Environmental Protection Administration Research Articles

Long-term exposure to particulate matter was associated with increased dementia risk using both traditional approaches and novel machine learning methods

Air pollution exposure has been linked to various diseases, including dementia. However, a novel method for investigating the associations between air pollution exposure and disease is lacking. The objective of this study was to investigate whether long-term exposure to ambient particulate air pollution increases dementia risk using both the traditional Cox model approach and a novel machine learning (ML) with random forest (RF) method. We used health data from a national population-based cohort in Taiwan from 2000 to 2017. We collected the following ambient air pollution data from the Taiwan Environmental Protection Administration (EPA): fine particulate matter (PM2.5) and gaseous pollutants, including sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), nitrogen oxide (NOx), nitric oxide (NO), and nitrogen dioxide (NO2). Spatiotemporal-estimated air quality data calculated based on a geostatistical approach, namely, the Bayesian maximum entropy method, were collected. Each subject's residential county and township were reviewed monthly and linked to air quality data based on the corresponding township and month of the year for each subject. The Cox model approach and the ML with RF method were used. Increasing the concentration of PM2.5 by one interquartile range (IQR) increased the risk of dementia by approximately 5% (HR = 1.05 with 95% CI = 1.04–1.05). The comparison of the performance of the extended Cox model approach with the RF method showed that the prediction accuracy was approximately 0.7 by the RF method, but the AUC was lower than that of the Cox model approach. This national cohort study over an 18-year period provides supporting evidence that long-term particulate air pollution exposure is associated with increased dementia risk in Taiwan. The ML with RF method appears to be an acceptable approach for exploring associations between air pollutant exposure and disease.

Development of an index based on fish, macroinvertebrates, phytoplankton, and physicochemical properties to assess urban aquatic ecosystems in Jinan, China

AbstractBecause of the rapid growth in urbanization over recent decades, urban aquatic ecosystems have been subjected to unprecedented threats and challenges. In this study, we visited 48 sites, of which 14 were reservoir sites, in water bodies in Jinan, China, on six occasions in May, August, and October of 2014 and 2015. We sampled fish, macroinvertebrates, and phytoplankton assemblages and physicochemical factors at each site. We used the richness and diversity of fish, macroinvertebrates, and phytoplankton to evaluate the condition of the aquatic ecosystems of the river sites. We also evaluated the water quality of the reservoir sites using the physicochemical factors of the State Environmental Protection Administration of China. We classified the results into five levels—excellent, good, moderate, poor, and bad—with the comprehensive evaluation index (CEI). More than 40% of the sampling sites were in either poor or bad condition. Nearly half of the excellent or good sites were in the south of Jinan. The CEI was significantly different between the reference and impaired sites; it was significantly and positively correlated with the qualitative habitat evaluation index and was significantly and negatively correlated with conductivity, total alkalinity, and ammonia nitrogen.

Overview of Biomass-to-Energy Supply and Promotion Policy in Taiwan

During the past two decades, Taiwan’s average dependence on imported energy was 97.6%, thus pushing the government to promote the indigenous energy supply. In this regard, the energy policy and regulatory incentives for promoting biomass-to-energy or bioenergy have been recently established. In this work, the updated statistics of biomass-derived waste and energy supply from biomass during the period of 2005–2021 were analyzed using national/official reports. It was found that the annual agricultural waste amounts in Taiwan ranged from 4.5 to 5.2 million metric tons, and about 80% of those were generated from rice-derived residues (rice straw and rice husk) and livestock/poultry-derived waste (manure). In addition, a decreasing trend was observed in the indigenous bioenergy supply, mostly from the solid-type biomass resources, including waste wood, rice husk, and sugarcane bagasse. In order to expand bioenergy diversification, the central competent authorities, including the Ministry of Economic Affairs (MOEA), Council of Agriculture (COA), and Environmental Protection Administration (EPA), have announced the relevant policies for bioenergy promotion under the authorization of acts. Among them, the Renewable Energy Development Act is the legal foundation for promoting bioenergy and its industry development through economic incentives like feed-in-tariff (FIT), installation supports (or subsidies), and electrical grid connection.

