Abstract  OBJECTIVE: Identify most likely health effects of occupational exposure to engineered nanoparticles (ENP). Recommend analytic approaches to address epidemiologic challenges.

METHODS: Review air pollution and occupational literature on health effects of fine particulate matter (PM). Provide example of mortality study of exposure to PM composed of metalworking fluid. Apply standard Cox models and g-estimation to adjust for potential healthy worker survival effect (HWSE).

RESULTS: In contrast with standard methods, g-estimation suggests that exposure to PM may cause chronic heart and lung disease; longer exposure reduces survival. HWSE appears stronger for chronic disease than for cancer.

CONCLUSIONS: We recommend hazard surveillance, short-term panel studies of biomarkers, and prospective cohort studies of cardiovascular and respiratory diseases. Building research capacity in g-estimation methods to reduce HWSE is necessary for future studies of chronic disease and ENP.

Abstract  The effects of particulate matter on the environment and public health were widely studied in recent years but agreement amongst these studies on the relative importance of the particle size and its origin with respect to health effects is still lacking. Nevertheless, air quality standards are moving towards greater focus on the smaller particles. In industrialized areas, anthropogenic activities are a major contributor to the particle concentrations. Then, it is important to characterize the emission sources as well as the evolution of particle size distribution in the proximity of these emission points. In this study, the authors evaluated the particle concentration and size distribution at a downwind receptor site of a linear (a major highway) and point (waste incinerator plant) source in an area characterized by high anthropic environmental impact. The particle emissions of the incinerator under examination were characterized by using a Scanning Mobility Particle Sizer (R) (SMPS), an Aerodynamic Particle Sizer (R) (APS) Spectrometer, a Rotating Disk Thermodiluter and a Thermal Conditioner (Matter Engineering AG). As regards the linear source, concentrations were determined at increasing distances from the most important Italian road, the A1 highway. Particle number, surface and mass exponentially decreases away from the freeway, whereas particle number concentration measured at 400 m downwind from the freeway is indistinguishable from upwind background concentration. Annual mean values of 8.6x10(3) +/- 3.7x10(2) particle cm(-3) and 31.1 +/- 9.0 mu g m(-3) were found for particle number and PM10 concentration, typical of a rural site. The particle apportionment and exposure assessment in respect of linear and point sources for ultrafine particles represent the major novelty of the present paper. The study here presented could be very important in developing appropriate management and control strategies for air quality in areas characterized by high anthropic pressure and to perform exposure assessment for populations involved. (C) Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License.

Abstract  An ensemble-based approach is applied to better estimate source impacts on fine particulate matter (PM2.5) and quantify uncertainties in various source apportionment (SA) methods. The approach combines source impacts from applications of four individual SA methods: three receptor-based models and one chemical transport model (CTM). Receptor models used are the chemical mass balance methods CMB-LGO (Chemical Mass Balance-Lipschitz global optimizer) and CMB-MM (molecular markers) as well as a factor analytic method, Positive Matrix Factorization (PMF). The CTM used is the Community Multiscale Air Quality (CMAQ) model. New source impact estimates and uncertainties in these estimates are calculated in a two-step process. First, an ensemble average is calculated for each source category using results from applying the four individual SA methods. The root mean square error (RMSE) between each method with respect to the average is calculated for each source category; the RMSE is then taken to be the updated uncertainty for each individual SA method. Second, these new uncertainties are used to re-estimate ensemble source impacts and uncertainties. The approach is applied to data from daily PM2.5 measurements at the Atlanta, GA, Jefferson Street (,JST) site in July 2001 and January 2002. The procedure provides updated uncertainties for the individual SA methods that are calculated in a consistent way across methods. Overall, the ensemble has lower relative uncertainties as compared to the individual SA methods. Calculated CMB-LGO uncertainties tend to decrease from initial estimates, while PMF and CMB-MM uncertainties increase. Estimated CMAQ source impact uncertainties are comparable to other SA methods for gasoline vehicles and SOC but are larger than other methods for other sources. In addition to providing improved estimates of source impact uncertainties, the ensemble estimates do not have unrealistic extremes as compared to individual SA methods and avoids zero impact days. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  Epidemiological findings concerning the seasonal variation in the acute effect of particulate matter (PM) are inconsistent. We investigated the seasonality in the association between PM with an aerodynamic diameter of less than 10 μm (PM10) and daily mortality in 17 Chinese cities. We fitted the "main" time-series model after adjustment for time-varying confounders using smooth functions with natural splines. We established a "seasonal" model to obtain the season-specific effect estimates of PM10, and a "harmonic" model to show the seasonal pattern that allows PM10 effects to vary smoothly with the day in a year. At the national level, a 10 μg/m(3) increase in the two-day moving average concentrations (lag 01) of PM10 was associated with 0.45% [95% posterior interval (PI), 0.15% to 0.76%], 0.17% (95% PI, -0.09% to 0.43%), 0.55% (95% PI, 0.15% to 0.96%) and 0.25% (95%PI, -0.05% to 0.56%) increases in total mortality for winter, spring, summer and fall, respectively. For the smoothly-varying plots of seasonality, we identified a two-peak pattern in winter and summer. The observed seasonal pattern was generally insensitive to model specifications. Our analyses suggest that the acute effect of particulate air pollution could vary by seasons with the largest effect in winter and summer in China. To our knowledge, this is the first multicity study in developing countries to analyze the seasonal variations of PM-related health effects.

