Long Range Cloud Diffusion in the Lower Atmosphere

Previous attempts to measure heavy metals in air are discussed with particular reference to lead. A polarographic method was developed for lead in air samples taken on glass fiber sheet. Using this method, the distribution of lead across the glass fiber sheet was investigated, and within experimental error, found to be uniform. Air samples from 18 Ontario cities, previously analyzed for benzo [a]pyrene content were analyzed.     

A Multipurpose Flare Stack for Control of Chemical Process Wastes

Abstract

To test the effectiveness of California’s vehicle inspection/ maintenance (I/M) program, exclusive of vehicle-owner intervention, a fleet of more than 1,100 vehicles that previously had failed California’s Smog Check test were sent to randomly selected Smog Check stations in the Los Angeles area for covert inspections and repairs. The two-speed idle test was used for repairs. For those vehicles that were repaired at the first inspection, their FTP emission reductions were 25%, 14%, and 11% for hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NO_x), respectively, although emissions testing for NO_x was not performed at the Smog Check stations. Idle HC and CO emissions increased for 35% and 43% of the vehicles, respectively, after repairs. This data set shows that most vehicles that fail the Smog Check inspection are only marginal emitters, with 61% and 44% of the total potential for HC and CO emission reductions, respectively, coming from only 10% of the vehicles that currently fail the inspection. When the vehicles were rank-ordered by idle emissions from dirtiest to cleanest, emission reduction costs for the highest-emitting 10% of the fleet averaged $l,100/ton and $250/ton for HC and CO, respectively, attributing all the costs to each pollutant exclusively. For the remaining vehicles, costs increased dramatically.     

Effects of Vertical Temperature Difference on Soiling Index

Changes in contaminant levels at monitoring stations do not necessarily represent changes in emission levels, since variations in meteorological parameters determine the transport and diffusion of contaminants between sources and receptors. To estimate annual changes in emission levels, and thus of control program effectiveness, the meteorological stratification of data was employed to provide “comparable days.”

For San Francisco Bay Area photochemical oxidant data, simple criteria based on maximum temperature and on height of inversion base were selected. Temperature provided a readily available integrated index of solar energy input and of ventilation, while the inversion data added a vertical dilution factor.

An earlier study, employing only the temperature criteria, showed that oxidant levels on comparable warm days had nearly doubled from 1954 through 1962. The current study of oxidant data for 1962 through 1969 shows a gradual rise through 1965, and a sharp reversal in 1966, when for the first time a simultaneous decrease was noted at each benchmark station. Data through 1969 show that average oxidant levels have been maintained at this 25% lower plateau, with minor fluctuations at individual stations.

The general improvement in air quality since 1965 is attributed to the reduction of reactive organics emitted from stationary and automotive sources.     

Platitudes or Performance?

Industry, government, and the public have come a long way in establishing the dialogue that is necessary if the reservations each has had of the others’ motives are to be dispelled. However, each tends to fall into a routine of accusations, charges, counter charges, and rebuttals. This paper deals with the action which must be forthcoming from industry if good community relations are to be maintained and the public interest is to be served.     

Air Pollution Aspects of Soap and Detergent Manufacture

Informative Report No. 8 on soap and detergent manufacture is one of a series of survey reports prepared by APCA’s Tl-2 Committee on air pollution problems and control methods encountered in the chemical industry today.     

The Effect of Fuel Composition on Atmospheric Aerosol Due to Auto Exhaust

Aerosols attributable to automobile exhaust can be classified as two types—primary aerosol (initially present in the exhaust) and secondary aerosol (generated photochemically from hydrocarbons and nitrogen oxides in the exhaust). In this study, investigation was made of possible effects of motor-fuel composition on the formation of these aerosols. Secondary aerosol, of principal interest in this work, was produced by irradiating auto exhaust in Battelle-Columbus’ 610 ft³ environmental chamber. A limited number of determinations of primary aerosol in diluted auto exhaust was made at the exit of a 36 ft dilution runnel. Determination of both primary and secondary aerosol was based on light-scattering measurements.