Classification of air quality zones and fine particulate matter sensitive areas by risk assessment approach

Many studies have shown that fine particulate matter can cause health problems. Thus, effectively controlling fine particulate matter concentration is an important issue around the world. The Taiwan Environmental Protection Administration (TWEPA) divides Taiwan into seven air quality zones based on counties and cities for managing air quality and analyzing pollution transmission. However, this artificial division by administrative areas relatively poorly match natural conditions and topographical and geographic factors and hence poorly represent air quality characteristics. This study proposes an air quality sensitive map analysis framework, which uses hierarchical agglomerative clustering with empirical orthogonal function and analysis of variance methods, to provide more detailed, reasonable, and township-level air quality zones incorporating the different spatial-temporal characteristics over the region. The risk concept is introduced to evaluate PM2.5 risk sensitivity for each administrative district, combining three aspects: hazard (PM2.5 exceedance probability), exposure (population density of sensitive groups), and vulnerability (average wind speed).Considering air quality spatial-temporal characteristics, Taiwan can be optimally divided into 14 air quality zones. PM2.5 risk is highest for western inland towns than western coastal towns, with eastern regions exhibiting least risk. Adopting the proposed air quality zones and clarifying high risk areas allows PM2.5 causes to be identified for different air quality zones. This allows a targeted control strategy for high risk areas to effectively improve domestic air quality. The proposed model also provides powerful reference for environmental management and environmental impact assessment for future construction and development.

Electrocatalytic reduction of nitrate at the stabilizedelectron-deficient Cu<sup><italic>δ</italic>+</sup> active sites

<p indent="0mm">With the extensive use of nitrogen fertilizers, sewage discharges and industrial processes that consume nitric acid, the exposure level of nitrate (NO₃⁻-N) in environmental water bodies has significantly increased in the past decades. The NO₃⁻ anion has a stable chemical structure, and is hardly removed by natrual self-cleaning. It has adverse effect, and is primarily responsible for the eutrophication in lakes as well as some physiological diseases in neighboring mammal inhabitants, such as the methemoglobinemia. Strict regulations on the maximum contaminant level of <sc>10 mg/L</sc> for NO₃⁻-N in the drinking water has then been set by the World Health Organization, the United States Environmental Protection Agency and the China Environmental Protection Administration. To minimize the adverse effects of NO₃⁻-N, various technologies, including ion exchange, electrolysis, biological denitrification, and catalytic reduction by H₂ or Fe⁰, have then been developed to eliminate the NO₃⁻-N from water. Among them, electrocatalytic reduction of nitrate (ENRR), driven by the renewable electric energy, is receiving increasing research interests, due to its substantial nitrate removal capacity, mild reaction conditions and minimal daily maintenances. Copper-based materials are favored as the ENRR catalysts by researchers because of their high activity, chemical stability and low cost. The electron-deficient Cu^{<italic>δ</italic>+} is the main active site at the catalyst surface, but it is readily to be reduced to Cu⁰ at the very negative ENRR potentials, leading to the performance deterioration during the long-term reaction process. In this paper, we reported a facile approach to construct the Cu^{<italic>δ</italic>+}-1,4-naphthalene dicarboxylic acid (1,4-NDC) catalytic active sites through the surface decoration of the Cu(OH)₂ particles with the 1,4-NDC molecule at room temperature, followed by an <italic>in-situ</italic> electrochemical activation process under a negative potential of <sc>−0.40 V</sc> vs. RHE (reversible hydrogen electrode, the same below) (the product is denoted as <sc>Cu(OH)₂/1,4-NDC-AT).</sc> In this structure, the Cu^{<italic>δ</italic>+} is confirmed by the X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to survive under the negative working potential during the long-term ENRR, possibly due to the high electronegativity and chemical stability of the oxygen atoms in carboxyl group (the carboxyl group is chelated with the Cu^{<italic>δ</italic>+} site). The batch ENRR activity test results show that the Cu(OH)₂/1,4-NDC-AT delivers a NH₃ selectivity of &gt;90% in product, a specific activity of <sc>1034.7 mg N/(h m²)</sc> and a mass activity of <sc>89.1 mg N/(h</sc> g_Cu) in treating <sc>22.5 mg/L</sc> NO₃⁻-N solution at <sc>−0.40 V.</sc> The specific and mass activities are nearly 2.3 and 5.1 times those achieved by the ligand-free Cu(OH)-AT, respectively, and also higher than that of most reported catalysts. Optimizing the 1,4-NDC dosage and working potential can further improve the ENRR performance, and the mass activity increases to 147.1 and <sc>104.6 mg N/(h</sc> g_Cu) at the <inline-formula id="INLINE13"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub other="0"><mml:mi other="0">n</mml:mi><mml:mrow other="1"><mml:mtext other="1">1</mml:mtext><mml:mo other="1">,</mml:mo><mml:mtext other="1">4-NDC</mml:mtext></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:msub other="0"><mml:mi other="0">n</mml:mi><mml:mrow other="1"><mml:mtext other="1">Cu</mml:mtext><mml:msub other="1"><mml:mrow other="1"><mml:mrow other="1"><mml:mo other="1">(</mml:mo><mml:mrow other="1"><mml:mtext other="1">OH</mml:mtext></mml:mrow><mml:mo other="1">)</mml:mo></mml:mrow></mml:mrow><mml:mtext other="2">2</mml:mtext></mml:msub></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula> of 2.16 and the potential of <sc>−0.50 V,</sc> respectively. Finally, this paper proposed the appratus for the treatment of nitrate wastewater in different concentrations. Specifically, an integrated “ENRR+NH₃-N adsorption” technology is proposed to deal with the dilute nitrate wastewater, which enables the elimination of the nitrogen-containing species in water. For the concentrated nitrate wastewater, an integrated “ENRR+NH₃-N recovery” technology is proposed, which can recover 98.0% of the produced NH₃-N via absorption by H₂SO₄ aqueous solution. This work provides new strategies and robust materials specific for NO₃⁻-N removal, which should advance the development of ENRR technology in water pollution remediation.

