NIES: 4 – Measure en interpret the results

So what do we need to look for?

If we start to look the elements that can influence air quality, the list is big. In fact, it’s so big, we can only influence a fraction of it unless you live on a daily basis in the Cheyenne Mountain Complex (and I guarantee you that this wont give you a longer life unless somebody start’s nuking the planet).

This read is a bit longer then anticipated but I wanted to provide a complete documentation where possible. And then still, there was a lot to leave out so I kindly provided links should you wish to know more…

If we start to look the elements that can influence air quality, the list is big. In fact, it’s so big, we can only influence a fraction of it unless you live on a daily basis in the Cheyenne Mountain Complex (and I guarantee you that this wont give you a longer life unless somebody start’s nuking the planet).

But if we zoom in a bit, we can identify some common pollutants that mess up that clean air we used to have a long time ago. According to a document published by the US EPA in 2014 (pdf) these are the most common indoor air pollutants:

  • Biological contaminants
  • Carbon dioxide (CO2)
  • Carbon monoxide (CO)
  • Environmental tobacco smoke (ETS) or secondhand smoke
  • Fine particulate matter (PM)
  • Nitrogen dioxide (NO2)
  • Radon (Rn)
  • Other volatile organic compounds (VOCs):
    Formaldehyde, solvents, cleaning agents, etc.

I removed a few such as Dust and Pesticides as it’s redundant with Fine Particulate Matter and VOCs. I also removed Lead (Pb) as this can be measured as a PM10 particle and further measurement options are out of the scope of this project.

Most of these pollutants can be identified on sight or smell and be prevented by keeping your home warm and clean. But for others, such as Carbon Monoxide, fine particles and Lead, we need sensors or specialist analysis, we need help with that.

Lets focus on the list and see what we possibly can analyze with our new N.I.E.S. device (given our limited budget). For each pollutant I want/need to know a couple of things:

  • What it is exactly
  • How bad is it to your health
  • It’s most common (indoor) origin
  • How to prevent it
  • What is a high, good and low concentration
  • Best course of action when a unhealthy concentration is found

As a source, I found a lot in the documentation from the World Health Organization. After some investigation, I judged that is is safest to follow their advises as the WHO does not to answer to voters or taxpayers. And you can see what effect this has on policies and law (really happy I live in the EU right now):


So lets follow the WHO for this project where possible:
WHO guidelines for indoor air quality (site)
WHO guidelines for indoor air quality: selected pollutant (PDF)
WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide (PDF)
WHO air pollution guidelines (site)
WHO Handbook on indoor Radon (PDF)

Biological contaminant

  • What it is exactly
    Common biological contaminants include mold, dust mites, pet dander (skin flakes), droppings and body parts from cockroaches, rodents and
    other pests or insects, viruses, and bacteria. Many of these biological contaminants are small enough to be inhaled.
  • How bad is it to your health
    Depends and there is not 1 wright answer. In an average, heated and regular cleaned house, most contaminants are harmless for the average person. However, is can range to deadly.
    If you have a Cat at home, read this wikipedia page about the Toxoplasmosis disease:
  • It’s most common (indoor) origin
    Biological contaminants are, or are produced by, living things. Biological contaminants are often found in areas that provide food and moisture. Damp or wet areas such as cooling coils, humidifiers, condensate pans, or unvented bathrooms can be moldy. Draperies, bedding, carpet, and other areas where dust collects may accumulate biological contaminants.

  • How to prevent it
    As a start, clean up your house and keep is clean. If you have pets, take special care of it. Take a look at the this site if you have any questions:
  • What is a high, good and low concentration
    How to measure this depends on your budget. Ranging from a light-scattering total particle detectors to a full blown professional equipment to give you more inside for specific contaminants. Safe to say that the later goes way over the budget for this project…

    If we are looking at specific contaminants it varies, it totally depends on what you are measuring and by what guidelines you judge.
    As an example, E.coli must be less than 1 CFU/100 mL for drinking water in the United States. The WHO states: “Must not be detectable in any 100-ml sample”.

