High Levels Of Particulate Matter Research Articles

Characterization of the size-distribution of aerosols and particle-bound content of oxygenated PAHs, PAHs, and n-alkanes in urban environments in Afghanistan

Abstract Air pollution is a common problem in mega-cities in Asia, resulting in high levels of particulate matter (PM). In this study, 24 h samples of airborne particulate matter (PM 2.5 and PM 10 ) was collected for two weeks in urban locations in Kabul and Mazar-e Sharif, Afghanistan. The samples were analyzed for twenty n -alkanes, fifteen polycyclic aromatic hydrocarbons (PAHs) and eighteen oxygenated PAHs (oxy-PAHs). The results were compared to a reference location in Umea, Sweden. The main objectives were: to characterize the organic fraction in PM 2.5 , with focus on oxy-PAHs, PAHs and n -alkanes, assess relationships between compound groups, and investigate possible source categories. Mean PM 10 , levels were 260 μg m −3 , and 334 μg m −3 and mean PM 2.5 levels were 86 μg/m 3 and 68 μg m −3 in Kabul and Mazar-e Sharif, respectively. The higher ratio of PM 2.5 to PM 10 in Kabul than Mazar-e Sharif or Umea was reflected in the high number of small particles, as collected by a particle counter. Kabul and Mazar-e Sharif had high levels of PAHs and oxy-PAHs compared to Umea and previously reported data from Western countries. Generally, the highest individual levels of oxy-PAHs were found for ketones (0.27–33 ng m −3 ), whereas the quinone levels were lower (0.027–3.1 ng m −3 ). High correlations ( r > 0.96) between PAHs and oxy-PAHs were found at both locations. Diagnostics for n -alkanes, such as the carbon preference index, and the most abundant species, C max , and the presence of unresolved complex mixture indicated a higher contribution from coal and petroleum sources in Kabul. Models generated by principal component analysis (PCA) and positive matrix factorization (PMF) both suggested separate sources for lower molecular weight n -alkanes and higher molecular weight n -alkanes. The PAHs and the oxy-PAHs were not separated in either the PCA or the PMF models, indicating that they had similar sources and are perhaps relatively unspecific as source markers. Nevertheless, the PAHs and oxy-PAHs were good markers for bad air quality in the urban locations in Afghanistan in comparison to data from Western countries. Based on the models and diagnostic ratios it is suggested that traffic and combustion of coal and biomass were the dominating sources of the high levels of particle-bound organic compounds.

Intercontinental influence of NOx and CO emissions on particulate matter air quality

Anthropogenic emissions of nitrogen oxides (NOx h NO þ NO2) and carbon monoxide (CO) affect particulate matter (PM) air quality on an intercontinental scale by changing background concentrations of oxidants (OH, ozone, H2O2) and thus increasing the oxidation rate of sulfur dioxide (SO2) to sulfate and NOx to nitrate. We conduct sensitivity simulations with the GEOSeChem chemical transport model and find that these intercontinental influences of NOx and CO emissions on PM can be greater than those from SO2 emissions (a direct PM precursor). The intercontinental impact of oxidant precursors is greatest in receptor regions with high domestic SO2 ,N Ox, and ammonia emissions and hence already high levels of PM. US NOx and CO emissions increase annual mean PM in northern Europe and eastern China by up to 0.25 m gm �3 . The increase in Europe is mostly as sulfate, whereas in China it is mostly as nitrate. East Asian NOx and CO emissions have a weaker intercontinental influence (w0.2 m gm �3 in northern Europe, w0.1 m gm �3 in the eastern US). These intercontinental effects of NOx and CO emissions on PM

