Emissions from lit-use Motor Vehicles in Los Angeles: A Pilot Study of Remote Sensing and the Inspection and Maintenance Program

As part of a major field study to understand the causes of persistent, elevated carbon monoxide pollution episodes in Los Angeles, we performed a project to understand the emissions of vehicles in use. In this experiment, we assessed the accuracy of a remote sensing instrument designed to measure CO concentrations from vehicles as they were driven on the road. The remote sensor was shown to be accurate within ten percent of the directly measured tailpipe value. We performed a roadside inspection on 60 vehicles and demonstrated that the remote sensor could be used as an effective surveillance tool to identify high CO-emitting vehicles. We also compared the roadside data set to the biennial Smog Check (I/M) tests for the same vehicles, and observed that carbon monoxide and exhaust hydrocarbons from high emitters were much higher than when the vehicles received their routine inspection. Furthermore, for the high-emitting vehicles in this data set, the length of time since the biennial Smog Check had little influence on the cars’ emissions in the roadside inspection.     

Canister-Based Method for Monitoring Toxic VOCs in Ambient Air

The availability of reliable, accurate and precise monitoring methods for toxic volatile organic compounds (VOCs) is a primary need for state and local agencies addressing daily monitoring requirements related to odor complaints, fugitive emissions, and trend monitoring. The canister-based monitoring method for VOCs is a viable and widely used approach that is based on research and evaluation performed over the past several years. This activity has involved the testing of sample stability of VOCs in canisters and the design of time-integrative samplers. The development of procedures for analysis of samples in canisters, including the procedure for VOC preconcentration from whole air, the treatment of water vapor in the sample, and the selection of an appropriate analytical finish has been accomplished. The canister-based method was initially summarized in the EPA Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air as Method TO-14. Modifications and refinements are being added to Method TO-14 in order to obtain a Statement of Work for the Superfund Contract Laboratory Program for Air. This paper discusses the developments leading to the current status of the canisterbased method and provides a critique of the method using results obtained in EPA monitoring networks.     

Particle Mass Emission Rates from Current-Technology,Light-Duty Gasoline Vehicles

ABSTRACT

Now that the U.S. Environmental Protection Agency has promulgated new National Ambient Air Quality Standards for PM_2.5, work will begin on generating the data required to determine the sources of ambient PM_2.5 and the magnitude of their contributions to air pollution. This paper summarizes the results of an Environmental Research Consortium program, carried out under the auspices of the U.S. Council for Automotive Research. The program focused on particulate matter (PM) emissions from representative, current-technology, light-duty gasoline vehicles produced by DaimlerChrysler Corp., Ford Motor Co., and General Motors Corp. The vehicles, for the most part taken from the manufacturer's certification and durability fleets, were dynamometer-tested using the three-phase Federal Test Procedure in the companies' laboratories. The test fleet was made up of a mixture of both low-mileage (2K-35K miles) and high-mileage (60K-150K miles) cars, vans, sport utility vehicles, and light trucks. For each vehicle tested, PM emissions were accumulated over 4 cold-start tests, which were run on successive days. PM emission rates from the entire fleet (22 vehicles total) averaged less than 2 mg/mile. All 18 vehicles tested using California Phase 2 reformulated gasoline had PM emission rates less than 2 mg/ mile at both low and high mileages.     

Preparation of Calcium Silicate Absorbent from Iron Blast Furnace Slag

ABSTRACT

Calcium silicate hydrate (CSH) solids were prepared from hydrated lime and iron blast furnace slag in an aqueous agitated slurry at 92 °C. While it was hoped a minimal lime/slag ratio could be used to create near-amorphous CSH, the surface area of the product improved by increasing the lime/slag weight ratio to 2. The addition of gypsum to the lime/slag system dramatically improved the formation of surface area, creating solids with 139 m²/g after 30 hr of reaction when only a minimal amount of lime was present. The SO₂ reactivity of solids prepared with gypsum greatly exceeded that of hydrated lime, achieving greater than 70-80% conversion of the alkalinity after 1 hr of reaction with SO₂. The use of CaCl₂ as an additive to the lime/slag system, in lieu of gypsum, also produced high-surface-area solids, 115 m²/g after 21 hr of reaction. However, the SO₂ reactivity of these sorbents was relatively low given the high surface area. This emphasized that the correlation between surface area and SO₂ reactivity was highly dependent on the solid phase, which was subsequently dependent on slurry composition.     

Workplace and Environmental Air Contaminant Concentrations Measured by Open Path Fourier Transform Infrared Spectroscopy: A Statistical Process Control Technique to Detect Changes from Normal Operating Conditions

Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions.

Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control.     

Multifoci effects of injustice on counterproductive work behaviors and the moderating roles of symbolization and victim sensitivity

Past research suggests that employees, in response to workplace experiences, selectively engage in targeted counterproductive work behaviors (CWBs). Taking a retributive justice and target similarity perspective, we predict that employee perceptions of unfairness from the organization uniquely predict CWB specifically targeted at the organization whereas employee perceptions of supervisory unfairness uniquely predict CWB specifically targeted at the supervisor. We further hypothesized that moral identity‐symbolization would strengthen these target‐similar relationships. Finally, drawing from the sensitivity to mean intentions model, we hypothesized that victim sensitivity would not only strengthen these target‐similar relationships but also lead to cross‐foci effects of multifoci fairness perceptions on targets of CWB. Results from 3 field studies of full‐time employees provided support for most of our hypothesized relationships.     

Influence of land use and land cover on the spatial variability of dissolved organic matter in multiple aquatic environments

Environmental Science and Pollution Research - Water quality of lakes, estuaries, and coastal areas serves as an indicator of the overall health of aquatic ecosystems as well as the health of the...     

Predator stimuli and calling behavior of Carolina chickadees (Poecile carolinensis), tufted titmice (Baeolophus bicolor), and white-breasted nuthatches (Sitta carolinensis)

Evidence from different chickadee species (Poecile genus) indicates that birds can modify the note composition of their “chick-a-dee” calls in the presence of predator stimuli. Here, we tested the effects of predator models and the distance of those models on calls of three species foraging together at feeding stations: Carolina chickadees (Poecile carolinensis) and tufted titmice (Baeolophus bicolor), both members of the Paridae family, and white-breasted nuthatches (Sitta carolinensis), a member of the Sittidae family. Model and distance affected seed-taking rates in all three species. “Chick-a-dee” calling rates were higher in the predator context for both chickadees and titmice, but we detected no predator context effects on “quank” call rates for nuthatches. Predator and distance contexts affected acoustic parameters of notes of the “chick-a-dee” calls of chickadees and titmice; no such effects were detected for nuthatch “quank” calls. These results suggest species differences in encoding of information in the primary social calls of these three species that commonly occur in multi-species flocks. Chickadees and titmice are “nuclear” species and nuthatches are “satellite” species, and these different roles might be related to the differences in vocal signaling that we detected.