    But as it is safe to say that for this project we are going to look for a simple particle sensor, the acceptable concentration levels can be found under “Fine particulate matter (PM)” paragraph.

  • Best course of action when a unhealthy concentration is found
    See the “Fine particulate matter (PM)” paragraph.

Carbon dioxide (CO2)

  • What it is exactly
    Carbon dioxide (CO2) is a colorless, odorless product of carbon combustion.
  • How bad is it to your health
    Exposure to high levels of CO2 can produce a variety of health effects. These may include headaches, dizziness, restlessness, a tingling or pins or needles feeling, difficulty breathing, sweating, tiredness, increased heart rate, elevated blood pressure, coma, asphyxia, and convulsions.
  • It’s most common (indoor) origin
    Human metabolic processes and all combustion processes of carbon fuels, like those in cars, buses, trucks, etc., are sources of CO2. Exhaled
    air is usually the largest source of CO2 in (class)rooms. In homes, most common sources are a fuel burning fireplace and from a gas appliance. Carbon dioxide is also used in fire extinguishers, in laboratories, and in theater and stage productions as dry ice to make fog…

  • How to prevent it
    Always ventilate and make sure their is enough fresh air coming into your home, especially when cooking or using fireplaces.
  • What is a high, good and low concentration
    Unfortunately, WHO dropped CO2 from its studies and guidelines due to “Current evidence uncertain or not sufficient for guidelines”. See the WHO “Development of WHO Guidelines forIndoor Air Quality” for more information about this.

    Luckily, the US Wisconsin Department of Health Services published information about concentration levels:

    250 – 350 ppm: background (normal) outdoor air level.
    350 – 1,000 ppm: typical level found in occupied spaces with good air exchange.
    1,000 – 2,000 ppm: level associated with complaints of drowsiness and poor air.
    2,000 – 5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
    5,000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
    40,000 ppm: this level is immediately harmful due to oxygen deprivation.

  • Best course of action when a unhealthy concentration is found
    Shut down any source, open your windows and ventilate!

Carbon monoxide (CO)

  • What it is exactly
    Carbon monoxide, or CO, is a toxic gas that you cannot see or smell. CO is given off whenever fuel or other carbon-based materials are burned. CO usually comes from sources in or near your home that are not properly maintained or vented.
  • How bad is it to your health
    Breathing CO can cause headache, dizziness, vomiting, and nausea. If CO levels are high enough, you may become unconscious or die. Carbon monoxide poisoning occurs when carbon monoxide builds up in your bloodstream. When too much carbon monoxide is in the air, your body replaces the oxygen in your red blood cells with carbon monoxide. This can lead to serious tissue damage, or even death.

    Exposure to moderate and high levels of CO over long periods of time has also been linked with increased risk of heart disease. People who survive severe CO poisoning may suffer long-term health problems.

    Scientists are not sure what the health effects are when a person is exposed to low levels of CO over a long period of time.

  •  It’s most common (indoor) origin
    Common sources of CO in homes are improperly vented furnaces, malfunctioning gas ranges, or exhaust fumes that have been drawn
    back into the building. Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces), or a flue that is improperly sized, blocked, disconnected, or leaking, can be significant sources. Auto, truck, or bus exhaust from attached garages, nearby roads, or idling vehicles in parking areas can also be sources..

  • How to prevent it
    Always ventilate and make sure their is enough fresh air coming into your home, especially when cooking or using fireplaces.
  • What is a high, good and low concentration
    WHO Guidelines:
    15 minutes – 100 mg/m3 (approx 90 ppm)
    1 hour – 35 mg/m3 (approx 31 ppm)
    8 hours – 10 mg/m3 (approx 9 ppm)
    24 hours – 7 mg/m (approx 6 ppm)

    0 ppm: Normal, fresh air.
    9 ppm: Maximum recommended indoor CO level (ASHRAE).
    10 – 24 ppm: Possible health effects with long-term exposure.
    25 ppm: Max TWA Exposure for 8 hour work-day (ACGIH).
    100 ppm: Slight headache after 1-2 hours.
    200 ppm: Dizziness, naseau, fagitue, headache after 2-3 hours of exposure
    400 ppm: Headache and nausea after 1-2 hours of exposure. Life threatening in 3 hours.
    800 ppm: Headache, nausea, and dizziness after 45 minutes; collapse and unconsciousness after 1 hour of exposure. Death within 2-3 hours.

