196 research outputs found
THE ROLE OF DASA WISMA IN SHAPING THE CHARACTER OF SOCIAL CARE OF DASA WISMA MEMBERS IN GUNUNG PAGAT HAMLET, LOA JANAN ULU VILLAGE, LOA JANAN DISTRICT, KUTAI KARTANEGARA REGENCY
No full textThe purpose of this study was to determine the role of Dasa Wisma in shaping the character of social concerns of Dasa Wisma members in Gunung Pagat Hamlet, Loa Janan Ulu Village, Loa Janan District, Kutai Kartanegara Regency and to find out Dasa Wisma's efforts in shaping the social care character of Dasa Wisma members in Gunung Pagat Hamlet, Loa Janan Ulu Village, Loa Janan District, Kutai Kartanegara Regency. This type of research is descriptive and qualitative. The techniques used in data collection in this study were observation, interviews, and documentation. The data analysis techniques used are data reduction, presentation (data display), and drawing conclusions. Based on the results of existing research and discussions, the author can conclude that the role of Dasa Wisma in shaping the character of social concerns of Dasa Wisma members in Gunung Pagat Hamlet, Loa Janan Ulu Village, is realized through the implementation of community data recording and reporting activities and citizen activities carried out by the Dasa Wisma group which has been running very well, data recorded such as recording and recording data on residents' activities. Dasa Wisma's efforts in shaping the character of social care Dasa Wisma members through counseling and coaching in shaping the character of social care for Dasa Wisma members have been well realized, members of the Dasa Wisma group are routinely given counseling and coaching both carried out by the PKK organization or the head of the Dasa Wisma group itself
Characterization and source apportionment of volatile organic compounds in Hong Kong : a 5 years study for three different archetypical sites
No full textVolatile organic compounds (VOCs) are important for mitigating the ozone pollution as its major precursors. This study compares VOC characteristics of roadside, suburban and rural sites in Hong Kong based on their compositions, concentrations, and source contributions. Here we show that the sum-up VOC concentrations were 23.05±13.24, 12.68±15.36, 5.16±5.48 ppbv for roadside, suburban and rural site, respectively. Vehicular related species dominated ambient VOCs in the roadside site while the rural site had larger influence from industrial sources than expected. Moreover, a gnificant decreasing trend for VOCs species only existed in roadside site. Obvious seasonal trend was discovered in all three sites over the five years with 0.52 ppbv in winter and 0.11 ppbv in summer as an average, yet roadside site had a higher concentration in summer as 0.22 ppbv due to the canyon effect. By using PMF model, six sources were resolved for the roadside site, including LPG usage, gasoline evaporation, fuel filling, aged air mass, gasoline exhaust and diesel exhaust. Likewise, six factors were distinguished for suburban site containing LPG usage, biogenic emission, gasoline evaporation, diesel exhaust, solvent usage and aged air mass while four factors for the rural site including solvent usage, biogenic emission, vehicular emission and aged air mass. LPG usage dominated the contribution in the roadside station, followed by aged air mass and gasoline evaporation. The main contributor were LPG usage, solvent usage and diesel exhaust in the suburban site and aged air mass for rural site. Finally, the ozone formation potential and OH loss rates of each source were calculated accordingly. For the roadside site, the major contributor in OFP was fuel filling and LPG usage for the OH reactivity. Yet in suburban and rural site, solvent usage and biogenic emission accounted for almost half in OFP and OH reactivity, respectively. This study revealed the difference in characteristics between archetypal sites, which could help the policymakers to better control the pollution case by case.</p
Detection and Retrieval of Atmospheric Trace Gases Using Thermal Infrared Sounders on Board the Fengyun Satellites
No full textCruise observation of ambient volatile organic compounds over Hong Kong waters
