228 research outputs found
Gaseous Pollutants Emission from Diesel Vehicles in Hong Kong
The current study presents the detailed investigation of diesel vehicles emissions utilizing chassis dynamometer test in Hong Kong. Gaseous pollutants from diesel vehicle exhaust, including nitrogen oxides (NOx), total hydrocarbon (THC) and carbon monoxide (CO), are chosen to be the targets of this study. These pollutants were monitored real-time during different testing cycles and the data collected were used to calculate the fuel-based emission factor of each pollutant. Results showed that emission standard and driving conditions are the two main factors governing the trend of emission of these pollutants. Outliers observed in these trends are probably caused by the difference in level of maintenance of the vehicles, which is another important factor affecting the emission of pollutants
Spatial Distribution of PM\u3csub\u3e2.5\u3c/sub\u3e-Related Premature Mortality in China
PM2.5 is a major component of air pollution in China and has a serious threat to public health. It is very important to quantify spatial characteristics of the health effects caused by outdoor PM2.5 exposure. This study analyzed the spatial distribution of PM2.5 concentration (45.9 μg/m3 national average in 2016) and premature mortality attributed to PM2.5 in cities at the prefectural level and above in China in 2016. Using the Global Exposure Mortality Model (GEMM), the total premature mortality in China was estimated to be 1.55 million persons, and the per capita mortality was 11.2 per 10,000 persons in the year 2016, resulting in higher estimates compared to the integrated exposure-response model. We assessed the premature mortality attributed to PM2.5 through common diseases, including ischemic heart disease (IHD), cerebrovascular disease (CEV), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and lower respiratory infections (LRI). The premature mortality due to IHD and CEV accounted for 68.5% of the total mortality, and the per capita mortality (per 10,000 persons) for all ages due to IHD was 3.86, the highest among diseases. For the spatial distribution of disease-specific premature mortality, the top two highest absolute numbers of premature mortality associated with IHD, CEV, LC, and LRI, respectively, were found in Chongqing and Beijing. In 338 cities of China, we have found a significant positive spatial autocorrelation of per capita premature mortality, indicating the necessity of coordinated regional governance for an efficient control of PM2.5. Plain Language Summary
Fine particulate matter (PM2.5) concentrations have increased in general, in most developing countries in recent decades. In China, PM2.5 pollution has become a major component of air pollution and has serious health impacts. To obtain a comprehensive understanding of the national health impacts of PM2.5 in China, we have used the Global Exposure Mortality Model (GEMM) to estimate the premature mortality associated with PM2.5 exposure in 338 cities in China at the prefectural level and above. In addition, we analyzed the spatial distribution of premature mortality attributed to PM2.5 for five diseases, including ischemic heart disease (IHD), cerebrovascular disease (CEV), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and lower respiratory infections (LRI). Our study finds that the total premature mortality associated with PM2.5 exposure in China for 2016 was 1.55 million persons. The top two highest absolute numbers of premature mortality associated with IHD, CEV, LC, and LRI, respectively were found in Chongqing and Beijing. Furthermore, cities with high per capita premature mortality tended to be spatially connected with other cities with high per capita premature mortality, indicating the coordinated regional governance should be adopted to reduce the impact of PM2.5 on human health
Spatial Distribution of PM\u3csub\u3e2.5\u3c/sub\u3e-Related Premature Mortality in China
PM2.5 is a major component of air pollution in China and has a serious threat to public health. It is very important to quantify spatial characteristics of the health effects caused by outdoor PM2.5 exposure. This study analyzed the spatial distribution of PM2.5 concentration (45.9 μg/m3 national average in 2016) and premature mortality attributed to PM2.5 in cities at the prefectural level and above in China in 2016. Using the Global Exposure Mortality Model (GEMM), the total premature mortality in China was estimated to be 1.55 million persons, and the per capita mortality was 11.2 per 10,000 persons in the year 2016, resulting in higher estimates compared to the integrated exposure-response model. We assessed the premature mortality attributed to PM2.5 through common diseases, including ischemic heart disease (IHD), cerebrovascular disease (CEV), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and lower respiratory infections (LRI). The premature mortality due to IHD and CEV accounted for 68.5% of the total mortality, and the per capita mortality (per 10,000 persons) for all ages due to IHD was 3.86, the highest among diseases. For the spatial distribution of disease-specific premature mortality, the top two highest absolute numbers of premature mortality associated with IHD, CEV, LC, and LRI, respectively, were found in Chongqing and Beijing. In 338 cities of China, we have found a significant positive spatial autocorrelation of per capita premature mortality, indicating the necessity of coordinated regional governance for an efficient control of PM2.5. Plain Language Summary
