USA — Where theres smoke theres fire runs the old saw, but the reverse is usually equally true: Where theres fire theres smoke. And where theres wildfires, theres lots of smoke, especially as fires become bigger and more destructive (although not automatically more common). Surely it’s a bad idea to be breathing that hazy residue.
A new study looking a four years worth of wildfires upwind from Reno, Nevada, puts some numbers on that common-sense observation and suggests that ill effects of wildfire smoke may be present as much as 300 miles from the burning. Researchers led by resource economist Klaus Moeltner of Virginia Tech compared the toll of acres burned to data on air pollution and hospital admissions for respiratory and cardiovascular problems.
Keeping in mind that the average fire they studied was 50,200 acresthe size of Madison, Wisconsinthey report:
Accounting for lagged effects, we find that an additional 100 acres burned cause between $60 and $210 in inpatient treatment costs for acute respiratory problems, depending on fire distance and primary fuel type. The analogous cost estimates for cardiovascular admissions range from $70 to $260. For the 2008 fire season this translates into total smoke-induced inpatient costs in Reno/Sparks of close to $2.2 million.
If those figures seem bearable in the scheme of things, keep in mind that these costs are limited to a metro area of about 350,000 people (granted it is the “the biggest little city in the world”) and to heart and lung issues. It doesnt look at the cost of cowering indoors afraid to venture outside, or the costs of visits to the emergency room, family doctor, or outpatient clinic. The authors themselves see their numbers as the lower bounds of a wildfires mixed economic toll:
Beyond medical expenses, our cost estimates are likely just the tip of a much larger iceberg of total economic losses from wildfire smoke in downwind communities. Additional costs would include non-market components such as decreased productivity and forgone recreational opportunities.
And its not all money. After Sumatras awful 1997 fires, researchers inferred that fetal and child mortality in Indonesia exceeded 15,000 due to the smoke.
The urban area of Reno offered Moeltners team an ongoing natural experiment for studying these issues thanks to the general dryness of the Great Basin location, prevailing winds that blow smoke into town, a large number of wildfires within 500 miles that vary in size from 700 acres to 190,000, and various habitatsgrasses, sage/juniper stands, full-blown foreststhat burn. Their study period ranged from March 2003 to December 2008; 2008 was a particularly intense fire year for the region.
What made their study different from the packand there are a number of wildfire/health surveys drawn from fire-prone study sites in North America, South Africa, and Australiais that these researchers looked at the day-to-day figures over 1,399 days, which gave them lots of fires to examine.
The researchers looked most at health issues that could be related to breathing in particles 2.5 microns or larger, a traditional yardstick for looking at pollution. At that size the particles cause both haze and health concerns. The researchers also looked at wildfire pollutants carbon monoxide and ozone, which, while definitely bad for you, usually dont lead directly to the hospital. Most of what we do know about the effects of smoke on health, by the way, comes from studying cooking fires using wood as a fuel and from industrial sources in big cities (not to mention studies on smoking).
A 2006 study found that about a third of the particulate matter in Canadas air came from forest fires, and the cost of dealing with the medical implications of that was rivaled only by the cost of lost timber itself. However, that paper reads, air quality concerns are not typically included in resource allocation decisions in fire management. Just ask the residents of Kuala Lumpur .
Thats one of the reasons this new study matters. “The design of efficient wildfire programs requires an understanding of the values at risk oralternatively putthe expected benefits from preventing or suppressing a fire event, the authors write.
For example, preemptive fuel reduction efforts may be more cost-effective in an area that is upwind from a large population zone, ceteris paribus. The same rationale holds for the allocation of combative resources after a fire has started. Furthermore, reducing wildfire smoke via such interventions may produce net gains even at a large distance from the impact area.
In other words, even where there isnt a nearby fire, there may be smoke.