No full textTo provide insight into the production of ozone (O3) over the water of Hong Kong (HK), we organized sixteen cruise campaigns between August 2020 and July 2021 to measure O3, nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs). Ten westbound, four eastbound and two southbound campaigns were conducted to investigate the characteristics of air pollutants over the Pearl River Estuary, Mirs Bay and Lamma Island anchorage, respectively. Based on cruise observations, this study examines the mixing ratios, reactivities and possible sources of VOCs. Alkanes, alkenes, aromatics, alkynes, halocarbons and alkyl nitrates were measured at a mean concentration of 8.94±5.64 ppbv, 1.18±1.09 ppbv, 1.90±1.48 ppbv, 1.05±0.63 ppbv 3.82±1.23 and 0.09±0.04 ppbv. According to source appointment results from positive matrix factorization (PMF) analysis, ship emissions accounted for an average of 15.6% of total VOCs. In addition, liquefied petroleum gas (LPG) usage (24.9%), biomass burning (19.4%), gasoline evaporation (16.2%), solvent usage (13.8%) and aged air mass (9.1%) were recognized. In general, the VOC sources over Hong Kong waters differ from previous studies conducted in the urban and suburban regions of PRD. This study suggests that differentiated control strategies are necessary to control ozone pollution in the PRD region as a whole.</p
Study of marine isoprene emissions and atmospheric impacts with satellite observations and earth system modeling
No full textStudy on characteristics and source origins of halogenated hydrocarbons in Hong Kong
No full textHalogenated hydrocarbons (halocarbons) play important roles in global warming and stratospheric ozone depletion due to their long atmospheric lifetimes, and they have been a research priority since the middle of last century. This study investigates the temporal and spatial variations of halocarbons in Hong Kong and their potential source origins. Overall 209 monthly samples were collected at three ground sites in Hong Kong, including HKUST Supersite Station (UST), Yuen Long (YL), and Tai Po (TP) from August 2020 to July 2022. In addition, 683 daily samples were collected at UST from November 1, 2020 to June 30, 2021. Seventeen halocarbon species were investigated in this thesis with three categories: Montreal Protocol (M-P) banned species (e.g., CFCs, CCl4, and CH3Br), M-P controlled species (e.g., HCFCs and HFCs), and non-regulated species (e.g., short-lived halocarbons). For M-P banned species, their concentrations in Hong Kong presented minimal enhancements above the background levels, demonstrating the effectiveness of the Montreal Protocol implementations. Non-regulated species with short lifetimes presented the most significant enhancements above the background levels, suggesting the needs of further regulations. In terms of seasonal variations, the M-P banned species exhibited little changes, while regulated species were more prevalent in summer, and non-regulated species were higher in winter. Comparing between three monitoring sites, YL has the highest halocarbon concentrations, followed by TP and UST. The Positive Matrix Factorization (PMF) results from the three sites also indicate that refrigeration sources contributed more at the urban site YL, while natural sources were more prevalent at the suburban site UST. The Potential Source Contribution Function (PSCF) results suggest significant transport influence from Yangtze River Delta (YRD) to observed C2HCl3, C2Cl4, and HFC-134a, and important impacts from Fujian to observed HCFC-141b. Finally, the investigation of long-range transport effects in the daily samples collected at UST revealed that solvent usage was mainly located in eastern China, while impacts from refrigeration replacements were found in western Guangdong and Hong Kong’s surrounding regions. This study offers valuable insights into the efforts to implement the Montreal Protocol in Hong Kong and the surrounding areas, emphasizing the need for continual control of halocarbon emissions.</p
Study of CH₄, CO₂, and CO in ambient air at a coastal site in Hong Kong
No full textChina is the largest contributor to global carbon emissions. To support the country’s goals of carbon peak and neutrality, a credible and coordinated greenhouse gas (GHG) monitoring network is essential for emission estimates. However, the current monitoring network is too sparse and uncoordinated, lacking representation of the most critical emission sources—urban areas. This results in significant uncertainties in the national carbon emission statistics. To gain a more comprehensive understanding of the carbon source-sink characteristics in one of the most industrialized regions of China, the Pearl River Delta (PRD) region, one-year monitoring of CH4, CO2, and CO using gas chromotography (GC) was conducted at a suburban coastal site in Hong Kong since February 2023. The study period was from 4th February 2023 to 5th