Research Hub

An integrated life cycle assessment and life cycle cost (LCC) model was developed to compare the life cycle performance of plug-in charging versus wireless charging for an electric bus system. The model was based on a bus system simulation using existing transit bus routes in the Ann Arbor–Ypsilanti metro area in Michigan. The objective is to evaluate the LCCs for an all-electric bus system utilizing either plug-in or wireless charging and also compare these costs to both conventional pure diesel and hybrid bus systems. Despite a higher initial infrastructure investment for off-board wireless chargers deployed across the service region, the wireless charging bus system has the lowest LCC of US$0.99 per bus-kilometer among the four systems and has the potential to reduce use-phase carbon emissions attributable to the lightweighting benefits of on-board battery downsizing compared to plug-in charging. Further uncertainty analysis and sensitivity analysis indicate that the unit price of battery pack and day or night electricity price are key parameters in differentiating the LCCs between plug-in and wireless charging. Additionally, scenario analyses on battery recycling, carbon emission pricing, and discount rates were conducted to further analyze and compare their respective life cycle performance.

Published Mar 24, 2016

Bi, Z., De Kleine, R., & Keoleian, G. A. (2017). Integrated Life Cycle Assessment and Life Cycle Cost Model for Comparing Plug-in versus Wireless Charging for an Electric Bus System. Journal of Industrial Ecology, 21(2), 344–355. https://doi.org/10.1111/jiec.12419

Mental acuity is essential to productivity in most professions and possibly associated with indoor air quality. I examine this potential link using a sample of university final examination results from a British institution. To account for potential confounders, I exploit the panel structure of the data to estimate models with subject and student fixed effects. I find that exposure to elevated levels of particulate matter (PM 10) has a statistically and economically significant effect on test scores and long-term academic indicators that are potentially correlated with future career outcomes. Furthermore, I find that the effect is larger among male, high ability and STEM subgroups and is present at levels considerably lower than current EPA standards. The results suggest that a narrow focus on traditional health outcomes, such as hospitalization, may understate the true cost of pollution as indoor air quality also affects productivity.

Published Mar 1, 2016

Roth, S. (2016). The Contemporaneous Effect of Indoor Air Pollution on Cognitive Performance: Evidence from the UK *. http://www.who.int/mediacentre/factsheets/fs292/en/.

Preterm birth (PTB) has been associated with exposure to air pollution, but it is unclear whether effects might vary among air pollution sources and components. Objectives: We studied the relationships between PTB and exposure to different components of air pollution, including gases and particulate matter (PM) by size fraction, chemical composition, and sources. Methods: Fine and ultrafine PM (respectively, PM2.5 and PM0.1) by source and composition were modeled across California over 2000–2008. Measured PM2.5, nitrogen dioxide, and ozone concentrations were spatially interpolated using empirical Bayesian kriging. Primary traffic emissions at fine scale were modeled using CALINE4 and traffic indices. Data on maternal characteristics, pregnancies, and birth outcomes were obtained from birth certificates. Associations between PTB (n = 442,314) and air pollution exposures defined according to the maternal residence at birth were examined using a nested matched case–control approach. Analyses were adjusted for maternal age, race/ethnicity, education and neighborhood income. Results: Adjusted odds ratios for PTB in association with interquartile range (IQR) increases in average exposure during pregnancy were 1.133 (95% CI: 1.118, 1.148) for total PM2.5, 1.096 (95% CI: 1.085, 1.108) for ozone, and 1.079 (95% CI: 1.065, 1.093) for nitrogen dioxide. For primary PM, the strongest associations per IQR by source were estimated for onroad gasoline (9–11% increase), followed by onroad diesel (6–8%) and commercial meat cooking (4–7%). For PM2.5 composition, the strongest positive associations per IQR were estimated for nitrate, ammonium, and secondary organic aerosols (11–14%), followed by elemental and organic carbon (2–4%). Associations with local traffic emissions were positive only when analyses were restricted to births with residences geocoded at the tax parcel level. Conclusions: In our statewide nested case–control study population, exposures to both primary and secondary pollutants were associated with an increase in PTB.

Published Feb 19, 2016

Laurent, Olivier, Hu, Jianlin , Li, Lianfa, Kleema, Michael J. , Bartell, Scott M., Cockburn, Myles, Escobedo, Loraine, and Wu, J. (2016). Research | Children ’ s Health A Statewide Nested Case – Control Study of Preterm Birth and Air Pollution. Environmental Health Perspectives, 124(9), 2001–2008. https://doi.org/10.1289/ehp.1002365

In 2010, the Louisiana Asthma Management and Prevention Program (LAMP) implemented the Asthma-Friendly Schools Initiative in high-risk Louisiana populations. The social ecological model (SEM) was used as a framework for an asthma program implemented in 70 state K-12 public schools over 2 years. METHODS: Activities included a needs assessment, identification of students with asthma, individualized asthma action plans (AAP), staff trainings, environmental quality improvement, and school system policy changes to address the asthma burden. RESULTS: There were 522 new or existing asthma cases recognized. Asthma knowledge/awareness was measurably improved among school personnel. School indoor air quality was improved across all locations. School-level polices were adopted that improved AAP collection, compliance to bus-idling restrictions, and asthma medication self-carry. CONCLUSIONS: The SEM framework can be used for school-based programs to address successfully and improve asthma-related issues from the individual through policy levels.

