Bricks have been manufactured in Nepal for hundreds of years. Large quantities of hazardous materials including high concentrations of particulate matter are emitted daily from brick kilns. Exposure to these hazardous materials can lead to adverse environmental and human health consequences. This study was conducted to estimate the prevalence of respiratory symptoms/illnesses and the magnitude of respirable and total dust exposures among Nepalese brick kiln workers.Methods
Respiratory symptoms/illnesses were evaluated by questionnaire among brickfield workers (n=400) and a referent group of grocery workers (n=400) in Kathmandu valley. Work zones (WZs): green brick moulding (GBM), green brick stacking/carrying (GBS/C), red brick loading/carrying (RBL/C), coal preparation (CP) and firemen (FM) were the similar exposure groups (SEGs) from where personal air samples and interviews were taken, among brickfield workers, personal monitoring was conducted across SEGs for total (n=89) and respirable (n=72). Applying multi-stage probability proportionate to size sampling technique, 16 kilns and 400 brick workers for interview were selected.Result
Chronic cough (14.3%), phlegm (16.6%) and bronchitis (19.0%) were higher (p<0.05) among brickfield compared with grocery workers (6.8, 5.8 and 10.8%). Mean respirable (5.888 mg/m3) and total (20.657 mg/m3) dust exposures were highest for red brick loading tasks. The prevalence of chronic cough, chronic phlegm, chronic bronchitis, wheezing and asthma were significantly higher for other WZs workers (p<0.05) compared with CP; for GBM: 22.9, 34.6, 15.0% and 7.5%; for GBS/C: 13.5, 15.8, 10.0, 8.8 and 7.5%; for RBL/C: 11.1, 17.1, 27.4, 19.0% and 11.9%; for FM: 18.4, 12.5, 28.4, 4.9 and 0.0%; and for CP:4.9, 6.3, 13.3, 9.3 and 4.0% respectively.Discussion
High dust exposures identified in this study may explain the increased prevalence of respiratory symptoms/illnesses among Nepalese brickfield workers, warranting action to reduce exposures.