Showing papers on "Air quality index published in 1994"

Air pollution control engineering

Abstract: Introduction to air pollution control air pollution effects air pollution control laws and regulations, air pollution control philosophies air pollution measurements, emission estimates air pollution meteorology air pollution concentration models general ideas in air pollution control the nature of particulate air pollutants control of primary particulate air pollutants control of volatile organic compounds (VOC) control of sulphur oxides control of nitrogen oxides the motor vehicle problem air pollutants and the global climate other topics.

Health effects of outdoor air pollution.

Abstract: One hundred sixty-four million Americans live in areas that fail to meet the National Ambient Air Quality Standards for six common air pollutants: particulates, sulfur dioxide, carbon monoxide, nitrogen dioxide, ozone and lead. The impact of these pollutants on health is significant. A Pollutant Standards Index (PSI) ranging from 0 to 500 is used to monitor air quality. When the PSI exceeds 100, the acceptable federal standard has been exceeded by at least one of four measured pollutants. When this occurs, all individuals should be advised to curtail physical activity between late morning and sunset and to remain indoors if possible. Athletes should be encouraged to train in the early morning, when photochemicals are usually at their lowest levels.

Detecting and tracking changes in ozone air quality.

Abstract: This paper presents a statistical method for filtering out or moderating the influence of meteorological fluctuations on ozone concentrations. Use of this technique in examining trends in ambient ozone air quality is demonstrated with ozone data from a monitoring location in New Jersey. The results indicate that this method can detect changes in ozone air quality due to changes in emissions in the presence of meteorological fluctuations. This method can be useful in examining the effectiveness of regulatory initiatives in improving ozone air quality.

Estimating the health effects of air pollutants : a method with an application to Jakarta

Abstract: To develop efficient strategies for pollution control, it is essential to assess both the costs of control and the benefits that may result. These benefits will often included improvements in public health, including reductions in both morbidity and premature mortality. Until recently, there has been little guidance about how to calculate the benefits of air pollution controls and how to use those estimates to assign priorities to different air pollution control strategies. The author describes a method for quantifying the benefits of reduced ambient concentrations of pollutants (such as ozone and particulate matter) typically found in urban areas worldwide. The author then applies the method to data on Jakarta, Indonesia, an area characterized by little wind, high population concentration (8 million people), congested roads, and ambient air pollution. The magnitude of the benefits of pollution control depend on the level of air pollution, the expected effects on health of the pollutants (dose-response), the size of the population affected and the economic value of these effects. The results for Jakarta suggest that significant benefits result from reducing exposure to both outdoor and indoor air pollutants. For example, if annual concentrations of particulate matter were reduced to the midpoint of the World Health Organization guideline (and former U.S. ambient standard), the estimates indicate a reduction per year of 1,400 premature deaths (with a range of 900 to 1,900), 49,000 emergency room visits, 600,000 asthma attacks, 7.6 million restricted activity days (including work loss), 124,000 cases of bronchitis in children, and 37 million minor respiratory symptoms. In the case of Jakarta, the methodology suggests that reducing exposure to lead and nitrogen dioxide should also be a high priority. An important consequence of ambient lead pollution is a reduction in learning abilities for children, measured as I.Q loss. Apart from that, reducing the proportion of respirable particles can reduce the amount of illness and premature mortality. Clearly, air pollution represents a significant public health hazard to residents of Jakarta and other cities consistently exposed to high levels of air pollution, such as Bangkok, Mexico City, and Santiago, Chile.

National air quality and emissions trends report, 1993

Abstract: This report presents national and regional trends in air quality from 1984 through 1993 for particulate matter, sulfur dioxide, carbon monoxide, nitrogen dioxide, ozone and lead. Air quality trends are also presented for 89 metropolitan areas. Both national and regional trends in each of these pollutants are examined. National air quality trends are also presented for both the National Air Monitoring Sites (NAMS) and other site categories. In addition to ambient air quality, trends are also presented for annual nationwide emissions. These emissions are estimated using the best available engineering calculations; the ambient levels presented are averages of direct measurements. International comparisons of air quality and emissions are contained in this report. The topics of air toxins and visibility are also addressed. This report also includes a section called Air Quality Status of Metropolitan Areas. Its purpose is to provide interested members of the air pollution control community, the private sector and the general public with greatly simplified air pollution information for the single year 1993. Air quality statistics are presented for each of the pollutants for all MSAs with data in 1993.

