Abstract
Background: Cleaner production technologies (CPT) techniques have become a critical topic
lately to address the magnitude of air pollution produced during the production of goods in
industries. In one cement manufacturing company in Zimbabwe, CPT interventions were
implemented, yet their effectiveness in addressing air pollution was never assessed. Conducting
this assessment formed the thrust of this research.
Aim: The study was aimed at assessing the effectiveness of selected air pollution abatement
and cleaner production interventions in the reduction of air pollution at a cement manufacturing
company in Gweru, Zimbabwe.
Methodology: Data for this study was from both primary and secondary sources, collected
strictly from permanent employees (162) of the company and its archived records, respectively.
The purposive sampling technique was used to select the respondents, with the sample size
then divided proportionately using stratified sampling amongst the departments in the company
to avoid oversampling of any 1 department. The final sample size was then determined using
Epi Info version 7.2.
The questionnaire data was analysed using the statistical library “psycho”, where a t-test was
done to determine the chemical concentrations of nitrogen oxides and sulfur oxides before and
after compliance was effected in 2009. The Cronbach's Alpha (α) test yielded a value of 0.673,
which is an acceptable indicator of the reliability of the questionnaire.
Results: In terms of the findings, the study found that the company workforce was relatively
new, with less than two years of experience. This most had a negative effect on their knowledge
and understanding of the company's operations and practices. Nevertheless, 62% of the
participants concurred that the implemented initiatives were successful in lowering the
concentrations of certain pollutants like particulates and sulphur oxide. Another 85% argued
that the interventions reduced the levels of fugitive dust through dust suppression. Most
employees thought that the implemented changes were an effective way to reduce pollution,
and they also largely agreed that the company should continue making such changes.
Furthermore, the results s indicate that nitrogen oxide levels showed no significant change post-
2009, with mean concentrations at the kiln (before 2009: 83.45 ± 23.30, after 2009: 92.41 ±
26.46) and slag dryer (before 2009: 67.70 ± 20.28, after 2009: 95.38 ± 26.10). However, there
was a substantial reduction in particulate concentrations at the kiln (before 2009: 107.20 ±
10.22, after 2009: 44.09 ± 33.30), supported by a significant (p < 0.05) reduction, while the
slag dryer showed no significant change (before 2009: 121.65 ± 10.80, after 2009: 66.70 ±
33.46). Notably, sulfur oxide concentrations decreased significantly (p < 0.05) at both kiln
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(before 2009: 45.95 ± 8.01, after 2009: 21.06 ± 12.78) and slag dryer (before 2009: 35.65 ±
4.93, after 2009: 14.77 ± 9.53) following compliance measures in 2009. These findings
underscore the effectiveness of compliance measures in reducing emissions, highlighting the
nuanced impact of interventions.
Conclusions: Based on these findings, the study recommended maintenance of the
implemented air pollution abatement and CPT interventions due to their effectiveness in
reducing particulate and sulphur oxide concentrations at the kiln and slag dryer. The study did
not reveal a significant difference between before and after compliance, hence more potent
alternatives should be taken into consideration to lower nitrogen oxide content.