Abstract  National Ambient Air Quality Standards (NAAQS) were first established in the United States to protect public health and welfare, and the concept has been adopted in China and many other countries. For particulate matter (PM), the NAAQS indicator evolved from total particle mass concentration, to PM10 and PM2.5 mass concentrations as defined by the PM size-selective properties of the monitoring instrument and human inhalation characteristics. Particle measurements started with optical microscopy in the early 18th century, and scientific research over the past 300 years has related particles to adverse environmental and health effects. Several options for PM2.5 measurement and assessment are available to China and other developing countries as they implement new PM2.5 ambient air quality standards. Although much can be learned from the experience of North America and Europe, China can leapfrog ahead in terms of PM2.5 monitoring and emission reduction technology. China-specific guidance documents should be created for network design, equipment selection and operation, quality control and quality assurance, database management, and interpretation. Future air quality management and standards will need to consider multiple pollutants and their effects on visibility, climate, materials, and ecosystems in addition to the primary concerns about public health.

Abstract  Polluting facilities and hazardous sites are often concentrated in low-income communities of color already facing additional stressors to their health. The influence of socioeconomic status is not considered in traditional models of risk assessment. We describe a pilot study of a screening method that considers both pollution burden and population characteristics in assessing the potential for cumulative impacts. The goal is to identify communities that warrant further attention and to thereby provide actionable guidance to decision-and policy-makers in achieving environmental justice. The method uses indicators related to five components to develop a relative cumulative impact score for use in comparing communities: exposures, public health effects, environmental effects, sensitive populations and socioeconomic factors. Here, we describe several methodological considerations in combining disparate data sources and report on the results of sensitivity analyses meant to guide future improvements in cumulative impact assessments. We discuss criteria for the selection of appropriate indicators, correlations between them, and consider data quality and the influence of choices regarding model structure. We conclude that the results of this model are largely robust to changes in model structure.

Abstract  Particle fouling in constant pressure submerged membrane filtration is analyzed. A particulate sample, with a wide size distribution ranging from submicron to micron, is filtered using a flat-sheet membrane module. The effects of filtration pressure and aeration conditions on the particle deposition probability, cake properties and filtration flux are discussed. Particle deposition is analyzed theoretically using a force balance model. The particle size distribution in a filter cake is smaller than that in the original suspension and gradually decreases during a filtration. An increase in filtration pressure leads to a higher filtration flux in the early period of filtration; however, after 3000 s the flux gradually approaches a pseudo-steady value. The filtration flux is significantly enhanced by sparging air bubbles. An increase in air volumetric flow rate or a decrease in bubble size leads to a smaller particle size distribution in the cake. The particle deposition probability, cake mass and average specific filtration resistance calculated by using the proposed models agree fairly well with available experimental data.

