Air Quality Index, What’s In Wildfire Smoke, and the Use Of Respirators.

In order to help you make sense of current circumstances, this quick article will provide a quick explanation of the Air Quality Index, what contaminants exist in fire smoke, and what cost-effective solutions are available to the average consumer to help keep themselves safe during such events.

AQI: What is it?

Each country's health authorities provide some measure of air quality indicator to the general public. In the United States, the so-called AQI is an index measuring the levels of five major pollutants relative to permissible levels established by the Clean Air Act. Those pollutants are:

• ground-level ozone
• particulate matter (fine particles - 2.5 microns / coarse particles - 10 microns)
• carbon monoxide
• sulfur dioxide
• nitrogen dioxide

The index is reported on a range of 0 to 500, with levels of 101 or higher considered unhealthy for those with respiratory or health conditions, 151 or higher considered unhealthy for everyone, and 301 and higher being outright hazardous for anybody who is exposed. Conversely, 100 or below is considered normal air quality for all these pollutants, as some level of harmful chemicals are always present in the air we breathe, especially if you live in suburban or urban areas.

While the AQI is helpful at a high level and should be paid attention to, it is important to understand that each of the pollutants it measures impact people differently. Here's an explanation of each so you can determine which of these harmful pollutants is of particular concern to you:

• Ozone - unhealthy AQI starts at .071 PPM avg. over an 8 hour period - people with lung disease or conditions like asthma, children, pregnant women, older adults, and those who are active outdoors (including in professional activities like contractors), and those who are considered medically overweight or obese
• Particulate Matter (PM 2.5 / PM10) - unhealthy AQI starts at 35.5 PPM avg. over an 8 hour period - People with heart or lung disease or conditions like asthma, pregnant women, older adults, and children, and those who are considered medically overweight or obese
• Carbon Monoxide - unhealthy AQI starts at 9.5 PPM avg. over an 8 hour period - people with heart disease is the group most at risk
• Sulfur Dioxide - unhealthy AQI starts at 76 PPB avg. over an 1 hour period - people with asthma, children, and older adults are the groups most at risk
• Nitrogen Dioxide - unhealthy AQI starts at 101 PPB avg. over an 1 hour period - people with asthma, children, and older adults are the groups most at risk

To explain some of the units referenced above, PPB is parts per billion and ppm is parts per million. Measurement volumes vary for each contaminant, with PPM and PPB being measured across a 1 liter volume, and particulate matter being measured across a 1 meter volume. The AQI we see reported on the news and in our weather apps is based on an aggregate data set of thousands of sampling sites in a given area.

Which AQI contaminants are contained in smoke?

All of them, simply put. Fire smoke, particularly wildfire smoke, contains a mix of hazardous gases, particulate contamination, and water vapor. Of principal concern to humans and animals are gaseous and particulate matter contaminants released, which can include a wide range of inorganic, organic, dust, and biological particles such as those measured by the AQI, but also elements from structures and other man-made items caught in the blaze. Cars, buildings, and other infrastructure go up and as a result trace amounts of lead, manganese, hydrogen fluoride, and dangerous chemicals are also present. Scientists refer to these as "HAPs" (Hazardous Air Pollutants) and they form as the result of incomplete combustion, meaning the fire's fuel source doesn't fully complete the transition into CO2.

Most HAPs are covered within the Particulate contamination levels measured by the AQI. There are two types of particulate matter measured, greater than 10 microns cannot enter your bloodstream by way of the lungs, and fine particles of 2.5 microns and below can enter your bloodstream. That is why those with heart disease and those who are pregnant or nursing are listed as being specifically at risk even though it feels counter-intuitive. For obvious reasons, those with asthma and lung disease are also at risk.



What solutions available to me?

Most public health agencies recommend an N95, like our Gerson N95 masks, for protecting yourself from the toxins and contaminants found in smoke-filled air. As we have said here many times, N95s are an imperfect solution as the efficacy of such masks relies on wearing them properly and in accordance with manufacturer guidelines. This means the wearer must be clean-shaven and the mask must be properly fitted over their nose and mouth. However, when worn properly, they are a low-cost and highly available way to keep yourself safe from limited exposure to airborne contaminants like wildfire smoke.

For those with particular breathing difficulties caused by lung disease or birth defects, allergies, beards that prevent an N95 from being worn properly, or those that N95 masks simply don't fit, the only option is to create a positive pressure zone around their nose and mouth by way of a PAPR or power-assisted respirator. Wearing a PAPR also comes with the additional benefit of preventing coarse particulate contamination from entering the body by way of the eyes / tear ducts. 

We hope that you've found the above information helpful. Stay safe out there.