251,371 research outputs found

    Black carbon as an additional indicator of the adverse health effects of airborne particles compared with PM10 and PM2.5.

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    Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM(10)) or ≤ 2.5 μm (PM(2.5))] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration

    Polycyclic Aromatic Hydrocarbons Bound to PM 2.5 in Urban Coimbatore, India with Emphasis on Source Apportionment

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    Coimbatore is one of the fast growing industrial cities of Southern India with an urban population of 1.9 million. This study attempts to evaluate the trends of airborne fine particulates (PM 2.5) and polyaromatic hydrocarbons (PAH) on them. The PM 2.5 mass was collected in polytetra fluoroethylene filters using fine particulate sampler at monthly intervals during March 2009 to February 2010. PAHs were extracted from PM 2.5 and estimated by high-performance liquid chromatography. It is alarming to note that PM 2.5 values ranged between 27.85 and 165.75 μg/m3 and exceeded the air quality standards in many sampling events. The sum of 9 PAHs bound to PM 2.5 in a single sampling event ranged from 4.1 to 1632.3 ng/m3. PAH diagnostic ratios and principal component analysis results revealed vehicular emissions and diesel-powered generators as predominant sources of PAH in Coimbatore

    California Wildfires of 2008: Coarse and Fine Particulate Matter Toxicity

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    BackgroundDuring the last week of June 2008, central and northern California experienced thousands of forest and brush fires, giving rise to a week of severe fire-related particulate air pollution throughout the region. California experienced PM(10-2.5) (particulate matter with mass median aerodynamic diameter > 2.5 mum to < 10 mum; coarse ) and PM(2.5) (particulate matter with mass median aerodynamic diameter < 2.5 mum; fine) concentrations greatly in excess of the air quality standards and among the highest values reported at these stations since data have been collected.ObjectivesThese observations prompt a number of questions about the health impact of exposure to elevated levels of PM(10-2.5) and PM(2.5) and about the specific toxicity of PM arising from wildfires in this region.MethodsToxicity of PM(10-2.5) and PM(2.5) obtained during the time of peak concentrations of smoke in the air was determined with a mouse bioassay and compared with PM samples collected under normal conditions from the region during the month of June 2007.ResultsConcentrations of PM were not only higher during the wildfire episodes, but the PM was much more toxic to the lung on an equal weight basis than was PM collected from normal ambient air in the region. Toxicity was manifested as increased neutrophils and protein in lung lavage and by histologic indicators of increased cell influx and edema in the lung.ConclusionsWe conclude that the wildfire PM contains chemical components toxic to the lung, especially to alveolar macrophages, and they are more toxic to the lung than equal doses of PM collected from ambient air from the same region during a comparable season

    Ambient air quality standards and policies in eastern mediterranean countries: a review

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    Objectives: National ambient air quality standards (NAAQS) are critical tools for controlling air pollution and protecting public health. We designed this study to 1) gather the NAAQS for six classical air pollutants: PM(2.5), PM(10), O(3), NO(2), SO(2), and CO in the Eastern Mediterranean Region (EMR) countries, 2) compare those with the updated World Health Organizations Air Quality Guidelines (WHO AQGs 2021), 3) estimate the potential health benefits of achieving annual PM(2.5) NAAQS and WHO AQGs per country, and 4) gather the information on air quality policies and action plans in the EMR countries. Methods: To gather information on the NAAQS, we searched several bibliographic databases, hand-searched the relevant papers and reports, and analysed unpublished data on NAAQS in the EMR countries reported from these countries to the WHO/Regional office of the Eastern Mediterranean/Climate Change, Health and Environment Unit (WHO/EMR/CHE). To estimate the potential health benefits of reaching the NAAQS and AQG levels for PM(2.5), we used the average of ambient PM(2.5) exposures in the 22 EMR countries in 2019 from the Global Burden of Disease (GBD) dataset and AirQ+ software. Results: Almost all of the EMR countries have national ambient air quality standards for the critical air pollutants except Djibouti, Somalia, and Yemen. However, the current standards for PM(2.5) are up to 10 times higher than the current health-based WHO AQGs. The standards for other considered pollutants exceed AQGs as well. We estimated that the reduction of annual mean PM(2.5) exposure level to the AQG level (5 mug m(-3)) would be associated with a decrease of all natural-cause mortality in adults (age 30+) by 16.9%-42.1% in various EMR countries. All countries would even benefit from the achievement of the Interim Target-2 (25 mug m(-3)) for annual mean PM(2.5): it would reduce all-cause mortality by 3%-37.5%. Less than half of the countries in the Region reported having policies relevant to air quality management, in particular addressing pollution related to sand and desert storms (SDS) such as enhancing the implementation of sustainable land management practices, taking measures to prevent and control the main factors of SDS, and developing early warning systems as tools to combat SDS. Few countries conduct studies on the health effects of air pollution or on a contribution of SDS to pollution levels. Information from air quality monitoring is available for 13 out of the 22 EMR countries. Conclusion: Improvement of air quality management, including international collaboration and prioritization of SDS, supported by an update (or establishment) of NAAQSs and enhanced air quality monitoring are essential elements for reduction of air pollution and its health effects in the EMR

