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. Author manuscript; available in PMC: 2014 May 1.
Published in final edited form as: Atmos Environ (1994). 2013 Jan 17;70:179–185. doi: 10.1016/j.atmosenv.2012.12.044

Table 2.

Indoor and outdoor concentrations of PM2.5 (ug/m3) in public and slum housing reported by households

Groups PM 2.5 (μg/m3)
N Mean SD Med p25 p75
Overall study
Indoor 169 64.8 36.6 58.8 38.1 81.2
Outdoor 169 57.6 34.8 45.9 35.3 70.2
Differences
Indoor-Outdoor		 169 7.3 35.5 4.1 −7.1 20.4
Public housing
Indoor 98 55.7** 34.6 46.7 29.4 71.2
Outdoor 98 51.5ı 31.3 37.7 34.4 57.5
Differences
Indoor-Outdoor		 98 4.2 33.6 2.3 −7.5 15.6
Slum housing
Indoor 71 77.8** 35.7 67.8 54.9 101.1
Outdoor 71 66.1 ı 37.9 59.4 39.2 80.5
Differences
Indoor-Outdoor		 71 11.6* 37.8 6.5 −5.6 27.9

Abbreviations: SD, standard deviation; Med, median; p25, 25th percentile; p75, 75th percentile.

*

Difference between indoor-outdoor within group is significant at Mann-Whitney test (* p-value <0.05)

**

Difference between public housing’s indoor vs slums houses’s indoor is significant at Mann-Whitney test (**p-value<0.01)

ı

Difference between public housing’s outdoor vs slums houses’s outdoor is significant at Mann-Whitney test (**p-value<0.01)