Category Archives: Medical Illness Environmental Home Testing

Indoor Air Quality (IAQ) Testing Services (including chemicals / carcinogens like Formaldehyde) Available – Fast Onsite Results!

Formaldehyde NFPA Diamond from MSDS (Material Safety Data Sheet)

Formaldehyde NFPA Diamond from MSDS (Material Safety Data Sheet)

Dallas IAQ Green Building Clearance Testing for 804.2 Ordinance

Dallas Green Building IAQ Indoor Air Quality Clearance Testing Post-Construction for 804.2 Certificate of Occupancy

ScanTech Technical Consulting performs indoor air quality tests including particulate matter in the air (residential and commercial) in the 0.3 – 2.5 micron and 2.5 micron + range  (PM 2.5 and PM10) in order to evaluate how clean your air is with respect to dust and other fine particles. We also offer formaldehyde and VOC levels testing due to chemicals used in the manufacture of pressed wood flooring, lumber, laminates, glues and other adhesives in your home and factory/office.

More information on formaldehyde can be found here:

https://emfsurvey.com/formaldehyde-indoor-air-pollutant-and-testing/

We can also test for VOCs, (Volatile Organic Compounds) CO2 (Carbon Dioxide) levels and O2 oxygen levels in your home to check ventilation quality. Datalogging over time available to show trends and measure the effects of HEPA filtration and electrostatic air ionization units.

Our background in organic and environmental chemistry, epidemiology, advanced microbiology, medical geology  and human physiology makes us uniquely qualified to answer your concerns regarding the invisible environment you breathe every day.

July 2016 ruling by the EPA on the emissions of formaldehyde of wood products produced or imported into the United States:

https://www.epa.gov/formaldehyde/formaldehyde-emission-standards-composite-wood-products-0#additional-resources

The following tables and information are from:

Health Effects Notebook for Hazardous Air Pollutants

To convert concentrations in air (at 25°C) from ppm to mg/m3: mg/m3 = (ppm) × (molecular weight of the compound)/(24.45) For formaldehyde which is CH20: 1 ppm = 1.23 mg/m3.

Explanation of Formaldehyde Levels

Formaldehyde Regulatory and Health Levels Comparison

Formaldehyde Regulatory & Health Levels Comparison

AIHA ERPG–American Industrial Hygiene Association’s emergency response planning guidelines. ERPG 1 is the maximum airborne concentration below which it is believed nearly all individuals could be exposed up to one hour without experiencing other than mild transient adverse health effects or perceiving a clearly defined objectionable odor; ERPG 2 is the maximum airborne concentration below which it is believed nearly all individuals could be exposed up to one hour without experiencing or developing irreversible or other serious health effects that could impair their abilities to take protective action.

ACGIH STEL–American Conference of Governmental and Industrial Hygienists’ short-term exposure limit expressed as a time-weighted average exposure; the concentration of a substance which should not be exceeded at any time during a workday.

LC50 (Lethal Concentration50)–A calculated concentration of a chemical in air to which exposure for a specific length of time is expected to cause death in 50% of a defined experimental animal population.

NIOSH IDLH–National Institute of Occupational Safety and Health’s immediately dangerous to life or health limit; NIOSH recommended exposure limit to ensure that a worker can escape from an exposure condition that is likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from the environment.

NIOSH REL–NIOSH’s recommended exposure limit; NIOSH recommended exposure limit for an 8- or 10-h time-weighted average exposure and/or ceiling.

OSHA PEL–Occupational Safety and Health Administration’s permissible exposure limit expressed as a time-weighted average; the concentration of a substance to which most workers can be exposed without adverse effect averaged over a normal 8-h workday or a 40-h workweek.

Radon Gas Risk Factor Safety Levels Comparison

How do you put the risk from radon into perspective, especially since all homes contain some level of radon gas in them and there is no “safe level” except zero?