    And the higher it go’s, the more deadly it gets. Basically, you want it to be zero at all times and currently always be under 10mg/m3 or 9ppm…

  • Best course of action when a unhealthy concentration is found
    Shut down any source, open your windows and ventilate!

(Tobacco) Smoke

  • What it is exactly
    Tobacco smoke consists of solid particles, liquid droplets, vapors, and gases resulting from tobacco combustion. Over 4,000 specific chemicals have been identified in the particulate and associated

    Tobacco smoke consists of solid particles and gases. More than 7,000 different chemicals have been identified in tobacco smoke. The number of these chemicals that are known to cause cancer in animals, humans, or both are reported to be about 70.

    The solid particles make up about 10 percent of tobacco smoke and include “tar” and nicotine. The gases or vapors make up about 90 percent of tobacco smoke. The major gas present is carbon monoxide. Others include formaldehyde, acrolein, ammonia, nitrogen oxides, pyridine, hydrogen cyanide, vinyl chloride, N-nitrosodimethylamine, and acrylonitrile. Of these, formaldehyde, N- nitrosodimethylamine and vinyl chloride are suspected or known carcinogens in humans. Acrylonitrile has been shown to cause cancer in animals.

  • How bad is it to your health
    Well, it’s bad, everybody agrees of that. To be honest, I just to smoke. Something with poor judgement when I was young…

    Among young people, the short-term health consequences of smoking include respiratory and non respiratory effects, addiction to nicotine, and the associated risk of other drug use. Long-term health consequences of youth smoking are reinforced by the fact that most young people who smoke regularly continue to smoke throughout adulthood. Cigarette smokers have a lower level of lung function than those persons who have never smoked. Smoking reduces the rate of lung growth.

  •  It’s most common (indoor) origin
    Tobacco product combustion (smoking).

  • How to prevent it
    Quit smoking, contact me if you need help…
  • What is a high, good and low concentration
    As its more then just one single pollutant its hard to say.
    Based on the main smoke component, carbon monoxide, its safe to say it should be (near) zero. See the Carbon Monoxide chapter for more information.
  • Best course of action when a unhealthy concentration is found
    Kick the smoker out of the house…

Fine particulate matter (PM)

  • What it is exactly
    Fine particulate matter (PM2.5), or soot, is a component of mostly diesel exhaust, and is less than 2.5 microns in diameter; in comparison, the average human hair is about 100 microns thick. It may consist as a tiny solid or liquid droplet containing a variety of compounds.
  • How bad is it to your health
    Since they are so small and light, fine particles tend to stay longer in the air than heavier particles. This increases the chances of humans and animals inhaling them into the bodies. Owing to their minute size, particles smaller than 2.5 micrometers are able to bypass the nose and throat and penetrate deep into the lungs and some may even enter the circulatory system.

    Studies have found a close link between exposure to fine particles and premature death from heart and lung disease. Fine particles are also known to trigger or worsen chronic disease such as asthma, heart attack, bronchitis and other respiratory problems.

  • It’s most common (indoor) origin
    The main source of PM2.5 is diesel engines in trucks, buses, and nonroad vehicles (e.g., marine, construction, agricultural, and
    locomotive). Diesel engines emit large quantities of harmful pollutants annually. But PM2.5 also comes from cooking, open fires such as your fire places and even from candles.

