Milton Feldstein

A new method for measuring average 24-hour nitrogen dioxide concentrations in the atmosphere.

A long-term manual sampling procedure for nitrogen dioxide is required to measure compliance with the recently adopted EPA ambient air quality standard for this substance. The method recommended by EPA has proven to be inadequate. This paper discusses a manual procedure involving absorption of NO2 in a triethanolamine solution or a triethanolamine impregnated molecular sieve surface. Absorption efficiencies of over 95% are attained, using either the liquid or solid absorbers. The NO2 (gas) to NO2 (ion) factor was found to be 0.85, evaluated against the Saltzman factor of 0.72. Field data as well as controlled laboratory trials indicate the method is comparable to continuous air monitoring instrumentation, utilizing the modified Saltzman reagent. Nitric oxide in concentrations as high as 0.6 ppm for 24 hr gave no interference. The presence of sulfur dioxide causes slightly lower results with the solid absorber, but has no effect on the liquid absorber at concentrations normally encountered in ambient air. ...

The Determination of Formaldehyde, Acrolein, and Low Molecular Weight Aldehydes in Industrial Emissions on a Single Collection Sample

Formaldehyde, acrolein, and low molecular weight aldehydes are collected in 1% NaHSO3 solution in Greenberg-Smith or midget impingers from industrial effluents. Efficiency of collection is excellent when two impingers are used in series. Formaldehyde is measured in an aliquot of the collection medium by the chromo-tropic acid procedure, acrolein by a modified mercuric-chloride-hexylresorcinol procedure, and C2-C5 aldehydes by a gas chromatographic procedure. The method permits the analysis of all C1-C5 aldehydes on a single collection sample. Data on aldehyde concentrations from a variety of effluents are presented.

A Critical Review of Regulations for the Control of Hydrocarbon Emissions from Stationary Sources.

The state of our knowledge on the necessary degree of stationary source organic emission control required to assist in meeting the goal of the Federal Oxidant Standard can be summarized as being intimately tied in with the larger problem of mobile source organic emission control. A satisfactory resolution of the problem will come only when the dynamics of atmospheric oxidant formation is more fully understood. However, it must be assumed that the control of reactive organic compounds, to the extent that they participate in these reactions, is directionally correct. 27 references, 5 tables.

Modifications to an H2S Tape Sampler for Increasing Sensitivity and Accuracy in H2S Sampling

The tape samplers using lead acetate impregnated paper tapes for continuous hydrogen sulfide sampling are subject to a number of errors which can throw considerable doubt on the accuracy of H2S concentrations being measured. Some of the errors have been minimized with a change in the humidification system and a reduction of the lamp intensity in the optical system.

Planning to meet air quality standards in the San Francisco Bay Area

The planning process and implementation of control measures required to meet the Clean Air Act mandate to attain and maintain Federal Ozone Standards are outlined and discussed. Actual efforts began in the early 1960s and progressed from stationary source controls to new motor vehicle emission reductions to transportation control measures to limit emissions from vehicles in use. Air quality measurements demonstrate the success that these approaches have had in bringing days over the standard from 70 in the late 1960s to 2 or 3 in the most recent years.