Does the presence of desert dust modify the effect of PM10 on mortality in Athens, Greece?

Recent reports investigate whether windblown desert dust may exacerbate the short-term health effects associated with particulate pollution in urban centers. We have tested this hypothesis by using daily air pollution and mortality data for Athens, Greece during the period 2001-2006.We investigated the effects of exposure to particulate matter with aerodynamic diameter < 0 μg/m³ (PM₁₀) on total and cause specific mortality, during days with and without windblown desert dust, for all ages, stratified by age groups and by sex. We identified 141 dust days between 2001 and 2006. We used Poisson regression models with penalized splines to control for possible confounding by season, meteorology, day of the week and holiday effect.A 10 μg/m³ increase in PM₁₀ was associated with a 0.71% (95% confidence interval (CI): 0.42% to 0.99%) increase in all deaths. The effects for total and cause specific mortality were greater for those ≥ 75 years of age, while for total mortality higher effects were observed among females. The main effect of desert dust days and its interaction with PM₁₀ concentrations were significant in all cases except for respiratory mortality and cardiovascular mortality among those < 75 years. The negative interaction pointed towards lower particle effects on mortality during dust events.We found evidence of modification of the adverse health effects of PM₁₀ on mortality in Athens, Greece with desert dust events: the particle effects were significantly higher during non-desert dust days. Our analyses indicate that traffic related particles, which prevail on non-desert dust days, have more toxic effects than the ones originating from long-range transport, such as Sahara dust.     

Impact of diesel policy banning on PM levels in urban areas

Increased use of diesel engine in on‐road vehicles presents a serious health concern, particularly in traffic‐congested urban areas. Diesel exhaust contains various gaseous and particulate pollutants, which, at high concentrations, pose adverse health effects. In this respect, various policy measures are being adopted worldwide to curtail emissions from diesel engines. This paper presents an assessment of diesel engine policy banning in the Greater Beirut Area. For this purpose, particulate matter levels in the air were measured after the ban and compared with concentrations reported prior to the ban. Health‐based socio‐economic benefits associated with improvement in air quality were then estimated using the long‐term decrease of particulate matter as an indicator.     

What do we know about effects of desert dust on air quality and human health in West Africa compared to other regions?

This study aims to compare, on the one hand, the geographical distribution of the desert dust source areas, their contribution to quantities emitted into the atmosphere, the trajectories and the quantities deposited, with on the other hand the areas of research interest focused on the desert dust impacts on air quality and/or human health. Based on a systematic review of the literature using the ISI Web of Knowledge database, we found 231 articles published over the last decade on the desert dust impacts on air quality. Of these, 48% concerned Asian dust and 39% Saharan dust, with the remaining 13% divided between the other dust source areas. However, only one of these studies addressed the worsening air pollution in West Africa, even though it is very close to the Sahara, the greatest contributor to the global dust budget. Moreover, there have been very few studies (41) looking at the direct links between desert dust and human health; in this context too, no interest has been shown in West Africa. Yet this region is also among the areas in which morbidity rates have been noted to be far higher than those found in other regions of the world, and where respiratory infections alone account for more than 20% of the causes of infant mortality. This survey highlights a clear imbalance between those areas most exposed to dust and the most studied areas in terms of dust impacts. Given these findings and the often alarming results published about other regions of the world, we advocate a revival of interest in research on West Africa in order to achieve a better understanding of the desert dust impacts on air quality and health among the populations of this region.     