February 2024, yielding 1072 valid whole air canister samples. This study reveals distinct seasonal variations, with higher concentrations observed during the cold season (winter and spring) and lower concentrations during the warm season (summer and autumn). These variations are influenced by both local source-sink dynamics and long-distance transport driven by the Asiatic monsoon. In the correlation analysis of the enhanced ratios of the three gases, CH4 exhibits a strikingly strong correlation with CO, while CO2 demonstrates a weaker correlation with the other two gases. This pattern contrasts with other Chinese cities, where CO2 and CO typically show higher correlation. The CO2 to CO ratio in Hong Kong is higher than other Chinese cities. These findings suggest that Hong Kong has a unique emission influence pattern and source-sink dynamics. Back-trajectory and potential source contribution function analyses highlight central China as the primary source regions for CH4 and CO, and east-central China as the primary source regions for CO2. These findings can assist in effective carbon neutrality policies in Hong Kong and China.</p
Dynamic Link-Level On-Road Transportation Emission Inventories in Hong Kong for Environmental Assessment and Roadside Environment Exploration
No full textEffective management of air quality requires a comprehensive understanding of on-road traffic air pollutant emission patterns, particularly in urban environments where capturing these dynamics poses significant challenges. This study addresses this gap by developing a novel approach that integrates traffic congestion index from Google Maps, a traffic density model, and local emission factors to create a dynamic on-road traffic emission inventory for Hong Kong. This inventory encompasses a wide range of pollutants, including NOx, CO, NMVOC, CO2, PM2.5, PM10, and CH4, as well as over 80 speciated VOCs from both exhaust and evaporative emissions. Our findings indicate that exhaust emissions on weekdays can increase by up to 50% compared to Sundays, primarily due to heightened traffic congestion, with significant emission rates observed on highways during weekday peak hours. Public light buses, goods vehicles, and taxis emerged as the largest contributors to NMVOC, NOx, and CO emissions, respectively. Control policy testing revealed that transitioning franchised buses to electric buses could substantially reduce NOx and PM emissions, while replacing liquefied petroleum gas-fueled public light buses with electric alternatives effectively manages NMVOC emissions. Additionally, phasing out older private cars proved beneficial in reducing CO emissions. Furthermore, we dynamically quantified the emissions of speciated VOCs from both tailpipe and evaporative emissions. employing a real-time model to assess street-scale evaporative emissions and their health and environmental impacts in urban areas for the first time. Notably, evaporative emissions of non-methane organic gases were found to be comparable to those from tailpipe sources, with aromatic compounds from evaporative sources being notably abundant. Multi-effects evaluation underscores the necessity to regulate aromatics emissions from evaporative sources and alkenes emissions from exhaust, while highlighting stricter controls on intermediate volatile organic compounds (IVOCs) from diesel vehicles. Although the average health index (HI) across the 18 districts remained below 1, indicating no chronic inhalation non-carcinogenic risks, certain locations exhibited high risks (HI > 1). Carcinogenic risks were observed in Wan Chai, Central & Western, Kowloon City, Kwun Tong, Sham Shui Po, and Yau Tsim Mong districts, primarily driven by benzene, 1,3-butadiene emissions. While evaporative emissions release more toxic aromatics, exhaust emissions still warrant attention. The vehicle types that contribute most significantly to health risks were identified. Vehicle electrification scenarios indicated that simply transitioning to electric vehicles may not effectively mitigate incremental health risks; instead eliminating the largest toxic species contributor would be more effective. Through an extensive observation of roadside VOC concentrations across diverse urban sites, we identified distinct VOC profiles at different sites. The identified contributors to health risks at roadsides, emphasizing the need for stringent policies to mitigate harmful pollutants as well. The comparative analysis of model simulations and observational data highlights the necessity for further refinement of chemical reaction mechanisms to enhance model simulation accuracy. In summary, this research provides a high-resolution, dynamic on-road emission inventory for Hong Kong, offering valuable insights into urban air pollution dynamics and informing effective policymaking aimed at improving air quality and public health.</p
