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.

Citation:

Allen JG, MacNaughton P, Satish U, Santanam S, Vallarino J, Spengler JD. 2016. 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. Environ Health Perspect 124:805–812; http://dx.doi.org/10.1289/ehp.1510037

Background:

There are > 7,000 e-cigarette flavors currently marketed. Flavoring chemicals gained notoriety in the early 2000s when inhalation exposure of the flavoring chemical diacetyl was found to be associated with a disease that became known as “popcorn lung.” There has been limited research on flavoring chemicals in e-cigarettes.

Objective:

We aimed to determine if the flavoring chemical diacetyl and two other high-priority flavoring chemicals, 2,3-pentanedione and acetoin, are present in a convenience sample of flavored e-cigarettes.

Methods:

We selected 51 types of flavored e-cigarettes sold by leading e-cigarette brands and flavors we deemed were appealing to youth. E-cigarette contents were fully discharged and the air stream was captured and analyzed for total mass of diacetyl, 2,3-pentanedione, and acetoin, according to OSHA method 1012.

Results:

At least one flavoring chemical was detected in 47 of 51 unique flavors tested. Diacetyl was detected above the laboratory limit of detection in 39 of the 51 flavors tested, ranging from below the limit of quantification to 239 μg/e-cigarette. 2,3-Pentanedione and acetoin were detected in 23 and 46 of the 51 flavors tested at concentrations up to 64 and 529 μg/e-cigarette, respectively.

Conclusion:

Because of the associations between diacetyl and bronchiolitis obliterans and other severe respiratory diseases observed in workers, urgent action is recommended to further evaluate this potentially widespread exposure via flavored e-cigarettes.

Citation:

Allen JG, Flanigan SS, LeBlanc M, Vallarino J, MacNaughton P, Stewart JH, Christiani DC. 2016. Flavoring chemicals in e-cigarettes: diacetyl, 2,3-pentanedione, and acetoin in a sample of 51 products, including fruit-, candy-, and cocktail-flavored e-cigarettes. Environ Health Perspect 124:733–739; http://dx.doi.org/10.1289/ehp.1510185

Background: Due to data collection challenges, the vertical variation in population and particulate air pollution are typically not accounted for in exposure assessments, which may lead to misclassification of exposures based on height of residency.

Aims: The objective of this work was to assess the vertical distribution of exposed populations and their relative potential exposures to air pollutants.

Methods: The vertical distribution of the potentially highly exposed population (PHEP), defined as all residents within the 100-m buffer zone of the above-ground highways or the 200-m buffer zone of a tunnel exit, was estimated by four floor categories in Boston’s Chinatown (MA, USA) using a three-dimensional digital geography (3DIG) methodology. Vertical profiles of particle number concentration (7-1000 nm; PNC) and PM2.5 mass concentration were measured by hoisting instruments up the vertical face of an 11-story (35-m) building near the study area on multiple days. The concentrations from all the profiles (n=23) were averaged together for each floor category. PHEP was multiplied by the average PNC at each floor category to assess the exposures for near-highway populations. Results: As measurement height increased from 0 to 35 m PNC decreased by 7.7%, compared to 3.6% for PM2.5. PHEP was multiplied by the average PNC at each floor category to assess the exposures for near-highway populations. This result of PHEP multiplied by PNC (residents × particles/cm3) suggested that adding vertical air pollution data could help to better define exposures for near-highway populations during certain meteorological conditions. Conclusion The results show that adding temporally-averaged vertical air pollution data had only a small effect on residential ambient exposures for our study population. Greater differences were observed when winds were from the northeast (off the highways).

Biophilic design, which incorporates natural elements into the built environment, has received increasing attention in both design and health fields. Epidemiological and experimental studies have provided sufficient evidence that contact with outdoor nature has positive impacts on human health and wellbeing. However, the potential for similar health benefits in indoor biophilic environments remains unclear. We designed a randomized crossover study to examine the physiological and cognitive responses to biophilic indoor environments by using virtual reality (VR) and wearable bio-monitoring sensors. In this study, 28 participants spent time in an indoor environment featuring biophilic design elements and one without, with the order of the visit randomized. In each visit, they experienced the same environment for 5-minutes in reality and virtually by using VR. The indoor biophilic environment was associated with a decrease in participants's blood pressure. The overall differential effects for participants experiencing an indoor environment with biophilic elements versus none was 8.56 (95%CI: 5.60-11.52) mmHg lower systolic and 3.57 (95%CI: 0.36-6.78) mmHg lower diastolic blood pressure. In addition, their skin conductance decreased by 0.18 (95%CI: -0.004-0.36) µS and short-term memory improved by 14% (95%CI: 5.3%-23.2%). Moreover, our findings indicate that participants had similar physiological and cognitive benefits in the virtual environment and actual environment. The results indicate that biophilic environment may be benefitial in reduce stress in indoor settings. Additionally, the parity in results in virtual and real environments provides evidence that using VR can be an effective tool to simulate visual exposures when access to the real environment is not feasible.

