Risk assessment of upper respiratory health problems among workers exposed to biogas residues at palm oil plants in Sabah, Malaysia

A cross-sectional study was carried out on the respiratory effects of biogas plant environment exposure in palm oil mills. The aim of this study was to determine whether respiratory health effects were more common among workers in biogas plant environment. Workers from 19 palm oil mills in Sabah with biogas plants were compared between exposure and unexposed of the biogas plant environment. They were evaluated using a standardised questionnaire, physical examination, oximetry measurements, and spirometry tests. All the data collected were analysed by using SPSS version 22. The results from the statistical analysis showed that there was a significant association between biogas plant environment exposure and lung function test (LFT) result using Pearson Chi-square (p = 0.019, x2 = 5.51) with risk estimates in risk effect (OR = 1.96, 95% CI 1.12, 3.45). There was a higher proportion of abnormal lung function test result in the exposed group as compared to workers in the unexposed group. Workers in biogas plants were two times at higher odds of having abnormal lung function test result as compared to those in the unexposed group. Hence, the results of this assessment shall be used in planning and implementing the optimal control measures to minimise the risk of respiratory disease in biogas plant environment exposure.