Table 3 24 hr indoor NO₂ concentrations related to household characteristics in a bivariate analysis, Butajira, Ethiopia, 2000-2002 (n = 16899)

Ecology

   Highland

9018

1.89 (0.45)

77.2 (2.82)

p < 0.0001

   Lowland

7857

1.70 (0.43)

50.5 (2.67)

Total

16875

1.80 (0.45)

63.3 (2.81)

Biomass fuel type

   Only wood

8379

1.85 (0.45)

71.2 (2.8)

p < 0.0001

p < 0.0001

   Only cow dung

297

1.83 (0.47)

67.5 (2.9)

   Only Crop residues

7400

1.75 (0.44)

56.1 (2.7)

Total

16076

1.80(0.45)

63.7 (2.8)

Purpose of having fire

   Any one activity

9256

1.84 (0.44)

69.2 (2.7)

p < 0.0001

p < 0.0001

   Any two activity

6657

1.76 (0.46)

57.1 (2.9)

   Any three and above

886

1.75 (0.45)

55.6(2.8)

Total

16799

1.80 (0.45)

63.4 (2.8)

Type of foods cooked

   Any one food item

649

1.76 (0.46)

58.1 (2.9)

p < 0.0001

p < 0.0001

   Any two food item

2442

1.74 (0.44)

54.7 (2.7)

   Any three food item

11806

1.81 (0.45)

65.3 (2.8)

   Any 4 food & above

1263

1.90 (0.43)

80.0 (2.7)

Total

16160

1.81 (0.45)

64.3 (2.8)

Time of having fire

   Any one time

322

1.50 (0.52)

30.8 (3.3)

p < 0.0001

p < 0.0001

   Any two time

2418

1.75 (0.42)

56.2 (2.6)

   Any three time

13530

1.82 (0.45)

65.7 (2.8)

   Any four times

605

1.82 (0.42)

66.2 (2.6)

Total

16875

1.80 (0.45)

63.3 (2.8)

Season

Dry season

8160

1.78 (0.45)

59.64 (2.8)

p < 0.0001

Wet season

8715

1.83 (0.45)

70.0 (2.8)

Total

16875

1.80 (0.45)

63.3 (2.8)