Linda Acha George

Public Perception of Climate Change. Voluntary Mitigation and Barriers to Behavior Change

Mitigating global climate change requires not only government action but also cooperation from consumers. Population-based, cross-sectional surveys were conducted among 1202 respondents in Portland OR and Houston TX between June and September 2007 regarding awareness, concern, and behavior change related to climate change. The data were subjected to both quantitative and qualitative analyses. Awareness about climate change is virtually universal (98% in Portland and 92% in Houston) with the vast majority reporting some level of concern (90% in Portland and 82% in Houston). A multivariate analysis revealed significant predictors of behavior change: individuals with heightened concern about climate change (p<0.001); respondents with higher level of education (p= 0.03); younger compared with older individuals (p<0.001); and Portlanders more likely to change behavior compared with Houstonians (p<0.001). Of those who changed behavior, 43% reported having reduced their energy usage at home, 39% had reduced gasoline consumption, and 26% engaged in other behaviors, largely recycling. Qualitative data indicate a number of cognitive, behavioral, and structural obstacles to voluntary mitigation. Although consumers are interested in global climate change-mitigation strategies and willing to act accordingly, considerable impediments remain. Government policy must eliminate economic, structural, and social barriers to change and advance accessible and economical alternatives. Individual-level mitigation can be a policy option under favorable contextual conditions, as these results indicate, but must be accompanied by mitigation efforts from industry, commerce, and government.

Measurement of free radicals OH and HO2 in Los Angeles smog

Atmospheric free radicals hydroxyl and hydroperoxyl (OH and HO2, collectively HOx) are the catalysts that cause secondary or photochemical air pollution. Chemical mechanisms for oxidant and acid formation, on which expensive air pollution control strategies are based, must accurately predict these radical concentrations. We have used the fluorescence assay with gas expansion (FAGE) technique to carry out the first simultaneous, in situ measurements of these two radicals in highly polluted air during the Los Angeles Free Radical Experiment. A complete suite of ancillary measurements was also made, including speciated hydrocarbons, carbon monoxide, aldehydes, nitric oxide, nitrogen dioxide, and ozone along with meteorological parameters. Using this suite of measurements, we tested the ability of a lumped chemical mechanism to accurately predict radical concentrations in polluted air. Comparison of model predictions with measured radical concentrations revealed generally good agreement for OH early and late in the day, including the early evening hours, when OH persisted at low concentrations after dark. During midday, however, modeled [OH] was high by about 50%. Agreement for HO2 was quite good in the early morning hours, but model-calculated HO2 concentrations were significantly too high during midday. When we used our measured HO2 concentrations as model input, agreement between calculated and measured OH concentrations was improved. It seems likely that (1) the models HOx sources are too large, (2) there are unaccounted HOx loss processes in Los Angeles air, and/or (3) the complex parameterization of RO2/HO2 radical chemistry in the reaction mechanism does not adequately describe the behavior of these radicals in the Los Angeles atmosphere.

Public perception and behavior change in relationship to hot weather and air pollution

BACKGROUND Changes in climate systems are increasing heat wave frequency and air stagnation, both conditions associated with exacerbating poor air quality and of considerable public health concern. OBJECTIVES Heat and air pollution advisory systems are in place in many cities for early detection and response to reduce health consequences, or severity of adverse conditions. Whereas the ability to forecast heat waves and/or air pollution episodes has become increasingly sophisticated and accurate, little is known about the effectiveness of advisories in altering public behavior. METHODS Air quality and meteorological conditions were measured during advisory and control days in Portland, OR and Houston, TX in 2005 and 2006 and 1962 subjects were interviewed by telephone about their perception and response to these conditions. RESULTS Elevated ambient temperatures were accurately recognized regardless of air conditioning use; in Portland, respondents resorted to active cooling behavior (AC, fan, etc.), while in Houston no such change was observed. More heat-related symptoms were reported in Portland compared to Houston, probably due to low air conditioning use in the northwest. One-third of study participants were aware of air quality advisories but only approximately 10-15% claimed to have changed activities during such an episode. Not the advisory, however, drove their behavior change, but rather the perception of poor air quality, which was not related to PM(2.5) or ozone measurements. CONCLUSIONS Messages are not reaching the public during potentially hazardous weather and air quality conditions. Climatic forecasts are increasingly predictive but public agencies fail to mount an appropriate outreach response.