Abstract  In this study, coarse- (PM2.5-10) and fine (PM2.5) fraction aerosol samples were collected using a dichotomous sampler, and their metallic composition (Mg, Al, Ti, Ca, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn) were analyzed using X-ray fluorescence. The average crustal enrichment factor (EFc) values of Pb, Cu, SO42-. and Zn are greater than 10 for both coarse- and fine-fraction aerosols, which indicates that anthropogenic sources account for the concentrations of these four elements in both the fractions. In this study, positive matrix factorization (PMF) was used for the source apportionment of PM2.5 mass in the Zonguldak atmosphere. A total of six factors were identified, which can be interpreted as either emission sources or physically meaningful factors. The goodness of the six-factor solution for the PMF model was tested by comparing the measured and the modeled PM2.5 masses. An excellent agreement was found between the measured and the modeled fine masses, which indicates that the six-factor-PMF solution adopted in this study accurately accounts for the observed PM2.5 mass in the city of Zonguldak, the city is located at the middle of the Black Sea coasts of Turkey. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  Daily PM2.5 samples were collected in Chengdu, a megacity in southwest China, for a period of one month in every season during 2009-2010. Mass concentrations of water-soluble inorganic ions, organic carbon (OC), elemental carbon (EC), levoglucosan (LC), water soluble organic carbon (WSOC), and elements were determined to identify the chemical characteristics and potential sources of PM2.5. The data obtained in spring were discussed in detail to explore the impacts of dust storms and biomass burning on the chemical aerosol properties. The daily PM2.5 mass concentrations ranged from 49.2 to 425.0 mu g m(-3) with an annual average of 165.1 +/- 85.1 mu g m(-3). The highest seasonal average of PM2.5 concentrations was observed in the winter (225.5 +/- 73.2 mu g m(-3)) and the lowest in the summer (113.5 +/- 39.3 mu g m(-3)). Dust storm influence was observed only during the spring, while biomass burning activities occurred frequently in late spring and early summer. In the spring season, water-soluble ions, total carbonaceous aerosols, and the sum of the dominant elements (Al, Si, Ca, Ti, Fe, Mn, Zn, Pb, and Cu) accounted for 30.0 +/- 9.3%, 38.6 +/- 11.4%, and 6.2 +/- 5.3%, respectively, of the total PM2.5 mass. Crustal element levels evidently increased during the dust storm episode and LG, OC, WSOC, Cl- and K+ concentrations increased by a factor of 2-7 during biomass burning episodes. Using the Positive Matrix Factorization (PMF) receptor model, four sources for spring aerosols were identified, including secondary sulfate and nitrate, motor vehicle emissions, soil dust, and biomass burning. The four sources were estimated to contribute 24.6%, 18.8%, 23.6% and 33.0%, respectively, to the total PM2.5 mass. (C) 2012 Elsevier B.V. All rights reserved.

Abstract  Current background ozone (O(3)) concentrations over the northern hemisphere's midlatitudes are high enough to damage crops and are projected to increase. Soybean (Glycine max) is particularly sensitive to O(3); therefore, establishing an O(3) exposure threshold for damage is critical to understanding the current and future impact of this pollutant. This study aims to determine the exposure response of soybean to elevated tropospheric O(3) by measuring the agronomic, biochemical, and physiological responses of seven soybean genotypes to nine O(3) concentrations (38-120 nL L(-1)) within a fully open-air agricultural field location across 2 years. All genotypes responded similarly, with season-long exposure to O(3) causing a linear increase in antioxidant capacity while reducing leaf area, light absorption, specific leaf mass, primary metabolites, seed yield, and harvest index. Across two seasons with different temperature and rainfall patterns, there was a robust linear yield decrease of 37 to 39 kg ha(-1) per nL L(-1) cumulative O(3) exposure over 40 nL L(-1). The existence of immediate effects of O(3) on photosynthesis, stomatal conductance, and photosynthetic transcript abundance before and after the initiation and termination of O(3) fumigation were concurrently assessed, and there was no evidence to support an instantaneous photosynthetic response. The ability of the soybean canopy to intercept radiation, the efficiency of photosynthesis, and the harvest index were all negatively impacted by O(3), suggesting that there are multiple targets for improving soybean responses to this damaging air pollutant.