I have found the following charts to be helpful in evaluating risk: (please click on the pictures for a full sized detailed view)

Radon Gas Cancer Radiation Risk Safety Dallas Houston Austin

Radon Gas Chart Safety Level Relative Risk Factors

Texas CMIS Mold Information Sheet

Radon Gas Cancer Risk Smokers Non-Smokers Chart

Radon Cancer Risk Chart for Smokers vs. Non-smokers

Notice that the risk for a radon level at the EPA action limit of 4 picoCuries/liter is similar to the same risk of dying in a car wreck. I have personally observed several residences that I have tested in Dallas county to EXCEED this limit including my own home.

Radon is linked to not just lung cancer, but recent epidemiological evidence also suggests that radon gas may also be a risk factor and contributor to

  1. Acute Myeloid Leukemia (AML)   13 % – 25 % of all cases worldwide.
  2. Kidney cancer
  3. Certain childhood cancers
  4. Melanoma

MERV (Minimum Efficiency Reporting Value) Ratings and Filters

You generally cannot place a True HEPA filter in your air furnace because of the flow restriction would place too heavy a load on the blower unit. But you can get a higher efficiency MERV filter that can give some of the benefits of better filtration and indoor air quality without unnecessarily straining the HVAC unit or restricting the air flow.

But to get a good balance between clean air and not damaging your HVAC unit, consult with an air conditioning professional and / or consult with the manufacturer regarding the recommended MERV filter range that can be used in your particular model. Also, the higher your MERV rating, the more often you may have to check and/or change it as it will tend to clog faster.

MERV ratings are numbers that generally measure the quality of an air filter, but can be hard to understand without some context and this chart is a handy reference.

 

MERV Chart Air Quality

MERV Rating Chart with application comparisons   *Note – the pm size designations listed should be in um or microns

Allergens Air Purifiers

Air Purifier Guide to Size Ranges of Allergens in microns (millionth of a meter or um)

The MERV rating is a filter standard established by ASHRAE  (American Society of Heating, Refrigerating and Air-Conditioning Engineers) but when you shop for a filter online, you may also find references to MPR and FPR.

MPR (Micro-Particle Performance Rating) is a standard used by 3M (notably the Filtrete series) that rates filter performance with respect to the ability to screen out sub-micron (less than 1 um) particles, but can be confusing when comparing to MERV. Note that less than a micron is on the low end of the PM2.5 Fine particle range as designated by the EPA. (0.5 – 2.5 microns)

FPR (Filter Performance Rating) works a little like MERV numbers (but on a 4 – 10 color coded scale) developed by Home Depot for filters they sell including Honeywell.

To get a relatively close comparison, the following chart may be useful when shopping for a more suitable HVAC filter.

MERV MPR FPR Ratings Compared and Explained from www.airfiltersdelivered.com

MERV MPR FPR Ratings Compared and Explained from www.airfiltersdelivered.com (not endorsed by ScanTech)

While this chart is useful, it is not guaranteed to completely stop all of the biological and inorganic contaminants that are listed. Your mileage may vary.

MERV Filter Models

 

Composition of Dust Particles and Particulate Matter in The Air

When I test for PM2.5 and PM10 which are Fine Particle and Coarse Particle designations used by the EPA, I am often asked what is the nature of this particulate matter. These may also be referred to as TSP (Total Suspended Particulate) or RSP (Respirable Suspended Particulate) matter. While it is very difficult to tell exactly what it is without microscopic analysis and will vary depending on the environment, an educated guess can be made based on what sources are nearby and the potential contribution of those sources based on typical size regimes.

Possible sources are pollen, toxic mold spores, smoke, bacteria, pet dander, construction dust, etc.

There are some useful reference charts that not only talk about the ranges of certain pollutants, but also give an indication of different filtration mediums which are relatively effective in removing these contaminants.

 

Particulate Matter in Air Quality

Air Filtration with Regard to Particle Size

*NOTE – HEPA (High Efficiency Particulate Air) filters are typically rated at 99.97% efficiency for particles of 0.3 um or larger. At this time, I am not sure that a HEPA filter will remove more than 95% of particles which are 0.01 microns in size as this chart seems to imply.

