Research Hub

The link between air pollution and human health is well-documented in the epidemiology and economic literature. Recently, an increasing body of research has shown that air pollution—even in relatively low doses—also affects educational outcomes across several distinct age groups and varying lengths of exposure. This implies that a narrow focus on traditional health outcomes, such as morbidity and mortality, may understate the true benefit of reducing pollution, as air pollution also affects scholastic achievement and human capital formation.

Published Jan 1, 2017

Roth, S. (2017). Air pollution, educational achievements, and human capital formation. https://ideas.repec.org/a/iza/izawol/journly2017n381.html

This IRIS assessment for Ethylene oxide consists of hazard identification and dose-response assessment data and provides support for EPA risk management decisions.

Published Dec 16, 2016

US EPA Integrated Risk Information System Division. (2016). Ethylene oxide CASRN 75-21-8 | IRIS | US EPA, ORD. December. https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm?substance_nmbr=1025

Previous well-to-wheels (WTW) analyses on electric vehicles (EVs) have reported tremendous results of potential energy and environmental effects. However, there remains a challenge to lower the uncertainties that were introduced when obtaining life-cycle parameters from a macro perspective (e.g., nationwide or regional scales). This study takes Beijing as a case, because it is an important regional hub for EV promotion and represents megacities with severe urban air pollution issues and congested traffic conditions. We collected up-to-date data concerning the electricity generation mix, fuel transport, end-of-pipe controls, real-world fuel economy and emissions, and estimated the WTW energy consumption and CO2and air pollutant emissions for various light-duty passenger vehicle technologies currently (2015) and in the mid-term future (2030). Unlike previous results, battery electric vehicles (BEVs) are shown to significantly reduce WTW CO2emissions by 32% for the present model year (MY) 2015 compared with their conventional gasoline counterparts, primarily due to the shift from coal to gas in local power plants in Beijing and the significantly higher real-world fuel consumption of conventional vehicles compared with the type-approval value. By 2030, WTW CO2emissions by BEVs should approach 100 g km−1due to the increased importation of non-fossil electricity, even lower than that of hybrid electric vehicles. Furthermore, significant improvements in end-of-pipe controls for coal-fired power plants have effectively lowered WTW emissions of air pollutants. In terms of VOCs and NOXthat are of most concerns among all pollutants emitted from passenger vehicles, the WTW emissions of VOCs for MY 2015 BEV are already significantly lower than their conventional counterparts by 95%. Although WTW NOXemissions for BEVs are currently higher by 66% than conventional gasoline vehicles, we expect that BEVs can achieve WTW emission reduction benefit of NOX(41%) by 2030. This study indicates the significance of fine-grained and real-world features when assessing the WTW energy and environmental effects of EVs.

Published Dec 11, 2016

Ke, W., Zhang, S., He, X., Wu, Y., & Hao, J. (2017). Well-to-wheels energy consumption and emissions of electric vehicles: Mid-term implications from real-world features and air pollution control progress. Applied Energy, 188, 367–377. https://doi.org/10.1016/j.apenergy.2016.12.011

Background: Relationships between air quality and health are well-described, but little information is available about the joint associations between particulate air pollution, ambient temperature, and respiratory morbidity. oBjectives: We evaluated associations between concentrations of particulate matter ≤ 2.5 μm in diameter (PM2.5) and exacerbation of existing asthma and modification of the associations by ambient air temperature. Methods: Data from 50,356 adult respondents to the Asthma Call-back Survey from 2006–2010 were linked by interview date and county of residence to estimates of daily averages of PM2.5 and maximum air temperature. Associations between 14-day average PM2.5 and the presence of any asthma symptoms during the 14 days leading up to and including the interview date were evaluated using binomial regression. We explored variation by air temperature using similar models, stratified into quintiles of the 14-day average maximum temperature. results: Among adults with active asthma, 57.1% reported asthma symptoms within the past 14 days, and 14-day average PM2.5 ≥ 7.07 μg/m3 was associated with an estimated 4–5% higher asthma symptom prevalence. In the range of 4.00–7.06 μg/m3 of PM2.5, each 1-μg/m3 increase was associated with a 3.4% [95% confidence interval (CI): 1.1, 5.7] increase in symptom preva-lence; across categories of temperature from 1.1 to 80.5°F, each 1-μg/m3 increase was associated with increased symptom prevalence (1.1–44.4°F: 7.9%; 44.5–58.6°F: 6.9%; 58.7–70.1°F: 2.9%; 70.2–80.5°F: 7.3%). conclusions: These results suggest that each unit increase in PM2.5 may be associated with an increase in the prevalence of asthma symptoms, even at levels as low as 4.00–7.06 μg/m3.

