Occupational hazards of carbon dioxide exposure

Scott, J.L.; Kraemer, David G.; Keller, Randal J.

doi:10.1016/j.jchas.2008.06.003

Cited by 53 publications

(34 citation statements)

References 6 publications

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“…Passengers exhale CO 2 at much higher concentrations, ranging from 38,000 to 56,000 ppm (Clayton and Clayton, 1991; NIOSH, 1976; Scott et al, 2009). Absent any outside ventilation, normal breathing from occupants in an enclosed space will tend to promote buildup of CO 2 .…”

Section: Introductionmentioning

confidence: 99%

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

Jung

Grady

Victoroff

et al. 2017

Atmospheric Environment

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Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

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Section: Introductionmentioning

confidence: 99%

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

Jung

Grady

Victoroff

et al. 2017

Atmospheric Environment

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“…In a confined space, such as in a vehicle cabin, the carbon dioxide (CO 2 ) concentration can build up due to human exhalation at the expense of oxygen (O 2 ) availability (Scott et al, 2009).There is no prescribed limit for passenger cars, but the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard 62-2001 recommendation suggests a permissible level of about 1200-1300 ppm for the cabin interior, and a maximum allowable exposure limit of 8 hr at concentration of 5000 ppm (ASHRAE, 2003). In excess of 30,000 ppm, nausea and decisionmaking impairment can occur.…”

Section: Introductionmentioning

confidence: 99%

In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand

Luangprasert

Vasithamrong

Pongratananukul

et al. 2017

Journal of the Air & Waste Management Association

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Drivers in tropical Asian countries typically use HVAC recirculation mode in their automobiles. This behavior leads to excessive buildup of cabin CO concentration levels. The paper describes the CO buildup in a typical commute in Bangkok, Thailand. Auto manufacturers can potentially take measures to alleviate such high concentration levels. The paper also discusses the diffusion of CO through the vehicle envelope, an area that has never been investigated before.

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“…Though carbon dioxide is the fourth most common gas in the atmosphere at about 300 ppm, higher concentrations of it can be toxic if inhaled. The average concentration in the air should not exceed 5000 ppm for longer periods of time [32]. Additional carbon dioxide in the air is not only toxic, but also displaces oxygen, which can lead to asphyxiation.…”

Section: Safety Aspectsmentioning

confidence: 99%

“…The dry ice power cell introduced in [18] produces a gas flow of about 0.4 L/min from the relief valve when the heat transfer is reduced and the output is closed. In comparison, an adult male breathes out up to 1.65 L/min of carbon dioxide during moderate exercise [32], so storing such a power cell at home is unproblematic. The maximum flow rate of carbon dioxide from the device is much higher at 1.8 L/s, so it should only be used in adequately ventilated areas.…”

Section: Safety Aspectsmentioning

confidence: 99%

On-Board Pneumatic Pressure Generation Methods for Soft Robotics Applications

Adami

Seibel

2018

Actuators

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The design and construction of a soft robot are challenging tasks on their own. When the robot is supposed to operate without a tether, it becomes even more demanding. While a tethered operation is sufficient for a stationary use, it is impractical for wearable robots or performing tasks that demand a high mobility. Choosing and implementing an on-board pneumatic pressure source are particularly complex tasks. There are several different pressure generation methods to choose from, each with very different properties and ways of implementation. This review paper is written with the intention of informing about all pressure generation methods available in the field of soft robotics and providing an overview of the abilities and properties of each method. Nine different methods are described regarding their working principle, pressure generation behavior, energetic considerations, safety aspects, and suitability for soft robotics applications. All presented methods are evaluated in the most important categories for soft robotics pressure sources and compared to each other qualitatively and quantitatively as far as possible. The aim of the results presented is to simplify the choice of a suitable pressure generation method when designing an on-board pressure source for a soft robot.

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Occupational hazards of carbon dioxide exposure

Cited by 53 publications

References 6 publications

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand

On-Board Pneumatic Pressure Generation Methods for Soft Robotics Applications

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