Anthropogenic and natural constituents in particulate matter in the Netherlands

Abstract. To develop mitigation strategies for reducing concentrations of both PM2.5 and PM10, the origin of particulate matter (PM) needs to be established. An intensive, one-year measurement campaign from August 2007 to August 2008 was carried out to determine the composition of PM10 and PM2.5 at five locations in the Netherlands, aiming at reducing the uncertainties on the origin of PM. Generally, a considerable conformity in the chemical composition of PM2.5 (and PM10) is observed. From all constituents present in PM2.5, the secondary inorganic aerosol is the most dominant (42–48%), followed by the total carbonaceous matter (22–37%). Contributions from sea salt (maximum 8%), mineral dust and metals (maximum 5%) are relatively low. For the first time, a detailed overview of the composition of the coarse fraction can be presented. Compared to the fine fraction, contributions of sea salt, mineral dust and metals are larger resulting in a more balanced distribution between the various constituents. Through mass closure a considerable part of the PM mass could be defined (PM2.5: 80–94%). The chemical distribution on days with high PM levels shows a distinct increase in nitrate as well as in the unaccounted mass. Contributions of the other constituents remain equal or are lower (sea salt) when expressed in percentages. A correspondence between nitrate and the unaccounted mass is observed hinting at the presence of water on the filters. The contribution from natural sources in the Netherlands (at a rural station) was estimated to be 19 to 24% for PM10 and 13 to 17% for PM2.5.

Comparison of indoor/outdoor carbon content and time resolved PM concentrations for gas and biomass cooking fuels in Nogales, Sonora, Mexico

Abstract A case study designed to investigate indoor and outdoor air quality in naturally ventilated homes near the US-Mexico border was conducted in Nogales, Sonora, Mexico from 14–30 March 2009. To better understand resident’s actual exposure to various sizes of particulate matter ( PM) , we compare measured concentrations in homes using different household stove cooking fuels (gas versus biomass) and investigate the spatial distribution of outdoor PM . Data from two home locations, one with a gas stove and one with both biomass and gas stoves are evaluated. In each home, continuous PM concentrations were sampled over a range of particle sizes. Indoor and outdoor concentration measurements were facilitated using a valve switching system. PM 2.5 was also sampled on quartz filters located inside and outside of the two homes for carbon analysis. This paper will present a subset of the field data to compare time resolved indoor PM concentrations and carbon content for the two homes; specifically, comparing cooking versus non-cooking time periods. Results indicate that indoor elemental carbon concentrations are dominated by indoor sources during biomass burning, and outdoor sources at all other times. The data indicate that the influence of indoor sources on organic carbon concentrations increases during both gas and biomass stove use; this information is correlated to continuous indoor PM concentrations and home activities. The mean 24 h indoor PM 10 concentration was 408 μg m −3 for the gas stove home and 648 μg m −3 for the home with biomass and gas stoves, while the outdoor concentrations were 609 μg m −3 and 381 μg m −3 , respectively. The average 24 h PM 10 Indoor/Outdoor ratio was 0.71 for the gas stove home and 1.79 for the home with both gas and biomass stoves. These ratios should be interpreted with caution as they appear to underestimate the indoor source contribution due to high outdoor PM levels.

Effect of Prenatal Exposure to Wildfire-generated PM2.5 on Birth Weight

O-29C4-3 Background/Aims: Prenatal exposure to air pollution is associated with adverse birth outcomes such as low birth weight. We sought to investigate whether prenatal exposure to high levels of particulate matter (PM2.5) from large wildfires were also negatively associated with birth outcomes, independent of background air pollution levels. Methods: In 2003, several large wildfires occurred across 6 counties in Southern California, burning more than 750,000 acres over several days. We investigated the effect of wildfire-generated PM2.5 on birth outcomes, using California vital statistics records for 2003–2004 and exposure estimates created at the zip-code level for the week of the wildfires in 8 counties in southern California, including 2 counties with no wildfire exposure. Exposure estimates were derived in a GIS framework using a combination of existing data from an extensive monitoring network, light extinction data, meteorological conditions, and smoke information extracted from MODIS satellite images. Exact addresses from records were geocoded and assigned an exposure estimate for wildfire PM2.5 and for background ambient PM2.5. Logistic and linear regression models were used to determine whether an association existed between wildfire PM2.5 exposure and birth weight, small-for-gestational age, and preterm birth, after adjustment for background ambient PM2.5 and other covariates. Results: Overall, pregnant women living in 1 of the 6 counties at the time the wildfires occurred delivered babies who weighed on average 18 g less (P = 0.01) than the babies of mothers living in 2 counties with no wildfires. Significant effects were observed by trimester, with a stronger association in the third trimester. When level of wildfire PM2.5 exposure was categorized into low, medium, or high, no strong dose-response was observed. However, the effects were also strongest in the third trimester. No effects were observed for small-for-gestational age or preterm birth. Conclusion: Exposure to wildfire-generated pollution may have an adverse effect on birthweight independent of background pollution.