Analysis of Malodorous Sulfur Gases in Hong Kong Ambient Air Using Gas Chromatography and Dispersion Modeling
No full textThe human sense of smell plays a significant role in perceiving the environment, with odors ranging from pleasant to unpleasant. While some odors are pleasant, others—particularly malodors—cause annoyance and discomfort. However, individual sensitivity varies, complicating odor management. In urban areas, where malodors often arise from mixed land uses, odor measurement is essential to address residents’ concerns and improve quality of life. Despite its importance, odor measurement faces significant challenges, particularly for sulfur compounds, which are highly reactive and difficult to capture using conventional sampling and analysis methods. These compounds often react with common instruments, leading to inaccurate measurements. To address these challenges, this study developed a Thermal Desorption-Gas Chromatography-Flame Photometric Detection (TD-GC-FPD) system, designed for inert and accurate measurement of sulfur-based odors. The system minimizes reactivity issues, ensuring reliable capture and analysis of sulfur compounds. The study focused on a busy street in Yau Ma Tei, Kowloon, which was chosen as it represents the typical urban environment of Hong Kong, characterized by dense populations, mixed land uses, and diverse odor sources. The area includes a refuse collection point, restaurants, street food stalls, clothing shops, outdoor seating areas, and a hospital, making it an ideal location to study odor emissions and their impact on sensitive receptors. To visualize the spatial distribution of odor impacts, tools such as AERMOD and CFD models were employed, providing insights into odor dispersion patterns across the study area. The results demonstrate the effectiveness of the TD-GC-FPD system in capturing and quantifying sulfur-based odors in a complex urban environment. By integrating accurate measurements with dispersion models, this study offers a comprehensive approach to odor assessment and management, particularly in areas with mixed land uses and high human activity. This research highlights the importance of advanced odor measurement and modeling techniques in addressing urban odor issues and improving the quality of life for residents in densely populated areas like Hong Kong.</p
Study of biogenic volatile organic compounds at a suburban coastal site in Hong Kong
No full textBiogenic Volatile Organic Compounds (BVOCs) from terrestrial vegetation dominate global VOC emissions, surpassing contributions from anthropogenic sources. BVOCs are crucial in forming ozone and secondary aerosols, impacting air quality and human health. However, little is known about BVOC emissions in Hong Kong, despite its significant vegetation cover of nearly 70%. To address this knowledge gap, a long-term measurement campaign was conducted at HKUST Supersite, a suburban coastal site in Hong Kong. The measurements revealed the temporal and diurnal variations of BVOCs, with higher concentrations observed in summer and lower concentrations in winter, indicating a correlation between temperature and BVOC emissions. Furthermore, to explore different emission factors (EFs) affecting BVOC emissions, the MEGAN-F0AM model was employed to compare three sets of EFs. The optimal EFs were selected for further simulation and comparison with observed data. The simulated results exhibited seasonal variation, consistent with the observed data, although some discrepancies suggested that the model may not fully capture real-world variability. This study also investigates the influence of ozone enhancement on isoprene emission rates through simulation. The results demonstrate improved agreement compared to previous simulations, highlighting the impact of elevated ozone levels on BVOC emissions, particularly isoprene. Overall, this research provides valuable insights into BVOC emissions in Hong Kong and emphasizes the importance of considering ozone levels when studying BVOC dynamics. The findings contribute to our understanding of air quality and the complex interactions between biogenic emissions and atmospheric chemistry.</p
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