Showing papers on "Air pollutant concentrations published in 1977"

A Case Study of Stratospheric Ozone Affecting Ground-Level Oxidant Concentrations

Abstract: During the predawn hours of 19 November 1972, the air pollution monitoring station at Santa Rosa, Calif., recorded five consecutive hours of oxidant concentrations in excess of the present National Ambient Air Quality Standard. The highest of the hourly averages was 0.23 ppm. From a detailed analysis of the meteorological conditions surrounding this incident, it is shown that the ozone responsible for the anomalous concentrations originated in the stratosphere and not from anthropogenic sources.

Burdens due to noise and air pollution in residents of areas near streets with heavy traffic

Abstract: The residents of different streets with varying traffic density and building density were questioned about annoyance due to traffic noise and air pollution. Frequency and extent of annoyance felt, effects of immissions on such living aspects as recreation, or communication, and also the reactions to the disturbance felt (such as closing windows and taking sleeping pills) were investigated. Noise levels as well as particulate matter and gaseous air pollutant concentrations were measured along the streets under investigation. The evaluation of 1300 questionaires showed that reactions to noise were different in different quarters although noise levels were the same. In general, about 40% of residents were heavily disturbed during daytime when the noise level Leq was around 65 dB(A); while for the same noise level at night about 55% reported to be heavily disturbed. Strong correlations were also obtained between annoyance due to noise and that due to air pollution. The results show that annoyance felt is dependent not only on the measured noise levels and/or air pollution concentrations, but that there do exist interactions between the residential quarters and annoyance. These interactions should be considered while fixing the limits and standards.

Developing regulatory programs for the control of acid precipitation

Abstract: The U.S. Clean Air Act provides mechanisms by which the public welfare may be protected from ‘any known or anticipated adverse effects associated with the presence of (an) air pollutant in the ambient air’. The history of the U.S. Environment Protection Agency's (EPA) efforts to establish and defend a secondary ambient air quality standard for S oxides is reviewed. The role of acid rain in producing ‘welfare effects’ is described. Emphasis is given to the fact that a wide range of effects not simply limited to forest vegetation must be considered when designing pollution control programs. The possible effects of ignoring acid rain in developing control strategies to meet health related standards for S oxides, N oxides and particulates are mentioned. Researchers need to be aware of the kinds of information which are needed by regulatory agencies before a regulatory program can be designed for alleviating the threat. Concern and speculation are not adequate. Accurate dose-response information and cumulative damage estimates are needed to quantify the effects of acid rain. Of vital importance are: (1) discovery of pollutant concentrations, mechanisms, and atmospheric conditions which lead to harmful effects: and (2) identification of major sources of the pollutant. The effect such information could have on techniques for meeting groundlevel air-quality standards such as tall stacks and Intermittant Control Systems (ICS) is discussed. The desirability of an integrated research effort in this area to answer these needs is stressed. EPA efforts in this regard are mentioned.

Air quality impact of aircraft at 10 usaf bases

Abstract: The contributions of Air Force aircraft to ambient air quality at 10 major bases were predicted from operational data using a computerized Gaussian dispersion technique. Annual arithmetic mean concentrations are presented for common air pollutants. The predictions are well below National Ambient Air Quality Standards for those pollutants with standards specified as annual averages. Hourly worst case predictions were converted to Pollutant Standards Index (PSI) values. Aircraft sources produced average PSI values of 4.9 for nitrogen dioxide, 2.1 carbon monoxide, 1.9 for total suspended particulates, and 1.4 for sulfur dioxide. The PSI scale ranges from 0 to 500 with 100 designated as the level above which health effects may occur. A PSI for hydrocarbons could not be computed since direct health effects have not been observed and indirect effects through oxidant formation could not be predicted within the scope of this analysis. The relative significance of pollutants emitted by AF aircraft indicated by this report is (from most significant to least significant): hydrocarbons, oxides, or nitrogen, particulate matter, carbon monoxide, and sulfur oxides. This ordering can be used as a guide to future design priorities and control strategy development.

Formation and Control of Air Pollutants

Abstract: Air pollutants are those substances—gases, mists, and particulate aerosols—which are present in the atmosphere in such concentrations that they can adversely affect man and his environment. Most of these substances—sulfur dioxide, the oxides of nitrogen, and many others—are naturally present in the atmosphere in low (background) concentrations. They are produced in nature, as well as from anthropogenic sources, and generally the natural background concentrations are such as to be harmless. Indeed, they may play a vital part in the natural cycles of growth and decay. Unusually high natural concentrations do occur; examples being methane (as “marsh gas”) and hydrogen sulfide from geothermal sources, but these are exceptional circumstances. So when we refer to air pollutants we consider these to be those in relatively high concentrations (compared with background values) which result from the chemical and biological processes used by man. Most notable among these are fuel combustion—for heating cooking and industrial processing—and the generation of electricity.

Environmental protection agency aircraft emissions standards

Abstract: Emissions of air pollutants from aircraft were investigated in order to determine: (1) the extent to which such emissions affect air quality in air quality control regions throughout the United States; and (2) the technological feasibility of controlling such emissions. The basic information supporting the need for aircraft emissions standards is summarized. The EPA ambient air quality standards are presented. Only the primary (health related) standards are shown. Of the six pollutants, only the first three, carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides, are influenced significantly by aircraft.