| Dear
EarthTalk: How safe are the fire retardants that
are used to quell forest fires across the American West?
-- Barbara, Minneapolis,
MN
| |
A
fire plane dropping fire retardants on a forest fire
in Sun Valley, Idaho. Nitrogen in some of these mixtures
harms the reproductive capacities of some native plants
and creates algae blooms in streams that kill fish
by choking out their oxygen.
© Getty Images |
So-called
long-term fire retardants—those usually dropped from
airplanes over forest fires—are comprised of water
mixed with a slurry of chemicals, thickeners and corrosion
inhibitors designed to prevent plants on the ground from
igniting, keep the ingredients from separating and dispersing
during targeted drops, and ensure that the harsh chemicals
on board the plane don’t endanger the flight’s
safety.
Firefighters
sometimes add iron oxide to make the fire retardant turn
red when applied so they can see where they have already
covered. Ammonium phosphate and ammonium sulfate, known
for their use as agricultural fertilizers, are also often
added to provide nutrients to help the forest regenerate
after a burn.
In recent years,
where global warming and droughts have exacerbated forest
fires across the American West, federal and state firefighting
agencies have upped their cumulative annual use of long-term
fire retardants to some 20+ million gallons a year spread
across tens of thousands of individual fly-overs.
While such chemicals
have been valuable in minimizing the damage of forest fires,
their use comes with a price. The nitrogen in ammonium phosphate
and ammonium sulfate can wreak terrible havoc on aquatic
ecosystems, creating algae blooms that kill fish by choking
out their oxygen. A 1998 study by the U.S. Geological Survey’s
Northern Prairie Wildlife Research Center, found long-term
fire retardants to be “very toxic to aquatic organisms
including algae, aquatic invertebrates and fish.” The
study also said that fire-fighting chemicals “could
cause substantial fish kills depending on the stream size
and flow rate.”
In 2000 the U.S.
Forest Service issued guidelines for use of fire retardants
by aerial fire fighting crews. While the focus of the document
was fire control and safety, it encouraged pilots to avoid
applying retardant within 300 feet of waterways or other sensitive
areas. The Forest Service acknowledges the risk of using retardants,
but believes that their use in moderation is a net gain; as
fewer “ground troops” need to be sent in to risky
situations while more property can be saved from the ravages
of a fast-moving fire. Fires
are actually an essential part of forest ecology and many
species of trees and plants thrive in part because of the
natural occurrence of fires (sequoia trees, for example,
depend upon the high temperatures of forest fires to pry
open their cones so new seeds can spring forth and take
root). The main reason that such catastrophic, news making
fires occur in the first place is that humans have sprawled
too closely to the forest edge. This has lead to forest
management policies that suppress natural fires, causing
large build-ups of tinder-like woody debris that eventually
ignites and burns out of control.
CONTACTS:
USGS
Northern Prairie Wildlife Research Center; U.S.
Forest Service Guidelines for Aerial Application of Retardants
and Foams.
Dear EarthTalk:
There are so many energy drinks on the market, but they
all seem very high in sugar, coloring and preservatives.
Are there any natural versions that offer a healthier kick-start?
-- John Hwang,
Cambridge, MA
| |
Some
500 new varieties of so-called energy drinks have
been introduced in recent years. Most contain excessive
amounts of sugar and caffeine and are far from healthy.
© aquarelle, courtesy Flickr |
Energy drinks
constitute one of the fastest growing sectors of the soft
drink market across the U.S. and around the world, with
some 500 new varieties introduced in recent years. But it’s
true that most are far from healthy. Besides containing
excessive amounts of sugar and caffeine, which alone can
be dangerous to those with diabetes or heart conditions,
many also feature a battery of supposedly beneficial herbal
supplements (taurine, guarana and ginseng) that are not
proven to increase energy and may actually sap energy, being
detrimental to bodies overloaded with new and unfamiliar
stimuli.
“Most of
the energy drinks contain high-tech-sounding ingredients
that are not controlled substances, of no value, and potentially
harmful” in large amounts, says sports nutritionist
Cynthia Sass. “The amount of the stimulants is not
always listed on the label, and even when the information
is listed, it is hard for consumers to interpret because
we are not familiar with these ingredients.”
Sass recommends
good old fashioned water as the best alternative to energy
drinks. Re-hydrating is a great way to stay alert and to
move other nutrients through the body. Other tried and true
ways to increase energy include maintaining a healthy diet,
regular physical activity and, of course, a good night’s
sleep.
But what about
those times when you really need a boost? Yerba mate tea,
which is derived from yerba mate plants that naturally contain
caffeine as well as other natural stimulants, is a popular
choice. Perhaps part of the reason some people swear by
it is that its brewed leaves contain theobromine—also
found in cocoa—an alkaloid known to help elevate the
mood. Boosters of the drink say it also helps strengthen
the immune system, relieve allergies and aid in weight loss.
Not a straight
tea drinker? Brewed yerba mate, which has an earthy flavor
that some call an acquired taste, is sold commercially not
just as tea but also blended in lattes, coffees and energy
drinks. Guayaki (available at Safeway, Wegmans, 7-Eleven
and elsewhere) is one of a handful of companies paving the
way for yerba mate in the U.S. The company sells flavored
versions with a hint of cane juice to sweeten it up for
otherwise sugar-addicted American consumers.
Another take
on healthy energy drinks comes from a handful of companies
selling products with vitamins and nutrients instead of
caffeine to give drinkers a kick. Zipfizz is a powder that
can be mixed in with water and contains a combination of
vitamins and minerals that provide the body with electrolytes,
antioxidants and vitamin B-12, among other natural, immune-strengthening
nutrients. Eniva Vibe, also packed with vitamins and minerals,
is another popular new entry into the healthy energy drink
market.
As with anything
you consume, mileage may vary, so to speak, so experts advise
going slow at first to make sure it agrees with you. And
if all else fails, remember you can always just go take
a nap.
CONTACTS:
Cynthia Sass;
Guayaki;
Eniva
Vibe; Zipfizz
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