Air quality measurements—From rubber bands to tapping the rainbow

It is axiomatic that good measurements are integral to good public policy for environmental protection. The generalized term for “measurements” includes sampling and quantitation, data integrity, documentation, network design, sponsorship, operations, archiving, and accessing for applications. Each of these components has evolved and advanced over the last 200 years as knowledge of atmospheric chemistry and physics has matured. Air quality was first detected by what people could see and smell in contaminated air. Gaseous pollutants were found to react with certain materials or chemicals, changing the color of dissolved reagents such that their light absorption at selected wavelengths could be related to both the pollutant chemistry and its concentration. Airborne particles have challenged the development of a variety of sensory devices and laboratory assays for characterization of their enormous range of physical and chemical properties. Advanced electronics made possible the sampling, concentration, and detection of gases and particles, both in situ and in laboratory analysis of collected samples. Accurate and precise measurements by these methods have made possible advanced air quality management practices that led to decreasing concentrations over time. New technologies are leading to smaller and cheaper measurement systems that can further expand and enhance current air pollution monitoring networks.

Implications: Ambient air quality measurement systems have a large influence on air quality management by determining compliance, tracking trends, elucidating pollutant transport and transformation, and relating concentrations to adverse effects. These systems consist of more than just instrumentation, and involve extensive support efforts for siting, maintenance, calibration, auditing, data validation, data management and access, and data interpretation. These requirements have largely been attained for criteria pollutants regulated by National Ambient Air Quality Standards, but they are rarely attained for nonroutine measurements and research studies.     

Pennsylvania’s Compuiterized Air Monitoring System

The Pennsylvania Air Pollution Commission has developed a regulatory program based upon the control of local air pollution problems and reduction of pollutant levels in air basins. The geographical boundaries of 10 air basins have been established. The Commission’s air basin regulations will provide for the reduction of over-all pollutant levels and for emergency procedures in the event of adverse meteorological conditions. The paper discusses the format and objectives of the program.

In order to effectively enforce the air basin regulations and maintain the necessary surveillance of the state’s air quality, a "computerized real time on-line integrated air monitoring-data handling system" has been designed. The system will incorporate a network to constantly monitor the air in each air basin.The primary objectives of the system are: 1. Constant surveillance of air pollution in the air basins.

2. Provide information on air pollution potential alerts.

3. Aid in further development of air quality criteria and regulations.

The air monitoring network is estimated to include approximately 25 remote stations. Each remote will contain air pollution and meteorological sampling equipment and hardware to telemeter to a central station. The data will be transmitted over leased telephone lines. The central station in Harrisburg will contain the necessary hardware to receive and process data, calculate and display results and permit supervisory control of the network. Output options will include immediate display of edited data, command and alarm information, and presentation of statistical results.

Although the air monitoring system is one of the principle ingredients of the program, the air basin concept encompasses other component systems designed to knit together the entire air pollution control program in Pennsylvania.     

Techniques and Procedures for the Measurement of Aircraft Gas Turbine Engine Emissions

In 1968 the Society of Automotive Engineers formed the Committee on Aircraft Exhaust Emissions Measurement (E-31) whose charge was the development of acceptable standards of measurement for the characterization of aircraft engine exhaust. This committee’s efforts have resulted in the issuance of two Aerospace Recommended Practices, ARP 1179 “Aircraft Gas Turbine Exhaust Smoke Measurement” and ARP 1256 “Procedure for the Continuous Sampling and Measurement of Gaseous Emissions from Aircraft Turbine Engines.” These Recommended Practices have in large part been adopted by the Environmental Protection Agency and promulgated in Federal Register Volume 38, Number 136, Tuesday, July 17, 1973.

For the past three years Pratt & Whitney Aircraft has been measuring emissions from aircraft gas turbine engines using on-line instrumentation systems designed both in accordance with these Aerospace Recommended Practices and in response to the operational needs of a large experimental engineering test facility. In addition to a discussion of these systems this paper describes the experience derived from continuous testing programs in support of this test facility with consideration being given to the specific problems of sampling, sample handling, system accuracy, and data recording and reduction. Comment is made as to the practical limitations of the recommended methods and procedures as applied to emission control technology programs and suggestions are presented for improving the measurement technology.     