Fine particulate matter (PM2.5) concentrations have increased in general, in most developing countries in recent decades. In China, PM2.5 pollution has become a major component of air pollution and has serious health impacts. To obtain a comprehensive understanding of the national health impacts of PM2.5 in China, we have used the Global Exposure Mortality Model (GEMM) to estimate the premature mortality associated with PM2.5 exposure in 338 cities in China at the prefectural level and above. In addition, we analyzed the spatial distribution of premature mortality attributed to PM2.5 for five diseases, including ischemic heart disease (IHD), cerebrovascular disease (CEV), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and lower respiratory infections (LRI). Our study finds that the total premature mortality associated with PM2.5 exposure in China for 2016 was 1.55 million persons. The top two highest absolute numbers of premature mortality associated with IHD, CEV, LC, and LRI, respectively were found in Chongqing and Beijing. Furthermore, cities with high per capita premature mortality tended to be spatially connected with other cities with high per capita premature mortality, indicating the coordinated regional governance should be adopted to reduce the impact of PM2.5 on human health
Use of antibiotics by primary care doctors in Hong Kong
© 2009 Lam et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Seasonal variations of anhydrosugars in PM2.5 in the Pearl River Delta Region, China
Anhydrosugars including levoglucosan and mannosan are the most effective organic tracers for biomass burning aerosol in the atmosphere. In this study, to investigate the contribution of biomass burning emissions to the aerosol burden in the Pearl River Delta (PRD) region, China, 24-hour integrated PM2.5 samples were collected simultaneously at four locations, (i) Guangzhou (GZ), (ii) Zhaoqing (ZQ) in Guangdong province, (iii) Hok Tsui (HT) and (iv) Hong Kong Polytechnic University (PU) in Hong Kong, in four seasons between 2006 and 2007. Levoglucosan and mannosan, together with water-soluble inorganic ions and water-soluble organic carbon (WSOC), were determined to elucidate the seasonal and spatial variations in biomass burning contributions. The concentrations of levoglucosan and mannosan were on average 82.4±123 and 5.8±8.6 ng m−3, respectively. The WSOC concentrations ranged from 0.2 to 9.4 µg m−3, with an average of 2.1±1.6 µg m−3. The relative contributions of biomass burning emissions to OC were 33% in QZ, 12% in GZ, 4% at PU and 5% at HT, respectively, estimated by the measured levoglucosan to organic carbon ratio (LG/OC) relative to literature-derived LG/OC values. The contributions from biomass burning emissions were in general 1.7–2.8 times higher in winter than those in other seasons. Further, it was inferred from diagnostic tracer ratios that a significant fraction of biomass burning emissions was derived from burning of hard wood and likely also from field burning of agricultural residues, such as rice straw, in the PRD region. Our results highlight the contributions from biomass/biofuel burning activities on the regional aerosol budget in South China
Parenting approaches, family functionality, and internet addiction among Hong Kong adolescents
© 2016 Wu et al. Background: Internet addiction (IA) among adolescents has become a global health problem, and public awareness of it is increasing. Many IA risk factors relate to parents and the family environment. This study examined the relationship between IA and parenting approaches and family functionality. Methods: A cross-sectional study was conducted with 2021 secondary students to identify the prevalence of IA and to explore the association between adolescent IA and familial variables, including parents' marital status, family income, family conflict, family functionality, and parenting approaches. Results: The results revealed that 25.3 % of the adolescent respondents exhibited IA, and logistic regression positively predicted the IA of adolescents from divorced families, low-income families, families in which family conflict existed, and severely dysfunctional families. Interestingly, adolescents with restricted Internet use were almost 1.9 times more likely to have IA than those whose use was not restricted. Conclusions: Internet addiction is common among Chinese adolescents in Hong Kong, and family-based prevention strategies should be aligned with the risk factors of IA.Link_to_subscribed_fulltex
Particle-induced oxidative damage from exposure to airborne PM2.5 components in the vicinity of Hong Kong landfills
Landfills are an essential component of Hong Kong’s waste management strategy. With a geographically small
size and a large population it is inevitable that many residents will live proximal to landfill sites, and this has
raised public concerns about landfill emissions causing low birth weights, cancer, neurological diseases,
nausea, and hospitalization of diabetics. This project has collected, physico-chemically characterise, and
determined the potential bioreactivity of landfill-derived PM2.5 particulates.
Many studies have demonstrated the health risks posed by landfill sites (Koshy et al., 2009), but unfortunately
there is lack of investigation in the bioactivity of PM2.5 from municipal landfill sites in Hong Kong. This study
has investigated the physicochemical characteristics of PM2.5 samples collected from locations near Municipal
Solid Waste (MSW) landfill sites. We determined the oxidative stress of PM2.5 samples from their generation
of reactive oxygen species. We determined the relationship between physical and chemical characteristics of
PM2.5 and their bioreactivity from particles collected near to the landfill sites and in downwind urban sites.