Abstract  Understanding of chemical, physical, and radiative processes-emissions, transport, deposition, and modification of aerosol optical properties due to ageing-is of major importance to global and regional climate simulations and projections as well as health impairment. This paper presents aerosol optical properties retrieved with the Multifilter Rotating Shadowband Radiometers (MFRSRs) and the source attribution based on back trajectories and in situ aerosol chemical composition analysis obtained during the Aerosol Life Cycle Intensive Observational Period at Brookhaven National Laboratory on Long Island, NY, during July and August 2011. The aerosol optical properties retrieved with the MFRSR exhibit excellent agreement with those obtained with a colocated Cimel sunphotometer. Apportioning aerosol optical depths by size modes reveals several episodes of high loading of fine aerosol (diameter less than 2.5 mu m). Analysis of optical and physical properties of aerosols as well as their chemical composition obtained by an in situ high-resolution time-of-flight aerosol mass spectrometer together with back trajectories indicates that the principal source of high concentrations of fine aerosols observed during July 18-24 was forest fires in western Canada, consistent with reports by the Canadian Forest Service and satellite observations by the Moderate Resolution Imaging Spectroradiometer (MODIS).

Abstract  By comparing short-term fluctuations in PM2.5 species concentrations among nearby air quality monitors and among species, it becomes possible to understand the regional and local events leading to higher concentrations. This approach was applied at thirteen sites in the Maryland area for the 20012006 timeframe in order to identify and explain the behavior of eighteen different analytes as well as the daily Air Quality Index.

Findings included identification of local upwind events such as fireworks displays, construction and demolition, the spatial extent of sulfate, nitrate, and ammonium correlations between ground-level monitors, correlations between some crustal species to indicate similar emissions sources in urban areas, and indicators of particle adsorption as a rate-limiting step for certain species. For example, the bromine behavior suggests that bromine concentrations on particulate matter may be limited by the particle adsorption rate and thus show a dependence on the Air Quality Index measurements. (c) 2008 Elsevier Ltd. All rights reserved.

Abstract  Source-oriented models are ideally suited to examine the impact of terrain and meteorology and source factors such as stack height when evaluating exposures to air pollutants. A source-oriented, Gaussian plume air pollution dispersion model AERMOD was used to estimate the spatial distribution of elemental mercury (Hg(0)) from a typical coal-fired boiler emitting 0.001 g Hg(0)/s. Hg(0) was chosen because of its health impact related to potential neurological and reproductive effects which may be especially important for high-risk populations. Results from four simulations using meteorological data from 2004 were compared for flat and hilly terrain from 20- and 55-m stacks at a distance of 1,350 m from the source. Variations within a quadrant were affected primarily by topography. For the 20-m stack, the average annual ambient concentration for individuals living within the northeast (NE) quadrant was significantly lower at 2.5 ng Hg(0)/m(3) (P < 0.001; confidence interval (CI), 2.4-2.6) in flat terrain versus 3.3 ng Hg(0)/m(3) in hilly (P < 0.001; CI, 1.2-1.3). NE concentrations of the source showed high spatial variability attributed to topography with 1-h maximums of 4.0 ng Hg(0)/m(3) flat versus 7.1 ng Hg(0)/m(3) hilly. Not unexpectedly, average annual concentrations were considerably lower for the 55-m stack although topography remained a significant variable with 0.1 ng Hg(0)/m(3) in flat terrain (p < 0.001; CI, 0.11-0.13) and double that exposure at 0.2 ng Hg(0)/m(3) in hilly terrain (p < 0.001; CI, 0.16-0.18). Annual average mercury concentrations due to emissions from the 20-m stack were similar to 20 times higher than ambient concentrations associated with the 55-m stack. A sensitivity analysis was performed for meteorological effects, using meteorological data from years 2001-2005. Varying the roughness factor had no significant effect on the results. For all simulations, the highest concentrations were located in the NE quadrant. During 2001-2005, the highest average annual ambient Hg concentration ranged from 6.2 to 7.0 ng Hg(0)/m(3) for the 20-m stack and 0.3-0.5 ng Hg(0)/m(3) for the 55-m stack. Thus, this model is robust. These results demonstrate the usefulness of a source-oriented model such as AERMOD for incorporating multiple factors for estimating air pollution exposures for communities near point sources. The importance of considering topography, meteorology, and source characteristics when placing air samplers to measure air quality and when using buffer zones to estimate ambient residential exposures is also illustrated. Residential communities in hilly terrain near industrial point sources may have between two to three times the exposures as those in flat terrain. Exposures will vary depending on the stack height of the point source.