Product Guide/1972

The Journal of the Air Pollution Control Association presents its fifth annual directory of air pollution products. This 14-page guide lists manufacturers of emission control equipment and air pollution instrumentation under product classifications which are shown below. These classifications are derived from McGraw-Hill’s Air Pollution Handbook, chapters 10, 11, and 13 . The final portion of this guide contains an alphabetical listing of manufacturers.

If any manufacturers or product categories have been inadvertently overlooked, the omission is regretted and should be brought to the attention of the editor. It will result in a more complete and accurate Product Guide/1973 to be published next December.     

An Overview of EPA’s Quality Assurance Program

Quality Assurance has been defined in many different ways to express concern for the “quality” of the output of some operation or function. For the purpose of this presentation, quality assurance is defined as the sum of those activities within an environmental monitoring or measurement program which are primarily for the purpose of documenting the precision, accuracy, representativeness, and completeness of the data that are produced. Further, we view quality assurance as a management tool which encompasses both administrative and technical functions which generally fall into three categories: (1) Prevention which includes those activities carried out prior to the proper placement and operation of the measurement system; (2) Evaluation which includes the continuous overview and checks on the performance of the systems and operators; and (3) Correction which includes changes made to improve or stabilize the capability and performance of the system.     

Feasibility of granular bed filtration of an aerosol of ultrafine metallic particles including a pressure drop regeneration system

A process for filtering an aerosol of ultrafine metallic particles (UFP) has been designed and tested, based on the principle of a multistage granular bed. The filtration system comprised a succession of granular beds of varying thickness composed of glass beads of different diameters. This system allows the pressure drop to be regenerated during filtration (“on-line” mode) using a vibrating probe. Tests monitoring the pressure drop were conducted on a “10-L/min” low airflow rate device and on a “100-m³/hr” prototype. Granular bed unclogging is automated on the latter. The cyclic operation and filtration performances are similar to that of filter medium-based industrial dust collectors.

Implications:?Filtration of ultrafine metallic particles generated by different industrial processes such as arc welding, metal cutting, or spraying constitutes a difficult problem due to the high filter clogging properties of these particles and to the high temperatures generally encountered. Granular beds represent an advantageous means of filtering these aerosols with difficult properties.     

The Australian Air Quality Forecasting System: The Use of Green Scenarios of Motor Vehicle Usage as an Educational Tool

Abstract

The Australian Air Quality Forecasting System (AAQFS) is one of several newly emerging, high-resolution, numerical air quality forecasting systems. The system is briefly described. A public education application of the air quality impact of motor vehicle usage is explored by computing the concentration and dosage of particulate matter less than 10 µm in aerodynamic diameter (PM₁₀) for a commuter traveling to work between Geelong and Melbourne, Victoria, Australia, under “business-as-usual” and “green” scenarios. This application could be routinely incorporated into systems like AAQFS. Two methodologies for calculating the dosage are described: one for operational use and one for more detailed applications. The Clean Air Research Programme-Personal Exposure Study in Melbourne provides support for this operational methodology. The more detailed methodology is illustrated using a system for predicting concentrations due to near-road emissions of PM₁₀ andapplied in Sydney.     

Evaluation of Byron Instruments Total Organic Carbon (Method 25) Monitoring System

The environment and its interactions with human systems, whether economic, social, or political, are complex. Relevant drivers may disrupt system dynamics in unforeseen ways, making it difficult to predict future conditions. This kind of “deep uncertainty” presents a challenge to organizations faced with making decisions about the future, including those involved in air quality management. Scenario Planning is a structured process that involves the development of narratives describing alternative future states of the world, designed to differ with respect to the most critical and uncertain drivers. The resulting scenarios are then used to understand the consequences of those futures and to prepare for them with robust management strategies. We demonstrate a novel air quality management application of Scenario Planning. Through a series of workshops, important air quality drivers were identified. The most critical and uncertain drivers were found to be “technological development” and “change in societal paradigms.” These drivers were used as a basis to develop four distinct scenario storylines. The energy and emissions implications of each storyline were then modeled using the MARKAL energy system model. NO_x emissions were found to decrease for all scenarios, largely a response to existing air quality regulations, whereas SO₂ emissions ranged from 12% greater to 7% lower than 2015 emissions levels. Future-year emissions differed considerably from one scenario to another, however, with key differentiating factors being transition to cleaner fuels and energy demand reductions.

