A re-examination of ambient air ozone monitor interferences

Attaining the National Ambient Air Quality Standard (NAAQS) for ozone (O3) could cost billions of dollars nationwide. Attainment of the NAAQS is judged on O3 measurements made by the Federal Reference Method (FRM), ethylene chemiluminescence, or a Federal Equivalent Method (FEM), predominantly ultraviolet (UV) absorption. Starting in the 1980s, FRM monitors were replaced by FEMs so that today virtually all monitoring in the United States uses the UV methodology. This report summarizes a laboratory and collocated ambient air monitoring study of interferences in O3 monitors. Potential interferences examined in the laboratory included water vapor, mercury, o-nitrophenol, naphthalene, p-tolualdehyde, and mixed reaction products from smog chamber simulations of urban atmospheric photochemistry. UV absorption O3 monitors modified for humidity equilibration were also collocated with UV FEM O3 monitors at six sites in Houston, TX, during the 2007 summer O3 season. The results suggest that humidity and interfering species can positively bias (overestimate) O3 measured by FEM monitors used to determine compliance with the O3 standards. The results also suggest that humidity equilibration can mitigate this bias.     

Mechanistic studies on the role of PAHs and related compounds in PCDD/F formation on model fly ashes

Model fly ashes containing Florisil, CuCl2.2H2O and PAHs with structures similar to dibenzo-p-dioxin or dibenzofuran were heated at 250 degrees C in He/O2 with regard to a supposed intramolecular reaction mechanism for oxygen incorporation. Highest reactivities in PCDF formation could be found for model compounds containing a biphenyl structure, while condensed pi-systems lead to a decrease in reactivity for such compounds. Biphenyl is almost completely converted to dibenzofuran. PCDD formation from six-membered rings like xanthene/9,10-dihydroanthracene is of minor importance. 18O-labeling of gaseous oxygen reveals no common reaction step for oxygen incorporation using 9-fluorenone, xanthene, diphenyl ether and diphenyl-2-carboxylic acid as model compounds. Pre-existing oxygen in reactants is a major source for ether groups in PCDD and PCDF. Determination of labeled and unlabeled CO and CO2 besides He/O2 reflects higher reactivities towards oxidation for model compounds containing ether groups than for compounds with carbonyl groups.     

Varieties of market-based policy: Instrument choice in climate policy

Since the 1970s, European and US regulators have used different varieties of market-based environmental policy, which are rooted in competing types of liberalism: price instruments and quantity instruments, respectively. In the case of climate change, however, the EU and the US have converged on hybrid policy mixes. This convergence in instrument choice is examined in two cases: the emergence of the EU Emission Trading Scheme, i.e. the import of quantity regulation to the EU; and the creation of California’s feed-in tariff, i.e. the import of price regulation to the US. Increasing convergence in instrument choice is the result of international diffusion through learning and shifting domestic coalitions. This demonstrates that the two varieties of market-based environmental policy increasingly blend, and how policy import is driven by domestic government–producer coalitions rather than by policy-maker ideas of ‘best practice.’     

Do you not like Pigou, or do you not understand him? Tax aversion and revenue recycling in the lab

Tax-aversion reduces the likelihood that price rationing can be a politically viable tool for environmental protection. We examine the case of the classic Pigouvian tax to control a negative externality, and consider how recycling the revenues, labeling of the tax and information about its purpose affects the support for taxation. We test the support for taxation within a single-price market experiment, in which purchases by some buyers impose external costs on others. Observing behavior consistent with tax-aversion, we also find that recycling the revenues to more narrowly targeted groups seems to increase support for taxation. In the absence of narrow revenue recycling, labeling a Pigouvian instrument as a ‘tax’ may significantly lower the likelihood of voter support.