ES&T Guest Comment: Celebrating Bidleman’s 1988 “Atmospheric Processes”

Since its 1988 appearance in ES&T, Terry F. Bidleman’s article, “Atmospheric processes: wet and dry deposition of organic compounds are controlled by their vapor-particle partitioning”, has had a notable impact on the field of contaminant science. The paper has been cited in over 600 journal articles published by authors from every continent. Far from fading into obscurity, the paper’s influence has been remarkably consistent. Citations over the last year match the annual average attained since publication

New device to measure dynamic intrusion/extrusion cycles of lyophobic heterogeneous systems

International audienc

Artefacts in semivolatile organic compound sampling with polyurethane foam substrates in high volume cascade impactors

<p>Polyurethane foam (PUF) is known to sorb gas-phase semivolatile organic compounds (SVOCs) from ambient air and is used routinely in conventional high volume filter-sorbent sampling of such pollutants. PUF rings have also been employed as impaction substrates in a high volume cascade impactor (HVCI) used as a sampler for the evaluation of particle toxicity. Though nonvolatile particles (e.g., trace metals, inorganic ions) have been the primary focus, the sampler has also been used to measure particulate SVOC concentrations in ambient air. The aim of this work is to investigate the validity of the latter approach. The results of three sets of experiments conducted in Canada and Denmark are reported herein. Model compounds included native and deuterated polycyclic aromatic hydrocarbons (PAHs). The experiments demonstrated that HVCI PUF substrates sorb gas-phase PAH compounds and that the sorbed mass is subject to mobilization through and out of the sampler. Particulate concentrations of low molecular weight and volatile PAHs are therefore prone to overestimation in samples that have been analyzed after extraction of whole PUF substrates. Sonication of collected particles in water before solvent extraction is effective at dislodging them from the PUF but also acts to redistribute their originally particulate PAH mass back to the PUF and to the sonication water. As a result, the PAH content of particles measured after sonication and subsequent filtration does not accurately represent their true values. These artefacts affect not only measured PAH concentrations but also the results of toxicological assays that are conducted to test the characteristics of particles collected using HVCI PUF samplers.</p

Air Toxics in Canada Measured by the National Air Pollution Surveillance (NAPS) Program and their Relation to Ambient Air Quality Guidelines

<div><p></p><p>This study reports ambient concentrations of 63 air toxics that were measured in Canada by the National Air Pollution Surveillance (NAPS) program over the period 2009 to 2013. Measured concentrations are compared to ambient air quality guidelines from Canadian jurisdictions and compounds that exceeded guidelines are identified and discussed. Though this study does not assess risk or cumulative effects, air toxics that approached guidelines are also identified so that their potential contribution to ambient air toxics pollution can be considered.</p><p>Eleven air toxics exceeded at least one guideline and an additional sixteen approached guidelines during the study period. Four compounds were measured using methods whose detection limits exceeded a guideline value, three of which could not be compared to guidelines since they were not detected in any samples. The assessment of several metal(loid) concentrations is tentative since they were measured only in fine particulate matter (PM) but compared to guidelines based on coarse or total PM. Improvements to sampling and analysis techniques for the latter compounds as well as for those whose methods are subject to known uncertainties would improve confidence in reported concentrations and their relation to applicable guidelines. Analysis of sampling strategies for all compounds found to exceed or approach guidelines would contribute to ensuring that their spatiotemporal coverage is adequate. Examination of the air toxics not measured by NAPS but having guidelines in Canadian jurisdictions or being included in other programs such as the US National-Scale Air Toxics Assessment (NATA) would contribute to ensuring that the full suite of pollutants relevant to ambient air quality in Canada is subject to adequate study. The results of this study can be applied to evaluating the effectiveness of toxic substances management in Canada. </p><p></p><p>Implications</p><p>Recent measurements of 63 air toxics in Canada by the National Air Pollution Surveillance (NAPS) program showed that eleven compounds exceeded daily or annual ambient air quality guidelines and that an additional sixteen compounds approached such guidelines within an order of magnitude. The results of this study can be applied to evaluating the effectiveness of toxic substances management in Canada and to identifying compounds that merit further investigation.</p><p></p><p></p></div

Polycyclic aromatic compounds (PACs) in the Canadian environment: A review of sampling techniques, strategies and instrumentation

A wide variety of sampling techniques and strategies are needed to analyze polycyclic aromatic compounds (PACs) and interpret their distributions in various environmental media (i.e., air, water, snow, soils, sediments, peat and biological material). In this review, we provide a summary of commonly employed sampling methods and strategies, as well as a discussion of routine and innovative approaches used to quantify and characterize PACs in frequently targeted environmental samples, with specific examples and applications in Canadian investigations. The pros and cons of different analytical techniques, including gas chromatography – flame ionization detection (GC-FID), GC low-resolution mass spectrometry (GC-LRMS), high performance liquid chromatography (HPLC) with ultraviolet, fluorescence or MS detection, GC high-resolution MS (GC-HRMS) and compound-specific stable (δC, δH) and radiocarbon (ΔC) isotope analysis are considered. Using as an example research carried out in Canada's Athabasca oil sands region (AOSR), where alkylated polycyclic aromatic hydrocarbons and sulfur-containing dibenzothiophenes are frequently targeted, the need to move beyond the standard list of sixteen EPA priority PAHs and for adoption of an AOSR bitumen PAC reference standard are highlighted. A comprehensive review of sampling methods, strategies and analytical techniques used to quantify and characterize PACs in the Canadian environment

Celebrating Bidleman’s 1988 “Atmospheric Processes”

The authors highlight the accomplishment of Terry F. Bidleman’s article, Atmospheric processes: Wet and dry deposition of organic compounds are controlled by their vapor-particle partitioning . Since its 1988 appearance in ES&T the article has had a notable impact on the field of contaminant science. The paper has been cited in over 600 journal articles published by authors from every continent. Far from fading into obscurity, the paper’s influence has been remarkably consistent. Citations over the last year match the annual average attained since publication