Implications: Application of scenarios in air quality management provides a structured means of sifting through and understanding the dynamics of the many complex driving forces affecting future air quality. Further, scenarios provide a means to identify opportunities and challenges for future air quality management, as well as a platform for testing the efficacy and robustness of particular management options across wide-ranging conditions.     

Effects of herbicide stress on wheat cultivars from organic and conventional cropping systems

Abstract

Wheat (Triticum aestivum L.) seedlings grown from seeds produced in “organic”; (non‐chemical) and “conventional”; cropping systems are characterized by a) similar rates of root and shoot growth, b) equal sensitivity to phytotoxicity by the herbicide glyphosate, and c) equivalent basal activity of the enzyme glutathione S‐transferase (both in the roots and in the shoots). In addition, treatment of these seedlings with glyphosate leads to significantly higher contents of this enzyme both in the shoots and in the roots. However, time‐course and dose‐response investigations indicate significant differences in the induction pattern of glutathione S‐transferase: the response of “conventional”; wheat seedlings takes place earlier and with higher efficiency, than that of the “organic”; ones.     

Developments In Sampling And Analysis Instrumentation For Stationary Sources

The body of information presented in this paper is provided as an orientation to instrument developers and users, and those individuals concerned with the measurement of pollutant emissions from stationary sources.

A system concept is presented and shows six unit operations comprising a complete measurement system. These operations include sample site selection, sample transport, sample treatment, sample analysis, data reduction and display, and data interpretation.

Five measurement approaches are discussed. The first two involve sample extraction from within the stack. The remaining three are new techniques using conventional and advanced electro-optical methods. The new approaches include in situ monitoring, remote sensing, and long-path sensing.

Attention is focused on the performance requirements of interface systems required to couple analyzers to sources for sample extraction. Current status of instrumentation is summarized in terms of commercially available systems, research and prototype developments, and feasibility studies for each of the five approaches.     

Magnetic signature,geochemistry, and oral bioaccessibility of “technogenic” metals in contaminated industrial soils from Sindos Industrial Area,Northern Greece

The objective of this study was to assess the contamination level of potentially harmful elements (PHEs) in industrial soils and how this relates to environmental magnetism. Moreover, emphasis was given to the determination of the potential mobile fractions of typically “technogenic” metals. Therefore, magnetic and geochemical parameters were determined in topsoils (0–20 cm) collected around a chemical industry in Sindos Industrial Area, Thessaloniki, Greece. Soil samples were presented significantly enriched in “technogenic” metals such Cd, Pb, and Zn, while cases of severe soil contamination were observed in sampling sites north-west of the industrial unit. Contents of Cd, Cr, Cu, Ni, Pb, Mo, Sb, Sn, and Zn in soils and pollution load index (PLI) were highly correlated with mass specific magnetic susceptibility (χ _lf). Similarly, enrichment factor (EF) and geoaccumulation index (I _geo) for “technogenic” Pb and Zn exhibited high positive correlation factors with χ _lf. Principal component analysis (PCA) classified PHEs along with the magnetic variable (χ _lf) into a common group indicating anthropogenic influence. The water extractable concentrations were substantially low, while the descending order of UBM (Unified BARGE Method) extractable concentrations in the gastric phase was Zn > Pb > As > Cd, yet Cd showed the highest bioaccessibility (almost 95%).

