Standards for Air Quality in California

Abstract

During the 1950s and 1960s, hundreds of thousands of underground storage tanks (and above-ground storage tanks) containing petroleum products and hazardous chemicals were installed. Many of these tanks either have been abandoned or have exceeded their useful lives and are leaking, thereby posing a serious threat to the nation’s surface and groundwater supplies, as well as to public health. Cleaning up releases of petroleum hydrocarbons or other organic chemicals in the subsurface environment is a real-world problem,

Biological treatment of hydrocarbon-contaminated soil is considered to be a relatively low-cost and safe technology; however, its potential for effectively treating recalcitrant wastes has not been fully explored. For millions of years, microorganisms such as bacteria, fungi, actinomycete, protozoa, and others have performed the function of recycling organic matter from which new plant life can grow.

This paper examines the biological treatment technology for cleaning up petroleum product-contaminated soils, with special emphasis on microbial enzyme systems for enhancing the rate of biodegradation of petroleum hydrocarbons. Classifications and functions of enzymes, as well as the microbes, in degrading the organic contaminants are discussed. In addition, the weathering effect on biodegradation, types of hydrocarbon degraders, advantages associated with enzyme use, methods of enzyme extraction, and future research needs for development and evaluation of enzyme-assisted bioremediation are examined.     

Air Quality Standards National And International

The advantages and disadvantages of establishingworldwide air quality standards are reviewed. Inter-national standards would represent the best and mostadvanced procedures and might lead to improvementin standards in some countries where air quality isfar from adequate. International standards alsowould permit accurate comparisons of air pollutionamong countries and would provide a sound basis forcombatting pollution.     

Selected International Receptor-Based Air Quality Standards

Abstract

The ambient air quality standards (AAQS) of twenty-one nations for eight commonly regulated substances are presented. Many countries are adding a receptor-based component to their air quality management, which traditionally have been emission oriented. Automation of air quality monitoring stations has meant that local air quality evaluation can now be more easily achieved. However, a majority of countries have no active air quality standards (emission or receptor-based) or ambient air quality monitoring. One possible monitoring procedure is outlined and the variation in international standards is discussed.     

Air Quality Standards for Fluoride Vegetation Effects

Facts that must be taken into consideration in developing fluoride standards for vegetation effects include: (1) Fluoride is an accumulative toxicant and injury is usually associated with long-term exposure; (2) gaseous and particulate fluorides differ in their phytotoxicity; (3) plant species and varieties differ greatly in susceptibility to fluoride; (4) extremely low concentrations can cause damage to sensitive species. Three possible approaches to standards are discussed: Atmospheric fluoride concentration, vegetation fluoride concentration, and the presence of leaf necrosis or chlorosis. Atmospheric fluoride concentration has the advantage that it fits the conventional concept of standards and that it is objective. Accurately measuring low fluoride concentrations, separating gaseous from particulate fluorides in the air sample, and establishing a safe concentration present technical problems, however. Vegetation analysis may more closely represent fluorides available to affect the plant. The presence of significant amounts of fluoride-induced leaf necrosis (e.g., 3% of the leaf area) may be the most practical approach to standards for fluoride vegetation effects. Advantages are that the combined effects of the forms of fluoride, species and varieties, and concentration-time relationships are all manifest in the factor that is measured. Relatively little time is required to examine the vegetation in a large area and only 2 or 3 surveys a year are required.     

An Approach to Air Quality Management Standards

The Clean Air Amendments of 1970 impose a stringent set of uniform air quality standards and a rigid timetable for achieving them. Such an approach is open to serious question, since it fails to take account of variations in relevant local conditions. This paper sketches a proposal for a more realistic approach to air quality. It suggests a program of management standards that would reflect the needs and circumstances of particular regions. An institutional framework is outlined that would consider the technical, economic, and social constraints that determine how quickly and how much any area can improve its air quality. The framework would provide the needed flexibility, and would employ a feedback approach that avoids the need to resolve all uncertainties before any progress can be made. At the same time, it would impose a timetable and planning process to assure that all feasible progress in air quality improvement is realized nationwide.     

Are We Ready for Ambient Air Quality Standards

The legal basis for the control of air pollution has progressed from nuisance law to the statutory regulation of specific substances as the sophistication of the sciences involved has progressed. But, the control of air pollution by pursuing air pollutants one by one as evidence accumulates against them seems clearly inadequate to a technology producing new pollutants at an almost geometric rate and inappropriate to the gathering body of evidence relating air pollution to health effects. To understand the need for changed control concepts it is necessary to understand the biological problem and the evidence that has been accumulated.     

