A Dynamic Air Resource Management Program,City of Chicago

A review of air pollution control activities since 1881, and the current needs to change from a smoke abatement to an air resource management program are presented. The rapid and dynamic transition made by the City of Chicago since 1962 in its air pollution control activities are explored in terms of organizational changes, training of professional and nonprofessional personnel, ambient air quality measurements, emission inventory of commercial and industrial operations directed toward issuance of certificates of operation, evaluation of health effects and materials damage, modifications to the municipal code, and the interrelationship of air pollution control activities with urban planning and the regional complex. The multidiscipline Public Health Service, Division of Air Pollution, Technical Assistance program initiated in October 1962, and planned for a period of five years, is discussed. The achievements, particularly since 1962, in the many faceted Chicago air resource management program together with some of its longrange plans are delineated.     

Evaluation of Risks from Urban Air Pollutants in the Southeast Chicago Area

Region V of the U.S. Environmental Protection Agency has conducted a comprehensive study of cancer risks from urban exposure to air pollutants in the Southeast Chicago area. This study estimated emissions of a list of 30 air carcinogens from a broad range of nontraditional, as well as traditional, source types. Using dispersion modeling and applying the appropriate unit risk factors and population data, this study estimated the risks at each receptor location and the total number of cancer cases attributable to air pollution in the area.

This analysis estimated that current concentrations would cause 77 cases of cancer over the next 70 years, an average risk of 2.0 × 10^?4. Contributions from different source types and different pollutants were estimated. The total contribution from nontraditional source types was less than 0.3 percent. Although these estimates are highly uncertain, the study does suggest the nature and general magnitude of cancer risks from air pollution in the urban area studied.     

The Air Resource Management Concept

The air resource management concept is defined and delineated. Existing successful urban air resource management programs are described. The federal role in this development is briefly noted. The broad or essential keys to a successful program involve the development of an active public policy on air conservation, a dynamic organization with active support by top management, and the use of long-range planning by the program director to attain the community’s realistic goals for air quality.     

Public Awareness and Concern with Air Pollution in the St. Louis Metropolitan Area

The public attitudes survey involving St. Louis City, St. Louis County, and Madison and St. Clair Counties, Illinois, was completed and published in the fall of 1964. A total of 1002 respondents gave needed information for the development of an acceptable abatement program. Substantial proportions from the study area expressed the view that they have had some negative reaction to the quality of the air. These respondents indicated that air pollution meant, primarily, odor and smoke with residents of some localities indicating other significant elements. The interviewed persons felt that factories and businesses were the prime causal agents in the existence of air pollution. Over 90 percent of all respondents felt that some governmental agency should do something about air pollution in the St. Louis area, with some bi-state metropolitan agency being the principal choice. The residents also expressed a willingness to pay minimal tax support for such a program. Indications as to the significance of air pollution in a general problems context, difference in attitudes between sub-sections of the study area, and more detailed analysis of the problem, its causes, and possible cures are contained in the study r     

Simulating Urban-Scale Air Pollutants and Their Predicting Capabilities over the Seoul Metropolitan Area

Abstract

Urban-scale air pollutants for sulfur dioxide, nitrogen dioxide, particulate matter with aerodynamic diameter >10 μm, and ozone (O₃) were simulated over the Seoul metropolitan area, Korea, during the period of July 2-11, 2002, and their predicting capabilities were discussed. The Air Pollution Model (TAPM) and the highly disaggregated anthropogenic and the biogenic gridded emissions (1 km × 1 km) recently prepared by the Korean Ministry of Environment were applied. Wind fields with observational nudging in the prognostic meteorological model TAPM are optionally adopted to comparatively examine the meteorological impact on the prediction capabilities of urban-scale air pollutants. The result shows that the simulated concentrations of secondary air pollutant largely agree with observed levels with an index of agreement (IOA) of >0.6, whereas IOAs of ～0.4 are found for most primary pollutants in the major cities, reflecting the quality of emission data in the urban area. The observationally nudged wind fields with higher IOAs have little effect on the prediction for both primary and secondary air pollutants, implying that the detailed wind field does not consistently improve the urban air pollution model performance if emissions are not well specified. However, the robust highest concentrations are better described toward observations by imposing observational nudging, suggesting the importance of wind fields for the predictions of extreme concentrations such as robust highest concentrations, maximum levels, and >90th percentiles of concentrations for both primary and secondary urban-scale air pollutants.     

