| Dear
EarthTalk: Is using nitrogen to inflate my
car’s tires really better for the environment than
using air? And if so, how?
-- Roger Mawdsley, Abbotsville, BC
| |
A
recent study found that 93.5 percent of cars in Europe
have under-inflated tires, wasting some 2.14 billion
gallons of high-priced, polluting fuel every year.
Analysts believe the situation is no less severe in
North America. But filling tires with costly nitrogen
instead of air would likely make little difference
-- best to just keep an eye on your tires and keep
them properly inflated.
© Getty Images |
Whether
or not it makes environmental sense to inflate car tires
with nitrogen instead of air is a matter of much debate.
Proponents of nitrogen say the element is a smart choice
for the environment primarily because it leaks from tires
at a slower rate than air, so tires stay inflated longer
at full capacity, which helps a vehicle attain maximum fuel
efficiency, i.e. better gas mileage. According to the Get
Nitrogen Institute, a Denver-based non-profit which advocates
for replacing the air in our tires with nitrogen, under-inflated
tires inadvertently are a big contributor to global warming
as they cause drivers to waste fuel.
Although
auto experts recommend checking your car’s tire pressure
weekly, studies show that the majority of drivers rarely
if ever check to see if their tires are properly inflated
and usually only add air when a tire is visibly low or beginning
to go flat. A recent study by the European division of tire
maker Bridgestone found that 93.5 percent of cars in Europe
have under-inflated tires, wasting some 2.14 billion gallons
of high-priced, polluting fuel every year. Analysts believe
that a similar percentage of North Americans are driving
around on under-inflated tires as well.
While
properly inflated tires certainly promote better fuel efficiency
and are thus good for the environment, not everyone is convinced
that filling tires with nitrogen instead of plain ol’
air makes a difference. Terry Jackson, who writes the influential
“Driving for Dollars” column for the Bankrate.com
website, points out that air is composed primarily of, you
guessed it, nitrogen; some 78 percent of the regular air
you put in your tires is nitrogen, with oxygen making up
most of the remainder. “So going to pure nitrogen
only squeezes out a small amount of the oxygen molecules
that nitrogen proponents argue are so detrimental,”
relates Jackson.
Nitrogen
proponents may quibble that it’s the oxygen in the
mix that causes problems, though, as oxidization can start
to degrade the rubber inside tires while corroding the interior
of the wheels as well. But Jackson counters that tires and
wheels will have been long worn out on the outside before
any oxygen-induced interior damage causes them to come apart.
Also, he adds that a lot of the leakage from tires happens
because the wheel and the tire do not line up perfectly,
and air (or nitrogen) escapes accordingly.
Another
factor, of course, is cost. Nitrogen-equipped service centers
will fill up your tires with nitrogen for something like
$10 per tire, which is a far cry from the couple of quarters
(if even that) it takes to trigger the air machine at your
local gas station. “When it comes down to a dollar
decision, it’s hard to argue that spending as much
as $40 for nitrogen in a set of tires is a good fiscal move,”
writes Jackson.
“Save
your money and just keep an eye on your tire pressures,”
he concludes.
CONTACTS:
Get
Nitrogen Institute; Bankrate.com.
Dear
EarthTalk: Backyard fire pits have become the
latest must-have gardening feature. How bad are they on
the environment?
-- Michael O’Laughlin, Tigard, OR
| |
Wood
smoke from backyard fire pits can cause health problems
such as burning eyes, runny nose and bronchitis. The
fine particles also aggravate heart and lung diseases.
Children are especially vulnerable as their respiratory
systems are still developing and they breathe more
air (and air pollution) per pound of body weight than
adults.
© Saffanna, courtesy Flickr |
With Fall setting
in and the mercury starting to drop, many of us want to
extend our time outdoors, and sitting around a backyard
fire pit has become one of the most popular means to do
so. But even though it may be fun—s’mores anyone?—it
is not good for the environment, especially during times
when air quality is already poor.
It’s hard
to assess the larger impact of backyard fire pits on local
or regional air quality, but no one questions the fact that
breathing in wood smoke can be irritating if not downright
harmful. According to the U.S. Environmental Protection
Agency (EPA), so-called fine particles (also called particulate
matter) are the most dangerous components of wood smoke
from a health perspective, as they “can get into your
eyes and respiratory system, where they can cause health
problems such as burning eyes, runny nose and illnesses
such as bronchitis.”
Fine particles
also aggravate chronic heart and lung diseases, and have
been linked to premature deaths in those already suffering
from such afflictions. As such, the EPA advises that anyone
with congestive heart failure, angina, chronic obstructive
pulmonary disease, emphysema or asthma should steer clear
of wood smoke in general. Children’s exposure to wood
smoke should also be limited, as their respiratory systems
are still developing and they breathe more air (and air
pollution) per pound of body weight than adults.
Geography and
topography play a role in how harmful wood smoke can be
on a community-wide level. People living in deep, steep-walled
valleys where air tends to stagnate should be careful not
to light backyard fires during smog alerts or other times
when air quality is already poor. Lingering smoke can be
an issue even in wide-open areas, especially in winter when
temperature inversions limit the flow of air.
The Washington
State Department of Ecology reports that about 10 percent
of the wintertime air pollution statewide can be attributed
to fine particles from wood smoke coming out of wood burning
stoves. While a wood stove may be a necessary evil as a
source of interior heat, there is no excuse for lighting
up a backyard fire pit during times when you could be creating
health issues for your neighbors.
Another potential
risk to using a backyard fire pit is sparking a forest fire.
Some communities that are surrounded by forestland voluntarily
institute seasonal burn bans so that residents won’t
inadvertently start a forest fire while they are out enjoying
their backyard fire pits. If you live in one of these areas,
you probably already know it and would be well advised to
follow the rules.
If you must light
that backyard fire pit, take some precautions to limit your
friends and family’s exposure to wood smoke. The Maine
Bureau of Air Quality recommends using only seasoned firewood
and burning it in a way that promotes complete combustion—small,
hot fires are better than large smoldering ones—to
minimize the amount of harmful smoke. The moral of the story:
If you need to burn, burn responsibly.
CONTACTS:
U.S. Environmental
Protection Agency (EPA); Washington
State Department of Ecology; Maine
Bureau of Air Quality. |