Published Dec 1, 2016

Mirabelli, M. C., Vaidyanathan, A., Flanders, W. D., Qin, X., & Garbe, P. (2016). Outdoor PM2.5, ambient air temperature, and asthma symptoms in the past 14 days among adults with active asthma. Environmental Health Perspectives, 124(12), 1882–1890. https://doi.org/10.1289/EHP92

African Americans are among the least responsible for contributing to Green House Gas (GHG) emissions that cause climate change, but are disproportionately burdened by the environmental harm, unemployment, economic hardship, and heath impacts from heat waves and other extreme weather events that result from this phenomenon. A 2004 report by the Congressional Black Caucus Foundation, Inc. (CBCF) examined the relationships between African Americans, climate change, and federal policy and, unfortunately, the findings of this report authored 12 years ago still ring true today. There is no lack of reports, research, and experiences that document how climate change impacts the lives of minorities, particularly African Americans, more negatively than others.

Published Sep 22, 2016

White-Newsome, J. L. (2016). A Policy Approach Toward Climate Justice. Black Scholar, 46(3), 12–26. https://doi.org/10.1080/00064246.2016.1188353

The growth of worldwide environmental awareness has prompted numerous countries to focus on developing energy-conservation and carbon-reduction technology. The advancement of such technology enables the emergence of low-noise, low-polluting alternatives for bus systems, such as hybrid-electric, battery-electric, and fuel-cell electric buses (e-buses). For such buses to serve the existing schedules and lines operated by their conventional counterparts, reorganizing bus transportation systems is a major challenge and entails construction costs that comprise the costs of e-buses, battery capacity, chargers, and bus scheduling. To facilitate the development of environmentally friendly public transportation, this study proposes a model for simulating the operation and battery charging schedule of plug-in e-buses on the basis of an existing schedule and line network. The model was used to estimate the overall construction cost of converting the existent bus transportation system into an all plug-in e-bus one. Focusing on the bus transportation system in Penghu, an archipelago of Taiwan, this case study examined the effects of day- and nighttime charging requirements on the construction cost of an e-bus transportation system to improve the practicability of e-buses. It also applied a genetic algorithm to determine the minimum construction cost, which varied depending on the number of e-buses, level of battery capacity, number of chargers, and electricity costs. The optimized parameters involved the hourly residual battery capacity and battery charging times during the daytime operating hours. The results showed that although daytime charging involved electricity uses during peak hours and thus incurred additional costs, it contributed to the use of e-buses and an overall reduction in the construction cost. In summary, the proposed optimization method would successfully reduce the construction cost of the Penghu e-bus transportation system.

Published Sep 1, 2016

Ke, B. R., Chung, C. Y., & Chen, Y. C. (2016). Minimizing the costs of constructing an all plug-in electric bus transportation system: A case study in Penghu. Applied Energy, 177, 649–660. https://doi.org/10.1016/j.apenergy.2016.05.152

Background The contribution of modifiable risk factors to the increasing global and regional burden of stroke is unclear, but knowledge about this contribution is crucial for informing stroke prevention strategies. We used data from the Global Burden of Disease Study 2013 (GBD 2013) to estimate the population-attributable fraction (PAF) of stroke-related disability-adjusted life-years (DALYs) associated with potentially modifiable environmental, occupational, behavioural, physiological, and metabolic risk factors in different age and sex groups worldwide and in high-income countries and low-income and middle-income countries, from 1990 to 2013. Methods We used data on stroke-related DALYs, risk factors, and PAF from the GBD 2013 Study to estimate the burden of stroke by age and sex (with corresponding 95% uncertainty intervals [UI]) in 188 countries, as measured with stroke-related DALYs in 1990 and 2013. We evaluated attributable DALYs for 17 risk factors (air pollution and environmental, dietary, physical activity, tobacco smoke, and physiological) and six clusters of risk factors by use of three inputs: risk factor exposure, relative risks, and the theoretical minimum risk exposure level. For most risk factors, we synthesised data for exposure with a Bayesian meta-regression method (DisMod-MR) or spatial-temporal Gaussian process regression. We based relative risks on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks, such as high body-mass index (BMI), through other risks, such as high systolic blood pressure (SBP) and high total cholesterol. Findings Globally, 90·5% (95% UI 88·5–92·2) of the stroke burden (as measured in DALYs) was attributable to the modifiable risk factors analysed, including 74·2% (95% UI 70·7–76·7) due to behavioural factors (smoking, poor diet, and low physical activity). Clusters of metabolic factors (high SBP, high BMI, high fasting plasma glucose, high total cholesterol, and low glomerular filtration rate; 72·4%, 95% UI 70·2–73·5) and environmental factors (air pollution and lead exposure; 33·4%, 95% UI 32·4–34·3) were the second and third largest contributors to DALYs. Globally, 29·2% (95% UI 28·2–29·6) of the burden of stroke was attributed to air pollution. Although globally there were no significant differences between sexes in the proportion of stroke burden due to behavioural, environmental, and metabolic risk clusters, in the low-income and middle-income countries, the PAF of behavioural risk clusters in males was greater than in females. The PAF of all risk factors increased from 1990 to 2013 (except for second-hand smoking and household air pollution from solid fuels) and varied significantly between countries. Interpretation Our results suggest that more than 90% of the stroke burden is attributable to modifiable risk factors, and achieving control of behavioural and metabolic risk factors could avert more than three-quarters of the global stroke burden. Air pollution has emerged as a significant contributor to global stroke burden, especially in low-income and middle-income countries, and therefore reducing exposure to air pollution should be one of the main priorities to reduce stroke burden in these countries. Funding Bill & Melinda Gates Foundation, American Heart Association, US National Heart, Lung, and Blood Institute, Columbia University, Health Research Council of New Zealand, Brain Research New Zealand Centre of Research Excellence, and National Science Challenge, Ministry of Business, Innovation and Employment of New Zealand.

