Prevalence of chronic respiratory symptoms among cement factory workers in Gauteng Province, South Africa

Figures & data

Figure 1. Location of the companies that participated in this study (map obtained from www.joburg.org) *alphabets represent regions. *95% CI= (0.53–10.93), **95% CI= (0.46–14.36), and ***95% CI= (1.2–10.63).

Table 1. Clinical and demographic characteristics of the study population.

Characteristics	Facility A (%) N = 31	Facility B (%) N = 50
Age, Median(Range)	39(31–49)	37(33–47)
<30 years	3(10)	6(12)
30–40years	13(42)	23(46)
≥40years	15(48)	21(42)
Gender
Female	4(13)	4(8)
Male	27(87)	45(92)
Ethnicity
Black	31(100)	38(96)
White	0(0)	2(4)
Colored	0(0)	2(4)
Indian/Asian	0(0)	8(16)
Highest level of education
Grade 11/standard 9 or lower	14(45)	17(34)
Grade 12 (Matric, standard 10)	11(35)	29(58)
Post Matric Diploma or certificate	6(19)	4(8)
Work History	n = 30	n = 49
<3 years	4(13)	12(24)
3–5 years	3(10)	20(41)
5–10 years	12(40)	14(29)
>10 years	11(37)	3(6)
Blood pressure (Median)
Systolic	132(120–139)	134(120–140)
Diastolic	77(74–85)	84(74–90)
Pulse, Median (Range)	71(66–81)	75(67–80)
Smoking
Yes	7 (23)	20(40)
No	23(74)	29(58)
Missing data	1(3)	1(2)
Median cigarettes per day	10(3–15)	10(5.5–18)
Smoking History(years)
Median (Range)	19(9–28)	16(8.5–21)
1–10	2(6)	5(10)
10–20	2(6)	8(16)
>20	3(10)	7(14)
Missing	24(77)	30(60)
Average cigarettes per day
<10	3(10)	9(18)
≥10	4(13)	11(22)
Missing	24(77)	30(60)
BMI
Underweight	0(0.00)	1(2)
Normal	13(50)	23(46)
Overweight	6(19.)	14(28)
Obese	12(39)	11(22)
missing	0(0)	1(2)
Area of residence
Suburb	7(23)	16(35)
Township	23(77)	30(65)
Suffered respiratory problems due to previous employment
Yes	0(0)	4(8)
No	29(100)	46(92)
Personal Protective Equipment Used (PPE)Mask
Yes	30(97)	23(46)
No	1(3)	27(54)
How often the mask changed
Daily	29(94)	10(21)
Weekly	0(0)	8(16)
Monthly	0(0)	2(4)
None	2(6)	29(59)
Lost time due to respiratory disease
Yes	0(0)	3(6)
No	22(71)	41(82)
Missing data	9 (29)	6(12)
Occupation
Admin/driver	1(3)	10(20)
Operators	30(97)	40(80)

Table 2. Association between job title and respiratory symptoms amongst workers from both facilities.

Factor	Admin/Drivers (n = 11)	Operator (n = 70)	Total	p-value
Bouts of cough
No	7(64)	58(83)	65(80)
Yes	4(36)	12(17)	16(20)	0.14
Chest pain
No	8(723)	57(81)	65(80)
Yes	3(27)	13(19)	16(20)	0.50
Blocked nose
No	5(46)	58(83)	63(78)
Yes	6(55)	12(17)	18(22)	0.01*
Chest tightness
No	8(73)	62(89)	70(86)
Yes	3(27)	8(11)	11(14)	0.15
Wheezing
No	8(73)	66(94)	74(91)
Yes	3(27)	4(6)	7(9)	0.02*
Phlegm
No	8(73)	65(93)	73(90)
Yes	3(27)	5(7)	8(10)	0.04*
Sneezing
No	8(73)	46(66)	54(67)
Yes	3(27)	24(34)	27(33)	0.65
Fatigue/tiredness
No	6(55)	47(67)	53(65)
Yes	5(46)	23(33)	28(35	0.41
Rapid breathing
No	10(91)	65(93)	75(93)
Yes	1(9)	5(7)	6(7)	0.82
Soreness/ watery eyes
No	10(91)	64(91)	74(91)
Yes	1(9)	6(9)	7(9)	0.96
Breathlessness
No	8(73)	66(94)	74(91)
Yes	3(27)	4(6)	7(9)	0.02*

*Chi-square significant.

Table 3. Reported symptoms of the respiratory system.

Clinical respiratory symptoms	Facility A	Facility B	Total	p-value
Bouts of cough
No	24(77)	41(82)	65(80)
Yes	7(23)	9(18)	16(20)	0.62
Chest pain
No	24(77)	41(82)	65(80)
Yes	7(23)	9(18)	16(20)	0.62
Recurring blocked nose
No	28(90)	35(70)	63(78)
Yes	3(10)	15(30)	18(22)	0.03*
Chest tightness
No	29(94)	41(82)	70(86)
Yes	2(7)	9(18)	11(14)	0.14
Wheezing
No	31(100)	43(86)	74(91)
Yes	0(0)	7(14)	7(9)	0.03*
Phlegm
No	30(97)	43(86)	73(90)
Yes	1(3)	7(14)	8(10)	0.11
Sneezing/stuffy nose
No	27(87)	27(54)	54(67)
Yes	4(13)	23(46)	27(33)	0.01*
Fatigue/tiredness
No	25(81	28(56)	53(65)
Yes	6(19)	22(44)	28(35)	0.02*
Rapid breathing
No	31(100)	44(88)	75(93)
Yes	0(0)	6(12)	6(7)	0.05*
Soreness/watery eyes
No	31(100)	43(86)	74(91)
Yes	0(0)	7(14)	7(9)	0.03*
Breathlessness
No	31 (100)	43(86)	74(91)
Yes	0(0)	7(14)	7(9)	0.03*

*Significant, **Marginally significant.

Figure 2. Factors associated with clinical respiratory symptoms.

Table 4. Correlation between pulmonary function indices and demographic characteristics.

Variables	FEV1 (% predicted)	FEV1/FVC (% predicted)	FVC (% predicted)
Age
Correlation	0.09	0.21	−0.03
Sig (2 tailed)	0.45	0.07	0.08**
Smoking
Correlation	0.21	−0.54	0.22
Sig (2 tailed)	0.07	0.01	0.05*
Number of cigarettes
Correlation	−0.57	−0.20	−0.56
Sig (2 tailed)	0.00	0.34	0.00*
BMI
Correlation	0.07	−0.01	0.08
Sig (2 tailed)	0.52	0.91	0.49
PPE (FFP2 mask)
Correlation	0.31	0.10	0.35
Sig (2 tailed)	0.01	0.39	0.00*
Change of mask
Correlation	−0.34	−0.07	−0.38
Sig (2 tailed)	0.01	0.53	0.01*
Work history
Correlation	0.21	−0.14	0.13
Sig (2 tailed)	0.07	0.23	0.25

*Significant, **marginally significant.

Data availability statement

None.