Abstract  During the TRAMP field campaign in August-September 2006, C2-C10 volatile organic compounds (VOCs) were measured continuously and online at the urban Moody Tower (MT) site. This dataset was compared to corresponding VOC data sets obtained at six sites located in the highly industrialized Houston Ship Channel area (HSC). Receptor modeling was performed by positive matrix factorization (PMF) at all sites. Conditional probability functions (CPF) were used to determine the origin of the polluted air masses in the Houston area. A subdivision into daytime and nighttime was carried out to discriminate photochemical influences. Eight main source categories of industrial, mobile, and biogenic emissions were identified at the urban receptor site, seven and six, respectively, at the different HSC sites. At MT natural gas/crude oil contributed most to the VOC mass (27.4%), followed by liquefied petroleum gas (16.7%), vehicular exhaust (15.3%), fuel evaporation (14.3%), and aromatics (13.4%). Also petrochemical sources from ethylene (4.7%) and propylene (3.6%) play an important role. A minor fraction of the VOC mass can be attributed to biogenic sources mainly from isoprene (4.4%). Based on PMF analyses of different wind sectors, the total VOC mass was estimated to be twofold at MT with wind directions from HSC compared to air from a typical urban sector, for petrochemical compounds more than threefold. Despite the strong impact of air masses influenced by industrial sources at HSC, still about a third of the total mass contributions at MT can be apportioned to other sources, mainly motor vehicles and aromatic solvents. The investigation of diurnal variation in combination with wind directional frequencies revealed the greatest HSC impact at the urban site during the morning, and the least during the evening.

Abstract  Abstract This study was undertaken to determine whether there was an association between fine particles (PM2.5) levels and hospital admissions for congestive heart failure (CHF) in Taipei, Taiwan. Hospital admissions for CHF and ambient air pollution data for Taipei were obtained for the period 2006-2010. The relative risk of hospital admissions was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality and long-term time trends. For the single pollutant model (without adjustment for other pollutants), increased CHF admissions were significantly associated with PM2.5 both on warm days (>23 °C) and cool days (<23 °C), with an interquartile range increase associated with a 13% (95% CI = 9-17%) and 3% (95% CI = 0-7%) increase in CHF admissions, respectively. In the two-pollutant models, PM2.5 remained significant after the inclusion of SO2 or O3 both on warm and cool days. This study provides evidence that higher levels of PM2.5 increase the risk of hospital admissions for CHF.

Abstract  Accurate air quality forecasts can allow for mitigation of the health risks associated with high levels of air pollution. During September 2003, a team of NASA NOAA and EPA researchers demonstrated a prototype tool for improving fine particulate matter (PM2.5) air quality forecasts using satellite aerosol observations. Daily forecast products were generated from a near-real-time fusion of multiple input data products, including aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS)/Earth Observing System (EOS) instrument on the NASA Terra satellite, PM 2.5 concentration from over 300 state/local/national surface monitoring stations, meteorological fields from the NOAA/NCEP Eta Model, and fire locations from the NOAA/National Environmental Satellite, Data, and Information Service (NESDIS) Geostationary Operational Environmental Satellite (GOES) Wildfire Automated Biomass Burning Algorithm (WFABBA) product. The products were disseminated via a Web interface to a small group of forecasters representing state and local air management agencies and the EPA. The MODIS data improved forecaster knowledge of synoptic-scale air pollution events, particularly over oceans and in regions devoid of surface monitors. Forecast trajectories initialized in regions of high AOD offered guidance for identifying potential episodes of poor air quality. The capability of this approach was illustrated with a case study showing that aerosol resulting from wildfires in the northwestern United States and southwestern Canada is transported across the continent to influence air quality in the Great Lakes region a few days later. The timing of this demonstration was selected to help improve the accuracy of the EPAs AIRNow (www.epa.gov/airnow/) next-day PM2.5, air quality index forecast, which began on 1 October 2003. Based on the positive response from air quality managers and forecasters, this prototype was expanded and transitioned to an operational provider during the summer of 2004.

Abstract  OBJECTIVES: Using urinary 1-hydroxypyrene (1-OHP) as a measure of total absorbed dose, the primary objective of this study was to evaluate the total effect of inhalation and dermal PAH exposures while considering other factors such as age, body mass index and smoking that may also have a significant effect on urinary 1-OHP.