Also, beware of filters and vacuum cleaners which claim to be “HEPA-like”, “HEPA-type” or “99% HEPA” as these are not true HEPA filters and are often inferior in quality with regard to air filtration efficiency.

BTW – the term DS efficiency mentioned in the Pleated Filter (40% DS ) refers to Atmospheric Dust Spot Efficiency which measures how well a filter removes staining dust from the air.

 

HEPA Air Filtration Particle Ranges

HEPA Filtration Particle Chart

 

Particle Filtration Size Chart HEPA vs. ULPA

Particle Filtration Size Chart HEPA vs. ULPA

 

Characteristics of Particles and Particle Dispersoids

Characteristics of Particles and Particle Dispersoids

This is a fairly technical diagram for general reference use.

 

Origin of Dust Particulate Matter

Origin of Dust Particulate Matter

Carbon Monoxide Safety Levels and Indoor Air Quality

An important component of indoor air quality testing is measurement of abnormal levels of carbon monoxide.

Carbon monoxide (CO) is a result from all forms of combustible sources, from smoking and wood fires to propane and fuel-powered automobiles. Poisoning of a human subject comes in two forms – short term exposure to high levels which can cause severe illness or death, or longer term exposures at lower levels which may cause chronic symptomatology.

While actual death is relatively rare, there are far more cases that occur with sub-lethal exposures over a broad range of concentrations. (30 – 100 ppm by volume or ppmv) At the lower end (40 – 60 ppmv) headache and low levels of fatigue, and at higher levels (75 – 200 ppmv) nausea, vomiting and especially sleepiness.

Symptoms with Different Blood COHb Levels

Symptoms with Different Blood COHb Levels

Carbon monoxide and oxygen both bond to hemoglobin in the blood and will compete with each other over binding sites, but CO has the advantage as it binding sites have an affinity or preference of binding with CO that is 200 times greater than O2. (atmospheric oxygen) The result is decreased oxygen carrying capacity in the blood with the consequent neurological symptoms of oxygen deprivation as listed above as well as reduced oxygen to other body tissues. It also binds to intracellular proteins such as tryptophan oxidase, cytochrome oxidase,  myoglobin, and dopamine hydroxylase which may cause extra-vascular effects.

The result of CO combining with hemoglobin is to form carboxyhemoglobin. (COHb) Exposure to CO can be evaluated by measurement of the levels of COHb in the blood which is typically less than 1% for unexposed individuals. This is the % amount of blood hemoglobin bound with carbon monoxide. Cigarette smokers typically have a level of 3% – 8%. OSHA has a permissible exposure limit (PEL) of 50 ppmv over an 8 hour time-weighted average (TWA) in which case an individual would have a COHb level of approximately 5%. At 100 ppmv, it would be over 10%.

COHb Levels Resulting from Exposure Duration

COHb Levels Resulting from Exposure Duration

Even low level carbon monoxide exposures can cause issues in compromised human subjects such as those with cardiovascular disease. The lowest level at which COHb can show as a physiological symptom is 3 %- 4 % COHb. At 6 % COHb, arrhythmia may be induced in exercising patients with coronary artery disease with a risk of sudden death. There is also evidence that suggests that carbon monoxide exposure may contribute to atherosclerosis.

Studies have shown that those with flu-like or neurological symptoms had COHb levels of 10% or greater. (24% and 3 % respectively. Sub-acute carbon monoxide poisoning commonly goes unrecognized and is not diagnosed because it mimics other conditions and is present at the residence / workplace – not the doctor’s office.

Those at higher risk include pregnant women, young children, the elderly, individuals with conditions that already compromise O2 availability, and those that use certain medications and drugs.

For a discussion of CARBON DIOXIDE poisoning which is an entirely different phenomena, see the post here:

New Homes and Carbon Dioxide Levels: The Overlooked Indoor Air Quality Health Hazard

If you live in the Dallas / Fort Worth, Houston or Austin metropolitan areas and suspect carbon monoxide / dioxide poisoning or other indoor air quality issues, then contact ScanTech Technical Consulting for an evaluation.