Product Description
Report on the air quality aboard passenger cabins of commercial aircraft, from the Committee on Air Quality in Passenger Cabins of Commercial Aircraft Board on Environmental Studies and Toxicology. Softcover. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The Models-3 Community Multi-scale Air Quality (CMAQ) modeling system with meteorological fields calculated by the Regional Atmospheric Modeling System (RAMS) was applied to East Asia to investigate the transport and photochemical transformation of tropospheric ozone during the Transport and Chemical Evolution over the Pacific (TRACE-P) field campaign. Modeled concentrations of hydroxyl radical, hydroperoxyl radical, nitric oxide, nitrogen dioxide, ethene, ethane, carbon monoxide, and ozone were compared with observations obtained onboard of two aircrafts in order to evaluate the model performance. Comparison indicates that the model reproduced the tempo-spatial distributions of ozone and its related chemical species reasonably well, and most model results were within a factor of 2 of the observations. ... Read more

Product Description
This digital document is a journal article from Environment International, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
In contrast to a majority of reported damage-cost literature being focused on outdoor pollution, this paper describes the development of a protocol that links population exposure data with reported epidemiological concentration-response coefficients. A change in indoor particulate level is expressed as a change in total exposure levels, which is then linked with a corresponding change in ambient particulate concentrations before evaluating the associated health benefits. In this study, the development of protocol is illustrated by using a typical office building environment and daily time activity patterns of office occupants in Hong Kong. Our results indicate that some benefit gains for the owners-employers and the society would be anticipated if certain filter set configurations had been adopted. However, the amount of benefit gains for the owners-employers is shown to be increased with the average salary level of employees and the duration of their stay in offices. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Mass conservation errors were discovered when the Community Multiscale Air Quality (CMAQ) model (version 4.3) was coupled with the Fifth-Generation PSU/NCAR Mesoscale Model (MM5). These errors can be severe particularly over complex terrain. A recent correction made to the vertical advection module (in version 4.4) reduces the mass conservation errors, but does not completely eliminate them. This means that the method of renormalizing concentrations according to air density, which is currently applied to address the inconsistency problem, is not an ideal solution. Reconstruction of the wind fields by adjusting the vertical wind is proposed as a simple remedy to make CMAQ strictly mass conservative. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A new approach has been developed at the Center for Space Research (CSR) to determine cloud boundaries from satellite data for use in air quality modeling. The approach combines remotely sensed cloud thickness, obtained from the MODIS cloud optical property products, with cloud base height measurements made at surface weather observing facilities to determine cloud top height. When compared to cloud truth estimates, compiled from measurements made at the Southern Great Plains Atmospheric Radiation Measurement Site in Oklahoma, errors in cloud top height from this new method were found to be significantly smaller than those in the MODIS (MOD06) cloud product. It was also found that relatively small errors in MOD06 cloud top temperatures can be magnified in MOD06 cloud top pressures because the interpolation scheme appears to not adequately consider humidity profiles in the NCEP data used to make these conversions. ... Read more

