Smoke from wildfires and prescribed fires is a serious concern as it can cause and exasperate health conditions for those of us that endure it. However by living in the fire adapted ecosystems of northern New Mexico we must accept that wildfire and smoke is inevitable.
Smoke is a complicated mixture of materials in the air including particulates of various sizes and gases that are released as materials burn. The emissions vary depending on what material is burning and whether it is smoldering or in flames. Smoke generally consists of carbon monoxide, carbon dioxide, water vapor, hydrocarbons, other organic chemicals, nitrogen oxides, trace minerals and particulate matter.
- Particulate matter consists of solid particles and liquid droplets suspended in the air. Particles with diameters less than 10 microns are upper respiratory tract and eye irritants.
- Smaller particles (2.5 PM) are the greatest health concern – they can be inhaled deep into the lungs, and can affect respiratory and heart health. (HEPA filters remove particles down to .3 PM)
- Carbon monoxide, a colorless, odorless gas produced by incomplete combustion, is a particular health concern and levels are highest during the smoldering stages of a fire.
Smoke causes a variety of health problems including:
- Eye, nose, and throat irritation (burning eyes and runny nose).
- Wheezing, coughing, shortness of breath, and headaches.
- Aggravation of existing lung, heart and circulatory conditions, including asthma and angina.
What can you do to reduce the impacts of smoke?
Smoke is a known health hazard and inhaling it is not good for anyone, and it especially affects sensitive groups such as people under the age of 18 and over the age of 65, pregnant women and people who are predisposed to respiratory ailments.
Limiting your exposure
Reducing the impacts of smoke is accomplished by limiting your exposure to smoke as much as possible.
- For people in a safe location, away from the fire, reducing physical activity is an effective strategy to lower the dose of inhaled air pollutants and reduce health risks during a smoke event. During exercise, people can increase their air intake as much as 10 to 20 times over their resting level. Increased breathing rates bring more pollution deep into the lungs.
- Staying inside in a safe place with the doors and windows closed can usually reduce exposure to air pollution by at least a third or more.
- Reduce other sources of indoor air pollution: smoking cigarettes, using gas, propane and wood-burning stoves and furnaces, spraying aerosol products, frying or broiling meat, burning candles and incense, and vacuuming can all increase particle levels in a home and should be avoided when wildfire smoke is present.
- Find a designated clean air shelter where you can go for respite from smoky conditions. This is particularly important for people without air conditioning on hot smoky days, when staying indoors with windows closed can be hazardous. Places to consider going include public libraries, hospitals, movie theaters, and other public buildings with good HVAC systems.
- Individuals who are particularly sensitive to smoke should consider temporarily evacuating an area with unhealthy levels of air pollution until air quality conditions improve.
- Use filters in your HVAC system or smaller portable air cleaners to provide clean air inside your home. Read more about these systems below.
Filtering your air
One of the best ways to reduce the impact of smoke is by reducing the amount of smoke that enters your building and filtering harmful particles from the air.
Tightly closed buildings reduce exposure to outdoor air pollution, smoke enters and leaves buildings in three primary ways:
- Mechanical ventilation systems, which actively draw in outdoor air through intake vents and distribute it throughout the building.
- Natural ventilation (opening of doors or windows).
- Infiltration, the passive entry of unfiltered outdoor air through small cracks and gaps in the building shell.
If you have a central air conditioning system in your home, set it to re-circulate or close outdoor air intakes to avoid drawing in smoky outdoor air. Upgrading the filter efficiency of the heating, ventilating, and air-conditioning (HVAC) system and changing filters frequently during smoke events greatly improves indoor air quality.
Smaller portable air cleaners are a great way to provide clean air in the areas where you spend most of your time. Essentially these are filters with an attached fan that draws air through the filter and cleans it. These cleaners can help reduce indoor particle levels, provided the specific air cleaner is properly matched to the size of the indoor environment in which it is placed, and doors and windows are kept shut. They should be placed in the bedrooms or living rooms to provide the most effectiveness.
When air quality improves, such as during a wind shift or after a rain, make sure to use natural ventilating to flush out the air in your building.