Gaseous and particulate air pollution in the Lanzhou Valley, China

Gaseous and particulate matter measurements were performed from January 1999 to December 2001 to assess seasonal and diurnal patterns of air pollutions in the Lanzhou Valley, China. The objectives are the determination of the temporal variability of total suspended particulate (TSP) matter and PM10 levels, and their relationship with the SO2 and NOx emissions and desert dust intrusions from the dust sources in the Hexi Corridor in Gansu Province. The results showed that concentrations of gaseous and particulate pollutants undergo seasonal variations characterized by a winter maximum levels for SO2 (0.094-0.208 mg/m3) and NO2 (0.068-0.089 mg/m3) and a spring maximum levels for TSP (0.885-1.037 mg/m3). Linear regression analysis indicated that the diurnal mean TSP/PM10 ratio may approximate to 3.0, and that the annual NO2/NOx ratio was approximately 0.86, with its highest monthly average of 0.91 in June and its lowest monthly average of 0.788 in January. The origin of PM10 episodes was investigated by correlating the PM10 episodes in the Lanzhou Valley with the high wind speeds in Jinchang (dust sources) in the Hexi Corridor, and also, by comparing the PM10 levels with the SO2 and NOx concentrations. Most of the 'high PM10 episodes' (1-h mean maximum >1.0 mg/m3) were attributed to the desert dust intrusions from the Hexi Corridor. The influence of the industrial and domestic emissions in the PM10 levels was evidenced during most of the periods with the PM10 levels less than 1.0 mg/m3.     

Particulate matter in urban areas: health-based economic assessment

The interest in the association between human health and air pollution has grown substantially in recent years. Based on epidemiological studies in several countries, there is conclusive evidence of a link between particulate air pollution and adverse health effects. Considering that particulate matter may be the most serious pollutant in urban areas and that pollution-related illness results in financial and non-financial welfare losses, the main objective of this study is to assess the economic benefits of reducing particulate air pollution in Lebanese urban areas. Accordingly, the extent and value of health benefits due to decreasing levels of particulate in the air are predicted. Health impacts are expressed in both physical and monetary terms for saved statistical lives, and productivity due to different types of morbidity endpoints. Finally, the study concludes with a range of policy options available to mitigate particulate air pollution in urban areas.     

Size fractionated particulate matter emissions from a broiler house in Southern Ontario, Canada

In 1999, the National Emission Inventory and Project Task Group developed particulate matter emission inventories for the Canadian poultry industry using Canadian poultry census data and emission factors for all types of poultry operations based on U.S. Environmental Protection Agency and British Columbia/Greater Vancouver Regional District data [MOE. A Compendium of Knowledge on Fine Particulate Matter in Ontario. Ontario Ministry of the Environment (MOE) Review Report (as released to the CRESTech/NERAM expert panel). PIBS 3798e, 1999.]. Recent studies conducted on various poultry operations suggested that the emission factors currently in use could lead to a substantial underestimation of the airborne PM levels in Canada generated by these poultry industries. This study measured real time PM concentrations and house ventilation rates from a commercial broiler operation in southern Ontario in order to develop characteristic PM emission factors and inventories. The averaged particulate matter emission factors obtained were 0.11+/-0.004, 0.13+/-0.005, and 0.56+/-0.02 kg(PM) (1000 birds)(-1) (production cycle)(-1) for PM(1), PM(2.5), and PM(10), respectively. The yearly emissions for the studied commercial broiler operation were 22, 27, 114 kg(PM) (year)(-1) for PM(1), PM(2.5), and PM(10), respectively. The estimated PM emissions for Canada from the broiler sector are 382.4+/-13.9, 472.7+/-16.3, and 2025+/-69.9 tonnes(PM)/year for PM(1), PM(2.5), and PM(10), respectively.     

Mixing of dust with pollution on the transport path of Asian dust--revealed from the aerosol over Yulin, the north edge of Loess Plateau

Both PM_2.5 and TSP were monitored in the spring from 2006 to 2008 in an intensive ground monitoring network of five sites (Tazhong, Yulin, Duolun, Beijing, and Shanghai) along the pathway of Asian dust storm across China to investigate the mixing of dust with pollution on the pathway of the long-range transport of Asian dust. Mineral was found to be the most loading component of aerosols both in dust event days and non-dust days. The concentrations of those pollution elements, As, Cd, Pb, Zn, and S in aerosol were much higher than their mean abundances in the crust even in dust event days. The high concentration of SO₄²⁻ could be from both sources: one from the transformation of the local emitted SO₂ and the other from the sulfate that existed in primary dust, which was transported to Yulin. Na⁺, Ca²⁺, and Mg²⁺ were mainly from the crustal source, while NO₃⁻ and NH₄⁺ were from the local pollution sources. The mixing of dust with pollution aerosol over Yulin in dust event day was found to be ubiquitous, and the mixing extent could be expressed by the ratio of NO₃⁻/Al in dust aerosol. The ratio of Ca/Al was used as a tracer to study the dust source. The comparison of the ratios of Ca/Al together with back trajectory analysis indicated that the sources of the dust aerosol that invaded Yulin could be from the northwestern desert in China and Mongolia Gobi.     

