University of Washington
The
U.S. Environmental Protection Agency allows drinking water to contain no more
than 10 parts per billion of arsenic. The wine samples ranged from 10 to 76
parts per billion, with an average of 24 parts per billion.
But
a companion study concluded that the likely health risks from that
naturally-occurring toxic element depend on how many other foods and beverages
known to be high in arsenic, such as apple juice, rice, or cereal bars, an individual
person eats. The highest risks from arsenic exposure stem from certain types of
infant formulas, the study estimated.
"Unless
you are a heavy drinker consuming wine with really high concentrations of
arsenic, of which there are only a few, there's little health threat if that's
the only source of arsenic in your diet," said Wilson.
"But
consumers need to look at their diets as a whole. If you are eating a lot of
contaminated rice, organic brown rice syrup, seafood, wine, apple juice -- all
those heavy contributors to arsenic poisoning -- you should be concerned,
especially pregnant women, kids and the elderly."
Arsenic
is a naturally occurring element that is toxic to humans in some forms, and can
cause skin, lung and bladder cancers, and other diseases. As rain, rivers or
wind erode rocks that contain arsenic, it leaches into water and soil. From
there, the toxic metalloid can work its way into the food chain.
The
UW study is the first peer-reviewed research in decades to look at the arsenic
content of American wines. As a group, they had higher arsenic levels than
their European counterparts, likely due to the underlying geology of U.S. wine
growing regions.
The
study looked at red wines, except from two areas in Washington where only white
wines were produced, because they are made with the skin of grapes where
arsenic that is absorbed from soil tends to concentrate.
Wilson
also tested for lead, which is a common co-contaminant. The study found lead in
58 percent of the samples, but only 5 percent -- all from New York -- exceeded
drinking water standards.
Washington
wines had the highest arsenic concentrations, averaging 28 parts per billion,
while Oregon's had the lowest, averaging 13 parts per billion.
"There
were no statistical differences among Washington, New York and
California," she said. "The only star in the story is Oregon, where
arsenic concentrations were particularly low."
Where
possible, the study also compared wines grown in "new" vineyards and
those that had been converted from other agricultural uses like orchards, where
farmers likely used arsenic-based pesticides that were popular in the early
20th century. It found some evidence that higher levels of arsenic in
Washington red wines could be a result of pesticide residue.
Because
the average adult drinks far more water (between 1.7 and 3.2 cups per day) than
even core or frequent wine drinkers (roughly a half cup per day on average),
it's an imperfect comparison to gauge health risks based on the EPA drinking
water standard of 10 parts per billion. That's why Wilson also evaluated how
much arsenic individuals can safely consume from all the sources in their diet.
In
a companion study, she compiled consumption data for foods that have been shown
to contain arsenic -- juice, milk, bottled water, wine, cereal bars, infant
formula, rice, salmon and tuna.
From
that, she was able to determine how much of an arsenic "dose" an
average child or adult would get from each food source and how close it would
come to risk thresholds set by the U.S. Agency for Toxic Substances and Disease
Registry for total arsenic consumption across a person's diet.
For
the core or frequent adult wine drinker, the arsenic consumed from that single
source would only make up 10 to 12 percent of the total maximum recommended
daily arsenic intake. But if that person also eats large quantities of
contaminated rice, tuna or energy bars, for instance, that could push that
individual's arsenic consumption beyond levels that are considered safe.
A
person who eats an average or large amount of contaminated rice would get
between 41 and 101 percent of the maximum recommended daily dose of arsenic
from that one source alone, the study found. A child who drinks apple juice
could get a quarter of the maximum daily arsenic dose from that single source.
The
food that posed the largest risk of arsenic poisoning was infant formula made
with organic brown rice syrup, an alternative to high-fructose corn syrup.
Wilson estimated that some infants eating large amounts of certain formulas may
be getting more than 10 times the daily maximum dose of arsenic.
Based
on recent studies that have found arsenic in numerous foods and beverages,
Wilson recommends that U.S. wineries test for arsenic and lead in irrigation
and processing water and take steps to remove those contaminants if levels are
found to be high.
But
rather than litigate against vineyards -- as some have done -- she would
encourage consumers to evaluate their diets more holistically and speak with a
doctor if they have concerns. Tests are available that can detect high arsenic
levels and tend to capture arsenic exposure over longer histories than other
toxic chemicals.
"The
whole idea that you would sue a winery for having arsenic in their wine is like
suing someone for having rocks in their yard," Wilson said. "My goal
is to get people away from asking the question 'who do we blame?' and instead
offer consumers a better understanding of what they're ingesting and how they
can minimize health risks that emerge from their diets."
More
information on the published article can be found at:http://www.neha.org/node/3232