METHODS: The study population included two groups of highway construction workers: 20 paving workers and 6 milling workers. During multiple consecutive workshifts, personal air and dermal samples were collected from each worker and analyzed for pyrene. During the same work week, urine samples were collected pre-shift, post-shift and at bedtime each day and analyzed for 1-OHP. Distributed lag models were used to evaluate the independent effect of inhalation and dermal exposures that occurred at each of several preceding exposure periods and were used to identify the relevant period of influence for each pathway.

RESULTS: The paving workers had inhalation (mean 0.3 micro g/m(3)) and dermal (5.7 ng/cm(2)) exposures to pyrene that were significantly higher than the milling workers. At pre-shift on Monday morning, following a weekend away from work, the pavers and millers had the same mean baseline urinary 1-OHP level of 0.4 micro g/g creatinine. The mean urinary 1-OHP levels among pavers increased significantly from pre-shift to post-shift during each work day, while the mean urinary 1-OHP levels among millers varied little and remained near the baseline level throughout the study period. Among pavers there was a clear increase in the pre-shift data during the work week, such that the average pre-shift level on day 4 (1.4 micro g/g creatinine) was 3.5 times higher than the average pre-shift results on day 1 (0.4 micro g/g creatinine). The results of the distributed lag model indicated that the impact of dermal exposure was approximately eight times the impact of inhalation exposure. Furthermore, dermal exposure that occurred during the preceding 32 h had a statistically significant effect on urinary 1-OHP, while the effect of inhalation exposure was not significant.

CONCLUSIONS: We found that distributed lag models are a valuable tool for analyzing longitudinal biomarker data and our results indicate that dermal contact is the primary route of exposure to PAHs among asphalt paving workers. An exposure assessment of PAHs that does not consider dermal exposure may considerably underestimate cumulative exposure and control strategies aimed at reducing occupational exposure to asphalt-related PAHs should include an effort to reduce dermal exposure.

Abstract  This study outlines how a glutathione reactivity assay (so-called in chemico data) can be used to define the applicability domain for the nucleophilic aromatic substitution (S(N)Ar) reaction for benzenes. This reaction is one of the six mechanistic domains that have been shown to be important in toxicological endpoints in which the ability to bind covalently to a protein is a key molecular initiating event. This study has analysed the experimental data, allowing a clear and interpretable structure-activity relationship to be developed for the S(N)Ar domain. The applicability domain has resulted in a series of structural alerts. The definition of the applicability domain for the S(N)Ar reaction and the resulting structural alerts are likely to be beneficial in the development of computational tools for category formation and read-across. The study concludes with how this information can be used in the development of adverse outcome pathways.

Abstract  OBJECTIVE: To analyze the impact of the measures for securing quality air for the 2008 Beijing Olympic and Paralympics Games on air pollution index (API) in Beijing and forecast the aftereffects.

METHODS: The time-distribution of API in Beijing from 2004 to 2008 was described. The time sequence analysis was used and the autoregressive integrated moving average model (ARIMA) was chosen to establish an API forecasting model to predict the API in December, 2008.

RESULTS: From 2004 to 2008, the average API in March (120 +/- 66) was the highest followed by November (116 +/- 72) and the average API in July (83 +/- 28) was the lowest followed by August (77 +/- 27). The proportion of "excellent" and "good" days from 2004 to 2008 were 9.56% (35/366), 54.37% (199/366), 8.49% (31/365), 54.52% (199/365), 7.12% (26/365 ), 58.90% (215/365 ), 8.77% (32/365), 58.63% (214/365), 16.67% (61/366), 58.20% (213/366) respectively, with an increasing trend year by year (chi2(trend) = 11.397, P = 0.001). The model of ARIMA (1, 0, 0) fitted well; according to the prediction of the ARIMA (1, 0, 0) model, the decrease of API that attributed to interim measures during the Olympic Games was 37. 1% and the average API of December was 82.

CONCLUSION: The interim measures during the Olympic Games were effective on promoting air quality. After the Olympic Games, air quality would still remain good.

Abstract  OBJECTIVE: To revise the South African Guideline for the Management of Chronic Obstructive Pulmonary Disease (COPD) based on emerging research that has informed updated recommendations.