  • How to prevent it
    For the world it’s a different question but for your own home you may think about ventilation (if the outdoor air is relative clean) or air filters (see the link further below under best course of action…

    Btw, we are not able to hit the WHO standards:

  • What is a high, good and low concentration
    WHO Guidelines (Air quality guidelines – global update 2005):
    Guideline levels for each pollutant (µg/m3 ):
    PM2.5 1 year 10
    24 h (99th percentile) 25
    PM10 1 year 20
    24 h (99th percentile) 50

    However, the US EPA sets other standards
    (EPA standard, published on December 14th 2012):

    AQI Category Breakpoints
    (µg/m3, 24-hour average)
    Good 0.0 – 12.0
    Moderate 12.1 – 35.4
    Unhealthy for Sensitive Groups 35.5 – 55.4
    Unhealthy 55.5 – 150.4
    Very Unhealthy 150.5 – 250.4
    Hazardous 250.5 – 350.4
    Hazardous 350.5 – 500

    Basically, you want it to be lower then 10µg/m3 based on the WHO advise… However, with the outdoor air being polluted as it is, this is most of the time not possible with the help of an HEPA air filtration system.

    PM2.5 PM2.5 Health Effects
    0 to 12.0 Little to no risk.
    12.1 to 35.4 Unusually sensitive individuals may experience respiratory symptoms.
    35.5 to 55.4 Increasing likelihood of respiratory symptoms in sensitive individuals, aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly.
    55.5 to 150.4 Increased aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; increased respiratory effects in general population.
    150.5 to 250.4 Significant aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; significant increase in respiratory effects in general population.
    250.5 to 500.4 Serious aggravation of heart or lung disease and premature mortality in persons with cardiopulmonary disease and the elderly; serious risk of respiratory effects in general population.
  • Best course of action when a unhealthy concentration is found
    When outdoor levels of PM2.5 are elevated, going indoors may reduce your exposure, although some outdoor particles will come indoors. If there are significant indoor sources of PM2.5, levels inside may not be lower than outside. Some ways to reduce exposure are to limit indoor and outdoor activities that produce fine particles (for example, burning candles indoors or open burning outdoors) and avoid strenuous activity in areas where fine particle levels are high.

    Other ways is to start using HEPA based air filtration systems.
    Take a look at these test results if you are interested:

Nitrogen dioxide (NO2)

  • What it is exactly
    The two most prevalent oxides of nitrogen are nitrogen dioxide (NO2) and nitric oxide (NO). Both are toxic gases, and NO2 is a highly reactive oxidant and corrosive. These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone.

    Nitric oxide (NO):
    Readily oxidised in the atmosphere to nitrogen dioxide. Non-toxic in small quantities, infact it serves a vital role as a regulator within the human body.

    Nitrogen dioxide (NO2):
    A major pollutant and component of smog. Its brown fumes may be familiar from school chemistry experiments. It reacts with water to produce nitric acid, which is why it is so irritating to the eyes and respiratory tract.

  • How bad is it to your health

    The main effect of breathing in raised levels of nitrogen dioxide is the increased likelihood of respiratory problems. Nitrogen dioxide inflames the lining of the lungs, and it can reduce immunity to lung infections. This can cause problems such as wheezing, coughing, colds, flu and bronchitis.

    Increased levels of nitrogen dioxide can have significant impacts on people with asthma because it can cause more frequent and more intense attacks. Children with asthma and older people with heart disease are most at risk.

  • It’s most common (indoor) originRemember the ‘Dieselgate’ scandal that chopped the head of the CEO (among others) of the Volkswagon group? That was NOx…

    The primary sources indoors are combustion processes, such as unvented combustion appliances (e.g., gas stoves, vented appliances
    with defective installations, welding, and tobacco smoke). Outdoor sources, such as vehicles and lawn and garden equipment, also contribute to nitrogen oxide levels.
    NOx gases are also produced naturally by lightning.