The rise of modernism and the decline of place: the case of Surrey City Centre,Canada

This paper reviews the ideology of modernism in a North American context and discusses how its various attributes are embodied in the Surrey City Centre development in the Greater Vancouver area of British Columbia, Canada. In doing so, it makes use of Calthorpe and Fulton's tri‐partite framework of specialization, mass production and standardization as being characteristic of the ethos of the age. After analysing the various interventions that design professionals and civic agencies have made in the Surrey City Centre area, it concludes that modernist ideology has a tendency to foster placeless settings lacking in vitality, security and comfort and appeal for pedestrians.     

Size distribution of airborne particles controls outcome of epidemiological studies

Epidemiological studies typically using wide size range mass metrics (e.g. PM₁₀) have demonstrated associations between airborne particulate matter and several adverse health outcomes. This approach ignores the fact that mass concentration may not correlate with regional lung dose, unlike the case of trace gases. When using measured particle size distributions as the basis for calculating regional lung dose, PM₁₀ mass concentration is found to be a good predictor of the mass dose in all regions of the lung, but is far less predictive of the surface area and particle number dose. On the other hand, measurements of particle number do not well predict mass dose, indicating that the chosen particle metric is likely to determine the health outcomes detectable by an epidemiological study. Consequently, epidemiological studies using mass metrics (PM_2.5 and PM₁₀) may fail to recognise important health consequences of particulate matter exposure, leading to an underestimate of the public health consequences of particle exposure.     

Exposure of children to airborne particulate matter of different size fractions during indoor physical education at school

Although moderate regular aerobic exercise is recommended for good health, adverse health consequences may be incurred by people who exercise in areas with high ambient pollution, such as in the centres of large cities with dense traffic. The exposure of children during exercise is of special concern because of their higher sensitivity to air pollutants. The size-segregated mass concentration of particulate matter was measured in a naturally ventilated elementary school gym during eight campaigns, seven to ten days long, from November 2005 through August 2006 in a central part of Prague (Czech Republic). The air was sampled using a five-stage cascade impactor. The indoor concentrations of PM_2.5 recorded in the gym exceeded the WHO recommended 24-hour limit of 25 μg m⁻³ in 50% of the days measured. The average 24-h concentrations of PM_2.5 (24.03 μg m⁻³) in the studied school room did not differ much from those obtained from the nearest fixed site monitor (25.47 μg m⁻³) and the indoor and ambient concentrations were closely correlated (correlation coefficient 0.91), suggesting a high outdoor-to-indoor penetration rate. The coarse indoor fraction concentration (PM_2.5–10) was associated with the number of exercising pupils (correlation coefficient 0.77), indicating that human activity is its main source. Considering the high pulmonary ventilation rate of exercising children and high outdoor particulate matter concentrations, the levels of both coarse and fine aerosols may represent a potential health risk for sensitive individuals during their physical education performed in naturally ventilated gyms in urban areas with high traffic intensity.     

Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 microg g(-1) (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass.     

Measurements of particulate matter within the framework of the European Monitoring and Evaluation Programme (EMEP) I. First results

Particulate matter (PM) monitoring presents a new challenge to the transboundary air pollution strategies in Europe. Evidence for the role of long-range transport of particulate matter and its significant association with a wide range of adverse health effects has urged for the inclusion of particulate matter within the European Monitoring and Evaluation Programme (EMEP) framework. Here we review available data on PM physico-chemical characteristics within the EMEP framework. In addition we identify future research needs for the characterisation of the background PM in Europe that include detailed harmonised measurements of mass, size and chemical composition (mass closure) of the ambient aerosol.     