Illnesses, Signs, and Symptoms Related to High Levels of Exposure of PM10 and Ozone, Guadalajara, México

PP-29-008 Background/Aims: Human exposure to high levels of particulate matter (PM10) and Ozone pollution is related to the presence of certain illnesses, signs, and symptoms (ISS). The aims of this study were to identify ISS shown by the inhabitants of Guadalajara's Metropolitan area, who have been exposed to air pollutants, which frequently exceed the safety levels of Mexican Standards (PM10 and Ozone). Methods: This is an observational, descriptive, and transversal study. Samples were collected from 414 dwellings and a direct survey was applied to identify, by means of self-reporting, the presence of ISS related to exposure to PM10 and Ozone. The variables analyzed were (a) time of residence, (b) a smoker within the dwelling, (c) illnesses of a family member, (d) month of the year during which the illness was suffered, and (e) signs and symptoms related to exposure. A descriptive analysis was conducted, using frequency distributions, percentages, and summary measurements. Results: In all, 59.7% stated having resided in the area studied for over 20 years. In 48% of the dwellings, at least one family member smoked. The illnesses reported, in order of importance, were bronchitis (41.4%), high blood pressure (37.8%), and rhinitis (32%). Those months of the ear when illnesses occurred more frequently were December with 55.2%, April 28%, and January 25.1%. The signs and symptoms mentioned by the population were teary and burning eyes in 79.2%, throat ache in 74.9%, headache in 70.8%, nose irritation 65.7%, fatigue 51%, skin irritation 28.8%, and aching chest/chest pains 22.3%. Conclusion: The 2 health conditions most affected were those of the respiratory system and the cardiovascular system, which according the inhabitants, bronchitis and high blood pressure with 41.4% and 37.8%, respectively were the illnesses suffered most frequently. The signs and symptoms they reported, confirms the presence of illnesses and symptoms most frequently mentioned in scientific literature on exposure to PM10 and Ozone.

Acute Decrease in HDL Cholesterol Associated With Exposure to Welding Fumes

To investigate acute changes in circulating lipids after exposure to relatively high levels of particulate matter through welding. Using a repeated measures panel study, lipid levels before and after welding and personal exposures to fine particulate matter (PM2.5) were measured in 36 male welders over 63 exposure and/or control days. There was a trend toward decrease in HDL (-2.3 mg/dL, P = 0.08) 18 hours after welding. This effect became significant (-2.6 mg/dL, P = 0.05) after adjustment for possible confounders. The effect was strongest (-4.3 mg/dL, P = 0.02) among welders who did not weld the day before the study. There were no significant changes in other lipids associated with welding or PM2.5 exposure. Welding exposure was associated with an acute decrease in circulating HDL, which may relate to the inflammatory and proatherosclerotic effects of fine particle exposure.