Effect of Air Humidification on the Sick Building Syndrome and Perceived Indoor Air Quality in Hospitals: a Four Month Longitudinal Study

Abstract: The sensation of dryness and irritation is essential in the sick building syndrome (SBS), and such symptoms are common in both office and hospital employees. In Scandinavia, the indoor relative humidity in well ventilated buildings is usually in the range 10-35% in winter. The aim of this study was to evaluate the effect of steam air humidification on SBS and perceived air quality during the heating season. The study base consisted of a dynamic population of 104 hospital employees, working in four new and well ventilated geriatric hospital units in southern Sweden. Air humidification raised the relative air humidity to 40-45% in two units during a four months period, whereas the other two units served as controls with relative humidity from 25-35%. Symptoms and perceived indoor air quality were measured before and after the study period by a standardised self administered questionnaire. The technical measurements comprised room temperature, air humidity, static electricity, exhaust air flow, aerosols, microorganisms, and volatile organic compounds in the air. The most pronounced effect of the humidification was a significant decrease of the sensation of air dryness, static electricity, and airway symptoms. After four months of air humidification during the heating season, 24% reported a weekly sensation of dryness in humidified units, compared with 73% in controls. No significant changes in symptoms of SBS or perceived air quality over time were found in the control group. The room temperature in all units was between 21-23 degrees C, and no significant effect of air humidification on the air concentration of aerosols or volatile organic compounds was found. No growth of microorganisms was found in the supply air ducts, and no legionella bacteria were found in the supply water of the humidifier. Air humidification, however, significantly reduced the measured personal exposure to static electricity. It is concluded that air humidification during the heating season in colder climates can decrease symptoms of SBS and perception of dry air.

Control for air quality machine

Abstract: A multi-functional room air conditioning unit that controls both heat and humidity as well as the concentration of airborne particulates A control unit monitors temperature, humidity and air quality parameters and automatically programs the apparatus to take corrective action when one or more of the parameters is outside of the desired range

Synoptic Circulation and Summertime Ground-Level Ozone Concentrations at Vancouver, British Columbia

Abstract: The Kirchhofer synoptic classification procedure is applied to both mean sea level and 500-hPa NMC gridded pressure fields for the vicinity of southwestern British Columbia. Exceedances of the Canadian 1-h Ambient O3 Air Quality Objective of 82 ppb at Port Moody, Vancouver, are associated with the coincidence of a low-level thermal trough and an upper-level ridge of high pressure. Analysis of synoptic sequences also reveals the importance of persistence in the development of elevated O3 concentrations. The application of synoptic climatology to ground-level O3 in Vancouver highlights the need for consideration of more than one atmospheric level in map-typing schemes. An extension of the basic Kirchhofer approach to permit multilevel computer-assisted map typing is advocated.

Design and characterization of the CLIMPAQ, chamber for laboratory investigations of materials, pollution and air quality

Abstract: A test chamber has been developed in order to provide a small and simple emission testing facility capable of testing construction products in a climate where the important climatic parameters such as temperature, ventilation rate and air velocity can be varied independently around typical indoor values. The test chamber CLIMPAQ is made of panes of window glass. Other main surface materials are stainless steel and eloxated aluminium. The chamber has a volume of 50.9 litres and is designed to meet the requirements for quantifying air pollution. In this investigation human subjects acted as air pollution judges, and chemical characterization of the air pollution was carried out. Carpet, linoleum, wall paint and seal- ant were tested simultaneously in the CLIMPAQ and in four other chambers ranging from a full-scale chamber of 28 m3 to a field and laboratory emission cell of 3.5· 10−5m3. Product ranking is the same in all chambers for the sensory measurements. Emission rates based on sensory measurements differ for all products less than 100 % except for tests in a 3-litre chamber where emission rates were higher. Chemical measurements differ up to approximately 10 times for the same product in different chambers. Deviations appear to be the result of different environmental parameters in the various chambers. Low air concentrations or high specific ventilation rates seem to increase emissions, while differences in air velocities and sink properties may also be the cause of differences in emission rates.

Fundamentals of air pollution. Third edition

Abstract: This book presents an overview of air pollution. In Part I, the history of air pollution and the basic concepts involved with air pollution such as sources, scales, definitions are covered. Part II describes how airborne pollutants damage materials, vegetation, animals, and humans. Six fundamental aspects of air pollution are included in the text: The Elements of Air Pollution; The Effects of Air Pollution; Measurement and Monitoring of Air Pollution; Meterology of Air Pollution; regulatory Control of Air Pollution; and Engineering Control of Air Pollution.

