Wild Fires and Particulate Matter in Smoke

Due to human-induced climate change, major fires are increasing worldwide. Misleading information is sometimes distributed for less-than-noble reasons.

Here is important information on how to project your home and family.

Any Amount Of Smoke Is Damaging

Any amount of smoke is damaging to lungs, which are designed to rapidly absorb whatever you breath in. The US EPA, a credible source of information despite having been severely DOGE’d by the Trump regime, still states on the AirNow website:

Fine particles, called “particle pollution,” are the pollutant of most concern in wildfire smoke. These microscopic particles can get deep into your lungs. They can cause many health problems from burning eyes and runny nose to aggravation of chronic heart and lung disease, leading to emergency department visits, hospital admissions and even premature death. Anyone with heart and lung disease is especially at risk. While not everyone reacts the same way to wildfire smoke, it’s always a good idea to reduce your exposure to smoke.

www3.epa.gov/airnow/airaware/wildfires.html

“Sensitive Populations”

Because everyone with lungs is highly sensitive to the damage from smoke pollution, this term actually refers to extremely sensitive people. This includes all children, all elderly, and everyone with compromised respiratory or circulatory systems.

Categorize one group as “sensitive” leads many to believe that everyone else is not sensitive. The fact is that we are all sensitive to smoke, and everyone sustains at least some damage from breathing the particulate matter in wildfire smoke.

The Dangers Of Wildfire Smoke

Smoke from wildfires contains many different toxins in the form of particulate matter and vapor. When forests burn most of the particulate matter in smoke is formed from burning vegetation. In urban fires, buildings, vehicles and factories burn, producing an extremely toxic mix of pollutants. Many of these pollutants are oil-based compounds which prevent N95 masks from working.

PM2.5 Particulate Matter

All particulate matter is dangerous. According to the CDC there is no minimum safe exposure level. The most dangerous particulate matter are very fine particles, often referred to as PM2.5 (less than 2.5 microns in diameter). They can be invisible and odorless. PM2.5 particles can linger in the air for days and float to far away regions that were otherwise unaffected by the fire.

The Dangers of Particulate Matter

Small particles can travel deep within the lungs, where they are difficult to cough out, and can more easily cross the blood barrier. Once such particles enter the blood they are free to travel throughout the body, and can cause or contribute to serious diseases in many different organs. Some may never be flushed out by the body, thus causing low-level, chronic and difficult to diagnose problems for many years.

The Most Dangerous Smoke

As smoke floats away from the fire, the largest and heaviest particles drift to the ground in the form of ash. These are not the most dangerous particles because they are easier for the mucus membrane to filter out and for the lungs to cough out. The longer smoke stays in the air, the higher the percentage of very fine particles. For this reason, smoke from faraway fires can potentially cause more long term health damage.

Protecting Children

Stay Home

The US EPA advises, “When it’s smoky outdoors, try to stay indoors.” (https://www3.epa.gov/airnow/airaware/wildfires.html)

Driving to school (often in long commutes through heavily polluted areas) is not staying indoors. The best place to be when air pollution is high is usually right where you are with the doors and windows closed, – preferably in your own home where you have what you need to wait out the emergency.

To preserve ADA funding, public school administrators may encourage families to bring children to school despite the known risks of commuting through hazardous air. They may even claim that spending the in a busy classroom with poorly-filtered air is safer than staying put at home. This advise is directly counter to clear CDC guidelines.

When To Stay Home

The NOAA-EPA Air Quality Index (AQI) is a simplified warning system that uses a complex formula to estimate average risks from a mix of typical airborne factors, some of which are unrelated to wildfire smoke. For this reason, it is not always an accurate measure of local smoke risks. Still, it is good enough. The CDC advises sheltering in place whenever the AQI reaches or exceeds 100. It’s best to ignore any administrative pronouncements that claim AQI estimates above 100 are safe for children.

The US EPA Air Quality Index (AQI)

Calculating the AQI

The calculation of the AQI involves several steps:

1. Pollutant Concentration Measurement: The Environmental Protection Agency (EPA) measures the concentration of various pollutants in the air, including:
   • Ground-level ozone (O₃)
   • Particulate matter (PM_2.5 and PM_1.0)
   • Carbon monoxide (CO)
   • Sulfur dioxide (SO₂)
   • Nitrogen dioxide (NO₂)
2. Individual Pollutant Scoring: Each pollutant is scored based on its concentration using specific breakpoints defined by the EPA.
3. Identifying the Highest Score: The AQI value is determined by the highest individual score among the pollutants. This means that the pollutant with the most significant health impact dictates the overall AQI.

Protect Your Home

Install a MERV 17 Or Higher Filter

Find out what kind of high efficiency filters (rated MERV 17 or higher) you can use in your HVAC system. Keep a few extra high-quality filters ready for emergencies.

More efficient filters are thicker, and so may not fit into your system. If you can’t switch to a more efficient filter, running the system continuously by switching the thermostat fan from “Auto” to “On” has been shown in some studies to reduce particle concentrations over time.

Air Filter Ratings

Many air filtration systems use filters measured with a MERV efficiency rating from 1 to 20. To protect your home from PM2.5, try to install filters with a rating of MERV 17 or higher. These are expensive, difficult to find, and do not fit in all HVAC systems. In any case, install the highest rating you can, and keep your duct tape handy.

Minimize Outside Trips

The following ideas can help minimize the need to open outside doors or travel in smoky conditions.

