Grantee Research Project Results
Final Report: Climate Change, Indoor Ozone and Vascular Function
EPA Grant Number: R835759Title: Climate Change, Indoor Ozone and Vascular Function
Investigators: Kipen, Howard , Ryan, P. Barry , Barr, Dana Boyd , Georgopoulos, Panos G. , Weschler, Charles J. , Lioy, Paul J. , Ohman-Strickland, Pamela , Meng, Qingyu
Institution: Rutgers
EPA Project Officer: Chung, Serena
Project Period: May 1, 2015 through April 30, 2018 (Extended to April 30, 2019)
Project Amount: $999,975
RFA: Indoor Air and Climate Change (2014) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Climate Change , Air
Objective:
1. Examine how changes in ambient O3 as a consequence of climate change may affect indoor air quality (IAQ) through both a direct effect on indoor O3 concentration and an indirect effect on indoor chemistry. We hypothesize that: 1) indoor O3 concentrations as well as the reaction products of O3 with typically abundant indoor alkenes, limonene and squalene, will increase with increasing outdoor O3 concentration; and 2) relative to outdoor O3, indoor O3 concentrations will increase with increasing ventilation rates, while the concentrations of O3/alkene reaction products will decrease with increasing ventilation rates.
2. Examine whether indoor exposures to air pollutants and cardiorespiratory responses can be modified by a portable air cleaner. We hypothesize that 3) The use of portable air cleaners can reduce indoor exposures to O3 and O3/alkene reaction products and 4) the use of portable air cleaners can significantly improve microvascular function and reduce markers of pulmonary oxidative stress, indicators of increased risk for adverse health outcomes.
3. Model climate change impacts on ambient O3 pollution, indoor exposures to O3 and its reaction products, and cardiovascular health outcomes. We hypothesize that 5) The impact of climate change on indoor exposures and health can be modeled based on data from Objectives 1 and 2; and 6) combining projections of indoor exposures to O3 and reaction products with results.
Summary/Accomplishments (Outputs/Outcomes):
- Use of a commercially available, relatively inexpensive air cleaner (approximately $200) was effective in significantly reducing indoor particle pollution concentrations.
- Despite the large and significant difference in indoor ozone and PM2.5 concentrations between the unfiltered and filtered treatment periods, this study did not find a significant difference in either vascular (microvascular function measured as Reactive Hyperemia Index) or respiratory outcomes (FeNO and exhaled breath condensate nitrite). However, despite our null biomarker results, based on the results of previous, although inconsistent studies, it is reasonable to consider this technique to reduce risk of cardiopulmonary effects from air pollutants. We were unsuccessful in demonstrating an effect of particle reduction on three separate biomarkers of adverse effects on health. This is disappointing but consistent with the overall heterogeneity of the same biomarkers in previous studies. Explanations for these null results include technical challenges of biomarker collection because of the suboptimal collection environment in homes, rather than laboratories, difficulty of elderly subjects performing required maneuvers, subjects who may have spent too much time away from their homes during the filtration period and thus been exposed to higher outdoor levels of PM, use of medications that interfered with the measures (although results remained similar after excluding such subjects from the analysis). The absence of an effect of treatment order (filtered or unfiltered condition first) argues against a residual effect of the unfiltered exposure on the filtered due to our not employing a washout period between treatments.
- This human research in a real-world setting in two different climates again demonstrates the ability to reduce exposure to indoor particle pollution, whether it originates from outdoor or indoor sources. Since individuals, particularly the elderly and very young spend the vast majority of their days at home, and since air pollutants are strongly associated with adverse cardiopulmonary outcomes these practical methods provide an opportunity to reduce the burden of such conditions in populations.
- We were able to demonstrate pollutant reduction even though we permitted ad lib use of windows and window-mounted air conditioners, a more realistic scenario than previously specifie
- Ozone chemistry was not a significant contributor to indoor pollution levels but further study is strongly indicated in various conditions which may be more favorable to these reactions. The lack of a significant relationship between ozone levels and 6MHO concentrations has a number of potential explanations including overall low ozone levels despite limiting data collection to warm months, and only one subject in most homes leading to lower availability of skin oil with which ozone can react.
- Our finding that air change rates (AERs) did not significantly affect indoor to outdoor ratios for ozone seems counter-intuitive. However given our overall low outdoor ozone and indoor ozone levels, (despite only studying in the warm season) as well as the low AERs, it is probable that our power for this effect was markedly limited.
- Existing observational databases and ambient photochemical air quality models (specifically USEPA’s CMAQ), complemented by customized data analytics codes, provide a valuable, robust and cost-effective framework for characterizing outdoor air quality. Similarly, indoor air quality can be related to outdoor levels via case-specific models.
- Various modeling and data analytics “tools” were developed (or refined) to complement and to facilitate application of existing modeling systems (specifically USEPA’s CMAQ) and utilization of national observational databases. These “tools” were demonstrated and evaluated in an initial phase through the present project and provide a useful set of codes that can be extended, improved, and utilized in ongoing and future studies of air pollution and of associated human exposures.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
Other project views: | All 6 publications | 2 publications in selected types | All 2 journal articles |
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Type | Citation | ||
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Cai J, Wei L, Baizhan YR, Zhang T, Guo M, Wang H, Cheng Z, Ziong J, Meng Q, Kipen H. Particle Removal efficiency of a household portable air cleaner in Real-world Residences:A single-blind Ross-over field study.Energy and Buildings 2019;203: 109464. |
R835759 (Final) |
Exit Exit |
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Laumbach R, Romar K, Adamkiewicz G, Carlsten C, Charpin D, Chan W, de Nazelle A, Forastiere F, Goldstein J, Gumy S, Hallman W, Jerrett M, Kipen H, Pirozzi C, Polivka B, Radbel J, Shaffer R, Sin D, Viegi G. Personal Interventions for Reducing Exposure and Risk for Outdoor Air Pollution. ANNALS OF THE AMERICAN THORACIC SOCIETY 2021;18(9):1435-1443. |
R835759 (Final) |
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Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.