| Dear
EarthTalk: What
green-friendly lawn and garden pesticides are available
today? I’m particularly interested in options that
won’t harm my cats.
-- Nancy Blanchard, via e-mail
| |
Synthetic
lawn and garden chemicals can poison people and pets
alike. American homeowners apply some 100 million
pounds of the stuff each year, but are fast discovering
the benefits of using more natural and less toxic
approaches.
© Getty Images |
Pesticides
have greatly boosted agricultural yields over the last half
century, so it is no wonder, given the commercial availability
of many of these synthetic chemicals, that American homeowners
apply 100 million pounds of the stuff each year to make
their own gardens grow bigger and faster, too.
But
the downside of using such chemicals is that they can poison
people and pets as well as backyard wildlife: “Common
insecticide ingredients such as 2,4-dichlorophenoxyacetic
acid (2,4-D), atrazine and dicamba have been shown to harm
mouse embryos at times equivalent to the first week after
conception in humans,” says Erica Glasener of The
Green Guide. Due to such revelations, home gardeners are
fast discovering the benefits of avoiding chemicals in favor
of natural, less toxic alternatives.
But
before thinking about applying pesticides, gardeners can
design (or re-design) their gardens to make the most of
native plants that have evolved over eons to thrive in local
conditions without synthetic aid or lots of water. Choosing
native plants appropriate to your elevation, soil type,
drainage and sun exposure will naturally repel many common
pests and also reduce the propagation of invasive exotic
species.
Similarly,
embedding your plants in healthy soil replete with beneficial
insects and worms can also help reduce the need for pesticides.
Laura Moran of Mainstreet.com suggests that home gardeners
compost their vegetable food waste—which is chock
full of nutrients that plants love—and mix it into
existing soil to give the garden a healthy boost. “Aside
from stimulating healthy root development,” she writes,
“the addition of rich compost also improves soil texture,
aeration and water retention.” It also provides a
nice home, she says, for the beneficial bugs that are destroyed
along with the bad ones by chemical pesticides.
If
pesticides are necessary, there are a handful of organic
varieties available. Bacillus thuringiensis (“Bt”)
is a naturally occurring bacterium that is lethal to most
leaf-eating caterpillars on trees, shrubs, flowers and vegetables.
According to gardening writer Jeff Ball, it is harmless
to all other insects, animals and humans. It comes in a
powder form for use as a dust, or, when diluted with water,
as a spray. Organic chemists have formulated varieties of
Bt to kill mosquitoes or potato beetles as well.
To
control slugs in an environmentally friendly manner, The
Green Guide’s Glasener suggests recycling the black
cell packs that vegetables and annuals are sold in, and
placing them (empty) upside down near the base of plants.
“Each morning, check the containers for pests, and
if you find any, simply throw the container away with the
pests inside,” she says. Another easy slug control
method is to use hollowed out grapefruit rinds in a similar
manner around the base of plants, disposing of them if they
turn up any slugs.
Pet
owners may already be familiar with insecticidal soaps used
to control fleas. Some of these soaps can also be used in
the garden to repel insects. For more information, consult
a local nursery specializing in organic methods and native
plants. Find one near you via the free online Native Plants
Nursery Directory.
CONTACTS:
The
Green Guide; MainStreet.com;
Native
Plants Nursery Directory.
Dear
EarthTalk: What’s going on with all the
cases of autism cropping up and no one seems to know why?
It stands to reason it must be something (or some things)
environmental, yet every study allegedly turns up no conclusion?
What are the possible causes?
-- Jessica W., Austin, TX
| |
Autism
affects one in every 150 children born today in the
U.S., up from one in 500 as recently as just 10 years
ago.
© jbcurio, courtesy Flickr |
No doubt about
it, autism rates have skyrocketed in the U.S. and beyond
in recent years. According to the Centers for Disease Control
and Prevention, the disease affects one in every 150 children
born today in the U.S., up from one in 500 as recently as
just 10 years ago. It’s become the fastest-growing
developmental disability—more prevalent than childhood
cancer, juvenile diabetes and pediatric AIDS combined—and
it continues to grow at a rate of 10 to 17 percent per year.
While researchers
think there is a genetic component to autism, they also
believe environmental factors are playing a role in its
recent increase. Environmental mercury and other heavy metal
exposure, contaminated water, pesticides, a greater reliance
on antibiotics—and even extensive television viewing
by very young children—may be factors in mounting
autism rates. Researchers at the American Academy of Pediatrics
and other institutes have also identified flame retardants
as possible culprits.
Vaccines containing
the mercury preservative thimerosal (now mostly removed
from the market) have long been blamed for causing autism,
but scientific links are inconclusive. In lieu of a smoking
gun, a more complex picture of autism’s environmental
causes is now emerging.
Some researchers
are focusing on the role of food in a young child’s
development. Many autistic children suffer from digestive
diseases or have genetic dispositions rendering them unable
to naturally rid their bodies of toxins. As such, exposure
to heavy metals, pesticides, contaminated water and even
processed food could have a devastating cumulative effect,
some researchers think. According to Brian MacFabe, a researcher
at the University of Western Ontario who has studied autism
triggers in rats, simple changes such as removing wheat
and dairy from the diet could potentially bring about improvements.
Groups such as
the nonprofit Healthy Child Healthy World say it’s
about time researchers are looking at environmental factors.
“Whatever triggered this current autism epidemic...autistic
kids clearly need extra protection from further environmental
assault,” the group writes on its blog. They advise
parents to be vigilant about the industrial cleaners used
in school buildings and the pesticides sprayed on playing
fields, where kids spend 25 to 30 hours per week. They and
other groups are also looking at the role of untested chemicals
in common cleaning products: phthalates, glycol ethers and
other known toxins.
Others wonder
if a collective “nature deficit disorder” among
children plays a factor in rising autism rates. Outdoor
exposure has long been associated with healthier cognitive
functioning in children, with reduction in Attention Deficit
Disorder symptoms and greater emotional capacity. But new
findings suggest it could impact autism, too. Last year,
Cornell University researchers found higher rates of autism
in counties where more households subscribed to cable and
children under the age of three regularly watched TV. The
Amish, with almost no exposure to TV, have little evidence
of autism, notes the study.
CONTACTS:
CDC
Autism Information Center; Healthy
Child Healthy World. |
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