Buildings consume nearly 40% of primary energy production globally. Certified green buildings substantially reduce energy consumption on a per square foot basis; however, the co-benefits to health through reductions in energy use and concomitant reductions in air pollution from fossil fuel power plants have not been examined. We calculated year by year LEED (Leadership in Energy and Environmental Design) certification rates in six countries (United States, China, India, Brazil, Germany and Turkey) and then used data from the Green Building Information Gateway (GBIG) to estimate energy savings in each country each year. Of the green building rating schemes, LEED accounts for 32% of green certified floor space and publically reports energy efficiency data. We employed Harvard&#8217;s Co-BE Calculator to determine pollutant emissions reductions by country accounting for transient energy mixes and baseline energy use intensities. Co-BE applies the social cost of carbon and the social cost of atmospheric release to translate these reductions into health benefits. Based on modeled energy use, LEED-certified buildings saved $7.5B in energy costs and averted 33MT of CO₂, 51kt of SO₂, 38kt of NO_x and 10kt of PM_2.5 from entering the atmosphere, which amounts to $5.8B (lower limit &#61; $2.3B, upper limit &#61; $9.1B) in climate and health co-benefits from 2000 to 2016 in the six countries investigated. The U.S. health benefits derive from avoiding an estimated 172-405 premature deaths, 171 hospital admissions, 11,000 asthma exacerbations, 54,000 respiratory symptoms, 21,000 lost days of work, and 16,000 lost days of school. Because the climate and health benefits are nearly equivalent to the energy savings for green buildings in the U.S., and up to ten times higher in developing countries, they provide an important and previously unquantified societal value.

Sensor-activated, dynamic portable air purifiers are a part of a growing market of smart home technologies aimed at improving energy efficiency and health. For vulnerable populations such as children, elderly and individuals with a pre-existing condition, air purification may reduce daily exposure to harmful concentrations of fine particles. Some new air purifiers are sensor activated such that filtration is triggered by air quality conditions in the space; however, the effectiveness of these &#8216;smart home&#8217; purifiers compared to traditional air purification has not been evaluated in a real-world setting. In summer 2017, a crossover study was completed in small urban residences (n&#61;32), which compared the change in continuous particulate matter less than 2.5 microns in diameter (PM_2.5) concentrations across three intervention arms: 1) No Air Purification, 2) Smart Home Purification and 3) Continuous Purification. Overall, continuous purification significantly reduced average PM_2.5 compared to baseline and smart home conditions by 1.171 µg/mand 1.210 µg/mrespectively. However, the average duration participants were exposed to concentrations above 30µg/m, the activation threshold for the device used in the study, was shortened by 60.8 minutes and 43.8 minutes with Smart Home purification compared to baseline and continuous filtration, respectively. The implication of these findings is that Smart Home purification can reduce peak exposures to PM_2.5, but may lead to higher cumulative exposures at lower levels compared to continuous filtration. As a result, Smart Home purification may be best suited to reduce exposures during acute PM2.5-emitting events such as cooking or rush hour traffic.

A growing body of research points to the effects of indoor air quality (IAQ) on health and cognitive performance. IAQ measurements allow for the evaluation of indoor environments, and new sensor technology has made measurement more accessible. However, effective decision making for improvement of these environments is only possible through an understanding of the spatiotemporal distribution of these elements indoors. We designed an augmented reality (AR) system that takes real time air quality data from multiple sensors and creates a spatial map of these conditions. The program interpolates between the data points and creates a real-time three-dimensional heatmap that represents the concentration of air quality indicators. This map is projected on the physical environment through an AR application. This overlaid map can be seen through a digital device such as android tablet, cell phone or through Microsoft HoloLens (an AR headset). Users can toggle between various environmental factors such as CO₂, particulate matter, humidity and temperature with the use of a virtual button. This novel system has the ability to make invisible environmental exposures visible through AR, which has implications for building design/operation, space use and occupant behaviors.

Recent studies suggest that carbon dioxide has an impact on cognitive functions of office workers at concentrations in the range of 1000-2500 ppm. Reports of CO₂ concentrations on airplanes are in the same range, so we were motivated to test the impact of CO₂ on airplane pilot performance. In this study, we recruited 30 active commercial airline pilots to fly three 3-hour flight segments in an FAA-approved flight simulator under three different CO₂ concentrations (700, 1500, 2500 ppm), each time blinded to test conditions and with the order of exposures randomized. CO₂ concentrations were directly modified by introducing ultra-pure CO₂ into the simulator with the ventilation rate unchanged. The pilots performed a series of pre-defined maneuvers of varying difficulty without the aid of autopilot and were assessed by an FAA Designated Pilot Examiner according to FAA Practical Test Standards. The results showed that airplane pilots performed better at lower CO₂ concentrations on the flight deck. Compared to segments at a CO₂ concentration of 2500 ppm, the odds of passing a maneuver as rated by the Examiner in the simulator were 1.52 (95% CI: 1.02 &#8211; 2.25) times higher when pilots were exposed to 1500 ppm and 1.69 (95% CI: 1.11 &#8211; 2.55) times higher when exposed to 700 ppm, controlling for maneuver difficulty, Examiner and order of maneuvers. The effect of CO₂ on passing rates became more pronounced the longer the pilots were in the simulator. These findings suggest that there is a direct effect of carbon dioxide on cognitive performance, independent of ventilation, with implications for many other indoor environments that routinely experience CO₂ concentrations above 1000 ppm.