| Dear
EarthTalk: I always thought eating fish was
healthy, but now I’m concerned about mercury in tuna
and other fish. Are there any fish that are still safe to
eat?
-- Brit Brundage, Fairfield, CT
| |
The
Environmental Defense Fund recommends minimizing consumption
of albacore (white) tuna, a large fish that accumulates
moderate amounts of mercury in its fatty tissue. But
other kinds of (smaller) tuna, such as skipjack (usually
canned as “light”), which accumulates
a third the amount of mercury as albacore, are OK
to eat in moderation, though consumption by those
under age seven should be limited.
© Mark H. Anbinder, courtesy Flickr |
You
should be concerned about contaminants in certain fish,
including some kinds of tuna. The non-profit Environmental
Defense Fund (EDF) recommends minimizing consumption of
albacore (white) tuna, a large fish that accumulates moderate
amounts of mercury in its fatty tissue. But other kinds
of (smaller) tuna, such as skipjack (usually canned as “light”),
which accumulates a third the amount of mercury as albacore,
are OK to eat in moderation, though consumption by those
under age seven should be limited.
To
further complicate the issue, some canned light tuna may
contain yellowfin tuna, which has mercury levels similar
to those of albacore; these products are sometimes but not
always labeled as “gourmet” or “tonno”—and
their consumption should be limited, even by adults.
Mercury,
a known “neurotoxin” (a poison that affects
the nervous system), is particularly insidious because it
is widespread in our oceans, primarily due to emissions
from coal-burning power plants. These smokestacks deposit
mercury into waterways, which carry it to the ocean where
bacteria convert it into methylmercury. Fish then ingest
it with their food and from water passing over their gills.
Generally
speaking, bigger, older and large predatory fish (such as
sharks, swordfish, tilefish, king mackerel and some tuna)
near the top of marine food chains are more likely to have
high levels of mercury than fish lower in the marine food
chain. People exposed to high levels or frequent doses of
mercury can suffer nervous system disorders, impaired mental
development and other health problems.
An
April 2003 study, published in Environmental Health Perspectives,
found that 89 percent of study subjects, chosen because
they ate a significant amount of fish, had blood mercury
levels above the U.S. Environmental Protection Agency’s
(EPA’s) safety threshold of five micrograms per liter.
Even though there are health benefits to eating fish (including
the intake of healthy omega-3 fatty acids), the EPA advises
that young children, pregnant women, nursing mothers and
women of childbearing age limit their intake of high-mercury
fish to one serving per week at most, while limiting their
overall intake of any fish or shellfish to no more than
two to three servings, or 12 ounces total, per week.
Mercury
isn’t the only harsh pollutant lurking in the ocean.
Industrial chemicals like PCBs and pesticides like DDT are
awash in marine food chains around the world. According
to EDF, it can take five years or more for women of childbearing
age to rid their bodies of PCBs, and 12-18 months to appreciably
reduce their mercury levels. EDF adds that moms who eat
toxic fish before becoming pregnant may have children who
are slower to develop and learn because fetuses are exposed
to stored toxins through the placenta.
To
learn more, visit the EPA’s Fish Advisories website.
It includes links to individual state advisories, which
have details on what fish should or shouldn’t be eaten
from nearby lakes or coastal areas. Catfish, Pollock, salmon,
shrimp and canned light tuna are currently on the EPA’s
safe list, as they feed toward the bottom of the food chain
and thus have less opportunity to accumulate mercury and
other contaminants.
CONTACTS:
EDF; EPA
Fish Advisories.
Dear
EarthTalk: What does it mean when one uses
the phrase, “building a green economy?” I’ve
heard it repeated a few times lately and would like to have
a better understanding of the concept.
-- Rosie Chang, Islip, NY
| |
In
a recent speech to Congress, President Barack Obama
said: "To truly transform our economy, protect
our security, and save our planet from the ravages
of climate change, we need to ultimately make clean,
renewable energy the profitable kind of energy.”
Pictured: A wind farm takes shape in Langdon, North
Dakota.
© P. Roth, courtesy Flickr |
The phrase “building
a green economy” means different things to different
people, but in general it refers to encouraging economic
development that prioritizes sustainability—that is,
working with nature and not against it in the quest to meet
peoples’ needs and wants—instead of disregarding
environmental concerns in the process of growing the economy.
The primary way governments around the world are trying
to “green” their own economies today is by increasing
investment in—and, by extension, creating jobs in—industries
on the cutting edge of non-polluting renewable forms of
energy, such as solar and wind power.
President Obama
has repeatedly invoked his vision of a green economy as
a tool for helping the U.S. lift itself out of recession
and position itself as an economic powerhouse in a carbon-constrained
future. The American Recovery and Reinvestment Act (ARRA)
of 2009, the $787.2 billion stimulus package that Congress
signed into law in 2009, was chock full of provisions to
boost renewable energy, energy efficiency and environmental
restoration initiatives. Examples include $4.5 billion to
convert government buildings into high-performance green
buildings, $8.4 billion for investments in public transportation,
and tens of billions of dollars more for research into new
technologies to amplify existing efforts. ARRA also earmark
$11 billion for the implementation of the “smart grid,”
a new approach to power distribution that will bring more
clean energy sources into the mix and promote energy efficiency.
Infusing such
huge amounts of cash into sustainability-oriented projects
is one way the Obama administration hopes to “green”
the U.S. economy while simultaneously pulling the country
out of recession.
“To truly
transform our economy, protect our security, and save our
planet from the ravages of climate change, we need to ultimately
make clean, renewable energy the profitable kind of energy,”
Obama told Congress a few months ago.
Of course, Americans
aren’t the only ones bent on building a green economy.
During the 1980s and 1990s, while the American government
was largely asleep at the wheel on environmental issues,
countries such as Denmark, Germany, Spain and Japan were
already busy investing in wind and solar research and implementation.
And while these nations’ ongoing efforts are nothing
to sneeze at, economists point out that what is most needed
is action on the part of the world’s fastest growing
economies—China and India.
A recent report
by the consulting firm McKinsey & Company found that
China—which surpassed the U.S. as the world’s
largest generator of greenhouse gases three years ago—has
great potential for building a green economy over the coming
decades. According to McKinsey, by 2030 China could reduce
its oil and coal imports by up to 40 percent and its greenhouse
gas emissions by 50 percent by investing upwards of 1.5
trillion yuan ($220 billion in U.S. dollars) per year in
both existing and new green technologies. China has begun
to see the light with regard to reducing emissions, increasing
energy efficiency and embracing renewable alternative energy,
but it has yet to make significant financial commitments,
which will be key to both warding off catastrophic climate
change and building a truly global green economy.
CONTACTS:
ARRA;
McKinsey
& Company. |
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