大气可吸入颗粒物对IAQ的影响研究进展

回顾了可吸和颗粒物对人体健康的影响及其量化指标和测量方法，重点介绍了一些国家关于大气颗粒污染对室内空气品质影响的研究成果和进展，并对国内现状进行了分析。最后得出结论：大气可吸入颗粒物对室内空气品质有着重大影响，需要引起我国室内空气品质、环境科学和公共卫生学者的高度重视，并共同努力促进问题的解决。     

A combined analysis of backward trajectories and aerosol chemistry to characterise long-range transport episodes of particulate matter: the Madrid air basin, a case study

This study has investigated the influence of synoptic weather patterns and long-range transport episodes on the concentration levels of airborne particulate matter (TSP, PM10 and PM2.5) and some major ions (SO(4)(2-), NO(3)(-) and NH(4)(+)) at a background rural station in central Spain. Air mass back-trajectories arriving at the site in 1999-2005 have been analysed by statistical methods. First, cluster analysis was used to group trajectories into 8 clusters depending on their direction and speed. Meteorological scenarios associated to each cluster have been obtained and interpreted. Then, the incidence of different air mass transport patterns on particle concentrations and composition recorded at this station was evaluated. This evaluation included PM10 and PM2.5 concentrations and chemical composition data, obtained at three representative sites of the Madrid air basin during sampling campaigns carried out in the course of the 1999-2005 period. Finally, a residence time analysis of trajectories was also performed to detect remote sources and transport pathways. Significantly elevated concentrations of TSP and PM10 were observed for Northern African flows as a consequence of the transport of mineral dust. Significant inter-cluster differences were also observed for PM2.5 and secondary inorganic compounds, with the highest concentrations associated with low baric gradient situations and Southern European flows. The residence time analysis confirmed that current TSP and PM10 concentrations in central Spain are likely to be influenced significantly by long-range transport of desert dust from different desert regions in North Africa. Furthermore, emissions from continental Europe with a high time of residence in the western and central areas of the Mediterranean basin, seem to significantly influence PM2.5 and secondary inorganic aerosol concentrations in this region.     

Reconfiguring the edge city: The use of ecological design parameters in defining the form of community

Suburban development in the Greater Vancouver Region of British Columbia, as with edge-city development elsewhere in North America, continues to erode forest and farm, disrupt hydrological patterns, and weaken the overall ecological integrity of the region. Fragmented landscapes and equally fragmented communities isolate citizens from nature as well as from one another. Alternative approaches and models for creating sustainable communities are urgently required. This paper presents one such model, using criteria developed from a wide range of exemplary sustainable community approaches employed elsewhere in North America and Europe. It compares this model sustainable community with an existing edge community in the region and concludes with the assertion that a high level of sustainability is not only attainable but also can improve a community's sense of the civic and sense of place.     

Dependence of urban air pollutants on meteorology

Dependence of air pollutants on meteorology is presented with the aim of understanding the governing processes pollutants phase interaction. Intensive measurements of particulate matter (PM10) and gaseous materials (e.g., CO, NO2, SO2, and O3) are carried out regularly in 2002 at 14 measurement sites distributed over the whole territory of Great Cairo by the Egyptian Environmental Affairs Agency to assess the characteristics of air pollutants. The discussions in this work are based upon measurements performed at Abbassiya site as a case study. The nature of the contributing sources has been investigated and some attempts have been made to indicate the role played by neighboring regions in determining the air quality at the site mentioned. The results hint that, wind direction was found to have an influence not only on pollutant concentrations but also on the correlation between pollutants. As expected, the pollutants associated with traffic were at highest ambient concentration levels when wind speed was low. At higher wind speeds, dust and sand from the surrounding desert was entrained by the wind, thus contributing to ambient particulate matter levels. We also found that, the highest average concentration for NO2 and O3 occurred at humidity相似文献   