Dynamic Routing Algorithm for Hazmat Transportation Problems

After a series of gas pipeline explosions in Kaohsiung City, Taiwan, in 2014, the Environmental Protection Administration (EPA) issued regulations in 2017 requiring all chemical tank trucks to be equipped with GPS for real-time monitoring and control. Hazmat transportation problems, along with solution algorithms and applications, have been studied extensively. However, most of the research has focused on the route planning level. Dynamic characteristics should be incorporated to reflect possible dynamic traffic situations with more advanced information and communication capabilities for chemical tank trucks. This research formulates a bi-objective dynamic model and proposes a solution algorithm based on a genetic algorithm (GA) for dynamic hazmat route optimization. A dynamic bi-objective model, including transportation cost and risk, is developed to reflect time-varying traffic conditions. Dynamic traffic characteristics are reflected through traffic volume and travel time, simulated from simulation models. Numerical experiments are conducted in the Kaohsiung City network. The results show that dynamic routes for hazmat transportation vary with respect to traffic flow conditions. The discussions of this research are expected to provide some insights into policy implications.

Source Apportionment of Heavy Metal Contamination in Urban-Agricultural-Aquacultural Soils near the Bohai Bay Coast, Using Land-Use Classification and Google Satellite Tracing

Heavy metal concentrations of Cd, As, Pb, Cu, Cr, and Hg were investigated for 86 soil samples in Jinzhou near the Bohai Sea in China, in order to identify what anthropological activities influenced their distribution levels. Ordinary cokriging (OCK) was utilized to map six heavy-metal distributions by incorporating their main environmental influencers. The resultant p values for the six OCK mapping models of 0–2.78% indicated good statistical significance of the models, and the relative mean absolute errors of 4.82–12.53% and relative root mean square errors of 6.23–18.21% indicated allowable predication precision for their concentrations. The contamination distributions by OCK mapping were then graded based on the standards of the China National Environmental Monitoring Center and the Chinese Environmental Protection Administration, which showed that Cu and As contaminations in parts of this area were over the natural level but not polluted, Cr contamination was omnipresent over the natural level in this area and even reached the polluted level in parts of this area. The graded contamination maps that were overlapped with land-use maps and Google satellite maps, as well as the verifications reported in literatures, enabled correlations of the different contamination levels of As, Cu, and Cr with human activities. Resultantly, it indicated that As and Cu contamination over the natural level may be related to agricultural planting and aquacultural activities along the coast of Bohai Bay, with the contaminants transported via watercourses; Cr contamination over the natural level may have been due to vehicle emissions; and, Cr pollution may have been from steel manufacturing and geochemical factories