     

Impact of Covid-19 partial lockdown on PM2.5, SO2, NO2, O3, and trace elements in PM2.5 in Hanoi,Vietnam

Covid-19 lockdowns have improved the ambient air quality across the world via reduced air pollutant levels. This article aims to investigate the effect of the partial lockdown on the main ambient air pollutants and their elemental concentrations bound to PM_2.5 in Hanoi. In addition to the PM_2.5 samples collected at three urban sites in Hanoi, the daily PM_2.5, NO₂, O₃, and SO₂ levels were collected from the automatic ambient air quality monitoring station at Nguyen Van Cu street to analyze the pollution level before (March 10th–March 31st) and during the partial lockdown (April 1st–April 22nd) with “current” data obtained in 2020 and “historical” data obtained in 2014, 2016, and 2017. The results showed that NO₂, PM_2.5, O₃, and SO₂ concentrations obtained from the automatic ambient air quality monitoring station were reduced by 75.8, 55.9, 21.4, and 60.7%, respectively, compared with historical data. Besides, the concentration of PM_2.5 at sampling sites declined by 41.8% during the partial lockdown. Furthermore, there was a drastic negative relationship between the boundary layer height (BLH) and the daily mean PM_2.5 in Hanoi. The concentrations of Cd, Se, As, Sr, Ba, Cu, Mn, Pb, K, Zn, Ca, Al, and Mg during the partial lockdown were lower than those before the partial lockdown. The results of enrichment factor (EF) values and principal component analysis (PCA) concluded that trace elements in PM_2.5 before the partial lockdown were more affected by industrial activities than those during the partial lockdown.

     

Autonomous mobile platform for monitoring air emissions from industrial and municipal wastewater ponds

Significant amounts of volatile organic compounds and greenhouse gases are generated from wastewater lagoons and tailings ponds in Alberta, Canada. Accurate measurements of these air pollutants and greenhouse gases are needed to support management and regulatory decisions. A mobile platform was developed to measure air emissions from tailings pond in the oil sands region of Alberta. The mobile platform was tested in 2015 in a municipal wastewater treatment lagoon. With a flux chamber and a CO₂/CH₄ sensor on board, the mobile platform was able to measure CO₂ and CH₄ emissions over two days at two different locations in the pond. Flux emission rates of CO₂ and CH₄ that were measured over the study period suggest the presence of aerobic and anaerobic zones in the wastewater treatment lagoon. The study demonstrated the capabilities of the mobile platform in measuring fugitive air emissions and identified the potential for the applications in air and water quality monitoring programs.

Implications: The Mobile Platform demonstrated in this study has the ability to measure greenhouse gas (GHG) emissions from fugitive sources such as municipal wastewater lagoons. This technology can be used to measure emission fluxes from tailings ponds with better detection of spatial and temporal variations of fugitive emissions. Additional air and water sampling equipment could be added to the mobile platform for a broad range of air and water quality studies in the oil sands region of Alberta.     

Kinetic constraints on theIn-situ remediation of soils contaminated with organic chemicals

Cleanup of contaminated soils to comply with soil quality limits currently receives much interest.In-situ remediation of contaminated soils relies on the ability of the techniques employed to enhance the rate of release of contaminants from the soil-sorbed and nonaqueous phase liquid (NAPL) phases into the aqueous or gaseous phases from which they can be more readily removed and treated. Contaminant concentrations in these “environmentally mobile” forms usually decline over time so that the economic efficiency and the overall success of remediation technologies are subject to the “law of diminishing returns”. In this paper we consider the “state of the art” in our understanding of NAPL dissolution and transport, desorption of soilsorbed contaminants and fluid flow in porous media. The extent to which these processes may constrain the success of bioremediation, pump-and-treat remediation and soil venting in relation to established soil quality limits is addressed. Finally, we suggest directions for future research and comment on legislative considerations.     

The copper level dependence in vegetable crops at pesticide treatment

Abstract

Pesticides containing copper are used on wide range in vegetable production, especially in the open field. Copper has an excellent fungicidal effect against diseases of tomato, pepper, onion and in practical use it is essential as bactericide in the above mentioned crops.