Published Jun 9, 2016

Feigin, V. L., Roth, G. A., Naghavi, M., Parmar, P., Krishnamurthi, R., Chugh, S., Mensah, G. A., Norrving, B., Shiue, I., Ng, M., Estep, K., Cercy, K., Murray, C. J. L., & Forouzanfar, M. H. (2016). Global burden of stroke and risk factors in 188 countries, during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. The Lancet Neurology, 15(9), 913–924. https://doi.org/10.1016/S1474-4422(16)30073-4

Human civilization is currently facing two particular challenges: population growth with a strong trend towards urbanization and climate change. The latter is now no longer seriously questioned. The primary concern is to limit anthropogenic climate change and to adapt our societies to its effects. Schools are a key part of the structure of our societies. If future generations are to take control of the manifold global problems, we have to offer our children the best possible infrastructure for their education: not only in terms of the didactic concepts, but also with regard to the climatic conditions in the school environment. Between the ages of 6 and 19, children spend up to 8 h a day in classrooms. The conditions are, however, often inacceptable and regardless of the geographic situation, all the current studies report similar problems: classrooms being too small for the high number of school children, poor ventilation concepts, considerable outdoor air pollution and strong sources of indoor air pollution.There have been discussions about a beneficial and healthy air quality in classrooms for many years now and in recent years extensive studies have been carried out worldwide. The problems have been clearly outlined on a scientific level and there are prudent and feasible concepts to improve the situation. The growing number of publications also highlights the importance of this subject. High carbon dioxide concentrations in classrooms, which indicate poor ventilation conditions, and the increasing particle matter in urban outdoor air have, in particular, been identified as primary causes of poor indoor air quality in schools. Despite this, the conditions in most schools continue to be in need of improvement. There are many reasons for this. In some cases, the local administrative bodies do not have the budgets required to address such concerns, in other cases regulations and laws stand in contradiction to the demands for better indoor air quality, and sometimes the problems are simply ignored.This review summarizes the current results and knowledge gained from the scientific literature on air quality in classrooms. Possible scenarios for the future are discussed and guideline values proposed which can serve to help authorities, government organizations and commissions improve the situation on a global level.

Published May 8, 2016

Salthammer, T., Uhde, E., Schripp, T., Schieweck, A., Morawska, L., Mazaheri, M., Clifford, S., He, C., Buonanno, G., Querol, X., Viana, M., & Kumar, P. (2016). Children’s well-being at schools: Impact of climatic conditions and air pollution. Environment International, 94, 196–210. https://doi.org/10.1016/j.envint.2016.05.009

Importance: Childhood bronchitic symptoms are significant public and clinical health problems that produce a substantial burden of disease. Ambient air pollutants are important determinants of bronchitis occurrence.

Objective: To determine whether improvements in ambient air quality in Southern California were associated with reductions in bronchitic symptoms in children.

Design, Setting, and Participants: A longitudinal study involving 4602 children (age range, 5-18 years) from 3 cohorts was conducted during the 1993-2001, 1996-2004, and 2003-2012 years in 8 Southern California communities. A multilevel logistic model was used to estimate the association of changes in pollution levels with bronchitic symptoms.

Exposures: Average concentrations of nitrogen dioxide, ozone, particulate matter with an aerodynamic diameter of less than 10 µm (PM10) and less than 2.5 µm (PM2.5).

Main Outcomes and Measures: Annual age-specific prevalence of bronchitic symptoms during the previous 12 months based on the parent’s or child’s report of a daily cough for 3 months in a row, congestion or phlegm other than when accompanied by a cold, or bronchitis.