흡기중의 수소첨가가 산업용 디젤기관의 성능에 미치는 영향

디젤기관은 공기만을 흡입 압축한 후에 연료를 분사하여 연소하기 때문에 높은 압축비가 가능하다. 높은 압축비에 의한 고효율의 장점과 연료의 직접분사에 의한 매연미립자의 배출 및 질소산화물의 배출이 많은 단점을 갖고 있다. 이러한 문제점을 해결하기 위하여 많은 연구들이 진행되었으며 수소를 흡기중에 공급하는 기술도 연구되고 있다. 본 논문에서는 미량의 수소를 연소실에 공급하여 엔진성능에 미치는 영향을 평가하였다. 토크와 엔진속도를 100%, 75%, 50%, 25%, 0%와 700rpm, 1000rpm, 1500rpm, 2000rpm로 구분하여 실험하였다. 실험결과 질소산화물이 약간 증가하였지만 연료소비율, 스모크와 일산화탄소 배출은 감소하였다. 수소의 첨가는 저부하 영역에서는 효과가 거의 없었지만 고부하 영역에서 큰 효과가 있었다.

Investigation into presence of atmospheric particulate matter in Marikana, mining area in Rustenburg Town, South Africa

An investigation to find out presence of particulate matter in Marikana, a mining area in Rustenburg town, South Africa, was carried out in the months of August and November of 2008. Samples were collected for measurements of particulate matter (PM) of particle diameters of PM10, PM2.5, and PM1. After gravimetric analysis of daily measurements, it was found that PM10 concentration values ranged between 3 and 9 μg/m(3), PM2.5 concentration values ranged between 16 and 26 μg/m(3), and PM1 concentration values ranged between 14 and 18 μg/m(3) for the month of August 2008. For the month of November, it was found that PM10 concentration values ranged between 2 and 8 μg/m(3), PM2.5 concentration values ranged between 0 and 5 μg/m(3), and PM1 concentration values ranged between 4 and 15 μg/m(3). This study was undertaken as preliminary work having in mind that mining activities could be emitting high levels of particulate matter in the atmosphere which might be degrading the quality of the air. It was observed, however, that the daily particulate matter especially of PM10 emitted were quite low when compared to laid down International Air Quality Standards. The standards did not give guidelines for particulate matter of diameter 2.5 μm. It was concluded that particulate matter came from three major sources: platinum mining, domestic biomass burning, and traffic emissions due to fuel burning.

High wintertime particulate matter pollution over an offshore island (Kinmen) off southeastern China: An overview

Both the Yangtze River Delta (YRD) and the Pearl River Delta (PRD), the two most rapidly developing areas in eastern China, have suffered from serious air pollution, and thus, numerous investigations were devoted to studying these problems. Other areas in eastern China have received less attention despite similar rapid development in their industries and economy. In this study, we analyzed air‐quality data from Kinmen Island (24°27′26″N, 118°19′36″E) located off Fujian Province and between the two above‐mentioned deltas. Our results clearly show that the study area is experiencing serious air quality deterioration. Particularly, high levels of suspended particulate matter (PM) were observed during winter, when the northeasterly monsoon prevails. For example, concentrations of wintertime PM10 (particles ≤ 10 μm in diameter) frequently exceeded 100 μg/m3 in the last three years. In addition to the air‐quality data analysis, aerosol samples were collected between 22 November 2007 and 6 March 2008 and subjected to chemical analyses of various species. Our findings show that the three principal PM components include organic, mineral, and sulfate species with moderate to minor fractions of nitrate, sea salt, elemental carbon, and trace metal oxides. The high PM levels observed over the island may be partly attributed to the transport from a mixed‐type industrial area located ∼40 km northeast of Kinmen. Our study could partially fill the air quality data gap between the YRD and PRD regions, and highlight the alarming fact that air pollution has gradually expanded along eastern China's coastal zone.