1. Create an emergency kit: In advance, create an emergency kit with enough food, water and other supplies to provide for your whole family for at least three weeks. This will help minimize the need to go outside to shop.
2. Create a “Clean room”: In advance of a smoke event, choose a room in your home where you and your family can shelter in place. This room should not have a fireplace, and should have few windows and doors. A large bedroom is often a good choice. Stock the room with books, games, art supplies, musical instruments, movies, munchies, water, blankets, duct tape, toilet paper, battery operated lighting, emergency kits, emergency radio, etc.
3. Get high-efficiency portable air filters": In advance of a smoke event, get a portable air cleaner that is the right size for the room where you plan to spend most of your time. Make sure it does not make ozone.
4. Cover air leaks: In advance of a smoke event, make cardboard or plastic covers to tape over any problem openings in your home. If your home uses natural gas, be sure such appliances are either correctly turned off or remain adequately vented. Learn how to close the fresh-air intake if your HVAC system or room air conditioner if it has one.
5. Contain children and pets: Keep children and pets inside as much as possible. Plan on spending long periods of time together in your safe room.

Protecting Yourself

Face Mask or Respirator

Face masks were traditionally loose fitting, disposable, single use, paper and rubber band devises, such as the ubiquitous N95 and KN95 face masks. Respirators were semi-hard rubber half- or full-face shields that filter air through replaceable cartridges.

42 CFR Part 84 now defines respirators as, “any device designed to provide the wearer with respiratory protection against inhalation of a hazardous atmosphere.”

These days, N95 face mask producers commonly refer to these products as respirators because they are rated as meeting N95 standards. However, an N95 face mask is simply a better face mask. It is not a real respirator as the term is otherwise understood. This distinction is important because the protection offered by even a better face mask is no match to that of a properly fitted respirator.

N95 face masks are cheap and convenient. They have their place. Unfortunately, due to specific limitations of face mask design, and the specific limitation of N95 filters, they are almost useless in most wildfire situations.

N95 Face Masks

For many, the first line of defense is often an N95 face mask. This is a loose-fitting, disposable device made of paper. If worn properly, it can filter up to 95% of airborne particles if warn correctly. N95 masks can not filter out PM2.5, the smallest and most dangerous particles in smoke. These are the particles that make up most of that last 5% or more that always gets through.

Why N95 Masks Are Widely Promoted

N95 masks are less expensive to produce than better options, such as N99 and P100 masks or full face shields. When the need to provide at least some protection to a large population becomes critical, the easiest, fastest and cheapest method is to distribute N95 masks.

To ensure widespread compliance – an important goal – certain limitations may be brushed aside. N95 masks are then promoted as the best choice, without mentioning important limitations or listing better options.

Specific N95 Face Mask Limitations

To be used effectively, the real limitations of an N95 face mask must be understood.

It’s critical to understand that the “N” in N95 means, “No protection from oil-based compounds” – and why this matters so much during wildfires. N95 masks can provide limited protection from the typical smoke of a forest fire, but they CAN NOT protect against the smoke produced in urban fires, which contains a highly toxic mix of compounds that quickly defeat electrostatic filters.

Recent guidelines suggest that an N95 masks can be use for up to 4 hours “if undamaged and used correctly”. That last phrase is critical. it conveniently puts the burden on the user. However, no matter how careful a person is, N95 masks can not last four hours without damage for the multiple reasons:

1. Disposable paper face masks were not designed to be used more than once or for extended periods.
2. Repeatedly putting N95 face masks on and taking them off again quickly distorts the shape. If they become damp (see more on that below), they are easily deformed and may develop small tears.
3. The loose fit between the edge of the mask and a person’s face is not an effective seal against fine particles.
4. Face masks are virtually useless for those with facial hair.
5. The water vapor in a person’s breath begins to compromise the electrostatic filter within 15 minutes.
6. Smoke from urban fires contains a complex mix of oil-based toxins, which will quickly disable the electrostatic filtering process, making the mask completely useless.
7. N95 face masks do not protect the eyes or skin, both highly vulnerable pathways for air born pollutants to enter the body.

Some Alternatives to N95 Face Masks

1. N99 Face Mask
   • N = No protection from oil-based toxins
   • 99 = Filters up to 99.9%, if undamaged and warn correctly.
   • No eye protection
   • Poor seal
2. P100 Face Mask
   • P = Protection from oil-based toxins
   • 100 = Filters up to 99.97%, if undamaged and warn correctly.
   • No eye protection
   • Poor seal
3. P100 Half Face Respirator
   • P = Protection from oil-based toxins
   • 100 = Filters up to 99.97%, if undamaged and warn correctly.
   • No eye protection
   • Strong seal
4. P100 Full Face Respirator
   • P = Protection from oil-based toxins
   • 100 = Filters up to 99.97%, if undamaged and warn correctly.
   • Eye protection from face shield
   • Strong seal

PurpleAir

PurpleAir is a proven, shared-source air quality monitoring solution for private citizens and air quality professionals alike. It uses a new generation of laser particle counters to provide real time measurement of PM1.0, PM2.5 and PM10.

The PurpleAir network of sensors update every 120 seconds, providing real time readings to the PurpleAir Map. In most areas, this system is more reliable and accurate than the government’s AQI system which has fewer sensors and is not updated as often.

Links

US NOAA Weather Forecasts US EPA Wildfire Smoke and Health Factsheets NIOSH Respirator Approval Program DIY Air Cleaner to Reduce Wildfire Smoke Indoors Purple Air