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Dear
EarthTalk: I just read an article that said air fresheners
contain chemicals that can cause health problems when inhaled.
Are scented candles any better?
-- Leanne Chacksfield,
Cincinnati, OH
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Many
scented candles release phthalates, potentially harmful
chemicals linked to the disruption of hormonal systems
and other human health problems. Healthier alternatives
include candles made from soy, plant waste, beeswax
or pure plant essential oils. Avoid paraffin candles
and those using synthetic chemicals with unintelligible
names.
© Martoons, courtesy Flickr
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Like
most air fresheners, many scented candles contain and release
phthalates, potentially harmful chemicals that have been
linked to the disruption of hormonal systems and other health
problems in people exposed to them. Burning candles can
also emit small amounts of acetaldehyde, formaldehyde and
naphthalene, organic chemicals that are also potentially
harmful and that can leave nasty black soot deposits on
floors and other surfaces.
According to
Pamela Lundquist of the nonprofit Children’s Health
Environmental Coalition (CHEC), this black soot deposit
“is primarily made up of elemental carbon, but may
also contain phthalates and volatile organic compounds like
benzene and toluene, which can cause cancer and neurological
damage.”
Children can
easily ingest these chemicals if their hands have been wandering
and end up in their mouths. The chemicals can lodge deep
in the lungs, disrupting the lower respiratory tract, exacerbating
existing problems like asthma, and potentially causing other
longer term breathing problems.
Despite laws
against it, many candlewicks still contain lead, long linked
to impaired learning and brain damage in children. Lead
dispersed from burning candles can be breathed in and also
constitute part of the dreaded black soot deposit. Candles
with lead-containing wicks are on the U.S. Consumer Product
Safety Commission ban/recall list now (thanks to efforts
by nonprofits like U.S. Public Interest Research Group (PIRG),
but many are still out there on store shelves. Consumers
can avoid them by sticking to candles with soft cotton wicks,
not stiff, metal ones.
Eco-conscious
candle burners should also avoid paraffin-based candles,
which are made from waxes derived in the process of refining
crude oil and literally consist of fossil-fuel generating
hydrocarbons. Unfortunately, the vast majority of commercially
available candles are made from paraffin, though many alternatives
are now available.
Soy-based candles
are a popular choice, as they are made from plant waste
and emit less soot than the paraffin variety. Beeswax candles
are another nice alternative, as well, especially if you
can pick them up at a local farmers’ market. For scented
or aromatherapy candles, look for varieties that use only
pure plant essential oils instead of synthetic chemicals
with unintelligible names. Some leader makers of Earth-
and people-friendly candles include Blue Corn Naturals,
Honeyflow Farm, Vermont Soy Candles and Aveda.
CONTACTS:
Children’s
Health Environmental Coalition (CHEC); Blue
Corn Naturals; Honeyflow
Farm; Vermont
Soy Candles; Aveda.
Dear EarthTalk:
I notice occasional solar panels on roadsides, powering
individual streetlamps or signs. Is any research being done
to expand on this idea and implant solar collectors in roads,
parking lots or sidewalks to generate power in a similar
but bigger way?
-- Emily Eidenier,
via e-mail
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A
roadside solar-powered sign in Houston, Texas. Civil
engineers are working on ways to embed solar collectors
in road surfaces themselves, to provide power for
de-icing roads in winter and to supply current to
local buildings. Caltech solar energy expert Nate
Lewis says that covering just 1.7 percent of continental
U.S. land surface with photovoltaic solar collectors
could produce enough power to meet the nation's total
electricity demand
© Zelda Go Wild, courtesy Flickr.
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The concept of
using road surfaces to generate clean solar power is actually
already moving beyond the idea stage. Roads absorb heat
from the sun every day and are usually free of sightline
obstructions that could otherwise block the transmission
of light rays. And if the roads built for cars and driving
are partly to blame for global warming, why not make them
part of the solution too?
Idaho-based company
Solar Roadways is one of the trailblazers. Electrical engineer
Scott Brusaw was inspired to start the company when he learned
that covering just 1.7 percent of continental U.S. land
surface with photovoltaic solar collectors could produce
enough power to meet the nation’s total energy demand.
Brusaw put two
and two together when he realized that the interstate highway
system already covers about that much of the nation’s
land surface, so he got to work designing a system that
combines a durable and translucent glass road surface with
photovoltaic solar collectors that could be wired directly
into the electricity grid. Brusaw’s innovative design
would also heat the roads in winter, thus providing a important
safety benefit.
With improvements
in the efficiency of solar collectors in recent years, Brusaw
believes his system, if implemented from coast-to-coast
in place of the tarmac on existing highways, could produce
enough energy to meet the entire world’s electricity
needs.
But skeptics
wonder whether such an expensive high-tech road surface
can stand up to the rigors of everyday use—from overloaded
18-wheelers putting extra stress on the highway to oil spills
seeping into expensive electronic circuitry—without
having to be replaced or repaired often. Brusaw acknowledges
that his system still needs fine-tuning, but he'd like to
pave a 45-mile stretch of road between the Idaho cities
of Coeur D’Alene and Sandpoint as a beta site for his
system. "Testing [the project] an hour from the Canadian
border," says Brusaw, "will show the world that
it will work anywhere." He estimates it will be another
year or two before his company has permission to install
the Solar Road Panels on any public roads.
Europeans are
also pioneering ways to use the sun’s rays to work
as they beat down on roadways. The British firm Astucia
has developed a road stud that contains small solar panels
and emits LED light to illuminate dark roadways. On the
120 U.K. roads where the new studs have been installed,
night-time accidents are down some 70 percent.
And the Dutch
firm Ooms Avenhorn Holding BV has developed a way to siphon
solar heat from asphalt road surfaces and use it to de-ice
roads and help power nearby buildings. A latticework of
pipes under the road surface allows water to heat up during
warm weather. The water is then pumped deep under ground
where it maintains its higher temperatures and can be retrieved
months later to keep road surfaces ice-free during winter
months. Apartment buildings, industrial parks and an air
force base have benefited from the innovation, and the firm
is working on exporting its system to other countries in
the coming years.
CONTACTS:
Solar
Roadways; Astucia;
Ooms
Avenhorn Holding BV.
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