Fuel use and emissions performance of fifty cooking stoves in the laboratory and related benchmarks of performance

Improved cooking stove projects in the developing world have the potential to reduce deforestation, improve health, and slow climate change. To meet these requirements, stoves must be carefully designed through thorough testing and verification of performance. The systematic investigation of the heat transfer and combustion efficiency of stove design in the laboratory sheds light on what technologies work best and helps to ensure that stoves being disseminated are truly a significant improvement over traditional cooking methods. Performance of 50 different stove designs was investigated using the 2003 University of California-Berkeley (UCB) revised Water Boiling Test (WBT) Version 3.0 to compare the fuel use, carbon monoxide (CO) and particulate matter (PM) emissions produced. While these laboratory tests do not necessarily predict field performance for actual cooking, the elimination of variables such as fuel, tending, and moisture content, helps to isolate and compare the technical properties of stove design. Stoves tested fell under 7 main categories: simple stoves without combustion chambers, stoves with rocket-type combustion chambers, gasifier stoves, fan-assisted stoves, charcoal-burning stoves, liquid/gas fuel stoves, and wood-burning stoves with chimneys. A carefully made three-stone fire was also tested for comparison. Results showed that: • Stoves without well-designed combustion chambers may reduce fuel use in comparison to the three-stone fire but do not necessarily decrease and can potentially increase emissions of CO and PM. • Rocket-type stoves can reduce fuel use by 33%, CO emissions by 75%, and PM emissions by 46% on average in comparison to the three-stone fire. • Use of a pot skirt can reduce fuel use and emissions by 25–30%. • When operating well, gasifier stoves can reduce particulate matter substantially, averaging 90% improvement over the three-stone fire. • Five forced air stoves reduced fuel use by an average of 40% and emissions by 90% over the three-stone fire. • Traditional charcoal stoves use about the same amount of energy as the three-stone fire to complete a task (not counting the energy lost in making the charcoal, which can be as much as 70%) and produce up to two times more carbon monoxide and 80% less PM. A rocket-type charcoal stove can reduce this energy consumption by one third and CO emission by at least one half. • Liquid fuels generally exhibit less energy use and emissions. Kerosene can emit higher levels of PM than some improved wood stoves when not operating properly. • Well-designed stoves with chimneys remove smoke from the kitchen while fuel use is generally directly related to how much of the pot is in direct contact with the flames. From this data, it was possible to recommend benchmarks of improved cookstove performance. Benchmarks were suggested at levels that were achievable using known materials and manufacturing techniques, yet still aspirational, ensuring each stove design is carefully tested and optimized for highest efficiencies. It is hoped that these benchmarks can be used as the first step toward international performance standards for cooking stoves. Five of the stoves presented here were also tested at the US EPA, with results agreeing within 20% or better on all fuel and emissions measures, suggesting standard evaluation at various locations is possible.

Impact of short-term preconceptional exposure to particulate air pollution on treatment outcome in couples undergoing in vitro fertilization and embryo transfer (IVF/ET)

To assess the potential effects of short-term exposure to particulate air pollution during follicular phase on clinical, laboratory, and pregnancy outcomes of women undergoing IVF/ET. Retrospective cohort study of 400 first IVF/ET cycles of women exposed to ambient particulate matter during follicular phase. Particulate matter (PM) was categorized into quartiles (Q(1): < or =30.48 microg/m(3), Q(2): 30.49-42.00 microg/m(3), Q(3): 42.01-56.72 microg/m(3), and Q(4): >56.72 microg/m(3)). Clinical, laboratory, or treatment variables were not affected by follicular phase PM exposure periods. Women exposed to Q(4) period during the follicular phase of conception cycles had a higher risk of miscarriage (odds ratio, 5.05; 95% confidence interval: 1.04-25.51) when compared to women exposed to Q(1-3) periods. Our results show an association between brief exposure to high levels of ambient PM during the preconceptional period and early pregnancy loss, although no effect of this exposure on clinical, laboratory, and treatment outcomes was observed.