Results: The 3 cohorts included a total of 4602 children (mean age at baseline, 8.0 years; 2268 girls [49.3%]; 2081 Hispanic white [45.2%] ) who had data from 2 or more annual questionnaires. Among these children, 892 (19.4%) had asthma at age 10 years. For nitrogen dioxide, the odds ratio (OR) for bronchitic symptoms among children with asthma at age 10 years was 0.79 (95% CI, 0.67-0.94) for a median reduction of 4.9 ppb, with absolute decrease in prevalence of 10.1%. For ozone, the OR was 0.66 (95% CI, 0.50-0.86) for a median reduction of 3.6 ppb, with an absolute decrease in prevalence of 16.3%. For PM10, the OR was 0.61 (95% CI, 0.48-0.78) for a median reduction of 5.8 µg/m3, with an absolute decrease in prevalence of 18.7%. For PM2.5, the OR was 0.68 (95% CI, 0.53-0.86) for a median reduction of 6.8 µg/m3, with absolute decrease in prevalence of 15.4%. Among children without asthma (n = 3710), the ORs were 0.84 (95% CI, 0.76-0.92) for nitrogen dioxide; 0.85 (95% CI, 0.74-0.97) for ozone, 0.80 (95% CI, 0.70-0.92) for PM10, and 0.79 (95% CI, 0.69-0.91) for PM2.5; with absolute decrease in prevalence of 1.8% for nitrogen dioxide, 1.7% for ozone, 2.2% for PM10, and 2.3% for PM2.5. The associations were similar or slightly stronger at age 15 years.

Conclusions and Relevance: Decreases in ambient pollution levels were associated with statistically significant decreases in bronchitic symptoms in children. Although the study design does not establish causality, the findings support potential benefit of air pollution reduction on asthma control.

Published Apr 12, 2016

Berhane, K., Chang, C. C., McConnell, R., Gauderman, W. J., Avol, E., Rapapport, E., Urman, R., Lurmann, F., & Gilliland, F. (2016). Association of Changes in Air Quality With Bronchitic Symptoms in Children in California, 1993-2012. JAMA, 315(14), 1491–1501. https://doi.org/10.1001/JAMA.2016.3444

Epidemiologic studies can measure exposure to volatile organic compounds (VOCs) using environmental samples, biomarkers, questionnaires, or observations. These different exposure assessment approaches each have advantages and disadvantages; thus, evaluating relationships is an important consideration. In the National Children’s Vanguard Study from 2009 to 2010, participants completed questionnaires and data collectors observed VOC exposure sources and collected urine samples from 488 third trimester pregnant women at in-person study visits. From urine, we simultaneously quantified 28 VOC metabolites of exposure to acrolein, acrylamide, acrylonitrile, benzene, 1-bromopropane, 1,3-butadiene, carbon disulfide, crotonaldehyde, cyanide, N,N-dimethylformamide, ethylbenzene, ethylene oxide, propylene oxide, styrene, tetrachloroethylene, toluene, trichloroethylene, vinyl chloride, and xylene exposures using ultra high performance liquid chromatography coupled with an electrospray ionization tandem mass spectrometry (UPLC-ESI/MSMS) method. Urinary thiocyanate was measured using an ion chromatography coupled with an electrospray ionization tandem mass spectrometry method (IC-ESI/MSMS). We modeled the relationship between urinary VOC metabolite concentrations and sources of VOC exposure. Sources of exposure were assessed by participant report via questionnaire (use of air fresheners, aerosols, paint or varnish, organic solvents, and passive/active smoking) and by observations by a trained data collector (presence of scented products in homes). We found several significant (p < 0.01) relationships between the urinary metabolites of VOCs and sources of VOC exposure. Smoking was positively associated with metabolites of the tobacco constituents acrolein, acrylamide, acrylonitrile, 1,3-butadiene, crotonaldehyde, cyanide, ethylene oxide, N,N-dimethylformamide, propylene oxide, styrene, and xylene. Study location was negatively associated with the toluene metabolite N-acetyl-S-(benzyl)-L-cysteine (BMA), and paint use was positively associated with the xylene metabolites 2-methylhippuric acid (2MHA) and 3-Methylhippuric acid & 4-methylhippuric acid (3MHA + 4MHA). A near-significant (p = 0.06) relationship was observed between acrylamide metabolites and observation of incense.

Published Mar 29, 2016

Boyle, E. B., Viet, S. M., Wright, D. J., Merrill, L. S., Alwis, K. U., Blount, B. C., Mortensen, M. E., Moye, J., & Dellarco, M. (2016). Assessment of exposure to VOCs among pregnant women in the national children’s study. International Journal of Environmental Research and Public Health, 13(4). https://doi.org/10.3390/ijerph13040376