High-efficiency carbon-coated steel wool filter for controlling cooking-induced oil smoke.

Cooking oil smoke (COS) contains many harmful substances, such as particulate matter, formaldehyde, and phenyl esters. Currently, commercial COS treatment equipment is expensive and requires a large space. Furthermore, a large amount of agricultural waste is generated and is mainly burned onsite, producing large amounts of greenhouse gases and air pollutants. This waste could be reused as a precursor for biochar and activated carbon. Therefore, this research used saccharification and catalytic hydrothermal carbonization to process rice straw and produce compact carbon-based filters (steel wool-C) for removing cooking-induced pollutants. Scanning electron microscopy indicated that carbon layers were coated on the steel wool. The Brunauer-Emmett-Teller surface area of the carbon filter was 71.595 m2/g, 43 times larger than that of steel wool. The steel wool filter removed 28.9%-45.4% of submicron aerosol particles. Adding a negative air ionizer (NAI) to the filter system enhanced the particle removal efficiency by 10%-25%. The removal efficiency of total volatile organic compounds was 27.3%-37.1% with the steel wool filter, but 57.2%-74.2% with the carbon-containing steel wool filter, and the NAI improved the removal efficiency by approximately 1%-5%. The aldehyde removal efficiency of the carbon filter with NAI was 59.0%-72.0%. Conclusively, the compact steel wool-C and NAI device could be promising COS treatment equipment for households and small eateries.

Association between satellite-based estimates of long-term PM2.5 exposure and cardiovascular disease: evidence from the Indonesian Family Life Survey.

Exposure to particulate matter with a diameter < 2.5 µm (PM2.5) 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 PM2.5 levels in urban areas in 2015. However, there is still no study examining the association between long-term PM2.5 exposure and CVD in Indonesia. In this study, we combined PM2.5 data and health survey data. Long-term (2000-2007) exposure to PM2.5 was measured based on satellite-derived aerosol optical depth measurements (1 × 1 km2) that could be used to predict ground-level PM2.5 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 PM2.5 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) PM2.5 concentration of 14.4 (6.4) µg/m3. In adjusted models, a 10-µg/m3 increase in annual average PM2.5 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 PM2.5 is associated with a higher prevalence of CVD in Sumatera, Indonesia.