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How SF will respond the next time toxic air hits

“There are not sufficient data to support the benefit of prolonged use of N95 respirators”

Smoke From Western Wildfires Triggers Air Quality Warnings In San Francisco
A smoky haze obstructs the view of the San Francisco skyline on August 24, 2018.
Photo by Justin Sullivan/Getty Images

The devastating Camp Fire in Butte County in 2018 stained San Francisco’s skies for nearly two straight weeks, spawning an unprecedented public health crisis as smoke and dangerous levels of particle matter from the fire blanketed the region.

In response, the city is working on a new Air Quality Emergency Plan, a draft version of which was presented to a city panel last week and the text of which the San Francisco Examiner uploaded here.

The work-in-progress report contains several key findings and directives to hopefully make the city better prepared and better informed the next time the air goes bad.

Among its most significant conclusions:

  • The smoky days of 2018 represent the most atmosphere ever recorded in the Bay Area: “On average, San Francisco benefits from comparably clean air relative to other urban areas, but the Bay Area is vulnerable to short term spikes in pollution due to increases in temperature and proximity to wildfires. [...] During the Butte Camp Fire AQ Event, San Francisco experienced l3 consecutive days of unhealthy or extremely unhealthy air quality, the worst air quality event on record prior.”
  • Even short-term exposure to such conditions is dangerous: “Acute impacts can include asthma attacks, shortness of breath, coughing, chest tightness, irritated mucus membranes, pulmonary inflammation, bronchitis, respiratory infection, and heart attacks. Acute impacts may be seen for days or weeks after an AQ emergency event. Chronic impacts can include asthma, lung cancer, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and premature death.”
  • N95 masks are not a viable solution to the problem: “Masks and N95 respirators are not a replacement for staying indoors. N95 respirators are not designed for children. N95 respirators are ineffective with facial hair. N95 respirators, properly fitted, increase the work of the cardiovascular system and can be dangerous for some people. [...] There are not sufficient data to support the benefit of prolonged use of N95 respirators in wildfire smoke air quality events.” Nevertheless the plan concedes that “N95 respirators may be helpful” for those who cannot simply remain indoors.
  • The city will be more aggressive cancelling events during bad air spells: “[But] the cancellation of outdoor events can be a complex process and can have unintended impacts, including adverse economic impacts. In addition, the cancellation of a permit for an event may not mean that the event does not occur. Participants may not receive notification of the cancellation or may choose to attend despite a permit cancellation.”
  • Emergency services must mitigate extreme heat as well as air hazards: “Messaging must change. Air quality messaging must change when the temperature is 85 degrees or higher. Messages to the population that people should stay indoors because of air quality, without cooling available to people, could result in increased deaths, particularly among vulnerable populations.”

While the plan notes that the Bay Area is naturally blessed with healthy air quality, it also warns that the effects of climate change will make wildfires and unusually hot days—the two factors most likely to sour the air—much more common in the near future.