KEY POINTS: (1) Smoking is the major cause of COPD, but exposure to biomass fuels and tuberculosis are important additional factors. (2) Spirometry is essential for the diagnosis and staging of COPD. (3) COPD is either undiagnosed or diagnosed too late, so limiting the benefit of therapeutic interventions; performing spirometry in at-risk individuals will help to establish an early diagnosis. (4) Oral corticosteroids are no longer recommended for maintenance treatment of COPD. (5) A therapeutic trial of oral corticosteroids to distinguish corticosteroid responders from non-responders is no longer recommended. (6) Primary and secondary prevention are the most cost-effective strategies in COPD. Smoking cessation as well as avoidance of other forms of pollution can prevent disease in susceptible individuals and ameliorate progression. Bronchodilators are the mainstay of pharmacotherapy, relieving dyspnoea and improving quality of life. (7) Inhaled corticosteroids are recommended in patients with frequent exacerbations and have a synergistic effect with bronchodilators in improving lung function, quality of life and exacerbation frequency. (8) Acute exacerbations of COPD significantly affect morbidity, health care units and mortality. (9) Antibiotics are only indicated for purulent exacerbations of chronic bronchitis. (10) COPD patients should be encouraged to engage in an active lifestyle and participate in rehabilitation programmes.

OPTIONS: Treatment recommendations are based on the following: annual updates of the Global Obstructive Lung Disease (GOLD), initiative, that provide an evidence-based comprehensive review of management; independent evaluation of the level of evidence in support of some of the new treatment trends; and consideration of factors that influence COPD management in South Africa, including lung co-morbidity and drug availability and cost.

OUTCOME: Holistic management utilising pharmacological and nonpharmacological options are put in perspective.

EVIDENCE: Working groups of clinicians and clinical researchers following detailed literature review, particularly of studies performed in South Africa, and the GOLD guidelines. BENEFITS, HARMS AND COSTS. The guideline pays particular attention to cost-effectiveness in South Africa, and promotes the initial use of less costly options. It promotes smoking cessation and selection of treatment based on objective evidence of benefit. It also rejects a nihilistic or punitive approach, even in those who are unable to break the smoking addiction.

RECOMMENDATIONS: These include primary and secondary prevention; early diagnosis, staging of severity, use of bronchodilators and other forms of treatment, rehabilitation, and treatment of complications. Advice is provided on the management of acute exacerbations and the approach to air travel, prescribing long-term oxygen and lung surgery including lung volume reduction surgery.

VALIDATION: The COPD Working Group comprised experienced pulmonologists representing all university departments in South Africa and some from private practice, and general practitioners. Most contributed to the development of the previous version of the South African guideline. GUIDELINE SPONSOR: The meeting of the Working Group of the South African Thoracic Society was sponsored by an unrestricted educational grant from Boehringer Ingelheim and Glaxo-Smith-Kline.

Abstract  Many rural mountain valley communities experience elevated ambient levels of fine particulate matter (PM*) in the winter, because of contributions from residential wood-burning appliances and sustained temperature inversion periods during the cold season. A wood stove change-out program was implemented in a community heavily affected by wood-smoke-derived PM2.5 (PM < or = 2.5 microm in aerodynamic diameter). The objectives of this study were to evaluate the impact of this intervention program on ambient and indoor PM2.5 concentrations and to identify possible corresponding changes in the frequency of childhood respiratory symptoms and infections and illness-related school absences. Over 1100 old wood stoves were replaced with new EPA-certified wood stoves or other heating sources. Ambient PM2.5 concentrations were 30% lower in the winter after the changeout program, compared with baseline winters, which brought the community's ambient air within the PM2.5 standards of the U.S. Environmental Protection Agency (U.S. EPA). The installation of a new wood stove resulted in an overall reduction in indoor PM2.5 concentrations in a small sample of wood-burning homes, but the effects were highly variable across homes. Community-level reductions in wood-smoke-derived PM2.5 concentration were associated with decreased reports of childhood wheeze and of other childhood respiratory health conditions. The association was not limited to children living in homes with wood stoves nor does it appear to be limited to susceptible children (e.g., children with asthma). Community-level reductions in wood-smoke-derived PM2.5 concentration were also associated with lower illness-related school absences among older children, but this finding was not consistent across all age-groups. This community-level intervention provided a unique opportunity to prospectively observe exposure and outcome changes resulting from a targeted air pollution reduction strategy.