Blood samples from several thousand current nonsmokers were collected by the National Center for Health Statistics between 1976 and 1980 in a national probability survey (NHANES II). The blood samples were analyzed for carboxyhemoglobin (COHb) levels using highly sensitive techniques by two laboratories under rigorous quality control procedures. COHb levels of 1528 persons were compared to the immediately preceding one-hour and eight-hour ambient carbon monoxide (CO) averages in 20 US cities. Spearman rank correlation coefficients between COHb and ambient CO were not significant for a large majority of fixed monitoring stations in the 20 cities. No improvement was shown when the comparisons were limited to central-city residents. A regression of all 1528 COHb values on the best ambient stations in each city resulted in an R/sup 2/ value of 0.03, i.e., 3% of the variance in COHb concentrations was explained by the fixed stations. The authors conclude that fixed outdoor CO monitors are not, in general, providing useful estimates of carbon monoxide exposures of urban residents. This finding calls into question the assumptions underlying the national policy of attempting to protect public health by setting an outdoor standard for CO.

Fuel usage data for New York City during 1965 were used to compute annual anthropogenic heat and moisture emission rates. These data were used to simulate spatial distributions of urban surface heat island intensity and mixing depth at 0700 EST on the cold winter morning of 9 March 1966. Calculations were carried out using a steady state well mixed urban advective model. Results showed a maximum surface heat island of 8 K and a maximum mixing depth of 373 m, values consistent with observations over New York City. Anthropogenic moisture production, as well as spatial distribution of average urban mixed layer absolute humidity excess, were computed for two cases, i.e., actual 1965 fuel usage distribution and a point and area source hypothetical conversion (on equal heat basis) to hydrogen gas fuel. Results for the 1965 emission pattern showed a peak grid-area anthropogenic moisture flux of 1.95 x 10/sup 12/ g per year. The peak urban absolute humidity excess was 0.13 g m/sup -3/, about 17% of the observed average mixed layer value. Results for the hypothetical conversion case show similar distributions of anthropogenic moisture production and absolute humidity excess. However, maximum values were increased by a factor of four formore » the first parameter and a factor of three for the other.« less

The body of information presented in this paper is directed to air pollution control personnel and public health officials responsible for community health and safety during hazardous waste site investigations and cleanups. A simplified procedure for developing community air standards for volatiles released during extensive investigation or cleanup of hazardous waste sites is presented. This procedure does not require air modeling and is independent of mass emission rates (Q), wind velocity, and the absolute concentration of substances on site. The method Is based on the Gaussian plume air dispersion model for a point source with no effective plume rise. An air standard for the hazardous site fence line (controlled access boundary line to the site) is derived using this procedure. This fence line criterion is based on a toxicologically acceptable air concentration for the most sensitive population nearest the hazardous waste material. A tiered implementation of the fence line standard requiring continuous real-time air monitoring, directly downwind, is suggested. Monitoring upwind/downwind differences minimizes the possibility of unnecessary site shutdown and should be used in areas where ambient substances affect monitoring.

The destruction/removal efficiency (DRE), and the ability to accurately measure it, is a function of the concentration of the chemical compound in the input waste, the incinerator design and operation, sampling methods, and the analytical procedures. All of these are interrelated. This paper discusses the basic DRE equation (DRE = W/sub in/ - W/sub out/)/W/sub in/ x 100) and how it relates to some of the other destruction parameters. Some example data from the literature are presented. While PCBs have been used as the example, the equation and graphs are equally valid for some other hazardous compounds (POHCs), with the substitution of the 99.99% DRE requirement in lieu of the 99.9999% DRE for PCBs. The use of the relationships discussed in this paper should allow incinerator operators to more efficiently plan demonstration test burns which will adequately demonstrate the DRE.

It is becoming increasingly evident that indoor air quality in nonindustrial environments is often less healthful than outdoor air quality. The short- and long-term health consequences of indoor exposures are not well defined, yet private citizens and organizations are becoming more concerned about potential adverse health effects. Questions and complaints about indoor environmental hazards are an expanding problem for federal, state, and local health agencies. This paper describes findings from a national survey of fee-for-service companies which make indoor air measurements in nonindustrial settings. Information is presented on the makeup of these firms, the types and numbers of buildings which have been investigated, typical contaminant measurements, and associated costs. Results indicate that a substantial private demand exists for goods and services which aid building occupants in evaluating and improving indoor air quality.

The so-called “Six Month Study” of the air toxics problem in the United States was initiated in November 1983 by the U.S. Environmental Protection Agency. The study focused on the magnitude, nature, and distribution of the problem—three major issues that were felt to be most useful to policy makers as they attempted to define the scope and direction of a national program for controlling toxic air pollutants. The following paper is based on a draft staff report on the study released for review in September 1984. The report has not been formally released by the U.S. EPA; a final report is due by late spring of 1985.

A simple apparatus has been devised for the release of SF/sub 6/ tracer from a small, single-engine aircraft. Up to 100 lb of tracer can be released and discharge rate varied by the use of different size nozzles. Since the SF/sub 6/ is released as a liquid, no heated manifold or other external heating is required. 24 references, 5 figures.

A number of key projects in the Environmental Protection Agency (EPA) particulate R&D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO2 removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion

The integrating nephelometer is widely used for the measurement of the light scattering coefficient of ambient particulate matter. This timely information report describes the essential features of the integrating nephelometer, the sources of interference, the procedures for calibration, and recommended methods of operation. The TE-5 Visibility Committee has prepared, reviewed, and is presenting this report according to the rules of the APCA Technical Council.