Published Feb 2, 2016

Nuss, H. J., Hester, L. L., Perry, M. A., Stewart-Briley, C., Reagon, V. M., & Collins, P. (2016). Applying the Social Ecological Model to Creating Asthma-Friendly Schools in Louisiana. Journal of School Health, 86(3), 225–232. https://doi.org/10.1111/josh.12369

Prior research demonstrates that mortality rates increase during economic booms and decrease during economic busts, but little is known about the role of environmental risks as a potential mechanism for this relationship. We investigate the contribution of air pollution to the procyclicality of deaths by combining county-level data on overall, cause-specific, and age-specific mortality rates with county-level measures of ambient concentrations of three types of pollutants and the unemployment rate. After controlling for demographic variables and state-by-year fixed effects, we find a significant positive correlation between pollution concentrations and mortality rates. Controlling for carbon monoxide, particulate matter, and ozone attenuates the relationship between overall mortality and the unemployment rate by 17%. The findings are robust to the use of state- rather than county-level data and to a variety of alternative specifications, although the attenuation of the unemployment-mortality relationship after controlling for pollution is insubstantial when including county-specific linear trends.

Published Feb 1, 2016

Heutel, G., & Ruhm, C. J. (2013). NBER WORKING PAPER SERIES AIR POLLUTION AND PROCYCLICAL MORTALITY. http://www.nber.org/papers/w18959

Typically, minority populations and impoverished peoples tend to be exposed to environmental hazards significantly more often than other demographic populations (Bullard, 2000). Oftentimes these exploited communities do not have the necessary resources to relocate, or have the political voice to deny the industry residency in their community. This research explores what environmental injustice looks like in Alabama, specifically examining the key players in local, state, and federal governance that have decision-making power in environmental justice (EJ) communities, the ways in which EJ issues affect residents and the community, and the ways in which communities are organizing for environmental justice. Our results have shown that frustration by EJ communities in Alabama have resulted from lack of participation in the decision-making process within local, state, and federal levels as well as a lack of effort to consider EJ as a serious issue by these entities. Residents perceive these issues as attacks on their quality of life, their culture, and their ability to pursue happiness. When organizing for environmental justice, important items residents and key informants highlighted were networking and building alliances across state lines, connecting environmental and social issues as a part of the framing of their issues, appropriate and representational leaders, and building connections amongst both social and environmental organizations. Through the use of Critical Race Theory as our theoretical framework, we were able to analyze racial dynamics at play between entities involved with environmental justice organizing in Alabama.

Published Jan 1, 2016

Pennington, M., & Ph.D, S. C. (2016). Unconventional Wisdom. University of Montevallo TRIO McNair Scholars Program 2016 Research Journal. https://www.montevallo.edu/wp-content/uploads/2018/09/journal-2016-complete.pdf#page=186

Climate change is inextricably linked to economic inequality: it is a crisis that is driven by the greenhouse gas emissions of the 'haves' that hits the 'have-nots' the hardest.

While COP21 in Paris will see a deal negotiated between governments on the basis of the total emissions produced in their territories, the real winners and losers will be their citizens. The true test of the deal will be whether it delivers something for the poorest people who are both the least responsible for and the most vulnerable to climate change, wherever they live.

In this briefing Oxfam presents new data analysis that demonstrates the extent of global carbon inequality by estimating and comparing the lifestyle consumption emissions of rich and poor citizens in different countries. See also the technical briefing on the methodology and the data sets.

Published Dec 2, 2015

Oxfam 2015. Extreme Carbon Inequality. http://hdl.handle.net/10546/582545

Background:
The indoor built environment plays a critical role in our overall well-being because of both the amount of time we spend indoors (~90%) and the ability of buildings to positively or negatively influence our health. The advent of sustainable design or green building strategies reinvigorated questions regarding the specific factors in buildings that lead to optimized conditions for health and productivity.
Objective:
We simulated indoor environmental quality (IEQ) conditions in “Green” and “Conventional” buildings and evaluated the impacts on an objective measure of human performance: higher-order cognitive function.
Methods:
Twenty-four participants spent 6 full work days (0900–1700 hours) in an environmentally controlled office space, blinded to test conditions. On different days, they were exposed to IEQ conditions representative of Conventional [high concentrations of volatile organic compounds (VOCs)] and Green (low concentrations of VOCs) office buildings in the United States. Additional conditions simulated a Green building with a high outdoor air ventilation rate (labeled Green+) and artificially elevated carbon dioxide (CO2) levels independent of ventilation.
Results:
On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001). VOCs and CO2 were independently associated with cognitive scores. Conclusions: Cognitive function scores were significantly better under Green+ building conditions than in the Conventional building conditions for all nine functional domains. These findings have wide-ranging implications because this study was designed to reflect conditions that are commonly encountered every day in many indoor environments.