Exhaust was generated with seven full-boiling motor gasolines, both leaded and nonleaded, in a 1967 Chevrolet which was not equipped with exhaust-emission control devices. Changes in fuel composition produced a maximum factor of three difference in light scattering due to primary aerosol. Aerosol yields, for consecutive driving cycles on the same fuel, vary considerably; as a result, ranking the fuels on the basis of average primary aerosol yield was not very meaningful. In addition to fuel composition, the more important independent variables are initial SO₂ concentration, relative humidity and initial hydrocarbon concentration. Statistical analysis of the data indicates that the seven test fuels can be divided into two arbitrary groups with regard to secondary aerosol-forming potential. The fuels in the lower light-scattering group had aromatic contents of 15 and 21%, while those in the higher light-scattering group had aromatic contents of 25, 48, and 55%. Although the fuels can be grouped on the basis of a compositional factor, the grouping of fuels with aromatic content ranging from 25 to 55% indicates that this compositional factor cannot be equated simply with aromatic content. In an associated study of the aerosol-forming potential of individual hydrocarbons prominent in auto exhaust, it was observed that aromatics produce substantially more photochemical aerosol than olefins and paraffins. However, experiments with binar/hydrocarbon mixtures containing aromatjcs, as well as in these exhaust experiments, a strong dependence of aerosol yield on the aromatic components is is not observed. Thus, the data indicate that the dependence of secondary aerosol formation on fuel factors is a complex one and cannot be predicted solely on the basis of a sirigle hydrocarbon component reactivity scale.

The two types of automobile aerosol did not have the same dependence on fuel, composition. The variation in total light scattering attributable to primary plus secondary aerosol was less than that due to either component alone. It therefore was concluded that the light scattering due to automobile exhaust emissions in these experiments was not significantly affected by changing fuel composition.     

Real Time Measurement of the Size Distribution Of Particulate Matter by a Light Scattering Method

The body of information presented in this paper is directed to those individuals concerned with the measurement of the size distribution of particulate matter in air. The light scattering instrument described herein is characterized by the fact that it can accurately size particles almost independently of their index of refraction. The basic concept involves the simultaneous measurement of the intensity of light scattered by a single particle at two small scattering angles. The ratio of the two intensities is directly related io ine size of ihe pariicle, and for scattering angles of 5° and 10° the effective range of the instrument is 0.2 to 4 μm. The air flows through the optical system at such a rate that approximately 25 μs are required to determine the size of each particle, and concentrations as high as 10⁴ particles/cc can be measured without dilution and without serious coincidence effects. By employing a multichannel analyzer as the data storage and readout device it is possible to detect changes in particulate size distribution within a few seconds. Calibration of the instrument has been performed using polystyrene latex spheres and materials having a wide range of index of refraction and shape including carbon black, iron oxide and spores.     

Welcome

Abstract

An indicator of solid waste generation potential (SWGP) is proposed as a versatile means to assist the development of integrated solid waste (SW) management plans. The proposed indicator is based on key sodoeconomic variables for the State of Illinois which were found to be highly correlated with variables describing the SW stream of the State. The proposed indicator was derived by applying the principal components analysis (PCA) technique. The technique is used to merge the rank transformed socioeconomic variables into a single variable, the SWGP indicator, while maintaining the regional information of the original variables. An innovative aspect of this indicator approach is the use of the ordinal scale for all these diverse variables. The validity of this approach was assessed and the proposed indicator was found to be directly proportional to a composite variable describing the SW stream for the State of Illinois. The use of Geographic Information Systems (GIS) to depict the spatial distribution of the SWGP will help planners visualize the expected overall refuse generation pattern and to identify critical regions. In addition, the proposed indicator could be used as an instrument to validate the solid waste generation (SWG) quantities reported by counties to state agencies.     

long Term Goals for Environmental Control— What’s Desirable and Possible in the Year 2000?

A panel discussion looking forward to the environment in the year 2000, was arranged by Lionel V. Baldwin, Program Chairman for APCA’s 67th Annual Meeting. To provide a lofty introduction of the subject he reached into outer space for a moderator—Captain Walter M. Schirra, one of the original astronaut team.