Impact of Asian dust and continental pollutants on cloud chemistry observed in northern Taiwan during the experimental period of ABC/EAREX 2005

Observations of particulate matter (PM), vertical cloud and aerosol structure and cloud water chemistry in northern Taiwan were conducted during the ABC/EAREX 2005 period. Five Asian continental outflow regimes reaching Taiwan were identified. One was coupled with a dust storm observed not only at Gosan, Korea, but also over Taiwan, suggesting the scope of its regional impact. The arrival of the dust event was determined by lidar, cloud water, and surface PM measurements. When continental outflow events correspond to the presence of significant dust concentrations, air quality can be drastically worsened due to high levels of PM. PM10 (PM with aerodynamic diameters &lt; 10 μm), pH, conductivity, and ion concentrations of cloud water increased drastically near the dissipating stage of the frontal passage/cloud event for the dust case. Cloud water may have become acidified by pollution from industrial and urban regions along the coast of eastern China. Nevertheless, abundant Ca2+ contributed to the neutralization of acidic cloud water during the dust stage. The much higher aerosol and chemical loading injected into these clouds caused an enrichment effect in the cloud water, which can double the cloud loading of total ions, when Ca2+ increases by approximately 7 times.

Chemical Characterization and Preliminary Source Contribution of Fine Particulate Matter in the Mexicali/Imperial Valley Border Area

The airshed shared by the Valley of Mexicali in Mexico and Imperial Valley in the United States frequently experiences high levels of particulate matter (PM) less than 10 µm (PM10). However, very little information exists on the concentration and composition of fine PM (PM <2.5 µm, or PM2.5) in the region, particularly on the Mexican side of the border. This paper presents the results of two monitoring campaigns (November 23–December 17, 2004 and April 12–22, 2005) that were conducted to obtain, for the first time, detailed composition of PM2.5 in the city of Mexicali. In both campaigns, 24-hr average PM2.5 samples were collected using low-volume equipment. Samples collected on Teflon filters were analyzed for mass and 38 metals (Na to Pb), whereas samples collected on quartz filters were analyzed for anions (sodium, potassium, ammonium), cations (chloride, nitrate, sulfate), and carbon (organic [OC] and elemental [EC]). During the fall campaign, the monitored concentration exceeded 65 µg/m3 (i.e., Mexico’s PM2.5 air quality standard for 24-hr average samples) on four different days at one or more Mexicali sites. No exceedances were reported during the spring campaign. The contribution of main chemical species to the total mass indicated that organic material was the principal component (62% in fall and 56% in spring). Average secondary OC contributions to the total observed OC for the fall data was estimated at 14% (no day exceeding 30% contribution) and 47% for the spring data (with the minimum being 33% and the maximum 68%). Ammonium sulfate contributions exceeded ammonium nitrate contributions during the spring (16% vs. 7%), whereas the reverse occurred during the fall (5% vs. 10%). Geological material contributed 6% of the mass in the fall versus 10% in the spring. Overall the results indicate that PM2.5 in Mexicali is heavily influenced by anthropogenic sources, rather than from soil resuspension. Spatial and meteorological analysis of the data gives an indication that during the fall campaign local sources were the principal contributor to high-PM events, whereas during the spring campaign regional sources from southern California could have also contributed to the observed PM2.5 levels.

