Associations of limestone dust and occurrence of respiratory conditions among stone crushers in Lusaka,Zambia

The study looked at the associations of limestone dust and occurrence of respiratory conditions among the stone crushers in Lusaka, Zambia. There have been some reports that inhalation of limestone dust might cause respiratory conditions such as cough, phlegm production, breathlessness and chest tightness and abnormal lung function
The study was a Cross Sectional Comparative Study involving 200 exposed (stone crushers) and 200 unexposed participants to limestone dust aged between 16 and 59 years living in Misisi Compound.Convenience and Systematic Random Sampling techniques were used to select study participants. A structured interview schedule (respiratory questionnaire) and portable spirometer (manual winspiro) were used to collect data on the respiratory conditions and Lung function impairment among participants.
The study findings showed that more participants exposed to limestone dust reported having cough, phlegm production, chest tightness, and breathlessness for a period ranging from three months to one year as compared to unexposed participants (cough 77.0% vs 24.5%; phlegm production 69.5% vs 17.5%; chest tightness 61.5 % vs 14.5% and breathlessness 20.5% vs 3.5%).More participants with the history of smoking in the exposed group reported having combination of respiratory conditions than participants in unexposed group (combination of two respiratory conditions 78.0%) vs 25.0%>; combination of three respiratory conditions 63.7% vs 25.0% and combination of four respiratory conditions 23.1% vs 6.3%).
Significantly, more exposed participants (73.3%) had abnormal lung function in comparison to unexposed participants (50.9%). Similarly, more exposed participants with combination of respiratory conditions had abnormal lung function than unexposed participants (combination of two respiratory conditions 71.2% vs 18.2%; combination of three respiratory conditions 56.2% vs 10.9% and combination of four respiratory conditions 18.5% vs 3.6%).
In conclusion, there was high prevalence of respiratory conditions and abnormal lung function among exposed participants in comparison to unexposed participants. The findings could be attributed to exposed participants' continuous exposure to limestone dust without protective measures for at least six months. Smoking also facilitated the occurrence of respiratory conditions and abnormal lung function among exposed participants.