Insights into the long-term fates and impacts of polybrominated diphenyl ethers in sediment samples in Taiwan: The national project for background monitoring of the environmental distribution of chemical substances (BMECs)

This study aimed to evaluate the impact factors and effectiveness of management policies on the presence of polybrominated diphenyl ethers (PBDEs) in sediment samples in Taiwan from the last 10 years. Twenty-four PBDE congeners were detected in 838 sediment samples collected from 4 stages (2006–2019) in 30 principal rivers, based on the national project for background monitoring of the environmental distribution of chemical substances. The ΣPBDE concentrations in the 4 stages ranged from 30.00 to 147.10 ng/g dw, 6.03–15.30 ng/g dw, 4.99–7.00 ng/g dw, and 1.20–2.10 ng/g dw in the northern, southern, central, and eastern areas, respectively. The concentrations of PBDEs (e.g., penta-BDE and octa-BDE) in sediment samples notably decreased (−6 to −73%) as the Taiwan Environmental Protection Administration implemented policies banning PBDEs (except deca-BDE). The PBDEs levels of the sediment samples collected in the dry season were higher than those collected in the wet season. The levels of ΣPBDEs in sediment samples were affected by season, the amount of general waste present, and nearby PBDE-related factories and e-waste recycling facilities. Reducing the release of PBDEs, especially deca-BDE, through sound waste management and recycling practices is still needed to improve environmental sustainability in Taiwan.

Impact of air pollutants on hospital visits for pediatric asthma in Fuzhou city, southeast China.

Rapid social development in China has resulted in severe air pollution and adverse impacts on people's health. Although studies have been conducted on the relationship between exposure to air pollutants and asthma exacerbation, most studies were performed in relatively heavily polluted areas, while little is known about the effect of air pollutants in less polluted areas. We assessed the effects of air pollutants on the risk of asthma-related outpatient and emergency visits of infants and children aged from 0 to 13years during 2018 to 2020 in Fuzhou city, southeast China. Data of six air pollutants: sulfur dioxide (SO2), nitrogen dioxides (NO2), carbon monoxide (CO), daily maximum 8-h average ozone (O3-8h), particulate matter with an aerodynamic diameter ≤ 10μm (PM10), and particulate matter with an aerodynamic diameter ≤ 2.5μm (PM2.5), were obtained from the Environmental Protection Administration of Fuzhou. Data of temperature, humidity, and wind speed were provided by the Meteorological Bureau of Fuzhou. Results revealed that on lag day 6, NO2, SO2, and CO were positively associated with the number of outpatient and emergency visits. Among the pollutants, SO2 had the highest effects on both outpatient visits (RR = 1.672, 95%CI 1.545, 1.809) and emergency visits (RR = 1.495, 95%CI 1.241, 1.800), and its effect on outpatient visits was stronger in children aged 0-4years than in those aged 5-13years (RR = 2.331 vs. 1.439). In conclusion, SO2 contributes substantially to the adverse effects of air pollutants on pediatric respiratory health in Fuzhou. Younger children were more affected by air pollution than their older counterparts.

Association of air pollution exposure with exercise-induced oxygen desaturation in COPD

