Urban Development in Air Pollution Basins: An Appeal to the Planners for Help

The air basin between the Mississippi River and the bluff in Illinois is of particular interest for this report. The autumnal temperature profiles were measured by a wiresonde. Each day through September and October had an inversion at dawn and/or dusk. During the entire three months, inversions 5° or more occurred at dawn 64% of the mornings, those 10° or more occurred 45% of the mornings; and those 15° occurred 23% of the mornings. Under intense inversions, the topography holds cool air in the basin like water in a saucer, and currents within this 200-ft air layer comprise a quasi-closed circulation system. A frequent pattern of air circulation involves a northwestward surface drift in the basin, with a southwest wind aloft and an updraft over St. Louis. This forms a horizontal semi-vortex along the river, concentrating the heavier particulates near East St. Louis and Granite City. Multiple evidence showed this pattern to exist one morning among four. Business interests would use the basin for industrial expansion, but air resource planners prefer to keep new air pollution sources out of this low land.     

A Method for Checking Instrument Performance at Remote Sampling Sites

This paper describes a quality control technique used by the central headquarters operation of the Continuous Air Monitoring Program in an ejjort to insure valid data production from instruments located at remote sampling stations.

The procedure consists of preparation of 0.10 to 2.00 ppm mixtures of SO₂ or NO₂ in duplicate Mylar bags, each encased in a corrugated paper box.

These mixtures are analyzed during make-up to insure duplication. One box is shipped to the field station where it is analyzed on-site. The control mixture is analyzed in the central lab at the same time. Correlation between measurements indicates the usefulness of this dynamic calibration check.

The techniques used are described and results of the program are presented.     

Dynamic Calibration of an Acid Aerosol Analyzer

A method is described for dynamic calibration of an acid aerosol analyzer based on a commercial modification of the Thomas Autometer and manufactured by the Instrument Development Company. This automated instrument removes acid aerosol from an air stream by sonic impaction, and the sulfuric acid collected is determined conductometrically. An all-glass aerosol generator based on the reaction of water vapor with sulfur trioxide vapor released from fuming sulfuric acid was built for the calibration. Air samples were withdrawn for instrument calibration before and after the concentration of the acid aerosol was determined by titration. The apparent particle size as determined by an Andersen sampler ranged from 2.0 microns to less than 0.68 micron and exhibited a sharp peak with mass median diameter at 1.3 microns in the distribution curve. The size of the aerosol, within certain limits, could be controlled by humidity. Data indicated a linear response with an aerosol collection efficiency of 80 percent in the important respirable size range.     

Visibility and Mass Concentration in a Nonurban Environment

Considerable interest is currently directed toward atmospheric visibility and its relationship to particle size and mass concentration. Previous work has been limited to heavily polluted urban areas, and visibility studies have not included particle size characterization. An air sampling program was carried out in a nonurban, low pollution area to relate: (a) total particulate mass concentration measured with a high-volume sampler, (b) particulate mass size distribution measured with aerodynamic size selective samplers, and (c) visual range measured by the integrating nephelometer. For low suspended particulate mass concentrations, the following relationship was defined between visual range (L_v) and mass concentration (M ? μg/m³):     

Sulfur Dioxide Emission Limitation (Sdel) Program at Tva Power Plants

TVA is conducting a program of intermittent control of SO₂ emissions at nine of its coal-fired power plants.The program is designed to limit SO₂ emissions by reducing generation during adverse atmospheric conditions to avoid exceeding ambient SO₂ standards. Each is identified as a Class I or Class II program—based primarily on its design and operational complexity. The four Class I programs (Paradise, Cumberland, Allen, Gallatin) operate 7 days/week from early morning through mid-afternoon. The five Class II programs (Kingston, Widows Creek, Colbert, Johnsonville, Shawnee) operate 24 hours/day and 7 days/week. Environmental data stations (EDS) are located at each plant site; the staff has the responsibility for the collection and validation of the onsite meteorological data, the SO₂ mobile and fixed monitoring network data, the plant operational data, and the meteorological forecast data from the Meteorological Forecast Center in Muscle Shoals, AL. At the EDS, the data are entered into a computer operating model for scheduling plant generation reductions.     

Response

ABSTRACT

The Las Vegas Valley PM₁₀ Study was conducted during 1995 to determine the contributions to PM₁₀ aerosol from fugitive dust, motor vehicle exhaust, residential wood combustion, and secondary aerosol sources. Twenty-four-hr PM₁₀ samples were collected at two neighborhood-scale sites every sixth day for 13 months. Five week-long intensive studies were conducted over a middle-scale sub-region at 29 locations that contained many construction projects emitting fugitive dust. The study found that the zone of influence around individual emitters was less than 1 km. Most of the sampling sites in residential and commercial areas yielded equivalent PM₁₀ concentrations in the neighborhood region, even though they were more distant from each other than they were from the nearby construction sources. Based on chemical mass balance (CMB) receptor modeling, fugitive dust accounted for 80–90% of the PM₁₀, and motor vehicle exhaust accounted for 3–9% of the PM₁₀ in the Las Vegas Valley.     

A Regujatory Framework for Setting Air Emission Limits for Noncriteria Pollutants

The information presented in this paper is concerned with the effects of ambient ozone on crop yield reduction and the resultant economic losses. Yield data for nine crops within the South Coast Air Basin (SCAB) of California were obtained for the 12-year period, 1964 through 1975. Ozone concentrations, temperature, precipitation, and relative humidity data were related to the yields by using regression models. Estimated yield reductions due to ozone for 1975, varied from zero to 57% depending on crop and location. Economic welfare losses calculated from the yield reductions were $57.3 and $45.7 million for producer’s and consumer’s surplus, respectively. The total loss from ozone to agriculture related economic sectors determined by input-output analysis was $276 million in the SCAB and $36.6 million in the remainder of the state.     

Relationships between Aerosol Extinction Coefficients Derived from Airport Visual Range Observations and Alternative Measures of Airborne Particle Mass

Epidemiological assessments of population exposures to airborne particles are often hampered by the scarcity of available fine particle mass measurements. In an attempt to overcome this serious problem, we analyze In this paper methods for predicting fine particle (M ₁) and Inhalable particle (IP) mass concentrations using relative humidity corrected light extinction coefficient (b _ext) estimated from airport visual range (V _r) observations. The analyses presented are based on theoretical determinations as well as statistical investigations utilizing EPA's NASN and Inhalable Particle Monitoring Network (IPMN) data bases and routine airport visual range observations In twelve large U.S. cities. Our results Indicate that, after controlling for certain limitations of airport visual range data, most of the regression models developed in this paper can be applied satisfactorily to predict M _t and IP. Furthermore, our findings Indicate that a more representative formula than the commonly used meteorological range formula to predict atmospheric b _ext values in urban areas may be b _ext = (1.8 ± 0.04)/V _r. Because of known local or regional influences, however, we do suggest calibration of any predictive model which utilizes airport visibility data against site-specific aerometric data on particle mass concentrations or scattering coefficient measurements.