Air quality-temperature controlled central conditioner and multi-zoned conditioning

Abstract: An air quality and temperature responsive air conditioning system wherein modules are employed to precondition the air for humidity control, to heat and cool the air, and to bypass the supply air in excess of the demand of a multiplicity of comfort zones (Z) with thermostat control (T), and featuring a bypass module (M) characterized by parallel ducting, one ducting (55) which is restricted by a damper (57) responsive to a supply air back pressure sensor (S1), and one ducting (56) which is opened by a damper (60) responsive to an air quality sensor (S2).

Vehicle Emissions and Effects on Air Quality: Indoors and Outdoors

Abstract: Vehicle emissions of non-regulated volatile organic compounds (VOCs), such as benzene, can form a major contribution to pollution of the indoor as well as the outdoor environment. Several of these compounds are considered to be a health risk and are important factors in the production of photochemical smog. The introduction of unleaded and particularly 'super unleaded' fuels has significantly increased levels of aromatic compounds in petrol world-wide and has led to changes in fuel composition with respect to olefins and the use of oxygenates. Increased aromatics, olefins and other compounds in fuels used in vehicles not fitted with catalytic converters have been shown to increase emissions of benzene, 1,3-butadiene and other VOCs as well as contributing to increases in photochemical smog precursors. Increases in VOC levels in ambient air clearly produce increased indoor air pollution, particularly in nat urally ventilated buildings.

Indoor air quality and ventilation assessment monitoring device

Abstract: A monitoring device system and a method for controlling ventilation in an enclosed or confined environment by regulating the effective ventilation rate, air exchange rate, mixing factors, stratification of air within the confined area, the percentage of outside air which is introduced (when possible), the percentage of recirculated air, mean air life, air half-life are described. The device may be used for controlling an HVAC system so that air quality conforms to predetermined air quality standards. The monitoring device consists of a multiport sample collection system and one or more sensors to detect determinants of air quality. The method of control uses a CPU to regulate fans, dampers, and other systems to maintain the air quality within predetermined ranges, based upon the monitoring data. A tracer gas, preferably CO 2 , is used to determine system parameters. Measurement of additional gases and particulates and local ventilation control responsive to such toxicants is limited only by the availability of suitable detection methods.

Principles of Air Quality Management

Abstract: The Atmosphere and Its Contaminants History of Air Pollution Terms and Definitions Components of the Atmosphere States of Air Pollutants Contaminant Classifications Photochemical Smog Effects of Air Pollution Time Effects and Sensitivities Criteria versus Noncriteria Air Pollutants Basic Principles of Toxicology Routes of Exposure Response to Airborne Chemicals Classes of Health Effects Effects on the Ecosystem Economic Losses Air Quality Standards and Monitoring Standards Ambient Air Standards and Exposures The Pollution Standard Index Noncriteria Air Contaminant Standards Risk Assessment Acceptable Air Quality Monitoring Ambient Air Quality Measurement Techniques Sources and Measurement Methodologies Global Sources Air Pollution Sinks Anthropogenic Air Emissions Evaporative Emissions Fugitive Emissions Waste-Related Emissions Criteria Air Pollutant Formation Source Inventories of Criteria Pollutants Hazardous Air Emissions Quantification of Emissions Meteorology, Dispersion, and Modeling Earth's Energy and Radiation Regional Air Pollution Meteorology Local Air Pollutant Dispersion Dispersion Modeling Visibility Mathematical Models Stationary-Source Control Approaches Source Reduction Management and Operational Changes Process-Optimizing Actions Combustion Modifications Fuels and Fuel Modification Planning and Design Emissions Characterization Collection of Air Contaminants Air Pollution Control Approaches Combustion Gas Control Technologies Technology Comparisons Mobile Sources and Control Approaches Engines and Air Pollutant Emissions Pollutant Formation in Spark-Ignited Engines Diesel Ignition Emission Characteristics Hybrid Internal Combustion Engines ICE Emission-Control Options Design Influences on ICEs External Control Approaches Fuel Change Effects Alternatives and the Future Global Concerns The Challenge Intercontinental Pollutant Transport Stratospheric Ozone Radiation Primer Acid Deposition Global Climate Change Alternative Views Air Quality Laws and Regulations General Law Approaches Federal Laws Affecting Air Quality Management The Clean Air Act International Treaties The Influence of Nonregulatory Governmental Actions Management, Trends, and Indoor Air Quality Elements of Air Quality Management Trends Indoor Air Quality Public Buildings Indoor Air Pollution in Developing Countries List of Acronyms Glossary Bibliography Index