The state of indoor air quality in Pakistan—a review

In Pakistan, almost 70% of the population lives in rural areas. Ninety-four percent of households in rural areas and 58% in urban areas depend on biomass fuels (wood, dung, and agricultural waste). These solid fuels have poor combustion efficiency. Due to incomplete combustion of the biomass fuels, the resulting smoke contains a range of health-deteriorating substances that, at varying concentrations, can pose a serious threat to human health. Indoor air pollution accounts for 28,000 deaths a year and 40 million cases of acute respiratory illness. It places a significant economic burden on Pakistan with an annual cost of 1% of GDP. Despite the mounting evidence of an association between indoor air pollution and ill health, policy makers have paid little attention to it. This review analyzes the existing information on levels of indoor air pollution in Pakistan and suggests suitable intervention methods. This review is focused on studies of indoor air pollution, due to biomass fuels, in Pakistan published in both scientific journals and by the Government and international organizations. In addition, the importance of environmental tobacco smoke as an indoor pollutant is highlighted. Unlike many other developing countries, there are no long-term studies on the levels of indoor air pollution. The limited studies that have been undertaken indicate that indoor air pollution should be a public health concern. High levels of particulate matter and carbon monoxide have been reported, and generally, women and children are subject to the maximum exposure. There have been a few interventions, with improved stoves, in some areas since 1990. However, the effectiveness of these interventions has not been fully evaluated. Indoor air pollution has a significant impact on the health of the population in Pakistan. The use of biomass fuel as an energy source is the biggest contributor to poor indoor air quality followed by smoking. In order to arrest the increasing levels of indoor pollution, there is a dire need to recognize it as a major health hazard and formulate a national policy to combat it. An integrated effort, with involvement of all stakeholders, could yield promising results. A countrywide public awareness campaign, on the association of indoor air pollution with ill health, followed by practical intervention would be an appropriate approach. Due to the current socioeconomic conditions in the country, development and adoption of improved cooking stoves for the population at large would be the most suitable choice. However, the potential of biogas as a fuel should be explored further, and modern fuels (natural gas and LPG) need to be accessible and economical. Smoking in closed public spaces should be banned, and knowledge of the effect of smoking on indoor air quality needs to be quantified.

Particulate Matter Exposure in Children: Relevance to Chronic Obstructive Pulmonary Disease

The effect of exposure to air pollution during childhood on the development of lung disease in adulthood remains to be defined. A common component of air pollution from fossil fuels, environmental tobacco smoke, and burning of solid fuels such as biomass is particulate matter (PM) less than 10 mum in aerodynamic diameter (PM(10)) consisting of aggregates of carbon spherules less than 10 nanometers. Epidemiologic studies suggest that the normal growth in lung function during childhood is impaired by long-term inhalation of carbonaceous PM(10). The most convincing evidence for an effect of PM on lung growth is from a longitudinal study performed in Southern California, where the majority of ambient PM is derived from fossil fuels. Whether exposure of children to high levels of PM from biomass fuel combustion also impairs lung function growth remains unclear. A direct link between exposure of children to PM and increased vulnerability to respiratory disease in adulthood is provided by studies showing an association between life-long biomass smoke and the development of chronic obstructive pulmonary disease (COPD) in non-cigarette-smoking women. Since carbonaceous PM is a component of mainstream cigarette smoke, there may be significant overlap in the cellular and molecular mechanisms underlying the adverse health effects of PM in children and the development of COPD in adult smokers. Studies of children, especially in the developing world, will therefore provide insights into the pathogenesis of COPD.

Effect of typhoon on atmospheric particulates in autumn in central Taiwan

Previous studies have suggested that the ongoing global climate change will likely increase the intensity and frequency of extreme weather, such as typhoons. Since the beginning of global warming, it has become necessary to understand the influence of typhoons on air quality. Rare data, especially particulate measurements data could be used to establish the relationship between the air pollution and typhoons. One of main limiting factors is that most of the previous chemical analyses of particulates used a relatively long sampling time, which could dilute the temporal impact of particulate characteristics and their sources. This work, depending more time-resolved measurements, focus on the characteristics and sources of high particulate matter levels and the influence of typhoons and the Pacific high system. Depending on the measurements, two pollutant groups were clearly identified in this work. The first pollutant group was the emissions from neighboring riverbeds under the strong circulation of the typhoon in the driest season and characterized as high coarse particle concentrations with high mass fraction of Ca 2+. The second pollutant group was characterized as the formation and transport of secondary particles with prevalent ions of NH 4 +, NO 3 −, and SO 4 2− and occurred in the sea-land breeze circulation under the influence the Pacific high system.

Could Dirty Air Cause Diabetes?

