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General Pollutant Information

Page history last edited by ashley.collier@... 13 years, 1 month ago

 

General Pollutant Level Information 

 

     skip to: CO2, CO, VOC, O3, NO, or other MAQS quantities

 

 


 

     The information below provides a brief description of the pollutants measured by M-Pods and their main sources, as well as, reference levels to compare to the M-Pod results.  Users can view what their current levels are using the MAQS app, and all of the levels they have encountered through the MAQS network.  Something to consider when viewing your MAQS data is how the individual pollutants vary from location to location or during different activities; a brief intorduction to these pollutants might help you understand the reasons for these variances.  

 

For some more detailed information on pollutants or indoor air quality, try these links:

 

http://epa.gov/airquality/urbanair/ or http://www.epa.gov/iaq/ia-intro.html

 


 

 

CO2 - Carbon Dioxide:

 

The primary source for CO2 indoors is human exhalation.  This compound is a byproduct of human metabolic activity and might be more likely to build up in areas with a lot of people or poor ventilation.  Some other sources include those resulting in combustion byproducts: car exhaust, leaking furnaces, cigarette smoke, etc…

(http://www.idph.state.il.us/envhealth/factsheets/indoorairqualityguide_fs.htm; http://www.health.state.mn.us/divs/eh/indoorair/co2/index.html)

Reference Levels: 

 

300 – 400 ppm

Typical levels outdoors

600 – 1000 ppm

Typical levels in properly ventilated buildings

> 1000 ppm

 Anything in this range suggests inadequate ventilation possibly leading to CO2 related complaints or problems from other compounds that might also be building up in the space

 

 

 

 

 

 

 

(http://www.idph.state.il.us/envhealth/factsheets/indoorairqualityguide_fs.htm)

 

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CO - Carbon Monoxide:

 

This pollutant is a result of the incomplete burning of fuels (such as natural gas, propane, coal, wood).  Some common sources of carbon monoxide are unvented gas space heaters, gas stoves, fireplaces, generators, gasoline-powered equipment, including automobiles.  In particular, dangerous sources can be old or poorly functioning combustion devices.  In certain quantities, this pollutant can pose immediate threats to human health.

(http://www.epa.gov/iaq/co.html#Levels%20in%20Homes) 

Reference Levels:

 

.5-5 ppm

Typical range in homes with no gas stove

5-15 ppm

Typical range in homes with a gas stove

1-70 ppm

Prolonged exposure to this range typically does not cause symptoms in healthy people

> 70 ppm

Symptoms of CO poisoning will begin to appear in healthy people

> 150-200 ppm

Dangerous levels of CO exposure

(http://www.epa.gov/iaq/voc.html#Levels%20in%20Homes; http://www.cpsc.gov/cpscpub/pubs/466.html)

 

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VOCs - Volatile Organic Compounds:

 

The compositions of VOC’s allow them to evaporate (from solid or liquid form) under normal indoor temperature and pressure conditions making them easier for people to accidentally ingest, thereby posing a threat to human health.  They are present in a wide variety of products from cleaning supplies and pesticides, to building materials, paints, and office equipment.  Some VOC’s are even know carcinogens. 

(http://www.epa.gov/iaq/voc.html) 

Reference Levels:

 

Unfortunately very little research has been done on overall VOC levels and their impacts, studies indicate that indoor levels are on average 2-5 times higher than outdoor levels.  Although there are several know VOC’s that are regulated individually; formaldehyde, for example, has a Permissible Exposure Level of .75 ppm as determined by OSHA.

(http://www.epa.gov/iaq/voc.html#Levels%20in%20Homes)

 

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O3 - Ozone:

 

The effects of ozone varying depending on where it is located; in the upper areas of earth’s atmosphere it occurs naturally and shields the earth from the sun’s ultraviolet rays.  However, on a ground level it poses a threat to human health as a pollutant.  Ozone is formed when VOC’s and nitrogen oxides react in sunlight, which is why ozone is typically highest on sunny days in urban environments.  The source of ozone forming compounds is emissions from vehicles, construction equipment, industry, and some consumer products.  Another factor to consider, is that ozone is more prevalent outdoors than in, and should be considered when engaging in outdoor physical activities. 

(http://www.airnow.gov/index.cfm?action=pubs.aqiguideozone) 

Reference Levels:

 

< .059 ppm

Good levels

.060 - .075 ppm

Moderate levels

.076 - .095 ppm

Unhealthy for primarily sensitive groups

.096 - .115 ppm

Unhealthy levels

.116 - .404 ppm (and higher)

Very unhealthy for both sensitive and healthy groups

(http://www.airinfonow.org/html/ed_ozone.html)

 

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NO - Nitrogen Oxides:

 

This measurement refers to the NO and NO2 levels in the air, both of which are toxic.  Indoors, these compounds primarily result from combustion reactions (gas stoves, gas heaters, tobacco smoke).  Outdoors, NO and NO2 come primarily from emissions (car exhaust, or industry).  They pose a threat to human health both in their NO and NO2 forms, and because NO2 is a contributor to ozone production. 

(http://www.epa.gov/air/nitrogenoxides/) 

Reference Levels:

 

Currently there are no standards or limits for indoor air levels of nitrogen oxides; for reference, levels in homes without combustion appliances are typically half of outdoor levels, while homes with combustion appliances can have levels exceeding outdoor levels.  Although outdoor annual average limit for NO2 is set at .053 ppm.

(http://www.epa.gov/air/nitrogenoxides/)

 

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Other MAQS Quantities

 

 

Temperature:

 

The temperature sensor is located inside the M-Pod, for this reason there are no drastic changes.  The device continuously emits energy in the form of heat, resulting in these consistent temperatures. 

 

Relative Humidity:

 

This sensor is also located inside of the M-Pod and records the relative humidity inside of the device. 

 

Light:

 

This aspect of the M-Pods is not yet functional, but once the sensor is implanted it will record the relative amount of light reaching the device, thereby providing information on light levels based on location. 

 

Battery:

 

            These levels provide the user with a percentage of remaining battery life for the M-Pod.

 

Voltage:

 

            These levels indicate the current operating voltage of the M-Pod.

 

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