BackgroundThere is a link between exposure to air pollution and the increased prevalence of chronic obstructive pulmonary disease (COPD) and declining pulmonary function, but the association with O2 desaturation during exercise in COPD patients with emphysema is unclear. Our aims were to estimate the prevalence of O2 desaturation during exercise in patients with COPD, and determine the association of exposure to air pollution with exercise-induced desaturation (EID), the degree of emphysema, and dynamic hyperinflation (DH).MethodsWe assessed the effects of 10-year prior to the HRCT assessment and 7 days prior to the six-minute walking test exposure to particulate matter with an aerodynamic diameter of < 10 µm (PM10) or of < 2.5 µM (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in patients with emphysema in this retrospective cohort study. EID was defined as a nadir standard pulse oximetry (SpO2) level of < 90% or a delta (△)SpO2 level of ≥ 4%. Ambient air pollutant (PM2.5, PM10, O3, and NO2) data were obtained from Taiwan Environmental Protection Administration (EPA) air-monitoring stations, usually within 10 km to each participant’s home address.ResultsWe recruited 141 subjects with emphysema. 41.1% of patients with emphysema exhibited EID, and patients with EID had more dyspnea, worse lung function, more severe emphysema, more frequent acute exacerbations, managed a shorter walking distance, had DH, and greater long-term exposure to air pollution than those without EID. We observed that levels of 10-year concentrations of PM10, PM2.5, and NO2 were significantly associated with EID, PM10 and PM2.5 were associated with the severity of emphysema, and associated with DH in patients with emphysema. In contrast, short-term exposure did not have any effect on patients.ConclusionLong-term exposure to ambient PM10, PM2.5 and NO2, but not O3, was associated with EID.

Prenatal Exposure to Air Pollution and Immune Thrombocytopenia: A Nationwide Population-Based Cohort Study.

IntroductionImmune thrombocytopenia (ITP) is one of the most common hematologic disorders in children. However, its etiology is still unclear. Epidemiological studies have shown that air pollution is a plausible risk factor in stimulation of oxidative stress, induction of inflammation, and onset of autoimmune diseases. The objective of this article is to examine the effects of prenatal exposure to air pollution on the occurrence of immune thrombocytopenia (ITP) in children.Materials and MethodsThis is a nationwide, population-based, matched case-control study. Using data from Taiwan’s Maternal and Child Health Database (MCHD), we identified 427 children with ITP less than 6 years of age and age-matched controls without ITP between 2004 and 2016. Levels of prenatal exposure to air pollutants were obtained from 71 Environmental Protection Administration monitoring stations across Taiwan according to the maternal residence during pregnancy. Patients who had outpatient visits or admission with diagnosis of ITP and subsequently received first-line treatment of intravenous immunoglobulin or oral glucocorticoids were defined as incidence cases.ResultsPrenatal exposure to particulate matter <10 μm (PM10) in diameter and the pollutant standard index (PSI) increased the risk of childhood ITP. Conversely, carbon monoxide (CO) exposure during pregnancy was negatively associated with the development of ITP.ConclusionCertain prenatal air pollutant exposure may increase the incidence of ITP in children.

Association of traffic air pollution with severity of obstructive sleep apnea in urban areas of Northern Taiwan: A cross-sectional study

BackgroundAlthough recent studies have indicated an association between obstructive sleep apnea (OSA) and air pollution, they have reported inconsistent results. Moreover, few studies investigated the effects of short-term air pollution exposure. ObjectiveTo estimate the health effects of short- and long-term exposure to traffic air pollution on mild OSA in Taipei. MethodsWe collected participants' data from Taipei Sleep Center and air pollution data from Taiwan Environmental Protection Administration. A spatiotemporal model was used to estimate the individual exposure level. Generalized linear models were used to assess the percent change of overall apnea-hypopnea index (AHI), AHI in rapid eye movement period (AHI-REM), AHI in non-REM (AHI-NREM), and oxygen desaturation index (ODI) associated with an interquartile (IQR) increase in personal pollution exposure. A generalized logistic model was used to estimate the ORs of different severities of OSA compared with the reference group. ResultsIn the patients with AHI of <15, both short- and long-term exposure to NO2 were significantly associated with AHI and ODI increases: an IQR increase in 2-year mean NO2 increased 7.3% of AHI and 8.4% of ODI; these values were the highest among all exposure windows. The effects of NO2 on AHI increase were stronger in the men and younger patients. Moreover, the association between AHI and NO2 in the patients with AHI of <15 was mediated by the REM stage. NO2 exposure was associated with an increased risk of mild OSA that reached up to 24.8% per IQR increase in NO2 averaged over 2 years. PM2.5 exerted no effects on AHI, but an IQR increase in 1-year and 2-year mean PM2.5 was associated with 6.8% and 8.8% increases in ODI, respectively. ConclusionsBoth short- and long-term exposure to traffic air pollution were associated with the risk of mild OSA, which was modified by REM stage.

