Associations of Cement Dust with Occurrence of Respiratory Conditions and Lung Function

Objective: To determine associations between cement dust on one hand and occurrence of respiratory conditions and lung function on the other.
Methods: Cross sectional and case series studies were conducted among employees of Chilanga cement company and persons residing close to the cement factory (exposed population to cement dust) and among residents of Chelstone (control population). Respondents were of age 15 to 59 years and stayed in the study areas for at least two years. Both systematic random samples (households and Chilanga clinic records) and a convenient sample (Chilanga workers and Chelstone clinic records) were drawn. A multivariate logistic regression was used to determine associations between cement dust on one hand and phlegm and lung function on the other.
Results: Totals of 243 respondents who were exposed to cement dust and 334 controls were interviewed. Out of 243 exposed persons, 8 (3.3%) had lung function impairment, compared to 29 (8.7%) controls. After adjusting for sex in which males were 3.45 (95%CI 1.53 to 7.77) times more likely to have had impaired lung function than females, exposed individuals were 62% less likely to have had impaired lung function than the controls (OR=0.38, 95%CI 0.17 to 0.86). Meanwhile, exposed persons were 2.24 (95%CI 1.46 to 3.44) times more likely to have had phlegm in the previous two weeks before the study. No significant differences in the rates of cough, wheezing, dyspnoea, shortness of breath, asthma, sinusitis and bronchitis were observed between exposed and non-exposed individuals.
Conclusion: No association was observed between cement dust and lung function impairment, partly because of the dust reduction measures that were in place in the Chilanga cement factory, and partly because most respondents had a short time of exposure to cement dust.