  • How to prevent it
    Don’t burn fuel in any form, that is the only way to really prevent it. Start using a bicycle from time to time, it’s even good for your health!
    But for indoors, make sure ventilation is in order, especially in your kitchen and with your fireplace.
  • What is a high, good and low concentration
    The WHO only states a guideline for NO2:
    Annual mean: 40 μg/m3
    1-hour mean: 200 μg/m3
  • Best course of action when a unhealthy concentration is found
    Shutdown the source and ventilate with outdoor air (open some windows).

Radon (Rn)

  • What it is exactly
    Radon is a colorless, odorless and radioactive gas. It forms naturally from the decay (breaking down) of radioactive elements, such as uranium, which are found in different amounts in soil and rock throughout the world. Radon gas in the soil and rock can move into the air and into underground water and surface water. Radon is present in nearly all air. Everyone breathes radon in every day, usually at very low levels.

    In the past when spoken about Radon they where actually mentioning about Radon and Thoron. In the past it deemed very difficult to measure these 2 isotopes separately and the Thoron isotope was incorrectly identified as Radon. When speaking about Radon we actually mean isotope Rn-222. And when speaking about Thoron we mean isotope Rn-220. A lot less is known about Thoron then Radon but we can safely assume there both equally bad for your health.

  • How bad is it to your health
    Exposure to radon in the home and workplace is one of the main risks of ionizing radiation causing tens of thousands of deaths from lung cancer each year globally (source: WHO). Although lung cancer can be treated, the survival rate is one of the lowest for those with cancer. From the time of diagnosis, between 11 and 15 percent of those afflicted will live beyond five years, depending upon demographic factors. In many cases lung cancer could have been prevented.

    Overall, radon is the second leading cause of lung cancer. Radon is responsible for about 21,000 lung cancer deaths (US, source) every year. About 2,900 of these deaths occur among people who have never smoked. On January 13, 2005, Dr. Richard H. Carmona, the U.S. Surgeon General, issued a national health advisory on radon.

  • It’s most common (indoor) origin
    Because it is a single atom gas (unlike oxygen, O2, which is comprised of two atoms) it easily penetrates many common materials like paper, leather, low-density plastic (like plastic bags, etc.) most paints, and building materials like gypsum board (sheetrock), concrete block, mortar, sheathing paper (tar paper), wood paneling, and most insulations.

    All materials with significant trace amounts of radium are potential contributors of radon. Masonry materials such as concrete, stone, and brick are the primary sources of radon among building materials, since they typically contain significant amounts of radium and several tons of such materials are used in a house. Wood and wood products are virtually radium-free and do not contribute to indoor radon.

    Other sources could be (contaminated) ground water and soil and off course air itself..

  • How to prevent it
    Basically, for new buildings make it a factor for your building methods and materials. For current buildings, testing and ventilation is the most important factor.

    Testing is the only way to know your home’s radon levels. There are no immediate symptoms that will alert you to the presence of radon. It typically takes years of exposure before any problems surface.

  • What is a high, good and low concentration

    Outdoors, radon quickly dilutes to very low concentrations and is generally not a problem. The average outdoor radon level (1) varies between 5–15 Bq/m3. However, indoors, radon concentrations are higher, with highest levels found in places like mines, caves and water treatment facilities. In buildings such as homes, schools, and offices, radon levels in the range of 10 Bq/m3 to more than 10 000 Bq/m3 have been found.
  • The risk of lung cancer increases by 16% per 100 Bq/m3 increase in long time average radon concentration. The dose-response relation is linear – for example, the risk of lung cancer increases proportionally with increasing radon exposure.

But, it’s difficult to measure. Even the WHO concludes this in their report:

The WHO does not set a real hard line for what is goed and safe. Instead, it states the following:

Many countries have defined an Action Level of radon concentration to guide their program to control domestic exposure to radon. The Action Level is not a boundary between safe and unsafe, but rather a level at which action on reduction of radon level will usually be justified. Some people may choose to take action when the Action Level is approached. For example, many countries consider radon concentration in the air of 200 Bq/ m3 as an Action Level at which mitigation measures should be taken to reduce radon level in homes. Guideline values (action levels) of radon vary among countries

  • Best course of action when a unhealthy concentration is found
    Radon levels in existing homes can be reduced by:
    • increasing under-floor ventilation;
    • installing a radon sump system in the basement or under a solid floor;
    • avoiding the passage of radon from the basement into living rooms;
    • sealing floors and walls; and
    • improving the ventilation of the house. Passive systems of mitigation have been shown to be capable of reducing indoor radon levels by more than 50%. When radon ventilation fans are added radon levels can even be reduced further. Other options that can be applied (source):

Volatile Organic Compounds (VOCs)

  • What it is exactly

    Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands.

