An assessment of dust exposure levels and factors associated with the occurrence of respiratory symptoms among workers in the road construction industry in Lusaka, Zambia
Date
2019
Authors
Nsofwa, Nsunge
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Research into dust exposure in the road construction industry and the prevalence of respiratory
symptoms in Zambia has not been extensively conducted despite the respiratory symptoms
forming the primary burden of occupational illnesses in Zambia. The absence of literature in this
industry on occupational respiratory health symptoms and database for these workers formed the
rationale for this present study.
This study assessed respirable dust exposure levels and factors associated with the occurrence of
occupation respiratory health symptoms in Lusaka district (n=145). A cross sectional survey
among road construction workers, conducted at three road construction sites; (Lusaka-Chisamba),
(Lusaka- Kafue) and (Matero - Lilanda) roads. Personal dust samplers were used to assess the dust
exposure levels and an adapted American thoracic health questionnaire was used to capture
respiratory symptoms and factors associated with the occurrence of respiratory health symptoms.
Spirometry test was also used to determine the lung function capacity of the road construction
workers. Fisher’s exact test was used to test for bivariate associations and logistic regression was
used for crude and adjusted multivariate analysis between social demographic factors, job
category, cumulative respirable dust, use of PPE, smoking and years exposed.
The prevalence of respiratory symptoms was nose irritation (59.3%), wheezing (45%) phlegm 29%
and shortness of breath (39.3%).The mean respirable dust exposure level was 1.768mg-yr/m3.
Exposure to a cumulative respirable dust concentration of ≥1.768mg-yrs/m3 was significantly
associated with shortness of breath (OR 1.317; 95% CI; 0.125-0.802), (p-value (0.015). On factors
associated with the occurrence of respiratory symptoms, education levels (tertiary education) was
significantly associated with nose irritation (OR 0.257,95%CI; 0.076-0.862), (p-value 0.028) and
job category (land clearing works) (OR 2.382; 95% CI;0.159-0.919), (P-value 0.032).The non-use
of personal protective equipment by workers was significantly associated with respiratory
symptom phlegm (OR 1.256, 95% CI;3.526-3.384), (p-value (0.007) and wheezing (OR
3.775,95% CI; 1.416-1.958), (p-value 0.008). The spirometry test results showed that 96% of the
road construction workers had normal lung function, while only 4% of the workers had mildly to
moderate lung impairment with the force expiratory volume ratio (FEV1) between 60% - 79%.
It is therefore, recommended that dust control measures be put in place at road construction sites in
order to prevent dust exposure and the occurrence of respiratory symptoms and diseases.
Key words: Dust Exposure, Factors Associated, Respiratory Symptoms, Prevalence and Use of
PPE
Description
Thesis
Keywords
Occupation health--Zambia , Environmental health , Dust exposure--construction workers