Diabetes is a growing epidemic, and it has become arguably one of the biggest health challenges of our time. Currently, more than 23 million Americans have diabetes, and the Centers for Disease Control and Prevention estimate that in the last 15 years, the number of people in the United States with diabetes has more than doubled. Diabetes is increasing at an alarming rate in Europe as well, and it is fast becoming a major health threat in developing countries such as India and China. Despite its high prevalence, however, diabetes remains somewhat of a mystery. Although type 1 diabetes mellitus could be attributed to insufficient insulin release by the β-cells of the pancreas, the origins of type 2 diabetes mellitus (which accounts for >90% of the cases of diabetes) remain obscure. Insulin resistance is a cardinal feature of type 2 diabetes mellitus; however, it is not clear how whole-body insulin resistance develops, which specific tissues are affected first and which ones later, and how metabolic changes in individual tissues contribute to the overall development of the disease and its many secondary complications. Article p 538 The origin of diabetes is equally complex. Although diabetes develops in genetically susceptible individuals, it is a complex trait and does not show simple mendelian inheritance. Because the rates of diabetes change with the environment in several population groups, it has been suggested that modifiable environmental factors and lifestyle choices account for more than 90% of adult-onset diabetes.1 Nevertheless, our understanding of the environmental causes of diabetes has remained rather rudimentary, being limited mostly to the impact of physical inactivity or unhealthy dietary choices. In this context, the study by Sun and coworkers published in the present issue of Circulation 2 is interesting because it provides new evidence showing that exposure to particulate air …

Size-Segregated Inorganic and Organic Components of PM in the Communities of the Los Angeles Harbor

The Los Angeles Ports complex consists of the port of Long Beach and the port of Los Angeles. Due to the high levels of particulate matter (PM) emitted from many sources in the vicinity of these ports and to their projected massive expansion, the Harbor area will be the focus of future governmental regulations. This study aims to characterize the physicochemical properties of PM at locations influenced by port-affiliated sources. PM samples were collected concurrently at six sites in the southern Los Angeles basin for a 7 week period between March and May 2007. Four sites were set-up within the communities of Wilmington and Long Beach; one site was located at a background location near the harbors of the Los Angeles port; the sixth site, near downtown Los Angeles, was chosen to represent a typical urban area. Coarse (PM 2.5 − 10 ), accumulation (PM 0.25 − 2.5 ), and quasi-ultrafine (PM 0.25 ) mode particles were collected at each site. Samples were analyzed for organic and elemental carbon content (OC and...

In-Cabin Commuter Exposure to Ultrafine Particles on Commuter Roads in and around Hong Kong’s Tseung Kwan O Tunnel

ABSTRACTOver half a million cars pass through Hong Kong’s tunnels every day. Commuters, taxi drivers, and other drivers who pass through these tunnels may be exposed to high levels of particulate matter and toxic gases present in the air. There is limited data on in-cabin exposure to pollutants, especially while the vehicle is driving through a tunnel under different cabin ventilation conditions. This study reports in-cabin measurements of fine particles (FP, dp < 2.5 μm) -- which includes nanoparticles and ultrafine particles (UFP, dp < 100 nm) -- in a 1998 Nissan Sunny EX passenger car while driving through Hong Kong’s Tseung Kwan O Tunnel. The vehicle tested did not contain a particle filtration system or an activated carbon filter, and was fueled with unleaded gasoline. The measurements were taken using a water-based condensation particle counter (WCPC) under different conditions consistent with driver behavior. The particle count readings were generally highest with the windows closed and air conditioning on. On average, these readings were more than three times higher than readings with the windows closed and the air conditioning off, and 68% higher than readings with the windows open and the air conditioning off. In-cabin particle concentrations inside the tunnel were up to twenty-one times higher than in-cabin particle concentrations outside the tunnel under comparable traffic conditions. The highest in-cabin particle count concentration reading, 1.94 million particles/cm3, was taken with the windows closed and air conditioning on while the test car was passing a double-decker diesel bus.