Canadian Activities in Ambient Air Quality Criteria and Development of Standards

Within recent years, increasing attention has been directed to the determination of contaminant levels in urban and industrial areas involving particulate matter (dustfall, suspended matter and smoke), sulfur dioxide, hydrogen sulfide, fluorides, ozone or oxidant, oxides of nitrogen and polycyclic aromatic hydrocarbons. However, with regard to criteria and evaluation of effects, none of these pollutants has been studied as thoroughly as sulfur dioxide. Presently, three provinces in Canada have adopted acts or regulations dealing with the control of air pollution. The Ontario Act, passed in 1958 and amended in 1963 and 1964, is the most comprehensive in scope. The Damage by Fumes Arbitration Act of Ontario provides for the awarding of compensation where crops, trees or other vegetation is damaged by sulfur fumes arising from the smelting or roasting of nickel-copper ore or iron ore or from the treatment of sulfides for the production of sulfur of sulfuric acid for commercial purposes. Regulations have also been enacted in Manitoba and Alberta. A provincial act is under consideration in Saskatchewan.     

Air Quality Standards for the Protection of Farm Animals from Fluorides

The ingestion of forages contaminated with inorganic fluorides from industrial sources constitutes an air pollution problem for domestic livestock. In cattle, which have been studied most extensively, the syndrome is characterized by dental and skeletal lesions, lameness, chemical evidence of increased fluoride ingestion, and in severe cases by effects on appetite and milk production. The only practical basis for a standard appears to be one based on forage fluoride concentrations. It is concluded that a standard should protect cattle from loss of milk production and from severe dental fluorosis, but need not be set so low that the animals will be protected against any discernible deviations from normal which do not influence their general health, productive ability, or the soundness and wearing quality of their dentition. As there may be wide seasonal variations in forage fluoride concentrations, the basic standard should be expressed as a yearly average of the forage fluoride concentration. However, as the developing teeth may be adversely influenced by short periods of high exposure, the standard should contain a provision which limits both the extent and duration of time that high concentrations may be tolerated even though they are balanced by lower values at other months. Based on these criteria, a tentative standard which limits forage fluoride to an average of 40 ppm, and limits the time that forage concentrations may exceed 60 or 80 ppm F is proposed.     

Consideration of Air Quality Standards for Vegetation With Respect to Ozone

Present evidence suggests that ozone is the most damaging of all air pollutants affecting vegetation. It is the principal oxidant in the photochemical smog complex. Concentrations of ozone have exceeded 0.5 part per million (ppm) in the Los Angeles area. One-tenth of this level for 8 hours is known to injure very sensitive tobacco varieties. Many plant species are visibly affected after a few hours exposure at concentrations much lower than 0.5 ppm. There is also some evidence that ozone reduces plant growth. Many factors must be taken into account when considering standards to protect vegetation from ozone damage. These include ozone concentration and methods of measurement, time of exposure, possible additive effects of other pollutants, sensitivity of plant species, their economic value, and the extent of injury which can be tolerated. The response of a species to the pollutant is conditioned by genetic factors and environmental conditions. Lack of specific routine methods for measuring ozone in ambient air is a handicap. California and Colorado established standards for oxidants at 0.15 and 0.10 ppm, respectively, for 1 hour. How these standards relate to the ozone dosage causing acute and chronic injury to various plant species is discussed.     

A Method for Using Air Pollution Measurements and Public Opinion to Establish Ambient Air Quality Standards

Air quality was comprehensively evaluated by means of sampling at 21 locations over metropolitan Birmingham during a period of one year. Thousands of integrated samples of three common atmospheric gaseous pollutants and two common particulate pollutants were collected and analyzed. Following the year of sampling in 1964, a random household survey was completed by conducting personal interviews at more than 7200 households over metropolitan Birmingham. Statistical reduction of household survey results by census tract and by neighborhood area provided domestic fuel and waste burning emission data as well as public (resident) opinion on specific air pollution effects. The relationship between ambient air quality and neighborhood opinion of air pollution effects on health and property are evaluated statistically. Ambient standards are suggested which are based upon those air pollution levels shown to have adverse effects on approximately one-third of the people.     

Application of Gas-Aerosol Adsorption Data to the Selection of Air Quality Standards

A quantitative approach is presented for selecting air quality standards which take into account pollutant gas-aerosol synergistic effects. These synergistic health effects have been postulated to be due to the adsorption or absorption of the pollutant gas by the aerosol particles. The approach presented in this paper assumes that the synergistic toxic agent is the adsorbed pollutant gas. Therefore, limiting the concentration of the adsorbed pollutant gas limits the magnitude of the synergistic effects. The concentration of the adsorbed pollutant gas is related to the concentrations of the gaseous phase pollutant gas and the atmospheric aerosol using the Langmuir adsorption isotherm. An example is presented of the selection of air quality standards for sulfur dioxide and the atmospheric aerosol using concentration data for these two pollutants along with health effect data.