USGS: Fall Foliage Is Major Source of Mercury in New England Environment

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Last week, the U.S. Geological Survey released the findings of two multiyear studies which concluded that — hang onto your sugaring buckets — fallen autumn leaves release mercury into the environment.

As if Vermont's tourism industry didn't have enough to worry about, what with Vermont Yankee's radioactive incontinence and Green Mountain dairy cows belching and farting out enough greenhouse gases to turn the state's much-heralded winter slopes into Slip 'n' Slides.

"We know that forest canopies scavenge mercury out of the air — because trees breathe every day — and they take in gases that include gaseous mercury," explains Martin Risch, a research hydrologist with the USGS in Indianapolis, Ind., who worked on the studies. Leaves and needles also capture mercury that settles as dry deposits on their surface. But when those leaves and needles fall, they release the environmental contaminant once again.

Mercury poses a health risk to humans and other living critters. Notably, methylmercury, the nasty organic variety that shows up in fish and seafood, is harmful to pregnant mothers because it can affect their fetuses' developing cognitive abilities, attention, language, fine motor skills and ... what was that last one? ... oh, yeah, memory. Another good reason to get those silver-amalgam fillings out of your mouth.

Scientists have known for years mercury moves from the atmosphere into the environment through precipitation. However, these new studies reveal that "litterfall"— that is, those beautiful leaves and needles — delivers at least as much mercury to eastern U.S. ecosystems as precipitation. And possibly more.

What's worse, the leaves' mercury levels peak just before Vermont's spike in out-of-state vehicular traffic. "We do know that mercury levels increase during growing season and reach their maximum [level] right before the leaves change color and drop," Risch notes.

One of these studies, which looked at 15 states in the eastern United States, including Vermont, found varying levels of mercury deposits that were dependent upon the types of trees that produced the leaves. According to Risch, Vermont's deciduous forests, which are high in oak, hickory, maple, beech and birch, had higher mercury loads than many other eastern states. Obviously, Vermont also has more overall acreage of trees compared to many states, which accounted for its higher leaf-mercury loading.

But wait: Before you bust out the chainsaws and start dropping the nearest sugarbush, it's worth pointing out the obvious: Though some mercury is naturally occurring, most mercury found in our atmosphere which ends up in leaves actually comes from human sources — coal-fired power plants, industrial boilers, cement manufacturing and trash incinerators.

Forest canopies naturally remove mercury from the air and incorporate the mercury into and onto the leaves and needles of trees. So, blaming the trees for all that mercury littering the ground is like blaming the vacuum cleaner for your muddy floors. Instead, try telling the kids to wipe their feet before they come inside.

"This has really helped advance the science of modeling," Risch explains, because scientists have long struggled to find ways of accurately measuring the total mercury load in our environment and how well it compares to computer predictions. Clearly, it's now been shown that measuring just the mercury that falls as rain accounts for maybe half the total mercury that's out there.

Regulatory agencies and scientists rely on computer models when, say, the Environmental Protection Agency wants to put limits on how much mercury is being released from coal-fired plants, and scientists need ways to measure if those limits are ultimately having an effect. One way they do that: Rake up some leaves and see what's in them.

Does this study have implications for how Vermonters dispose of their leaves? While Risch admits that wasn’t a goal of their research, he does say that composting leaves is a better practice than landfilling or burning leaves, to prevent even trace amounts of mercury from going into the air.

"We don’t want people to think that there’s enough mercury in those [burning] leaves to cause them harm," he notes, adding "but when there are large forest fires, we can detect more mercury in the air."

Risch also says that this research shouldn't affect Vermont's leaf-peeper dollars. As he puts it, "I don’t think it’s hurting the trees by any means." Still, raking and jumping into big piles of leaves will never feel the same way again.

So, what's up next from government researchers? Eating too much Vermont cheddar and maple syrup can cause heart disease and diabetes? 

Oh. Right.

Photos courtesy of the Vermont Department of Tourism and Marketing

Comments

[Tim]

Government mandates for replacing the classic lightbulb in all it's waste heat generating glory with mercury containing flourescents will put more mercury into our environtment too-but nobody talks about that.

[Doug Hoffer]

The mercury in lightbulbs is only a problem if they are not disposed of properly.

[Jeanne K]

If we compost the leaves and then use the compost on the garden, aren't we putting the mercury into our gardens? What then should we do with the leaves?

Oh, dear god.