Five sampling sites were selected for this study. Two sites adjacent to the landfill areas, Two urban sites in a
mixture of residential and commercial areas, and one sampling site is in a remote area far removed from any
anthropogenic activities. The PM2.5 samples were collected simultaneously at all sites with URG PM2.5
samplers. Wind and real-time PM2.5 monitors were installed at two locations in proximity to the landfill sites
in order to determine diurnal variations of particulate level, wind speed and direction. Twenty-four hours
integrated PM2.5 samples were collected in winter (December to March, 2014-15) and summer (July to
November, 2015) in every 3 days intervals. Samples were weighed to a 1 μg precision for the mass
concentration measurements. Field emission scanning electron microscope (FESEM) analysis was used for
particle imaging. Total metal concentrations were analysed using inductively coupled plasma mass
spectrometry (ICP-MS). Ion chromatography (IC) was employed for water-soluble inorganic ions analysis.
Organic carbon (OC) and elemental carbon (EC) were analysed by thermal optical reflectance. Thermal
desorption-gas chromatography-mass spectrometry (TD-GC/MS) was used for polycyclic aromatic
hydrocarbons (PAHs) analysis. A plasmid scission assay (PSA) was used to determine the capability of each
sample to induce plasmid DNA damage. Statistical analysis was performed using SPSS 21.0 software. The
average PM2.5 concentrations were generally higher in winter than summer at all locations and significant
differences between seasons were observed at the landfill sites. The average concentrations of most chemical
species demonstrated summer minimum and winter maximum. The contributions of OC and EC in PM2.5 in
winter are in a range of 17.2-29.1 and 4.4-5.0%, respectively. However, the contributions of OC is lower in
summer. The NO3-, SO42- and NH4+ are the three most abundant inorganic ions, with sulphate contributed in
a range of 6.6-42.3 % in PM2.5 in winter. The amount of damage to the plasmid DNA induced by PM2.5
varied in a range of 24-92 % and 27-96 % in winter and summer, respectively. The DNA damage in summer
were higher than winter in all locations
High PM2.5 levels were observed during daytime downwind from landfills. Significant associations were
observed between DNA damage and heavy metals/PAHs in summer. Emissions from landfill-related
machinery are potential important particle sources. No significant associations were observed between DNA
damage and landfill particles, which indicates that PM2.5 loading from other regional sources was an important
factor for DNA damage
Characterization and health risk assessment of airborne pollutants in commercial restaurants in northwestern China: Under a low ventilation condition in wintertime
Impacts on indoor air quality of dining areas from cooking activities were investigated in eight categories of commercial restaurants including Szechwan Hotpot, Hunan, Shaanxi Noodle, Chinese Barbecue, Chinese Vegetarian, Korean Barbecue, Italian, and Indian, in Northwestern China during December 2011 to January 2012. Chemical characterization and health risk assessment for airborne carbonyls, and particulate-bound polycyclic aromatic hydrocarbons (PAHs) and heavy metals were conducted under low ventilation conditions in wintertime. The highest total quantified carbonyls (Sigma(carbonyls)) concentration of 313.6 mu g m(-3) was found in the Chinese Barbecue, followed by the Szechwan Hotpot (222.6 mu g m(-3)) and Indian (221.9 mu g m(-3)) restaurants. However, the highest Sigma(carbonyls) per capita was found at the Indian restaurant (4500 mu g capita(-1)), suggesting that cooking methods such as stir-fly and bake for spices ingredients released more carbonyls from thermal cooking processes. Formaldehyde, acetaldehyde, and acetone were the three most abundant species, totally accounting for >60% of mass concentrations of the Sigma(carbonyls). Phenanthrene, chrysene, and benzo[a]anthracene were the three most abundant PAHs. Low molecular weight fraction (Sigma PAHs(<= 178)) had the highest contributions accounting for 40.6%-65.7%, much greater than their heaver counterparts. Diagnostic PAHs ratios suggest that cooking fuel and environmental tobacco smoke (ETS) contribute to the indoor PAHs profiles. Lead was the most abundant heavy metal in all sampled restaurants. High quantity of nickel was also found in samples due to the emissions from stainless-steel made kitchen utensils and cookware and ETS. Cancer risk assessments on the toxic substances demonstrate that the working environment of dining areas were hazard to health. Formation of reactive organic species (ROS) from the cooking activities was evidenced by measurement of hydroxyl radical (center dot OH) formed from simulating particulate matter (PM) react with surrogate lung fluid. The highest center dot OH concentration of 294.4 ng m(-3) was detected in Chinese Barbecue. In addition, the elevation of the concentrations of PM and center dot OH after non-dining periods implies that the significance of formation of oxidizing-active species indoor at poor ventilation environments. (c) 2018 Elsevier B.V. All rights reserved
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