Contribution of Liquefied Petroleum Gas to Air Pollution in the Metropolitan Area of Mexico City

ABSTRACT

An estimation of hydrocarbon emissions caused by the consumption of liquefied petroleum gas (LPG) in the Metropolitan Area of Mexico City (MAMC) is presented. On the basis of experimental measurements at all points of handling, during the distribution process, and during the consumption of LPG in industrial devices and domestic appliances, an estimated 76,414 tons/year are released to the air. The most important contribution is found during the domestic consumption of LPG (70%); this makes the control initiatives available to the consumer. By developing a control program of LPG losses, a 77% reduction in emission is expected in a 5-yr period.

The calculated amounts of LPG emissions when correlated with the consumption of LPG, combined with information from air samples from the MAMC, do not point to LPG emissions as the most important factor contributing to tropospheric ozone in the air in Mexico City.     

Oxidant Trends in the Detroit Metropolitan Area

This report reviews the interpretation and measurement of visibility. The selection of 1) variables that appropriately characterize visibility and 2) instruments that measure these variables must be integrated with our understanding of what happens when a person views distant scenes. The process by which we see distant objects is based on characteristics of the object, its surrounding, the air quality and the illumination of the sight path, and the eye and the brain. Additionally, visibility is an integrative parameter in that the ability to “see” depends on all types of aerosol in the atmosphere as well as on all aerosol contained in the sight path. When establishing a standard, some consideration should be given to choosing a variable which is representative of that quality of the environment that requires protection as well as a variable which can be monitored directly. Classically, visibility has usually been interpreted as visual range, which, roughly speaking, is the distance an observer would have to back away from a target before it disappears. Visual range cannot be measured directly nor is it necessarily representative of what an observer “sees.” A documentation of target contrast (either with the sky or another object) or color and color change may be a better way to characterize visibility. Contrast and color change can be monitored directly and both depend on integrative long-path measurements.     

Mesoscale Air Pollution Transport in the Chicago Lake Breeze

A two-day field program in Chicago studied mesoscale pollution transport during typical lake breezes. Streamlines calculated from serial pibal data suggest that a nearly closed circulation cell traps pollutants emitted near a shore line. Optically tracked tetroons confirm the helical trajectory of air within the lake breeze regime. Pollutants released within the inflow layer move inland, rise in a narrow zone of updrafts (100 cm/sec) at the lake breeze front, advect lakeward in the return flow layer aloft, and then subside back down into the inflow layer. Pollution then fumigates back to the surface as the air returns inland a second time causing concentrations higher than would otherwise be expected. Spectral aerosol measurements (0.5-3.0 and 7.0-9.0 micrometer size ranges) made by an instrumented aircraft reveal a marked particle size sorting.     

Fuel reformulation in the Metropolitan Area of Mexico City

Two models frequently used to simulate the dispersion of pollutants in the atmosphere have been compared. This is necessary because only a well-tested and well-calibrated simulation model can be a good representation of the reality of the dispersion of pollutants. The models evaluated (HYSPLIT_4 with its four variants and MEDIA) were run using as input parameters the same meteorological dataset (for 23-26 October 1994) from the French model ARPEGE. The following statistical criteria were compared: the space and time evolution of the pollutant cloud; the variation of statistical parameters in time and space; and the differences between the simulated and measured values of concentration in time for six different stations. The results emphasise the characteristics of the two models and their abilities in the framework of the air quality monitoring.     