Climate change and climate variability: personal motivation for adaptation and mitigation

BackgroundGlobal climate change impacts on human and natural systems are predicted to be severe, far reaching, and to affect the most physically and economically vulnerable disproportionately. Society can respond to these threats through two strategies: mitigation and adaptation. Industry, commerce, and government play indispensable roles in these actions but so do individuals, if they are receptive to behavior change. We explored whether the health frame can be used as a context to motivate behavioral reductions of greenhouse gas emissions and adaptation measures.MethodsIn 2008, we conducted a cross-sectional survey in the United States using random digit dialing. Personal relevance of climate change from health threats was explored with the Health Belief Model (HBM) as a conceptual frame and analyzed through logistic regressions and path analysis.ResultsOf 771 individuals surveyed, 81% (n = 622) acknowledged that climate change was occurring, and were aware of the associated ecologic and human health risks. Respondents reported reduced energy consumption if they believed climate change could affect their way of life (perceived susceptibility), Odds Ratio (OR) = 2.4 (95% Confidence Interval (CI): 1.4 - 4.0), endanger their life (perceived severity), OR = 1.9 (95% CI: 1.1 - 3.1), or saw serious barriers to protecting themselves from climate change, OR = 2.1 (95% CI: 1.2 - 3.5). Perceived susceptibility had the strongest effect on reduced energy consumption, either directly or indirectly via perceived severity. Those that reported having the necessary information to prepare for climate change impacts were more likely to have an emergency kit OR = 2.1 (95% CI: 1.4 - 3.1) or plan, OR = 2.2 (95% CI: 1.5 -3.2) for their household, but also saw serious barriers to protecting themselves from climate change or climate variability, either by having an emergency kit OR = 1.6 (95% CI: 1.1 - 2.4) or an emergency plan OR = 1.5 (95%CI: 1.0 - 2.2).ConclusionsMotivation for voluntary mitigation is mostly dependent on perceived susceptibility to threats and severity of climate change or climate variability impacts, whereas adaptation is largely dependent on the availability of information relevant to climate change. Thus, the climate change discourse could be framed from a health perspective to motivate behaviour change.

Impact of Bicycle Lane Characteristics on Exposure of Bicyclists to Traffic-Related Particulate Matter

Bicycling as a mode of transportation is increasingly seen as a healthy alternative to motorized transportation modes. However, in congested urban areas, the health benefits of bicycling can be diminished by the negative health effects associated with inhalation of particulate matter. Particles of small size (ultrafine particles <0.1 μm) are the most harmful, even during short-duration exposure. Because vehicular exhaust is the major source of ultrafine particles, the impact of traffic levels and bicycle lane characteristics on exposure of bicyclists was studied. Ultrafine particle exposure concentrations were compared in two settings: (a) a traditional bicycle lane adjacent to the vehicular traffic lanes and (b) a cycle track design with a parking lane separating bicyclists from vehicular traffic lanes. Traffic measurements were made alongside air quality measurements. The cycle track design mitigated ultrafine particle exposure concentrations for cyclists. Results showed statistically significant differences in terms of exposure levels for the two bike facilities, as well as correlations between traffic levels and exposure level differences. Results also suggested that ultrafine particle levels and spatial distribution were sensitive to proximity to signalized intersections. Findings of this research indicated that, in high traffic areas, bicycle facility design had the potential to lower air pollution exposure levels of bicyclists.

