Local Wildfires and Air Quality Precautions

1. Caltech Instruments: Localized data is available at breathe.caltech.edu, where air quality is measured using instruments installed on Caltech Hall.
2. EPA Website (AirNow): Provides real-time air quality information for your region.
3. Additional resources, including guidance on Returning Home After a Fire (available in ENGLISH and SPANISH), are provided by Los Angeles County Public Health for Wildfire Smoke.

The noticeable odor following a fire is primarily due to the presence of volatile organic compounds (VOCs) released during combustion. These VOCs are a diverse group of organic chemicals that easily become vapors or gases, contributing significantly to the characteristic smell of smoke.

During the Eaton Fire, strong winds transported smoke, particulate matter, and gases far downwind, allowing pollutants to infiltrate homes through windows and doors. Air quality monitors recorded that particulate levels, even miles away from the fire, were 50 to 100 times higher than usual when the fires were most active. Notably, these particulates included hazardous substances such as lead, released from burning structures and vehicles. Since the fire has been largely extinguished, particulate levels, including those containing lead, have returned to pre-fire conditions.

• In residences, you can keep your windows open to ventilate your home and help remove any residual smoke (as long as the air smells better outside than inside).
• In office buildings, the HVAC system will support the ventilation and air exchange. Therefore, it is preferable to keep doors and windows closed.
• There's generally no need to wear a mask outdoors when air quality is good. However, if you are doing activity that may stir up dust or debris, such as yard work, public health officials do recommend that a high-quality mask is worn.

Standalone air cleaners are effective for:

• Removing particulates like dust, pollen, and smoke.
• Reducing VOCs when equipped with an activated carbon filter.

However, they have limited capacity for VOCs and require frequent filter changes to maintain performance.

• Wear a high-quality, well-fitted mask to avoid inhaling dust and ash.
• Open windows for ventilation if the outdoor air quality is better than indoors.
• Wash your clothes immediately after cleaning.

• Avoid sweeping, as it resuspends dust into the air.
• Wet mop and wipe down hard, horizontal surfaces using diluted soapy water (less toxic than TSP) working from clean areas toward dirty areas.
• Ensure proper disposal of used cleaning materials.

• Use a HEPA-filtered vacuum cleaner.
• Avoid using vacuum accessories like mechanical brushes or beaters until you've vacuumed surfaces several times.
• If possible, clean rugs and furniture outdoors or with windows open for ventilation.

• Smoke odors persist because semi volatile compounds accumulate in porous materials like carpets and furniture.
• Open windows to ventilate when air quality permits (a good AQI and the air is clear of the smell of smoke), as professional cleaning services often only clean surfaces without addressing embedded compounds.

• Remove street shoes before entering your home.
• Wipe off dog paws after outdoor walks.
• Wash down hardscape surfaces like patios and driveways.
• Avoid using or allowing lawn services to use leaf blowers, as they stir up contaminants.
• Use sticky clean mats to capture particles on shoes

Caltech continues to share relevant updates and information through the Caltech Alerts system and information posted on the Caltech.edu/fire website.

Caltech utilizes multiple methods to monitor air quality:

• On-Campus Monitoring: An air quality monitoring station is located on the roof of Caltech Hall, providing real-time data accessible at breathe.caltech.edu.
• Governmental Resources: Caltech references data from governmental agencies, such as the EPA's AirNow Interactive Map, to assess regional air quality.
• Indoor Spot Checks: Portable equipment is used for spot-check testing inside buildings whenever needed.

To enhance indoor air quality, Caltech is:

• Upgrading Air Filters: Installing MERV 15 air filters in HVAC systems where feasible to capture finer particulates.
• Modulating Air Intake: Adjusting the intake of outside air based on outdoor air quality—introducing fresh air when quality is good to flush buildings and restricting intake when it deteriorates.
• Installing Carbon Filters: Adding carbon filters to reduce smoke odors, enhancing indoor comfort.

The Institute is able to adjust air circulation at a building system level through the HVAC system. 

At the system level, facilities can set the level of internal and external air to have circulating inside the building in a streamlined and controlled manner. This also ensures that we can make necessary adjustments as outdoor air conditions change. If building occupants open and close windows and doors, facilities ability to control for air quality at a building level is compromised. For this reason, we have asked building occupants on campus to refrain from opening and closing their windows for the time being. 