Detoxificant Enzymes in Pumpkin Grown in Polluted Ambient Air

Abstract: Pumpkin [Cucurbita pepo (L.) cv. Ambassador] plants were grown under either nonfiltered or filtered ambient air in open-top field chambers (OTCs) near the urban area of Milan, Northern Italy. The effects of ambient air pollution on the enzymatic detoxfication system of the leaves, both in terms of activity and isoform pattern were investigated. The data on air quality showed that ozone was the main phytotoxic pollutant present in ambient air, reaching a 7 h mean of 63 nL L{sup -1} and a maximum hourly peak of 104 nL L{sup -1} The peroxidase and catalase activities increased fourfold and twofold, respectively in the nonfiltered air plants In comparison to the filtered air ones. The peroxidase patterns were very modified in the polluted plants. In contrast no significant changes were found in the activity and isoenzyme pattern of superoxide dismutase. The data reported here suggest that in field-grown pumpkin plants exposed to ambient levels of photooxidants, a stimulation of the peroxddase-catalase detoxification system takes place. 32 refs., 3 figs., 3 tabs.

Clearing the air at Great Smoky Mountains National Park

Abstract: Great Smoky Mountains National Park, located in the southern Appalachians on the border of Tennessee and North Carolina, was designated by Congress in 1977 as a Class I area, where resources are to be protected from damage due to air pollution. The National Park Service, Air Quality Division, collected and then used data on levels of pollutants and response of sensitive resources in the park and found that forests, soils, surface waters, and visibility in the park were experiencing adverse impacts from air pollution. We reviewed the data and process that supported this finding as well as the legal tools available to federal land managers confronted with evidence that sources of air pollution outside the boundaries of Class I areas are affecting resources. We prepared this case study to describe how the National Park Service has used scientific information in regulatory arenas to address air pollution problems at Great Smoky Mountains National Park. Based on this case study we show that the requirement for Federal Land Manager review of permits for new stationary sources of air pollution is not sufficient to protect the parks from what has become a regional air quality problem.

Mesoscale Meteorological Model Evaluation Techniques with Emphasis on Needs of Air Quality Models

Abstract: The objective of this article is to review techniques used to evaluate mesoscale meteorological models with emphasis on the parameters used as input to air quality models. Our definition of “mesoscale” is broad enough to encompass so-called regional models. The characteristics of existing model evaluations are compared with the components of an optimum comprehensive model evaluation system.

Environmental control of indoor biologic agents

Abstract: The indoor environment contains unique pollutants, such as environmental tobacco smoke and indoor allergens. In addition, air pollutants may reach higher levels indoors than outdoors, and in some instances may exceed the national standards for outdoor exposure. Nonindustrial indoor settings, such as offices, residences, and vehicles, also have air quality problems. Although the role of occupational air pollutants (organic and inorganic) in causing complaints in the workplace has been clearly documented, the relationship between poor air quality and health complaints is often controversial. The main causes of poor indoor air quality are an inadequate ventilation or fresh air intake, biologic contamination of the indoor environment, and an accumulation of noxious compounds. A list of important indoor air pollutants is shown in Table I. Because indoor allergen concentrations are higher in homes than in public places, a greater effort should be made to control allergens at home. A reason for this difference may be the more aggressive chemical treatment of carpets in public places. However, in some instances high mite, cat, and dog allergen levels have been detected in schools and day care centers. These findings have important implications for families who are practicing allergen avoidance at home because the effort and time spent controlling allergen exposure could be jeopardized by exposure in the school environment.' Studies conducted in schools have demonstrated that carpets contain high levels of a variety of allergens including pollen, cat, dog, food, mite, and mold allergens.2 Carpets in schools and homes are an important reservoir of allergens.

Modeling the concentrations of gas-phase toxic organic air pollutants: direct emissions and atmospheric formation.

Abstract: An Eulerian photochemical air quality model is described for the prediction of the atmospheric transport and chemical reactions of gas-phase toxic organic air pollutants. Model performance was examined in the Los Angeles, CA, area over the period August 27-28, 1987. The organic compounds were drawn from a list of 189 species selected for control as hazardous air pollutants in the Clean Air Act amendments of 1990. The species considered include benzene, various alkylbenzenes, phenol, cresols, 1,3- butadiene, acrolein, formaldehyde, acetaldehyde, and perchloroethylene among others. It is found that photochemical generation contributes significantly to form-aldehyde, acetaldehyde, acetone, and acrolein concentrations for the 2-day period studied. Phenol concentrations are dominated by direct emissions, despite the existence of a pathway for atmospheric formation from benzene oxidation. The finding that photochemical production can be a major contributor to the total concentrations of some toxic organic species implies that control programs for those species must consider more than just direct emissions.

