7. Modesto

Population: 211,266 | Air Quality Index: 215 | Hours lost per person: 9.6

Total years of life lost: 231

Photo: The Modesto Junior College class cancellation notice.

6. Fremont

Population: 232,206 | Air Quality Index: 178 | Hours lost per person: 8.0

Total years of life lost: 212

N95 filter mask search results for Fremont.

5. Oakland

Population: 417,870 | Air Quality Index: 173 | Hours lost per person: 7.9

Total years of life lost: 376

Smoke over the San Francisco-Oakland Bay Bridge. (Photo: David Paul Morris/BB)

4. Sacramento

Population: 490,712 | Air Quality Index: 263 | Hours lost per person: 12.8

Total years of life lost: 719

A 2012 CalFire wildfire awareness event in Sacramento. (Photo: CalFire)

3. Fresno

Population: 527,438 | Air Quality Index: 191 | Hours lost per person: 7.7

Total years of life lost: 464

Butte County and Fresno County sheriff officers remove a victim of the Camp Fire. (David Paul Morris/BB)

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2. San Francisco

Population: 884,521 | Air Quality Index: 155 | Hours lost per person: 6.9

Total years of life lost: 695

Many San Francisco residents have been wearing kerchiefs, surgical masks or respirator masks. (Michael Short/BB)

1. San Jose

Population: 1,026,908 | Air Quality Index: 162 | Hours lost per person: 6.0

Total years of life lost: 698

The AirNow.gov report for the area around San Francisco and San Jose.

(Related: 5 Reasons This Week’s NAIC Meeting Is… Different)

People in northern California are asking how all of the smoke from the Camp Fire will affect their health.

Actuaries and underwriters at life insurance and annuity issuers are wondering the same thing. If climate change makes wildfires more common in the United States, and wildfire smoke affects life expectancy, that could affect the lifespan of life insurance policyholders and annuity contract holders.

The Camp Fire started Nov. 8 in Butte County, California. As of press time, it had killed 77 people and destroyed 10,364 homes. The fire was still only 65% contained.

The fire has been sending smoke over an area in California that’s home to at least about 8 million people. The smoke has forced school closures and other closures and cancellations throughout the region.

On normal days, the typical Environmental Protection Agency (EPA) Air Quality Index  (AQI) for a community in the region is about 30 to 60. This week, the Camp Fire has pushed the AQI over 300 for brief periods, over 250 for extended periods in some communities, and over 150 throughout much of the region.

An AQI over 150 to 200 will make almost everyone uncomfortable, and it can increase the risk that simply breathing will lead to asthma attacks and heart attacks. Higher AQI levels increase the risk that healthier people will have problems, and that the problems will be more severe.

One way to get a very rough idea of the impact of high AQI levels on human health is to convert the AQI levels into cigarettes smoked equivalents, and to convert the cigarettes smoked estimates into estimates of the amount of human life that might be lost.

Richard A. Muller and Elizabeth A. Muller have estimated at Berkeley Earth that dividing a specified AQI level by 22 reveals how many cigarettes would have to be smoked during a day to be the equivalent of breathing air with the specified AQI level for that day.

Mary Shaw and colleagues estimated in 2000, in an article published in the BMJ, that each cigarette smoked reduces an individual’s lifespan by an average of about 11 minutes.

We used the “divide the AQI by 22″ rule and the “11 minutes per cigarette” rule to come up with a crude estimate of how much the Camp Fire smoke could affect the average life expectancy for people in the affected region, if people are exposed to high levels of smoke for about a week.

Those calculations suggest that the Camp Fire smoke could shorten the lifespan of the average person in the region by about six to 10 hours. If all 8 million people in the region were exposed to that level of smoke for about a week, it’s possible that the smoke could rob all of the people in the region of about 5,000 hours of life.

For the results for the seven most populous cities in the region, see the slideshow above.

Methods

We used 2016 Census data to create a list of the seven most populous cities in northern California.

We obtained each city’s average AQI from USA.com, and its Nov. 19 AQI from PurpleAir.com

To show how much smoke from the Camp Fire changed each city’s AQI, we subtracted the average AQI from the Nov. 19 AQI.

We calculated the cigarette-equivalent figure, and multiplied that figure by 11, to show many minutes of life an individual in the region might lose per day due to the Camp Fire.

We multiplied the minutes-lost result by seven, to reflect the possibility that the typical individual in northern California will breathe smoke-filled air for about a week.

We multiplied by the per-person averages by each city’s population to get each city’s loss-of-life total.

We then converted the per-person loss figures into hours, and the city loss totals into years.

Note that there are many limitations on this analysis. The overall regional AQI estimate, for example, was based on a look at typical AQI numbers in the PurpleAir.com AQI map for the region, and it’s possible that many people in the region could succeed at using steps, such as wearing masks and staying indoors, to limit their exposure to smoky air.

What Scientists Say

In a recent study published in GeoHealth,  researchers estimated that chronic inhalation of wildfire smoke may cause a total of about 15,000 deaths per year in the United States today.

If climate change makes wildfires more common, the average number of deaths caused by wildfire smoke could increase to about 40,000 per year by the end of the 21st century, the researchers predicted.

If inhaling smoke from wildfires does cause about 15,000 deaths per year in the United States, wildfires may causes about as many deaths per year as ovarian cancer, according to a comparison of that figure and the causes of death figures in the U.S. Centers for Disease Control and Prevention final death report for 2016.

If the number of U.S. deaths caused by wildfire smoke increased to 40,000 per year sometime in the future, wildfire smoke could kill about as U.S. residents per year as pancreatic cancer does now.

— Read 3 Steps to Disaster-Proofing Your Firmon ThinkAdvisor.

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