Product Description
This digital document is a journal article from Science of the Total Environment, The, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
In China, 76% of all energy comes from coal consumption, which is the major cause of air pollution. One of the major barriers to developing sound policies for controlling air pollution is the lack of information related to the value of the health consequences of air pollution. We conducted a willingness-to-pay (WTP) study using contingent valuation (CV) methods in Chongqing, China to estimate the economic value of saving one statistical life through improving air quality. A sample of 500residents was chosen based on multistage sampling methods. A face-to-face household interview was conducted using a series of hypothetical, open-ended scenarios followed by bidding game questions designed to elicit the respondents' WTP for air pollution reduction. The Two-Part Model was used for estimations. The results show that 96% of respondents were able to express their WTP. Their mean annual income is $490. Their WTP to save one statistical life is $34,458. Marginal increases for saving one statistical life is $240 with 1year age increase, $14,434 with 100yuan monthly income increase, and $1590 with 1year education increase. Unlike developed country, clean air may still be considered as a ''luxury'' good in China based on the estimation of income elasticity. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
In order to characterize sources of fine carbonaceous aerosols, PM"2"."5 aerosols were sampled at 5 sites in forest, tunnel, urban, rural, and forest/urban areas in the Lower Fraser Valley (LFV) during the Pacific 2001 Air Quality Study. All sample filters were analyzed for cis-pinonic acid and n-fatty acids. cis-Pinonic acid varied from 0.6-46.5ngm^-^3 at the sites in the forest, rural and forest/urban mixing area, and was low, from ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The impact of long-range transport on the air quality of Taiwan was assessed by using measurements at stations of the air quality monitoring network of the Taiwan Environment Protection Administration over the winter monsoon periods of 2000 and 2001. The primary long-range transport process can be clearly identified to be the prevailing northeasterly following the cold front of winter monsoon that originates in the Asian continent. Based on pollutants concentration differences among different meteorological conditions, we estimate that the long-range transport of particulate pollutants contributes to about 30@mgm^-^3 to the PM"1"0 concentrations in northern and eastern Taiwan. A smaller contribution is estimated for the western plain of Taiwan. Contributions of the long-range transport to CO and SO"2 are about 230 and 0.5ppb, respectively. The identified, dust events have the highest average inflow concentration (about 71+/-34@mgm^-^3) of PM"1"0. The dust impacts on PM"1"0 have been estimated to be nearly 100% at windward background stations along the north and northeast coast. In the northern cities of Taiwan, such as Taipei and Hsinchu, the impacts decrease to around 60-80% as local emission increase. Due to geographic blocking, a smaller impact is estimated for the western plain of Taiwan. However, the identified frontal pollution cases have significant impact on CO and SO"2, which is more evident than the impact of dust events. In general, impacts of long-range transport on air pollutants at coastal stations are greater than those in urban areas. e in urban areas. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The widely used mesoscale meteorological model, MM5 and a recently released US EPA air quality model, Models-3/CMAQ were employed to investigate the effect of mass inconsistency in air quality modeling. During a 24-h simulation using a hydrostatic MM5 output, the mass inconsistent error, as measured by trace species concentration, grew by 242%. The nonhydrostatic simulation produced approximately 6 times larger mass inconsistent error than the hydrostatic model. This is because the nonhydrostatic model is not strictly mass consistent by neglecting terms representing pressure increase due to heating in a pressure perturbation equation, another form of the continuity equation. In both the hydrostatic and nonhydrostatic models, mass inconsistency was produced due to inconsistent numerical schemes and integral time steps between the meteorological model and the air quality model. Temporal interpolation of meteorological data in air quality modeling partly caused the mass inconsistency as well. The mass inconsistent error was removed successfully by conserving the mixing ratio of the trace species in both the hydrostatic and the nonhydrostatic cases. ... Read more

Product Description
This digital document is a journal article from Building and Environment, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The uncertainties of professional choice of 'representative' sampling locations for general indoor air quality (IAQ) assessment are reported from the perspective of probable errors deviated from the sample-spatial average pollutant concentration of an indoor environment. In this study, associations between the professional choices of the sampling locations and attributes of the assessors were examined to quantify the uncertainties of the IAQ assessment results for a typical air-conditioned office in Hong Kong. In particular, a long-term (one-year) measurement result of the spatial indoor carbon dioxide (CO"2) concentrations in this office was used as a basis to investigate the probable errors due to the choices of sampling locations. Comparing with the random choices, the assessment accuracy with the expert choices would be significantly improved for coarse sampling point densities at certain engineering acceptable error limits. It was reported that the location choices and assessment accuracy would be significantly influenced by the academic background of the assessors. An assessor group with higher academic level would make a choice leaning towards more accurate assessment results. To avoid an inappropriate level of reliance on the assessment results, uncertainties must be quantified for IAQ assessment. This study provided a template for further investigations into the uncertainties of IAQ assessment results involving professional choice of 'representative' sampling locations and the results might be a useful reference for assessing indoor environment elsewhere. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A method for semi-continuous (10min time resolution) PM"2"."5 nitrate and sulfate measurements, based on the humidified impaction with flash volatilization design of Stolzenburg and Hering (Environ. Sci. Technol. 34 (2000) 907), was evaluated during the Pittsburgh Air Quality Study (PAQS) from July 2001 to August 2002. The semi-continuous measurements were corrected for several operating parameters. The overall corrections were less than 10% on average, but could be quite large for individual 10min measurements. These corrections resulted in an improvement in the agreement of the measurements with the filter-based measurements, with a major axis regression relationship of y=0.83x+0.20@mgm^-^3 and R^2 of 0.84 for nitrate and y=0.71x+0.42@mgm^-^3 and R^2 of 0.83 for sulfate. The corrected semi-continuous measurements were calibrated over the entire year using collocated denuder/filter-pack-based measurements. These calibrated semi-continuous measurements are used in conjunction with temporally resolved gas-phase measurements of total (gas- and aerosol-phase) nitrate and meteorological measurements to investigate short-term phenomena at the Pittsburgh Supersite. The gas-to-particle partitioning of nitrate varied daily and seasonally, with a majority of the nitrate in the particle phase at night and during the winter months. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Fires contribute substantial emissions of trace gases and particles to the atmosphere. These emissions can impact air quality and even climate. We have developed a modeling framework to estimate the emissions from fires in North and parts of Central America (10-71^oN and 55-175^oW) by taking advantage of a combination of complementary satellite and ground-based data to refine estimates of fuel loadings. Various satellite drivers, including the MODIS Thermal Anomalies Product, the Global Land Cover Characteristics 2000 dataset, and the MODIS Vegetation Continuous Fields Product were used in conjunction with data mined from literature to determine fire location and timing, fuel loadings, and emission factors. Daily emissions of particulate matter and numerous trace gases from fires were estimated using this method for three years (2002-2004). Annual emission estimates differ by as much as a factor of 2 (CO emissions for North America ranged from 22.6 to 39.5Tgyr^-^1). Regional variations in emissions correspond to different fire seasons within the region. For example, the highest emissions from Central America and Mexico occur in the late spring whereas the highest emissions from the United States and Canada occur during the summer months. Comparisons of these results with other published estimates of CO emission estimates from fire show reasonable agreement, but substantial uncertainties remain in the estimation techniques. We suggest methods whereby future emissions models can reduce these uncertainties. ... Read more

