | Median | Minimum | Maximum |
---|---|---|---|---|---|
CO2 6:30 am | 458.54 | 30.44 | 453 | 406 | 550 |
CO2 5:00 pm | 429.12 | 27.05 | 422 | 401 | 548 |
T °C 6:30 am | 14.27 | 0.94 | 14 | 12 | 16 |
T °C 5:00 pm | 19.02 | 3.08 | 20 | 15 | 24 |
RH%6:30 am | 39.37 | 14.25 | 45 | 21 | 61 |
RH%5:00 pm | 36.37 | 13.89 | 39 | 14 | 57 |
PM2.5 6:30 am | 68.18 | 43.42 | 48 | 18 | 173 |
PM2.5 5:00 pm | 12.82 | 3.38 | 13 | 7 | 22 |
PM10 6:30 am | 138.06 | 68.64 | 129 | 42 | 277 |
PM10 5:00 pm | 55.92 | 22.06 | 51 | 21 | 144 |
Isolated bacterial species
School ID | Number of classrooms | Bacterial Isolates | ||
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SA | BA | CoNS | ||
School 1 | 5 |
–
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+
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+
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School 2 | 7 |
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+
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+
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School 3 | 3 |
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+
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+
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School 4 | 8 |
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+
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+
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School 5 | 7 |
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+
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–
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School 6 | 8 |
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+
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+
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School 7 | 7 |
+
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+
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+
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School 8 | 6 |
+
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+
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–
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Total | 51 | 7 | 8 | 6 |
Bacterial | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Sampling time | 6:30–7:30 am | 5:00–6:00 pm | |||||||||
Range of values (CFU/m3) | < 50 | 50–100 | 100–500 | 500–2000 | > 2000 | < 50 | 50–100 | 100–500 | 500–2000 | > 2000 | |
Degree of Air Pollution | Very low | Low | Intermediate | High | Very high | Very low | Low | Intermediate | High | Very high | |
School | School 1 |
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School 2 |
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School 3 |
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School 4 |
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School 5 |
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School 6 |
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School 7 |
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School 8 |
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Variables | Bacteria | CO2 | T (°C) | RH (%) | PM2.5 | PM10 |
---|---|---|---|---|---|---|
Morning | ||||||
Bacteria | 1.00 | |||||
CO2 | 0.1049 | 1.00 | ||||
T °C | 0.0007 | −0.0928 | 1.00 | |||
RH% | −0.7034a | 0.2237 | −0.0839 | 1.00 | ||
PM2.5 | 0.5723a | 0.2226 | −0.0767 | − 0.3634a | 1.00 | |
PM10 | 0.6856a | 0.1573 | −0.0762 | −0.5493a | 0.9447a | 1.00 |
Afternoon | ||||||
Bacteria | 1.00 | |||||
CO2 | −0.1641 | 1.00 | ||||
T °C | 0.3838a | −0.1820 | 1.00 | |||
RH% | −0.4014a | 0.4510a | −0.8420a | 1.00 | ||
PM2.5 | −0.1100 | 0.6676a | −0.2036 | 0.4368a | 1.00 | |
PM10 | 0.1856 | 0.5418a | 0.2903a | −0.0771 | 0.4460a | 1.00 |