MERV (Minimum Efficiency Reporting Value) 15 filters are high-efficiency filters capable of capturing particles as small as 0.3 microns, including bacteria, smoke particles (not odors), and fine dust, thereby significantly improving indoor air quality.

By adjusting the amount of outside air brought into buildings, Caltech can:

• Flush Buildings: Introduce fresh air when outdoor quality is good to remove indoor pollutants.
• Protect Indoor Environment: Limit the entry of polluted air when outdoor quality is poor, maintaining a healthier indoor environment.

To minimize eye irritation caused by airborne dust, consider the following measures:

• Wet Cleaning of Surfaces: Regularly clean surfaces using damp cloths or mops to effectively capture and remove dust particles, preventing them from becoming airborne.
• Use of Air Purifiers: Implement air purifiers equipped with HEPA filters to reduce airborne dust and improve indoor air quality.
• Proper Ventilation: Ensure adequate ventilation to help disperse and remove airborne particles.
• Personal Protective Equipment (Q: What symptoms might I experience due to lingering smoke and its odor after a wildfire?

After a fire, hazardous materials such as asbestos, lead particles, and other heavy metals can settle on surfaces, posing health risks if disturbed. To minimize exposure, it's crucial to clean these surfaces thoroughly using wet cleaning methods.

Recommended Cleaning Steps:

1. Personal Protective Equipment (PPE): Before beginning any cleanup, wear appropriate PPE, including gloves, safety goggles, and a high-efficiency particulate air (HEPA) filter mask, to protect against inhalation of hazardous particles.
2. Wet Cleaning Method: Avoid dry sweeping or dusting, as these actions can resuspend hazardous particles into the air. Instead:
   • Dampen Surfaces: Lightly mist the affected areas with water to suppress dust and prevent particles from becoming airborne.
   • Wipe Down: Use a damp cloth or mop to gently clean the surfaces, ensuring that contaminants are effectively captured.
   • HEPA Vacuuming: For carpets and upholstery, utilize a vacuum equipped with a HEPA filter to trap fine particles.

Implementing these wet cleaning practices helps reduce the risk of exposure to hazardous substances that may linger after a fire, safeguarding your health and that of others in the affected environment.

Wildfire smoke contains hazards such as fine particulate matter (PM2.5). PM2.5 refers to particles with a diameter of 2.5 micrometers or smaller, which are particularly harmful due to their ability to penetrate deep into the lungs and can:

• Reduce lung function.
• Worsen asthma and other heart or lung conditions.
• Cause symptoms like coughing, wheezing, and difficulty breathing.

The AQI describes air quality levels as follows:

• 0-50 (Good): Air quality is satisfactory, with little or no risk.
• 51-100 (Moderate): Air quality is acceptable; some individuals sensitive to pollution may experience mild effects.
• 101-150 (Unhealthy for Sensitive Groups): Sensitive individuals may experience health effects; the general public is unlikely to be affected.
• 151-200 (Unhealthy): Everyone may begin to experience health effects; sensitive groups may experience more serious effects.
• 201-300 (Very Unhealthy): Health alert; everyone may experience serious health effects.
• 301+ (Hazardous): Health warning of emergency conditions; everyone is more likely to be affected.

• Stay Indoors: Keep windows and doors closed or seek shelter in an area with better air quality.
• Limit Outdoor Activity: Avoid vigorous exercise and minimize time spent outdoors.
• Use Air Purifiers: Operate air purifiers indoors if available.
• Clean Ash Safely:
  • Lightly spray surfaces with water to suppress dust.
  • Use pre-moistened wipes or damp cloths/paper towels to clean.
• Wear an N95 mask: If you can see particles or smell smoke, it is recommended that you wear a high-quality mask.

• N95 masks are available during operating hours at the Caltech Bookstore.
• Watch the OSHA video on the voluntary use of N95 masks for guidance.

• Consult with your Supervisor about exposure-reduction options such as:
  • Relocating to enclosed buildings, structures, or vehicles with filtered air.
  • Voluntarily using an N95 respirator, per the Institute's Respiratory Protection Program.
• Avoid outdoor activities and monitor your symptoms if exposed to poor air quality.