The fungicides containing copper are freely available on the market, they are not expensive and widely used without any special knowledge. They are popular in simple home gardens as well as in hi‐tech vegetable production and are used even in all forms of “bio”; culture.

From the other side, copper can be toxic. The allowable level is 10 mg Cu/kg product. This concentration may be found after the first treatment and it increases after every further application.

In our experiments the copper absorbancy and accumulation has been investigated at different pesticide doses and under different experimental conditions.

The analytical measurements, the sample preparation, the instrument calibration have been made by the Inductively Coupled Plasma Spectrometer at the Department of Chemistry of the University of Horticulture and Food Industry.     

Wet vs Dry Gas Cleaning In the Steel Industry

Deciding whether the gas should be cleaned by a “dry” system or a “wet” system requires a full consideration of all factors of which the capital cost is only one. Anticipating the various problems which might be expected and designing adequate measures for each calls for major engineering effort,but onlythen can a best choice be made. The principles which govern the above are illustrated by a typical selection of gas cleaning equipment to be used as part of a BOF steel making installation. Two entirely different gas cleaning systems are presently in BOF service in North America. Both will do an excellent job if properly designed. Either system will cost in excess of $2,000,000 and will require careful control and large amounts of electrical power. One system, the dry electrostatic precipitator, requires humidification of the gas; protection against explosions; elaborate electrical controls, insulators, etc.; and a rugged handling system for the bone dry dust collected. The other system, wet washing with water, Is easier to control but uses large quantities of water and electric power. As in the case of the “dry” system, handling the dirt collected is a difficult problem requiring careful study and choice of equipment. In either case the dust may be discarded or reused, but it must be handled with care lest it become an air or stream pollution problem all over again.     

Estimates of community exposure and health risk to sulfur dioxide from power plant emissions using short-term mobile and stationary ambient air monitoring

To estimate plausible health effects associated with peak sulfur dioxide (SO₂) levels from three coal-fired power plants in the Baltimore, Maryland, area, air monitoring was conducted between June and September 2013. Historically, the summer months are periods when emissions are highest. Monitoring included a 5-day mobile and a subsequent 61-day stationary monitoring study. In the stationary monitoring study, equipment was set up at four sites where models predicted and mobile monitoring data measured the highest average concentrations of SO₂. Continuous monitors recorded ambient concentrations each minute. The 1-min data were used to calculate 5-min and 1-hr moving averages for comparison with concentrations from clinical studies that elicited lung function decrement and respiratory symptoms among asthmatics. Maximum daily 5-min moving average concentrations from the mobile monitoring study ranged from 70 to 84 ppb (183–220 µg/m³), and maximum daily 1-hr moving average concentrations from the mobile monitoring study ranged from 15 to 24 ppb (39–63 µg/m³). Maximum 5-min moving average concentrations from stationary monitoring ranged from 39 to 229 ppb (102–600 µg/m³), and maximum daily 1-hr average concentrations ranged from 15 to 134 ppb (40–351 µg/m³). Estimated exposure concentrations measured in the vicinity of monitors were below the lowest levels that have demonstrated respiratory symptoms in human clinical studies for healthy exercising asthmatics. Based on 5-min and 1-hr monitoring, the exposure levels of SO₂ in the vicinity of the C.P. Crane, Brandon Shores, and H.A. Wagner power plants were not likely to elicit respiratory symptoms in healthy asthmatics.

Implications: Mobile and stationary air monitoring for SO₂ were conducted to quantify short-term exposure risk, to the surrounding community, from peak emissions of three coal-fired power plants in the Baltimore area. Concentrations were typically low, with only a few 5-min averages higher than levels indicated during clinical trials to induce changes in lung capacity for healthy asthmatics engaged in exercise outdoors.     

Treatment of Nonhazardous Petroleum-Contaminated Soils by Thermal Desorption Technologies

Spills, leaks, and accidental discharges of petroleum products have contaminated soil at thousands of sites in the United States. One remedial action technique for treating petroleum contaminated soil is the use of thermal desorption technologies.