General Smoke Information:
New Mexico Fire Info, Smoke Management - New Mexico Fire Information - an interagency effort by federal and state agencies in New Mexico
Air Now, Interactive Map of Smoke Monitors & Fire Current Conditions - Environemntal Protection Agency
Protect Your Health on Smoky Days - from New Mexico Environmental Public Health
Wildfire Smoke Frequently Asked Questions - Environmental Protection Agency
New Mexico’s Smoke Management Program - New Mexico Environment Department’s Air Quality Bureau
PRESCRIBED FIRE and SMOKE
By intentionally setting fires we are reintroducing fire under carefully prescribed conditions that limit impacts of smoke compared to the uncontrolled conditions of a wildfire. One of the many purposes of using prescribed fire is to limit the possibility of large wildfire events and their great smoke impacts.
Smoke mitigation of prescribed fire is considered from the beginning planning phases all the way to the day of a burn. A plan is created that defines communities that would be impacted and identifies the strict conditions under which a burn must be carried out to minimize these impacts. Fire managers must obtain a permit from the New Mexico Environment Department’s Air Quality Bureau and closely monitor conditions to determine the optimal time to burn. During a burn smoke is closely monitored and if adverse impacts are observed the burn may be postponed or lighting patterns may be changed to alter the generation of smoke.
Some smoke is unavoidable during prescribed fire operations though so, the Greater Santa Fe Fire Shed Coalition is creating a HEPA filter loan system to assist people with smoke sensitivities. HEPA filters have been shown to greatly reduce the impacts of smoke inside your home.
HEPA Filter Loan Program
With support from the City of Santa Fe Fire Department the Forest Stewards Guild is pleased to offer a HEPA Filter Loan program. These filters are available to smoke sensitive individuals during periods of smoke impacts in the Fireshed area. We have a small amount of portable air cleaners that will filter the air in a large room such as a living room or bed room. These will be distributed on a first come- first served basis for predetermined time periods. You will need to provide contact info and come to the Forest Stewards Guild office in Santa Fe to sign for the filter and pick it up. Please look over the HEPA Air Filter Check-Out Contract.
To check out a HEPA Filter contact Sam Berry at firstname.lastname@example.org or by calling 505-983-8992 x 16.
Selecting a Filter - For either portable filters or HVAC filters make sure to select a filter that is true HEPA or has a MERV rating of 13 or higher. These ratings refer to the size of particles that the filter will remove from the air and in this case they are certified to remove particles down to .3 microns in size. This is the minimum needed to remove the small harmful particles in smoke.
When selecting a portable filter, the other rating to pay attention to is CADR or Clean Air Delivery Rate. This refers to the volume of air that passes trough the unit. A CADR of 200 means the unit provides 200 cubic feet of clean air per minute, and often this number is equated to the room size that it will effectively purify the air in. In a 300 sq foot room a filter with a rating of 200 CADR will cycle the air through the filter 4-5 times per hour. While any filter will provide clean air those with lower CADRs will simply work more slowly.
Lastly, make sure to avoid filters that claim to produce ozone to destroy pathogens, as ozone is a respiratory irritant.
More information about filters and guides to selecting one can be found in the Resources section below.
Face Masks - Face masks can be an effective way to reduce your exposure to smoke when they are fit correctly and are the proper rating. Make sure the mask you use is rated at least N95 or N100 and that you take care to fit it properly. These masks will filter out the small particles that are the most hazardous to your health. They are commonly available at hardware stores and can be purchased online. Paper masks only filter out large particles and will not provide the filtration needed to protect you from smoke. More information about selecting and fitting masks can be found in the Resources section below.
Filter and Air Cleaner Information:
What to Know Before Buying an Air Purifier to Clear Wildfire Smoke, by Kristin Wong, The New York Times
The Best Air Purifier: Reviews - by the Wirecutter
Air Cleaning Devices for the Home FAQ - California Environmental Protection Agency
Build a do-it-yourself air purifier for about $25 - University of Michigan
The information on this page is from the Environmental Protection Agency, the Washington Department of Health.