Product Description
This digital document is an article from The Register-Guard (Eugene, OR), published by The Register Guard on November 11, 2003. The length of the article is 749 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.

Citation Details
Title: Air quality progress planned by Baxter.(Environment)(The air pollution agency will join the creosoting factory to draft a plan to cut fumes)
Publication: The Register-Guard (Eugene, OR) (Newspaper)
Date: November 11, 2003
Publisher: The Register Guard
Page: b1

Distributed by Thomson Gale ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
The statistical evaluation of an air quality model is part of a broader process, generally referred to as 'model assessment', including sensitivity analysis and other tools. The evaluation process is usually implemented through the comparison of model predicted data with point-wise observations. However, this analysis is based on several (implicit) assumptions which are difficult, if not impossible, to assess: e.g.unbiased observations, measurements errors small enough in comparison to the typical usage of observed data, observations representative of the true area-averaged values within each computational cell, numerical model errors small enough in comparison to mis/un-represented physics/chemistry, and so on. In this work we address the problem of the comparison between point measured data and cell-averaged model values. We present a Bayesian approach for the space-time interpolation of measured data and the prediction of cell-averaged values. We used cell-averaged observations to validate the results from the CAMx air quality model. We found that a relevant fraction of the model bias can be explained by the subgrid spatial variability. This analysis may be important in all cases in which one is interested in a model and/or process comparison exercise. ... Read more

Product Description
This digital document is a journal article from Atmospheric Environment, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
This study investigates the relationship between aerosols number size distribution on the one hand, and air quality in terms of particulate matter (PM) mass concentrations (as usually monitored in the air quality networks) on the other hand. For this purpose, time series of trace gases levels, submicron aerosol size distributions, both recorded at a rural site in Northern Italy (ISPRA), and of trace gas levels and PM mass concentrations, recorded in the air quality network operating in this region, have been compared and interpreted. Because of the regional nature of the PM pollution events, the daily mean levels of the aerosol volume (V), surface area (S) and black carbon (BC) concentrations at ISPRA rural site are well correlated with the daily mean levels of PM mass concentrations recorded at the other air quality monitoring sites. At ISPRA, the submicron aerosol size distribution is strongly influenced by two main competing processes: nucleation of new particles and condensation of gas-phase components onto pre-existing particles (resulting in particles growth). These processes influence on the daily, seasonal and day-to-day variations of the submicron aerosol features. Because increasing aerosol S concentrations favour condensation and hinder nucleation (and vice versa) the 'mean' particle size D"pN (mode of the dN/dlogD size distribution) increases with increasing PM concentrations (e.g. 45nm for V=4@mm^3cm^-^3 and 110nm for V=45@mm^3cm^-^3). Owing to this, time series of aerosol D"pN and V, S, mass and BC concentrations are strongly anti-correlated with those of the smallest ultrafine particle number concentration (N, 5-10 and 10-20nm). Nucleation episodes occur under the clean air conditions prompted by the North-Foehn meteorology. This anti-correlation between submicron aerosol mass and N<20nm concentrations (prompted by the low contribution of the ultrafine particles to the aerosol mass) has important implications for a proper air quality monitoring: the parameters classically used for the air quality assessing (e.g. PM2.5) are not suitable for monitoring of this ultrafine PM pollution and consequently a specific monitoring of the ultrafine PM number concentration should be performed. The significance of this specific ultrafine PM number concentration monitoring is supported by facts already proven: a significant fraction of the current urban PM emissions occurs in the ultrafine PM fraction and exposure to ultrafine PM is associated with adverse effects on human health. ... Read more