Malaysia is the world’s third largest exporter of liquified natural gas and the second largest oil and natural gas producer in Southeast Asia, following Indonesia. The potential air pollutants released from the industry may affect the health of the population. The primary objective of this study was to determine the potential health risk among the population in the zone of impact. This was a comparative case study between controlled and uncontrolled emissions based on the air dispersion modelling. Hazard quotient (HQ) was used to assess non-carcinogenic risk, while lifetime cancer risk (LCR) was used to assess carcinogenic risk. All ambient air pollutant levels were within permissible levels and adhered to the standard. The HQ for hydrogen sulphide and benzene was less than one in all scenarios. The LCR for benzene was acceptable in all scenarios. Advanced pollution prevention equipment should be installed within the gas emission system to treat the final emission to meet prescribed permissible limits. Continuous ambient air monitoring and effective control measures should be practiced to ensure the sustainability of clean air. The health risk assessment showed no risk of developing malignancy and non-cancer disorder among the workers and general population living surround the petrochemical plants. This allows the development of the petroleum refinery plants to be continued.
Zika virus (ZIKV) has had a history in Malaysia since its first isolation in 1966. However, it is believed that the immunity status among forest fringe communities has been underreported. We conducted cross-sectional surveillance of forest fringe communities from 10 Orang Asli villages and their peripheral communities in Perak, Pahang, and Sabah in Malaysia. A total of 706 samples were collected from 2019 to 2020 and screened for ZIKV exposure using an anti-ZIKV IgG ELISA kit. A neutralization assay against ZIKV was used to confirm the reactive samples. The seroprevalence results reported from the study of this population in Malaysia were 21.0% (n = 148, 95% CI, 0.183-0.273) after confirmation with a foci reduction neutralization test. The presence of neutralizing antibodies provides evidence that the studied forest fringe communities in Malaysia have been exposed to ZIKV. Multivariate analysis showed that those older than 44 years and those with an education below the university level had been exposed significantly to ZIKV. In addition, higher seropositivity rates to ZIKV were also reported among secondary school students from Bentong (Pahang) and residents from Segaliud (Sabah). No associations were identified between Zika seropositivity and gender, household size, house radius to the jungle, and income level. The presence of neutralizing antibodies against ZIKV among the study population might indicate that the causative pathogen had already circulated widely in forest fringe regions. Intervention for vector control, protection from mosquito bites, and awareness improvement should be encouraged in this population.