Atmospheric Factors Influencing Daily Sulfate Concentrations in Chicago Air

Abstract

Confidence interval construction for central tendency is a problem of practical consequence for those who must analyze air contaminant data. Determination of compliance with relevant ambient air quality criteria and assessment of associated health risks depend upon quantifying the uncertainty of estimated mean pollutant concentrations. The bootstrap is a resampling technique that has been steadily gaining popularity and acceptance during the past several years. A potentially powerful application of the bootstrap is the construction of confidence intervals for any parameter of any underlying distribution. Properties of bootstrap confidence intervals were determined for samples generated from lognormal, gamma, and Weibull distributions. Bootstrap t intervals, while having smaller coverage errors than Student's t or other bootstrap methods, under-cover for small samples from skewed distributions. Therefore, we caution against using the bootstrap to construct confidence intervals for the mean without first considering the effects of sample size and skew. When sample sizes are small, one might consider using the median as an estimate of central tendency. Confidence intervals for the median are easy to construct and do not under-cover. Data collected by the Northeast States for Coordinated Air Use Management (NESCAUM) are used to illustrate application of the methods discussed.     

Note On The Use of Law Students as an Air Management Resource

Abstract

In this research, pilot-scale trickle bed biofilter systems have been analyzed to determine their effectiveness in controlling toluene in waste gas streams. These studies evaluated two synthetic microbial attachment media—a monolithic channelized medium and a pelletized ceramic medium. Operational parameters considered included toluene loading, empty bed residence time (EBRT), temperature, and long-term operation. The channelized medium provided 99% removal efficiency for a toluene loading of 0.725 kg COD/m³-day during the initial stages. However, continuous operation resulted in reduced and erratic efficiencies, due to air channeling caused by random plugging. After biomass accumulated within the channels and was subsequently removed by hosing, performance of the channelized medium never regained the previous levels. Similarly, the pelletized medium exhibited consistently good performance until the accumulation of excess biomass in the medium interstices also caused overall performance to deteriorate.

Implementation of a suitable backwashing strategy for biomass control was achieved for the pelletized medium by using full medium fluidization. This strategy permitted long-term operation of the biofilter at a toluene loading of 2.27 kg COD/m³-day and 1 minute EBRT, with efficiencies consistently over 99% and no appreciable back-pressure development between successive periods of backwashing.     

Variability of Ozone Air Quality Indicators in Selected Metropolitan Statistical Areas

This article analyzes numerical variability In ozone air quality data to understand how this variability affects the number of violations seen each year in metropolitan statistical areas (MSAs). Three commonly cited violation indices are used: 1) the annual number of expected exceedances averaged over 3 years is greater than 1; 2) the n+ 1th hourly value in n years of data is greater than 0.12 ppm; and 3) the annual number of expected exceedances is greater than 1. Only the first index is consistent with applicable regulations. The analyses indicate that about 23 percent of all MSAs with valid data had one or more change In their ozone violation status between 1979 and 1987. This change in status occurred for approximately 7 percent of all MSA-years of available data. This statistic was about one-third of the value usually obtained when the two incorrect, but commonly used, criteria of ozone violations are used.     

Hazardous air pollutants from mobile sources in the Metropolitan Area of Mexico City

Environmental agencies are currently in the process of implementing a new air management program, which includes the improvement of fuel quality. In this work, exhaust emissions data and estimated relative risk for various fuels testing in-use vehicles, equipped with three different exhaust emission control technologies, are presented. Aromatics, sulfur, and olefins contents; type of oxygenated compound; and Reid vapor pressure were varied. The aim also includes calculating the ozone (O3) forming potential and a relative cancer risk of emissions from current and formulated gasoline blends in Mexico. The proposed gasoline decreases carbon monoxide, total hydrocarbons (THC), and nitrogen oxides emissions by 18 and 14%, respectively, when compared with gasoline sold in the rest of the country and within ozone nonattainment metropolitan areas in Mexico, respectively.     