Effects of process conditions on simultaneous removal and recovery of boron from boron-laden wastewater using improved bipolar membrane electrodialysis (BMED)

The anthropogenic emission of boron to the environment has posed a serious risk to human and animal health due to its non-biodegradability and the resulting accumulation in the body. Bipolar membrane electrodialysis (BMED) has been proven to be an economical and effective process to remove and recover boron from wastewater. In this work, we verified multiple process parameters to evaluate the efficiency of boron removal and recovery using intermittent and continuous BMED modes. Higher initial boron concentrations appeared to reduce the boron processing rate, but this reduction may be ameliorated by increasing current density. Similarly, higher initial pH was observed to retard the removal rate of boron with increasing mass transfer rate. When solution pH was controlled from 9.5 to 10.5 and the current density was 6.36 A/m2 under maximum allowable voltage of 12 V, boron removal and recovery efficiencies were 98.6% and 86.5%, respectively. During the pH-control process, current variation pattern indicated that current density was associated with initial boron concentrations in salt apartment. When the current variation pattern was applied to a five-cycle sequential feed-batch BMED process, it accurately reflected the timing of complete boron removal and recovery on a batch fill-and-draw process. The overall boron removal and recovery efficiencies were 98.53% and 81.2%, respectively, with an energy consumption of 31.5 Wh/g. Under these conditions, the final boron concentrations in effluent were less than 10 mg/L, as required by the Taiwan Environmental Protection Administration (EPA). Overall, BMED is a cost-effective treatment process for boron-containing wastewater. The proposed process indicator reflecting sequential BMED process progression based on process information will further elucidate the automatic process control in industrial applications.

The Prediction of Influenza-like Illness and Respiratory Disease Using LSTM and ARIMA.

This paper proposed the forecasting model of Influenza-like Illness (ILI) and respiratory disease. The dataset was extracted from the Taiwan Environmental Protection Administration (EPA) for air pollutants data and the Centers for Disease Control (CDC) for disease cases from 2009 to 2018. First, this paper applied the ARIMA method, which trained based on the weekly number of disease cases in time series. Second, we implemented the Long short-term memory (LSTM) method, which trained based on the correlation between the weekly number of diseases and air pollutants. The models were also trained and evaluated based on five and ten years of historical data. Autoregressive integrated moving average (ARIMA) has an excellent model in the five-year dataset of ILI at 2564.9 compared to ten years at 8173.6 of RMSE value. This accuracy is similar to the Respiratory dataset, which gets 15,656.7 in the five-year dataset and 22,680.4 of RMSE value in the ten-year dataset. On the contrary, LSTM has better accuracy in the ten-year dataset than the five-year dataset. For example, on average of RMSE in the ILI dataset, LSTM has 720.2 RMSE value in five years and 517.0 in ten years dataset. Also, in the Respiratory disease dataset, LSTM gets 4768.6 of five years of data and 3254.3 of the ten-year dataset. These experiments revealed that the LSTM model generally outperforms ARIMA by three to seven times higher model performance.

Relationship between exposure to ozone and exacerbation requiring hospital admission among patients with asthma: a case-control study in central Taiwan

ObjectiveThe convergence of asthma and air pollutants in ageing populations is currently a growing health issue worldwide, and hence there is an essential need to investigate the association between exposure...

Multimedia Pollution Prevention of Mercury-Containing Waste and Articles: Case Study in Taiwan

In response to the Minamata Convention on Mercury, effective 16 August 2017, the Taiwan government in recent years started to implement the sustainable material management of mercury-containing waste and articles. This was completed by a cross-ministerial collaboration for preventing the adverse effects of mercury on human health and the environment, based on the multimedia approach. The legislative or regulatory frameworks on the control and prevention of mercury emissions and releases have been established in environmental distributions, including air, water, soil, waste, food, and article (or commodity). Therefore, the central authorities included the Environmental Protection Administration (EPA), Council of Agriculture (COA), Ministry of Health and Welfare (MOHW), Ministry of Economic Affairs (MOEA), and Ministry of Labor (MOL). Furthermore, the implementation plans covered the reduction in mercury-containing products by restricted use and bans on its use, remediation of soil and groundwater for mercury-pollution sites, control of stationary source emissions, environmental monitoring, and compulsory recovery of mercury from electronic waste such as waste lightings. A successful case study on the recovery of mercury from electronic waste using a thermal treatment, and its capture control by activated carbon, was also addressed in this work. Due to the effectiveness of source control in Taiwan, the annual reported amount of mercury emissions from the stationary air pollution sources indicated a decreasing trend from 1.989 metric tons in 2016 to 1.760 metric tons in 2019. More significantly, the ministerial collaboration in implementing the Convention in Taiwan also echoed the United Nations (UN) Agenda 2030 for sustainable development goals (SDGs).