A Sub-Neighborhood Scale Land Use Regression Model for Predicting NO2

This study set out to develop a land use regression model at sub-neighborhood scale (0.01-1 km) for Portland, Oregon using passive measurements of NO(2) at 77 locations. Variables used to develop the model included road and railroad density, traffic volume, and land use with buffers of 50 to 750 m surrounding each measurement site. An initial regression model was able to predict 66% of the variation in NO(2). Including wind direction in the regression model increased predictive power by 15%. Iterative random exclusion of 11 sites during model calibration resulted in a 3% variation in predictive power. The regression model was applied to the Portland metropolitan area using 10 m gridded land use layers. This study further validates land use regression for use in North America, and identifies important considerations for their use, such as inclusion of railways, open spaces and meteorological patterns.

FAGE determination of tropospheric HO and HO

Abstract FAGE (fluorescence assay with gas expansion) was developed as a sensitive technique for the detection of low-concentration free radicals in the atmosphere. The application of FAGE to tropospheric hydroxyl (H0) and hydroperoxyl (H02) radicals has yielded calibrated measurements of both species in both clean air and highly polluted urban air. For HO calibration, a continuously stirred tank reactor provides a uniform external HO concentration, which can be measured by gas chromatography of an HO-reactive hydrocarbon. The aerodynamics of the air-sampling process has been modeled computationally, with results that agree with empirical observations of the effects of nozzle diameter on HO loss during sampling. The authors have also modeled airborne fluid dynamics of a FAGE probe. They have recently obtained FAGE sensitivity as high as ± 1 × 106 cm−3 for a 6-minute averaging period, during field studies in highly polluted Los Angeles air, yielding a 7:1 signal-to-noise ratio near midday. Multipass excita...

Development of an ambient pressure laser-induced fluorescence instrument for nitrogen dioxide

Concerns about the health effects of nitrogen dioxide (NO2) and its role in forming deleterious atmospheric species have made it desirable to have low-cost, sensitive ambient measurements of NO2. We have developed a continuous-wave laser-diode laser-induced fluorescence (LIF) system for NO2 that operates at ambient pressure, thereby eliminating the need for an expensive pumping system. The current prototype system has achieved sensitivity several orders of magnitude beyond previous efforts at ambient pressure (limit of detection of 2 ppb, 60 s averaging time). Ambient measurements of NO2 were made in Portland, Oregon using both the standard NO2 chemiluminescence method and the LIF instrument and showed good agreement (r2 = 0.92).

Investigating the urban heat island effect with a collaborative inquiry project

Modification of the earths surface through urbanization can have a dramatic impact on local climate. A phenomenon known as the Urban Heat Island (UHI) effect, which is a measure of the near-surface air temperature contrast between urbanized and adjoining rural areas, can be evaluated with readily available instruments. Students in an undergraduate general education science course study this phenomenon in the Portland, Oregon area through a collaborative research project. This inquiry project includes background content and literature review, preliminary studies, development of research questions, experimental design and implementation, data analysis and report writing. This project successfully enables students to collaboratively generate a data set that is amenable to sophisticated and interesting analysis and provides an opportunity to study a phenomenon in their local environment.

Assessing the Potential of Land Use Modification to Mitigate Ambient NO2 and Its Consequences for Respiratory Health

Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO2 is modeled based on spatially dense summer and winter NO2 observations in Portland-Hillsboro-Vancouver (USA), and the spatial variation of NO2 with LULC investigated using random forest, an ensemble data learning technique. The NO2 random forest model, together with BenMAP, is further used to develop a better understanding of the relationship among LULC, ambient NO2 and respiratory health. The impact of land use modifications on ambient NO2, and consequently on respiratory health, is also investigated using a sensitivity analysis. We find that NO2 associated with roadways and tree-canopied areas may be affecting annual incidence rates of asthma exacerbation in 4–12 year olds by +3000 per 100,000 and −1400 per 100,000, respectively. Our model shows that increasing local tree canopy by 5% may reduce local incidences rates of asthma exacerbation by 6%, indicating that targeted local tree-planting efforts may have a substantial impact on reducing city-wide incidence of respiratory distress. Our findings demonstrate the utility of random forest modeling in evaluating LULC modifications for enhanced respiratory health.