[Patricia Crocker]

Mr. Hoffer:

I had a CFL break in my house in the middle of winter last year when it was minus 20 degrees outside. I followed the instructions...sequestered my kids upstairs, opened all the windows in my downstairs (waste of energy to re-heat my house) put on the hazmat gear, etc. Upon recounting my story to numerous people, their response was, "why did you do that? I just throw them out in the trash". So how many people do you really think dispose of them properly? How much mercury do you think is leaking out from our landfills because people don't want to dispose of them properly? The CFL lightbulb is a debacale and useless attempt at the government legislating failed policies. I work with individuals with autism, and the CFLs bother them immensely. They are hypersensitive to sensory input and can hear noises coming from them and are bothered by a constant flicker. Most people, like myself are stockpiling the incadescent bulbs. After that stash runs out, there is going to be a "black market" for incadescent bulbs.

[Melissa]

And just how many Americans actually know how to properly dispose of a CFL? I certainly did not until very recently, but I jumped on the bandwagon early trusting that CFL's were a wonderful planet-saving option. NO ONE told me that the disposal of these bulbs should be so radically different from disposal of a normal bulb, and I doubt if the tens of millions of Americans currently using them have a clue either. What do I do with a CFL when it burns out? What is the proper disposal of a CFL bulb?

From GE's website - and even they give the option of household garbage unless "better options exist":

Follow these guidelines to dispose your CFL properly:

Like paint, batteries, thermostats, and other hazardous household items, CFLs should be disposed of properly. Do not throw CFLs away in your household garbage if better disposal options exist. To find out what to do first check www.earth911.org (where you can find disposal options by using your zip code) or call 1-800-CLEAN-UP for local disposal options. Another option is to check directly with your local waste management agency for recycling options and disposal guidelines in your community. Additional information is available at www.lamprecycle.org. Finally, IKEA stores take back used CFLs, and other retailers are currently exploring take back programs.
If your local waste management agency offers no other disposal options except your household garbage, place the CFL in a plastic bag and seal it before putting it in the trash. If your waste agency incinerates its garbage, you should search a wider geographic area for proper disposal options. Never send a CFL or other mercury containing product to an incinerator.

[Alan Sexton]

I'm far more concerned about the observable stress caused people by government-funded scientists who need to justify their salaries, and also those ridiculous CFL's, than I am about something that occurs naturally* being present in autumn leaves.
*(http://www.greenfacts.org/en/mercury/l-3/mercury-1.htm#2p0)

[caleb]

"The mercury in lightbulbs is only a problem if they are not disposed of properly."

And how many people do that?

I use CFLs almost exclusively in my house. Frankly, they are a big hassle. Despite the claim of long life, I actually replace them at least as often as I used to replace the incandescents -- because they are not designed to be turned on and off repeatedly. And they are more expensive. And they are not as easy to handle as incandescents. And if you accidentally break one, it's a major clean up hassle. And, they can't be thrown away but must be returned to the store where you bought them. (And can we trust that the hardware store isn't just throwing them in the trash?)

I question whether they are really appropriate for residential use.

[Randomarrow]

The discerning reader will note that the article cited coal burning power plants as one of the principal sources of atmospheric mercury. The inefficiency of the tungsten bulb means that each one is responsible for many times the amount of mercury emitted by damaged or improperly disposed of CFC bulbs. The future belongs to LED lighting technology. They are already almost as cost effective over their lifetime as either tungsten and or CFC, without any mercury release. In a few more years only the tungsten hoarding yahoos will be mercury emitters.

Tried Extortion Already? Vote Sanity!

[Sue]

Way to ruin every last great Vermont thing 7daze. What's next? Maple syrup causes cancer?

[Ken Picard]

Sue, did you even read to the end of this blog post?

[Josh]

Is disposing of your CFL lights more of a hassle than acquiring your morning coffee? Something to think about every time your turn your key in the ignition. Lazy americans. Gee, I wonder why we're in a recession? Oh, yeah..it's everyone's fault but mine.

[Doug Hoffer]

Ms. Crocker said, "The CFL lightbulb is a debacale and useless attempt at the government legislating failed policies...Most people, like myself are stockpiling the incadescent bulbs. After that stash runs out, there is going to be a "black market" for incadescent bulbs."

It would appear that the government mandated nothing more than greater efficiency. This from a recent piece by Jim Hightower: http://www.nationofchange.org/dim-bulbs-congress-1314025410

"There was never a proposed ban on incandescent bulbs — just a new standard for all bulbs to consume less energy. And this standard was not set by Democrats, but by a Republican-sponsored law signed in 2007 by George W. Bush. "

Oops. It appears the fear mongering about government mandates re. CFLs was BS. You have to hand it to Fox News and the Koch brothers; they know how to stoke their base. Too bad the base is not a bit more discerning.