Oxygenates in Exhaust from Simple Hydrocarbon Fuels

Photochemical air pollution is known to be caused largely by automotive emissions such as hydrocarbons and oxygenated hydrocarbon derivatives. Unlike the hydrocarbons, the contribution of the oxygenates has been virtually unexplored, mainly because of lack of appropriate analytical methods. The objective of this study was to identify and estimate the levels of oxygenated hydrocarbon derivatives in exhaust from simple hydrocarbon fuels. This information is expected to yield ultimately estimates of the relative levels of various classes of oxygenates in exhaust from full-boiling-range gasolines. Identification and measurement of oxygenates in exhaust from the simplified fuels were accomplished using gas chromatography in conjunction with time-of-flight mass spectrometry. The analytical procedure involved concentration of the exhaust organics, followed by a two-stage chromatographic separation of the resultant mixture of oxygenates and hydrocarbons. Identified oxygenates in exhaust from nine test fuels included saturated and unsaturated aldehydes, ketones, and alcohols, as well as ethers, esters, and nitroalkanes; analytical data on organic acids were inconclusive. Of the identified noncarbonyl oxygenates, phenols, cyclic ethers and nitromethane appear to be relatively the most abundant.     

Scientific Basis of an Improved EPA Policy on Control of Organic Emissions for Ambient Ozone Reduction

ABSTRACT

This article describes an effort to re-examine the scientific bases of the existing, more than two decades-old U.S. Environmental Protection Agency (EPA) policy on volatile organic compound reactivity in light of recent scientific knowledge and understanding. The existing policy allows “negligibly reactive” organic emissions, that is, emissions with ambient ozone production potential lower than that of ethane, to be exempted from all ozone regulations. It relies on use of k_OH and incremental reactivity data for determining whether an organic compound is negligibly reactive. Recent scientific evidence suggests that (1) exempting the negligibly reactive organic emissions from all regulations is unjustifiable, (2) the choice of ethane as the benchmark organic species for distinguishing reactive from negligibly reactive organics may be inappropriate, (3) the assumptions and methods used for classifying organic compounds as “reactive” and “negligibly reactive” should be reconsidered, and (4) the volatility factor should be considered, more appropriately, in much the same way as the reactivity factor.     

Coastal landscape preference evaluation: A comparison among tourists in Greece

An evaluation of coastal landscape of pine forest in Greece by summer visitors of various nationalities was carried out. The visual preferences for a set of landscape, represented in photographs, expressed by these various nationality groups were compared. The subjects used in this research came from Greece, Germany, Italy, France, Great Britain, Austria, Yugoslavia, and Scandinavian countries. The findings show that there is an agreement over the basic preference, but, nevertheless, there are differences of opinion between the nationality groups that might be attributed to cultural influences and the effect of being familiar with their own environments. Since coastal landscape plays an important role in the tourist industry, these findings could be very useful to policy-making agencies.     

Using Continuous PM2.5 Monitoring Data to Report an Air Quality Index

Abstract

As stated in 40 CFR 58, Appendix G (2000), statistical linear regression models can be applied to relate PM_2.5 continuous monitoring (CM) measurements with federal reference method (FRM) measurements, collocated or otherwise, for the purpose of reporting the air quality index (AQI). The CM measurements can then be transformed via the model to remove any bias relative to FRM measurements. The resulting FRM-like modeled measurements may be used to provide more timely reporting of a metropolitan statistical area’s (MSA’s) AQI.¹ Of considerable importance is the quality of the model used to relate the CM and FRM measurements. The use of a poor model could result in misleading AQI reporting in the form of incorrectly claiming either good or bad air quality.

This paper describes a measure of adequacy for deciding whether a statistical linear regression model that relates FRM and continuous PM_2.5 measurements is sufficient for use in AQI reporting. The approach is the U.S. Environmental Protection Agency’s (EPA’s) data quality objectives (DQO) process, a seven-step strategic planning approach to determine the most appropriate data type, quality, quantity, and synthesis for a given activity.² The chosen measure of model adequacy is r², the square of the correlation coefficient between FRM measurements and their modeled counterparts. The paper concludes by developing regression models that meet this desired level of adequacy for the MSAs of Greensboro/Winston-Salem/High Point, NC; and Davenport/Moline/Rock Island, IA/IL. In both cases, a log transformation of the data appeared most appropriate. For the data from the Greens-boro/Winston-Salem/High Point MSA, a simple linear regression model of the FRM and CM measurements had an r² of 0.96, based on 227 paired observations. For the data from the Davenport/Moline/Rock Island MSA, due to seasonal differences between CM and FRM measurements, the simple linear regression model had to be expanded to include a temperature dependency, resulting in an r² of 0.86, based on 214 paired observations.     

Private Participation Going Public? Interpreting the Nexus Between Design,Frames, Roles,and Context of the Fracking ‘InfoDialog’ in Germany

At an early stage of the rising fracking controversy in Germany, ExxonMobil initiated a rather large and costly company dialogue to defuse public concerns over fracking. To shed light on the public implications of private participation, this study analyses how this so-called InfoDialog attempted to reach this goal, and what the consequences were. For this purpose, an interpretive analytical perspective that employs concepts of conflict and participation analysis is adopted. Following this perspective, several design features of the InfoDialog and their implications for the framing of the fracking issue are reconstructed. This provides the ground for analysing the roles that the InfoDialog could play in coping with the fracking controversy. Finally, the dialogue's embeddedness in the context of the emerging fracking debate in Germany is examined. The analysis suggests that the InfoDialog could not defuse the public controversy over fracking by scientization. However, as a forerunner in the emerging politics of expertise, it has supported a particular framing of the public controversy. These insights provoke further critical questions about the implications of privately organized participation arrangements regarding public controversies.     

Methodology in Air Pollution Studies Using Irradiation Chambers

Experimentation in large irradiation chambers has been useful in providing insight into the chemistry of the photochemical smog formation problem. Initial efforts to reproduce the atmospheric phenomena artificially at controllable scale were successful in that gross atmospheric smog symptoms were observed in irradiation chambers. However, as the experimentation and evidence produced were becoming more elaborate, the question arose as to how much one could rely on chemical data in understanding and interpreting atmsopheric phenomena. The question becomes highly pertinent in view of the difference in concentration levels between atmosphere and chamber work. This issue was discussed during recent American Chemical Society meetings,^4,8 and the conclusions from presentations and discussions were as follows: (1 ) There is qualitative agreement between chamber data and atmospheric data wherever comparison is feasible. (2) There is need for more precise chamber work at concentration levels more nearly equal to those in the atmosphere. Experimentation in chambers under typical atmospheric conditions presents some special problems associated with the chamber design and chemical analysis. Chamber methodology has been the focus of considerable research effort, and it appears to be an important factor affecting further progress in air pollution research. This paper describes methods and techniques used at the Bartlesville Petroleum Research Center.