    Organic chemicals are widely used as ingredients in household products. Paints, varnishes and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing and hobby products. Fuels are made up of organic chemicals. All of these products can release organic compounds while you are using them, and, to some degree, when they are stored.

    Where are Volatile Organic Compounds (VOCs) found?
    – Consumer products:
      Household, building, and hobby products; cigarettes
    – Air
      Indoors and outdoors: vehicle exhaust, cigarette and secondhand      
      smoke, and emissions from fuels and VOC products.

  • How bad is it to your health

    Short-term exposure to various VOCs may cause:
    * Irritation of the eyes and respiratory tract
    * Headaches
    * Dizziness
    * Visual disorders
    * Memory problems

    Long-term exposure to various VOCs may cause:
    * Irritation of the eyes, nose, and throat
    * Nausea
    * Fatigue
    * Loss of coordination
    * Dizziness
    * Damage to the liver, kidneys, and central nervous system
    * Cancer

    At present, not much is known about what health effects occur from the levels of organics usually found in homes.

  • It’s most common (indoor) origin

    Household products, including:

    • paints, paint strippers and other solvents
    • wood preservatives
    • aerosol sprays
    • cleansers and disinfectants
    • moth repellents and air fresheners
    • stored fuels and automotive products
    • hobby supplies
    • dry-cleaned clothing
    • pesticide

    Other products, including:

    • building materials and furnishings
    • office equipment such as copiers and printers, correction fluids and carbonless copy paper
    • graphics and craft materials including glues and adhesives, permanent markers and photographic solutions.
  • How to prevent it
    – Increase ventilation when using products that emit VOCs.
    – Meet or exceed any label precautions.
    – Do not store opened containers of unused paints and similar materials within the school.
    – Formaldehyde, one of the best known VOCs, is one of the few indoor air pollutants that can be readily measured.
    — Identify, and if possible, remove the source.
    — If not possible to remove, reduce exposure by using a sealant on all exposed surfaces of paneling and other furnishings.
    – Use integrated pest management techniques to reduce the need for pesticides.
    – Use household products according to manufacturer’s directions.
    – Make sure you provide plenty of fresh air when using these products.
    – Throw away unused or little-used containers safely; buy in quantities that you will use soon.
    – Keep out of reach of children and pets.
    – Never mix household care products unless directed on the label.
  • What is a high, good and low concentration
    Well, here is the fun thing about VOC’s…
    VOC is not just one type of pollutant but a accumulation of a lot of different compounds. And it changes from one country to another what is part of the VOC’s and what not. To make it even more complicated, each country sets different standards for what healthy levels are.

    Formaldehyde is one of the most prevalent VOCs in homes, but fortunately, it is also one of the most measurable.

    Various organizations have established guidelines or recommendations (none are legally enforceable limits) for maximum formaldehyde concentrations, based on examinations of the scientific literature. Table 1 provides examples of these guidelines, which are discussed again later in this document. It is evident in this table that, despite differences in guidelines from different organizations, the longer exposure periods (longer than 8 hours) consistently specify lower guideline concentrations of formaldehyde (7-40 ppb) relative to the guidelines for periods of 8 hours or less (44-750 ppb). An exception is the relatively high chronic guideline of 100 ppb from the World Health Organization (WHO).

    This basically draws the line around 80 or less ppb at a given time.
    Lower is better in this case.

  • Best course of action when a unhealthy concentration is found
    Remove the source and ventilate…

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