Water management for a megacity: Mexico City Metropolitan Area

The paper presents an overview of the present situation of the Mexico City Metropolitan Area (MCMA). The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices, to become sustainable. The MCMA is one of the most rapidly growing urban centers of the world, with a population of about 21 million people, a very high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, successive governments have focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of USD and the construction of major infrastructure projects for interbasin water transfer. Environmental, economic and social policies associated with water management are mostly inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socioeconomic conditions of a population living in one of the largest urban agglomerations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far.     

Determination of Motor Vehicle Profiles for Non-Methane Organic Compounds in the Mexico City Metropolitan Area

ABSTRACT

Non-methane organic compound (NMOC) profiles for on-road motor vehicle emissions were measured in a downtown tunnel and parking garages in Mexico City during 1996. Hydrocarbon samples from the tunnel and ambient air samples (C2-C12) were collected using stainless steel canisters, and carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated cartridges. Canister samples were analyzed by gas chromatog-raphy/flame ionization detection (GC/FID) to ascertain detailed hydrocarbon composition. DNPH samples were analyzed by high performance liquid chromatography (HPLC). NMOC source profiles were quantified for evaporative emissions from refueling, cold start, and hot soak, and on-road operating conditions. The ultimate purpose will be to determine the apportionment of ambient NMOC concentrations using the Chemical Mass Balance (CMB) model. The tunnel profile contained 42.3 ppbC% of alkanes, 20.6 ppbC% of unsaturated compounds, and 22.4 ppbC% of aromatics. The most abundant species were acetylene with 7.22 ppbC%, followed by ipentane with 5.69 ppbC%, and toluene with 5.42 ppbC%. These results were compared with those from studies in the United States. The cold start profile was found to be similar to the tunnel profile, although there were differences in the content of acetylene, isopentane, and oxygenates. The abundance of saturated NMOC in the hot soak profile was similar to gasoline head space profiles; it was also much larger than saturated NMOC in the roadway profile.     

Source apportionment of PM2.5 for supporting control strategies in the Monterrey Metropolitan Area,Mexico

The Monterrey Metropolitan Area (MMA) in Northeast Mexico has shown high PM_2.5 concentrations since 2003. The data shows that the annual average concentration exceeds from 2 to 3 times the Mexican PM_2.5 annual air quality standard of 12 µg/m³. In a previous work we studied the chemical characterization of PM_2.5 in two sites of the MMA during the winter season. Among the most important components we found ammonium sulfate and nitrate, elemental and organic carbon, and crustal matter. In this work we present the results of a second chemical characterization study performed during the summer time and the application of the chemical mass balance (CMB) model to determine the source apportionment of air pollutants in the region. The chemical analysis results show that the chemical composition of PM_2.5 is similar in both sites and periods of the year. The results of the chemical analysis and the CMB model show that industrial, traffic, and combustion activities in the area are the major sources of primary PM_2.5 and precursor gases of secondary inorganic and organic aerosol (SO₂, NOx, NH₃, and volatile organic compounds [VOCs]). We also found that black carbon and organic carbon are important components of PM_2.5 in the MMA. These results are consistent with the MMA emission inventory that reports as major sources of particles and SO₂ a refinery and fuel combustion, as well as nitrogen oxides and ammonium from transportation and industrial activities in the MMA and ammonium form agricultural activities in the state. The results of this work are important to identify and support effective actions to reduce direct emissions of PM_2.5 and its precursor gases to improve air quality in the MMA. Implications: The Monterrey Metropolitan Area (MMA) has been classified as the most air-polluted area in Mexico by the World Health Organization (WHO). Effective actions need to be taken to control primary sources of PM_2.5 and its precursors, reducing health risks on the population exposed and their associated costs. The results of this study identify the main sources and their estimated contribution to PM_2.5 mass concentration, providing valuable information to the local environmental authorities to take decisions on PM_2.5 control strategies in the MMA.