In-situ Measurement of Aerosol Water Content in an Urban Area Using a Sequential Aerosol-Water Measurement System (SAWMS)

Aerosol water content (AWC) significantly affects secondary aerosol formation and atmospheric visibility. Most ambient AWC values are obtained from models because the direct measurement is challenging. In this study, the sequential aerosol-water measurement system (SAWMS) was applied to measure AWC at the Xiaogang (XG) air-quality monitoring site of the Taiwan Environmental Protection Administration (TEPA), located in an industrialized seaport city. The relative humidity (RH) was set at 90% in the SAWMS during measurement, and the PM2.5 AWC was 39.0 ± 14.3 μg m-3 on average, which was 140% higher than the monitored PM2.5 average concentration. Water-soluble inorganic ions (WSIIs) were analyzed offline and used in ISORROPIA II to model the AWC. The modeled and measured AWC was well-correlated (R2 = 0.85; n = 39, p < 0.05), indicating that WSIIs contributed the most to AWC. During high AWC periods, NO3- concentrations were relatively higher, suggesting that NO3- was the predominant species contributing to AWC. Humidographs were constructed to analyze the AWC values under varying RH levels during the humidification and dehumidification processes for the three selected samples. The humidification results revealed a significant difference between the measured and modeled AWC within 60–80% RH. This might be due to deviations of aerosol combination types and the mixing state from atmospheric conditions. The modeled AWC was close to the measured AWC when the RH was over 80%. The nitrogen oxidation ratio and the AWC were well-correlated (R2 = 0.60) throughout the sampling period, implying that the measured AWC was beneficial to NO3- formation in the urban area. In summary, significant differences between modeled and measured AWC appeared during the humidification and dehumidification processes when the RH was below 80%, indicating that direct measurement of AWC under varying RH levels is still necessary.

Remediation Efficiency of the In Situ Vitrification Method at an Unidentified-Waste and Groundwater Treatment Site

The subject of this study was the dust collected from an electric arc furnace at an unidentified-waste treatment site in southern Taiwan. The dust underwent an in situ vitrification (ISV) process and was tested using the toxicity characteristic leaching procedure (TCLP), at the end of which the final product was analyzed for its stability and weather resistance. This study then examined the above results to determine whether the ISV process helps to enhance the efficiency and economic benefits of said waste-treatment site. A TCLP test conducted on the dust that had been treated with ISV revealed that concentrations of various heavy metals were not only far below those of the unprocessed sample dust but also fell below the limit stipulated in the TCLP regulation of Taiwan’s Environmental Protection Administration. The results show that after undergoing ISV treatment, heavy metals in the dust were either encapsulated or bound in silicon lattices and thus barely leached from the dust. Analyses using scanning electron microscopy (SEM) and an energy dispersive spectrometry (EDS) indicate that the surface of the dust appeared more compacted after going through the ISV process. In addition, the highly contaminated dust that underwent ISV treatment saw a pronounced decrease in or elimination of wave crests. Another analysis applying X-ray diffraction (XRD) showed that the SiO2 crests disappeared in the processed dust, suggesting that the crystal structure was replaced with quasi-vitreous products after ISV treatment. In the event that pollutants were extant, they were usually characterized by smaller size, high stability, excellent weather resistance, an innocuous nature, and recyclability.

