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The concentration of PM 2.5 (particulate matter with a diameter < 2.5 µm) on Sumatra Island has increased, mainly because of forest and peatland fires, transportation, and industry. Biomass burning releases partially burned carbon into the atmosphere, resulting in a smoky haze containing PM 2.5 . Air quality has deteriorated quickly, and PM 2.5 has become a major health hazard in Indonesia. Studies on long-term exposure to PM 2.5 have indicated its associations with both morbidity and mortality. Here, we measured long-term (2000-2014) exposure to PM 2.5 on the basis of satellite-derived aerosol optical depth measurements (1 × 1 km 2 ) used to predict ground-level PM 2.5 concentrations. Additionally, population data on Sumatra Island residents from the fourth wave of the Indonesian Family Life Survey (IFLS) were obtained. We investigated the association between long-term PM 2.5 exposure and mortality with a retrospective cohort study design. A total of 2409 subjects aged ≥ 40 years participated in the IFLS-3 beginning in November 2000, and we examined mortality outcomes until the IFLS-5 in September 2014. We used Cox regression models to calculate hazard ratios (HRs) of mortality associated with PM 2.5 exposure. According to the adjusted model, the mortality HRs per 10 µg/m 3 increase in PM 2.5 concentration were 1.10 (95% CI 1.03, 1.17) for all natural causes, 1.17 (95% CI 1.05, 1.25) for cardiovascular causes, and 1.19 (95% CI 1.04, 1.36) for respiratory causes. Long-term exposure to PM 2.5 was associated with all-natural, cardiovascular, and respiratory mortality on Sumatra Island, where PM 2.5 levels exceed the WHO and US-EPA air quality standards., (© 2024. The Author(s).)

Exposure to particulate matter with a diameter < 2.5 µm (PM 2.5 ) increases the risk of cardiovascular disease (CVD), which is the leading cause of both morbidity and mortality in Indonesia, accounting for one-third of all deaths. Indonesian authorities started to monitor PM 2.5 levels in urban areas in 2015. However, there is still no study examining the association between long-term PM 2.5 exposure and CVD in Indonesia. In this study, we combined PM 2.5 data and health survey data. Long-term (2000-2007) exposure to PM 2.5 was measured based on satellite-derived aerosol optical depth measurements (1 × 1 km 2 ) that could be used to predict ground-level PM 2.5 concentrations. Population data on residents of Sumatra Island were obtained from the fourth wave of the Indonesian Family Life Survey (IFLS). A cross-sectional study was performed with 2324 participants who were aged ≥ 40 years old, and a report of doctor-diagnosed CVD determined CVD status. We used logistic regression to analyze the association between PM 2.5 and CVD prevalence, adjusting for multiple covariates. Of the sample, 52.1% were women, and 47.9% were men. The sample was divided into those aged 40-59 (adults) and those ≥ 60 (older adults). The CVD prevalence was 4.05% (n = 94), with a mean (standard deviation) PM 2.5 concentration of 14.4 (6.4) µg/m 3 . In adjusted models, a 10-µg/m 3 increase in annual average PM 2.5 levels was associated with 29% higher odds of having CVD (odds ratio = 1.29; 95% confidence interval: 1.02, 1.47). In this population-based IFLS data, long-term exposure to PM 2.5 is associated with a higher prevalence of CVD in Sumatera, Indonesia., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Open-air burning of rice straw (RS) on sites after harvesting produces tremendous amounts of air pollutants in Southeast Asia. Additionally, cooking oil smoke (COS) from high-temperature frying is classified as "Probably carcinogenic to humans" (Group 2A) by the International Agency for Research on Cancer. To mitigate the air pollution from COS, RS was recycled to prepare activated carbon (AC), which was used as a bed filter (BF) packing material for COS removal, and to our best knowledge, this study is the first one. Besides, a negative air ionizer (NAI) was firstly utilized to enhance the removal efficiency (η) of COS particles. Other biomass waste, including tea leaves (TL), wood dust (WD), rice hulls (RH), and coffee grounds (CG), were also used as packing materials for comparison. Specific surface area and pore volume of the packing materials were determined by nitrogen adsorption/desorption isothermal. Laser airborne particle counters and volatile organic compound (VOC) monitors (photoionization detector) were utilized for real-time recording of the particle and VOC concentration of COS. Economic assessments for the control of COS was also conducted. For submicron particles, the removal efficiency of the BFs ranged from 0 to 98% and the AC filter had the highest quality factor. The NAI remarkably enhanced the η value and filter quality factor. For the removal of particles larger than 2.5 μm, all BFs had η > 96%. The removal efficiency of volatile organic compounds (VOCs) (η VOC ) of the test BFs ranged from 18.22 to 90.8%. The AC filter had the largest pore volume (0.432 cm 3 /g) and surface area (877 m 2 /g) among all packing materials, causing this filter to have the highest η VOC and adsorption capacity (over 28.3 mg-VOCs/g-AC). The annual operating costs of the TL, WD, RH, CG, and AC filters were 319.4, 23.3, 29.1, 189.4, and 62.9 US$, respectively. Therefore, using RS to prepare an AC bed filter for the removal of COS is a practical and sustainable strategy for COS control.

Fungal spores are known as critical indoor allergens, and indoor air purification techniques including photocatalytic disinfection using titanium dioxide (TiO2), ultraviolet germicidal irradiation (UVGI) and ozonation, have been considerably investigated. However, most of the research is in regard to photocatalytic disinfection, focused on the anti-bacterial efficacy of TiO2 nanoparticles (NPs). Furthermore, some research even showed that the photocatalytic antifungal efficacy of TiO2 NPs may not be that significant. Thus, investigating the reasons behind the non-significant antifungal efficacy of TiO2 photocatalytic disinfection and enhancing the antifungal efficacy is indispensable. In this study, ozone was employed to improve the photocatalytic antifungal efficacy of the TiO2 NPs and nano-metal supported on TiO2 NPs. The commercial TiO2 NPs (Degussa (Evonik) P25) served as a good support, and incipient wetness impregnation was successfully exploited to prepare oxidized nano-metals (Ag, Cu and Ni) in this study. There were two surfaces (quartz and putty) used in the inactivation experiments of Aspergillus niger spores which were manipulated under two conditions: exposed to ultraviolet (UVC) light , and exposed to UVC and ozone simultaneously. The SEM images demonstrated that the spores were sheltered from UVC light in the microcracks between TiO2 agglomerates. When irradiating with UVC, the A. niger spores on the two testing surfaces, without TiO2 NPs, were inactivated faster than those with TiO2 NPs, implying a "sun block" effect of this material and a lower photocatalytic antifungal efficacy than UVGI. On both surfaces, the inactivation rate constants (k) of A. niger spores exposed to UVC and ozone simultaneously (on quartz: k = 2.09-6.94 h(-1), on putty: k = 3.17-6.66 h(-1)) were better than those exposed to only UVC (on quartz: k = 1.80-5.89 h(-1); on putty: k = 2.97-3.98 h(-1)), indicating ozone can enhance the UVGI antifungal efficacy.