Published Oct 26, 2015

Allen, J. G., MacNaughton, P., Satish, U., Santanam, S., Vallarino, J., & Spengler, J. D. (2015). Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments. Environmental Health Perspectives, 124(6), 805–812. https://doi.org/10.1289/EHP.1510037

IMPORTANCE: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and neurotoxic environmental contaminants. Prenatal PAH exposure is associated with subsequent cognitive and behavioral disturbances in childhood. OBJECTIVES: To identify the effects of prenatal PAH exposure on brain structure and to assess the cognitive and behavioral correlates of those abnormalities in school-age children. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional imaging study in a representative community-based cohort followed up prospectively from the fetal period to ages 7 to 9 years. The setting was urban community residences and an academic imaging center. Participants included a sample of 40 minority urban youth born to Latina (Dominican) or African American women. They were recruited between February 2, 1998, and March 17, 2006. MAINOUTCOMES AND MEASURES: Morphological measures that index local volumes of the surface of the brain and of the white matter surface after cortical gray matter was removed. RESULTS: We detected a dose-response relationship between increased prenatal PAH exposure (measured in the third trimester but thought to index exposure for all of gestation) and reductions of the white matter surface in later childhood that were confined almost exclusively to the left hemisphere of the brain and that involved almost its entire surface. Reduced left hemisphere white matter was associated with slower information processing speed during intelligence testing and with more severe externalizing behavioral problems, including attention-deficit/hyperactivity disorder symptoms and conduct disorder problems. The magnitude of left hemisphere white matter disturbances mediated the significant association of PAH exposure with slower processing speed. In addition, measures of postnatal PAH exposure correlated with white matter surface measures in dorsal prefrontal regions bilaterally when controlling for prenatal PAH. CONCLUSIONS AND RELEVANCE: Our findings suggest that prenatal exposure to PAH air pollutants contributes to slower processing speed, attention-deficit/hyperactivity disorder symptoms, and externalizing problems in urban youth by disrupting the development of left hemisphere white matter, whereas postnatal PAH exposure contributes to additional disturbances in the development of white matter in dorsal prefrontal regions.

Published Jun 1, 2015

Peterson, B. S., Rauh, V. A., Bansal, R., Hao, X., Toth, Z., Nati, G., Walsh, K., Miller, R. L., Arias, F., Semanek, D., & Perera, F. (2015). Effects of prenatal exposure to air pollutants (polycyclic aromatic hydrocarbons) on the development of brain white matter, cognition, and behavior in later childhood. JAMA Psychiatry, 72(6), 531–540. https://doi.org/10.1001/jamapsychiatry.2015.57

China is facing serious issues involving energy sufficiency, greenhouse gas (GHG) emissions and air pollution caused partly by the rapid growth of vehicles. In order to relieve those problems, new energy vehicles are introduced into the bus and car market. We adopt life cycle analysis to evaluate the well-to-wheels (WTW) energy consumption, CO2 emissions and pollutant emissions from the traditional diesel bus and new energy buses, including diesel hybrid electric vehicles (HEVs), compressed natural gas vehicles (CNGVs) and battery electric vehicles (BEVs). This study reports the current situation and projects future scenarios for the BEV bus for several regions in China due to significant regional differences in the power generation mix. Compared to the diesel bus, the HEV bus can reduce petroleum, fossil fuel use and CO2 emissions by about 20%, and, at the same time, produce stable reduction benefits for all air pollutants. The CNG bus achieves reductions of WTW primary PM2.5 emissions by 70% over its diesel counterpart and, of course, uses little petroleum; but increases fossil fuel consumption moderately and has no benefit in GHG emissions. The BEV bus can deliver a substantial petroleum consumption advantage and greatly reduce the WTW NOX, VOC and CO emissions; but, if the electricity is generated from burning coal, the BEV bus has no PM2.5 emission benefit compared to the conventional diesel bus. Currently, the BEV bus increases fossil energy use and CO2 emissions in the coal-dominated regions; but, in the future, it can achieve substantially lower fossil energy use and CO2 emissions with more penetration of clean electric energy. To reach the win-win strategy, a city's initial reliance on diesel buses for the public fleet has to give way to a mixture of these new energy buses; and the fleet mix should be diversified over the region and modified over time to accommodate changes in these energy and environmental parameters.

Published Jun 1, 2015

Wang, R., Wu, Y., Ke, W., Zhang, S., Zhou, B., & Hao, J. (2015). Can propulsion and fuel diversity for the bus fleet achieve the win-win strategy of energy conservation and environmental protection? Applied Energy, 147, 92–103. https://doi.org/10.1016/j.apenergy.2015.01.107