    Mexico City Normal Weight Children Exposed to High Concentrations of Ambient PM\u3csub\u3e2.5\u3c/sub\u3e Show High Blood Leptin and Endothelin-1, Vitamin D Deficiency, and Food Reward Hormone Dysregulation versus Low Pollution Controls. Relevance for Obesity and Alzheimer Disease

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    Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM 2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer’s disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM2.5 and O3 concentrations above the standards and exhibit systemic, brain and intrathecal inflammation, cognitive deficits, and Alzheimer disease neuropathology. We investigated adipokines, food reward hormones, endothelial dysfunction, vitamin D and apolipoprotein E (APOE) relationships in 80 healthy, normal weight 11.1±3.2 years olds matched by age, gender, BMI and SES, low (n: 26) versus high (n:54) PM 2.5 exposures. Mexico City children had higher leptin and endothelin-1 (p 2.5 exposed children. Mexico City APOE 4 v 3 children had higher glucose (p=0.009). Serum 25-hydroxyvitamin D \u3c 30 ng/mL was documented in 87% of Mexico City children. Leptin is strongly positively associated to PM 2.5 cumulative exposures. Residing in a high PM2.5 and O3 environment is associated with 12 h fasting hyperleptinemia, altered appetite-regulating peptides, vitamin D deficiency, and increases in ET-1 in clinically healthy children. These changes signal the future trajectory in urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer’s disease. Increased efforts should be made to decrease pediatric PM 2.5 exposures, to deliver health interventions prior to the development of obesity and to identify and mitigate environmental factors influencing obesity and Alzheimer disease

    AMBIENT AIR QUALITY NEAR KAZIRANGA NATIONAL PARK, ASSAM

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    The work investigates the concentration of the pollutants PM 10, PM 2.5, SOx, and NOx from various sources like automobiles, oil refinery etc in and around the Kaziranga National park.  3 sampling sites were selected including 1 industrial(InT), 1 residential(TS) within the refinery 1 roadside(BP) within the kaziranga national park area.  At each site all 4 pollutants were monitored twice a week and eight times in a month using PM 2.5/10 sampler for particulates and High volume Sampler with gaseous attachment for SO2 and NO2 during the year June 2013 to May 2014. The values of all these pollutants (particulates and gaseous) are observed to be very much below according to National Ambient Air Quality Standards. However the area is mostly covered with forest reserve

    Special issue of \u3ci\u3eAtmospheric Environment\u3c/i\u3e on findings from EPA’s Particulate Matter Supersites Program

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    In July 1997, the US Environmental Protection Agency (EPA) issued new National Ambient Air Quality Standards (NAAQS) for fine particulate matter (PM2.5, atmospheric particles with aerodynamic diameters less than 2.5 μm). The PM2.5 NAAQS was developed by the EPA based on the results of numerous epidemiological studies that found persistent associations between outdoor concentrations of particulate matter (PM) and significant adverse health effects. However, considerable uncertainty existed concerning mechanisms by which various classes of particles might cause adverse health effects, as well as more detailed information on the composition and concentrations of ambient fine PM, that would be critical in implementing the new standards
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