Occupation

N

AM (95% CI),

mg/m³

GM (95% CI),

mg/m³

GSD, mg/m³

% (n) > PEL

Respirable dust (p = 0.004)

Maintenance laborer

197

1.23

(0.87 - 0.1.60)

0.44

(0.36 - 0.53)

0.58

8.1 (16)

Operators

98

0.61

(0.40 - 0.83)

0.27

(0.21 - 0.34)

0.54

2.0 (2)

Heavy vehicle drivers

58

0.37

(0.25 - 0.48)

0.22

(0.17 - 0.29)

0.41

-

Crusher

40

0.88

(0.53 - 1.23)

0.43

(0.29 - 0.64)

0.53

5.0 (2)

Welder

39

1.15

(0.48 - 1.82)

0.50

(0.33 - 0.77)

0.57

10.3 (4)

Miller

27

0.60

(0.31 - 0.88)

0.36

(0.24 - 0.54)

0.45

3.7 (1)

Drill machinist

22

0.89

(0.34 - 1.43)

0.32

(0.16 - 0.63)

0.66

4.5 (1)

Crane machinist

20

0.32

(0.23 - 0.42)

0.25

(0.17 - 0.37)

0.37

-

Blaster

17

1.62

(0.05 - 3.20)

0.31

(0.12 - 0.78)

0.78

17.6 (3)

Steel smelter

10

2.75

(0.81 - 4.69)

1.58

(0.62 - 4.02)

0.57

40.0 (4)

Ore sampler

12

0.94

(0.08 - 1.80)

0.41

(0.17 - 0.98)

0.59

8.3 (1)

Filterer

10

0.24

(0.10 - 0.39)

0.19

(0.11 - 0.32)

0.33

-

Surveyor

9

0.28

(−0.10 - 0.66)

0.13

(0.06 - 0.31)

0.47

-

Rigger and spotter

11

0.89

(0.27 - 1.51)

0.55

(0.27 - 1.09)

0.45

-

Other

11

0.33

(0.17 - 0.49)

0.24

(0.13 - 0.44)

0.38

-

Respirable crystalline silica (p = 0.0001)

Maintenance laborer

90

0.051

(0.029 - 0.072)

0.011

(0.008 - 0.017)

0.74

12.2 (11)

Operators

32

0.098

(0.044 - 0.152)

0.027

(0.013 - 0.052)

0.81

34.4 (11)

Heavy vehicle drivers

33

0.011

(0.004 - 0.018)

0.004

(0.003 - 0.007)

0.55

-

Crusher

24

0.105

(0.071 - 0.139)

0.073

(0.048 - 0.111)

0.43

41.7 (10)

Welder

19

0.018

(0.002 - 0.035)

0.009

(0.004 - 0.015)

0.53

5.3 (1)

Miller

11

0.021

(−0.014 - 0.057)

0.006

(0.002 - 0.015)

0.62

9.1 (1)

Drill machinist

14

0.064

(0.035 - 0.093)

0.032

(0.012 - 0.082)

0.71

21.4 (3)

Blaster

8

0.018

(−0.014 - 0.050)

0.005

(0.001 - 0.018)

0.67

12.5 (1)

Steel smelter

8

0.046

(0.017 - 0.076)

0.033

(0.014 - 0.076)

0.44

-

Ore sampler

7

0.017

(0.005 - 0.029)

0.014

(0.007 - 0.027)

0.33

-

Filterer

10

0.024

(−0.007 - 0.055)

0.006

(0.002 - 0.022)

0.73

10.0 (1)

Other

8

0.012

(−0.001 - 0.027)

0.013

(0.002 - 0.019)

0.61

-