Ambient air pollutants and indoor air quality are associated with cognitive impairment in older adults: A six‐year cohort study

AbstractBackgroundExposure to air pollutants have known to increase the risk of cognitive impairment. Some older adults spend a long time indoors. However, limited studies have evaluated the effect of time staying indoors on the association between exposure to ambient air pollutants and cognitive function in older adults.MethodThis cohort study is part of the ongoing Taiwan Initiative for Geriatric Epidemiological Research (2011‐present). A total of 605 older adults were recruited at baseline (2011‐2013) with three biennial follow‐ups, and 496 participants were included after exclusion. The data of six air pollutants including sulphur dioxide, nitrogen dioxide, particulate matter in diameter ≤ 2.5µm (PM2.5) and 2.5‐10µm (PMcoarse), carbon monoxide, and ozone were obtained from 26 monitor stations of Taiwan Environmental Protection Administration (TEPA) between 1993 and 2019. Spatial‐Time Analysis Rendering with Bayesian Maximum Entropy was utilized to estimate the individual air pollutants’ exposure. Hours staying indoors were collected across four seasons. Generalized linear mixed model was utilized to explore the association between long‐term exposure to air pollutants and global or domain‐specific cognitive function (memory, attention, executive function, and language) over 6 years adjusted for some covariates. Stratified analyses were performed by median hours staying indoors every day.ResultThe mean age of the study participants were 72.4 years at baseline. PM2.5 was the only pollutant with a 14‐year average level (29.0 µm/m3) higher than the TEPA air quality standards. An interquartile range (IQR) increase in PM2.5 was associated with poor global cognition (β=‐0.19) and executive function (β=‐0.08), and the former effect became more evident in those with hours staying indoors &lt; 13 hours/day (β=‐0.31). An IQR increase in PMcoarse was associated with poor global cognition (β=‐0.21) and verbal fluency (β=‐0.10), which became more evident in those stayed indoors ≥13 hours/day (β=‐0.32 and ‐0.13, respectively). Exposure to PMcoarse was associated with poor attention (β=‐0.15). No significant association was observed between other air pollutants and the performance of logical memory.ConclusionLong‐term exposure to PM2.5 or PMcoarse showed detrimental effect on cognitive function in community‐dwelling older adults and indoor air quality may play a role on these associations.

Association of ambient air pollution and retinal layer thickness with cognitive impairment in community‐dwelling older adults: A two‐year cohort study

AbstractBackgroundThe anatomical structure is close between retina and brain. Our team for the first time found a nonlinear relationship between retinal markers and cognition (Liu et al. 2019). Exposure to ambient air pollution was also known to affect cognition. However, the relationship between long‐term air pollution, retina markers and cognition remains unclear. Therefore, we aimed to clarify this association in a community‐based prospective cohort study.MethodParticipants of this study (2015‐2019) were part of the ongoing Taiwan Initiative for Geriatric Epidemiological Research. A total of 232 older adults (≥ 65 years old) were enrolled at baseline (2015‐2017) with a two‐year follow up. Ganglion cell‐inner plexiform layer (GC‐IPL) and retinal nerve fiber layer (RNFL) thickness were measured by Cirrus High‐Definition Optical Coherence Tomography at baseline. Data of air pollutants were obtained from monitors of Taiwan Environmental Protection Administration between 1993 and 2010. Global cognition and domain‐specific cognition were assessed by a battery of neuropsychological test. Generalized linear mixed model were utilized to assess the association of retinal markers and air pollution with cognition adjusted for important covariates.ResultWe found a nonlinear association between GC‐IPL and poor logical memory over 2 years (immediate theme recall: β=‐0.30×10‐2; immediate free recall: β=‐0.22×10‐2; delayed free recall: β=‐0.17×10‐2). No association was not found between RNFL and cognition. High‐level NO2 (≥ 27.23 ppb) exposure was associated with poor logical memory (immediate theme recall: β=‐0.56; immediate free recall: β=‐0.71; delayed free recall: β=‐0.67). Similarly, high‐level O3 (≥ 41.75 ppb) exposure was associated with poor logical memory (immediate free recall: β=‐0.32). No significant association was found for other air pollutants. After stratification by levels of air pollutants, association remain non‐significant.ConclusionThinning and thickening of GC‐IPL was associated with cognitive impairment over two years. Long‐term high‐level exposure to NO2 or O3 was associated with poor logical memory over the same duration. More studies are need to clarify the association between retinal markers and air pollution on the performance of cognition.