This paper describes key elements of the U.S. Environmental Protection Agency report titled “Thermal Desorption Applications Manual for Treating Nonhazardous Petroleum Contaminated Soils.”¹ The applications manual describes the types, mechanical and operating characteristics of thermal desorption technologies that are commercially available to treat petroleum-contaminated soils. It also provides step-by-step procedures to rate the critical success factors influencing the general applicability of thermal desorption at a particular site. These factors include site, waste and soil characteristics, regulatory requirements, and process equipment design and operating characteristics. Procedures are provided to determine the types of thermal desorption systems that are most technically suitable for a given application and to determine whether on-site or off-site treatment is likely to be the most cost-effective alternative. Key factors that determine process economics are identified, and estimated cost ranges for treating petroleum-contaminated soils are presented. Spreadsheets are provided that can be used for performing cost analyses for specific applications.

The aforementioned report is applicable only to the treatment of petroleum-contaminated soils that are exempt from being classified as hazardous wastes under the Resource Conservation and Recovery Act (RCRA) or as toxic materials under the Toxic Substances Control Act (TSCA). Although much of the technical discussion in this paper is applicable to the treatment of both nonhazardous and hazardous ortoxic materials, permitting requirements and treatment costs are significantly different forthe individual categories of waste materials.     

Modeling Analyses of the Effects of Changes in Nitrogen Oxides Emissions from the Electric Power Sector on Ozone Levels in the Eastern United States

Abstract

In this paper, we examine the changes in ambient ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for summer 2002 under three different nitrogen oxides (NO_x) emission scenarios. Two emission scenarios represent best estimates of 2002 and 2004 emissions; they allow assessment of the impact of the NO_x emissions reductions imposed on the utility sector by the NO_x State Implementation Plan (SIP) Call. The third scenario represents a hypothetical rendering of what NO_x emissions would have been in 2002 if no emission controls had been imposed on the utility sector. Examination of the modeled median and 95th percentile daily maximum 8-hr average ozone concentrations reveals that median ozone levels estimated for the 2004 emission scenario were less than those modeled for 2002 in the region most affected by the NO_x SIP Call. Comparison of the “no-control” with the “2002” scenario revealed that ozone concentrations would have been much higher in much of the eastern United States if the utility sector had not implemented NO_x emission controls; exceptions occurred in the immediate vicinity of major point sources where increased NO titration tends to lower ozone levels.     

“The Clean Air Act — A Time for Evaluation”

The Third Government Affairs Seminar sponsored by the Air Pollution Control Association was held in Washington, D. C. on April 16-17, 1975. The APCA South Atlantic Section was host for this very successful meeting. The General Chairman of the Seminar Committee was John V. Brink and the Program Chairman was Richard D. Grundy.

The seminar this year was conducted in three sessions. The first session, entitled “The Clean Air Act: State vs Federal Roles,” considered a topic that is receiving increasing emphasis as the national air pollution control program matures. This discussion was chaired by M. Barry Meyer, Chief Counsel and Chief Clerk, Senate Committee on Public Works.

The second session was “Land Use Planning Aspects of the Clean Air Act—Federal, State and Regional Roles.” Mrs. Mary Jane Due, Chairman of the Public Land and Land Use Committee, Natural Resources Section, American Bar Association, served as Moderator of this discussion of indirect source regulations, no significant deterioration, air quality maintenance—concepts that rely heavily on comprehensive land use planning.

“Clean Air Priorities—The Need for Flexibility,” was the title of the third session which was chaired by Austin H. Phelps, Manager Corporate Air Pollution Control, Procter and Gamble Company and President of APCA. The panelists considered the question of how appropriate the standard setting mechanisms of the Clean Air Act are for the resolution of present and future problems.

In this report condensed versions of the prepared statements of the participants are presented. A more extensive summary of the Proceedings, which includes questions and answers, is available from APCA headquarters. The remarks of John R. Quarles, EPA Deputy Administrator, who was the luncheon speaker, were summarized in the June APCA Journal(p. 642).