Traffic-generated airborne particles in naturally ventilated multi-storey residential buildings of Singapore: Vertical distribution and potential health risks

The main objective of the study is to quantify the mass concentration exposure levels of fine traffic-generated particles (PM_2.5) at various heights of typical multi-storey public housing buildings located in close proximity, i.e. within 30 m and along a busy major expressway in Singapore. The secondary objective is to compare the potential health risks of occupants in the buildings, associated with inhalation exposure of fine traffic-generated particulate matter, based on estimated dose rates and the lowest observed adverse effect levels (loael) at the various floors of these buildings. Two typical public housing buildings, both naturally ventilated residential apartment blocks, of point block configuration (22-storey) and slab block configuration (16-storey) were selected for the study. Particulate samples were collected for both mass and chemical analysis (OC/EC ratio) at three representative floors: the lower, the mid, and upper floors of the buildings. Key meteorological parameters such as wind speed, wind direction, ambient temperature, and relative humidity were also concurrently measured at the sampling locations. For the potential health risk analysis, the occupants have been divided into four age categories namely, infants, children (1 year), children (8–10 years) and adults. The analysis takes into account age-specific breathing rates, body weights for different age categories. Experimental results explicitly showed that PM_2.5 mean particle mass concentration was highest at the midfloors of both buildings when compared to those measured at upper and lower floors during a typical day. Although the lower floors were closest to traffic emissions, the mean particle mass concentration was lower there than that at the midfloors, which could presumably be due to the interception of PM_2.5 particles by tree leaves or the inflow of clean and drier air from higher altitude with lower aerosol burden mixing with the traffic-polluted air at the lower levels thus lowering the concentration at the lower floors similar to induced chimney effect or both. The upper floors had the least fine particulate matter mass concentration due to dilution following pronounced mixing of traffic-polluted air with ambient air. The only difference between both blocks is that at corresponding floors, the mass concentration levels for slab block is much higher than that of point block. This could be attributed to the configuration of the blocks. Observational data show the slab block tends to slow down the approaching wind thus allowing the accumulation of the fine traffic-generated particulate matter in front of the building. For point block, the HR values at the mid and lower floors suggest that occupants living in these floors experience 1.81 and 1.34 times more health risk, respectively, in contracting respiratory diseases when compared to those living at the upper floors for all age categories. Similarly, for the slab block, occupants living in the mid and lower floors had 1.62 and 1.28 times more risk, respectively, in contracting respiratory diseases when compared to those living at the upper floors for all age categories.     

Particulate matter in the atmosphere: which particle properties are important for its effects on health?

Whilst epidemiological studies have consistently demonstrated adverse effects of particulate matter exposure on human health, the mechanism of effect is currently unclear. One of the major issues is whether the toxicity of the particles resides in some particular fraction of the particles as defined by chemical composition or size. This article reviews selected data on the major and minor component composition of PM2.5 and PM10 particulate matter showing quite major geographic variations in composition which are not reflected in the exposure-response coefficients determined from the epidemiology which show remarkably little spatial variation. The issue of particle size is more difficult to address due to the scarcity of data. Overall, the data presented provides little support for the idea that any single major or trace component of the particulate matter is responsible for the adverse effects. The issue of particle size is currently unclear and more research is warranted.     

Evaluation of trace elements in human lung tissue II. Recovery and analysis of inhaled particulates

Inhaled particulate material, deposited in the lungs of eight Belgian individuals, is differentiated from the tissue with a digestion procedure using the enzyme ficin. This method is simple and efficient and yields a small amount of insoluble dust. The total element concentration of the tissue samples was determined by neutron activation analysis. The radioactive residues obtained after the digestion of the tissue were counted and are considered to represent the insoluble dust fraction. A major part of the Co, Cr, Sb and Sc was recovered in the residues, but only small fractions of the Cs, Rb and Zn. These findings confirm the assumption that Co, Cr, Sb and Sc are enriched in the lungs as a result of the accumulation of atmospheric contaminants. Further proof can be derived from the analogy between the elemental composition of the residue and that of atmospheric particulate matter collected in Belgium.