Predicting air flow and thermal comfort in offices

Abstract: People expect the office environment to be as comfortable as possible. Consequently, more and more offices are being equipped with mechanical ventilation or air-conditioning systems. The need for accurate prediction of the air flow in occupied spaces has become even more crucial because, with mechanical ventilation, large quantities of air supplied at a few locations have to be evenly distributed in the space being ventilated. Without adequate air distribution, excessive air movement (draft) can occur in some zones, whereas stagnant air may be present in other zones of the same room. Poor air distribution can affect the indoor climate and degrade the air quality. Until recently, the air movement in a space was predicted from air jet diffusion data and/or testing a physical model, as described by Awbi. Computational fluid dynamics (CFD) is now being applied in the simulation of room air movement. However, in most of the available CFD programs, the radiant heat transfer is simplified or not accounted for when dealing with thermal comfort. Kaizuka and Iwamoto calculated the distribution of a thermal comfort index caused by radiative interaction in a heated room under the assumptions of uniform air temperature and given air velocity. Awbi and Gan andmore » Gan et al. have developed a CFD program called Vortex in which the radiative heat exchange is taken into consideration and that is used to predict the air movement and thermal comfort in both mechanically and naturally ventilated buildings. In this article, the predictions of air movement and thermal comfort in a mechanically ventilated office module and a naturally ventilated office are presented.« less

Carbon monoxide emissions from road driving: evidence of emissions due to power enrichment

Abstract: The Clean Air Act Amendments of 1990 place a great deal of importance on the use of transportation controls to meet air quality standards in nonattainment areas. Inherent in the approach to estimating the beneficial impacts of such transportation measures is an estimation of current levels of emissions (the emissions inventory) and then a determination of what changes in emissions would occur given changes in the operation and use of the transportation system. One aspect of vehicle emissions behavior, that is, emissions due to engine power enrichment, which is not well represented in existing models, is examined. A 46-instrumented vehicle data base was used to analyze the importance of enrichment emissions to overall vehicle trip emissions records while relating these emissions to velocity-acceleration characteristics. It is concluded that enrichment emissions can be a significant contributor to overall vehicle emissions. In addition, policy implications of these results on current public policy and emissions model development are discussed.

An assessment of air quality in Karachi, Pakistan.

Abstract: An atmospheric pollution survey was carried out at 13 sites in Karachi, Pakistan, simultaneously from 0600 h to 2100 h for 15 consecutive days in May 1990 which also included meteorological measurements. The monitoring sites were included along the prevailing wind patterns in Karachi. Carbon monoxide levels in the ambient air were found to reach 9-10 ppm along the busy urban streets whereas CO2 level exceeded 370 ppm in these areas. Our survey indicates that NO2 levels were exceeding U.S. ambient air quality standards. Maxmum NO2 concentrations were observed (0.3-0.5 ppm) during the daytime from 0600 h to 2100 h. The surface ozone maximum around noon at the inland sites reached the levels of 40 ppb and 50 ppb respectively compared to upwind coastal Sites 1 level of 25 ppb. The Pb concentrations were approximately 3- to 7-fold higher than average, which corresponded well to urban air. Fossil fuel SO4 (excess) and NO3 were apportionally based on the assumption that these two anions were present as (NH4)2SO4, and NH4NO3 in the aerosols. In the eastern part of the city atmospheric sulphate (SO4) shows the combustion of coal as its source from the vicinity and downwind of a steel manufacturing plant.

Automobiles, the environment and metropolitan spatial structure

Abstract: More than 20 years ago, in a conference on Cities, Regions and Public Policy held at the University of Glasgow, a basic theme emerged that negative externalities should not be addressed or other urban problems that tamper with city sizes. Rather, these externalities should be handled via direct policies. This paper argues a variation of that theme--it is not efficient to correct these negative externalities via attempts to change metropolitan spatial structure. More specifically, trying to put suburbanization and decentralization in reverse is not a sound strategy for reducing air pollution levels. Discussions focus on suburbanization and air quality, air pollution and urban form, jobs-housing balance, congestion pricing and air quality, and emissions technology and control.