[Pharmwaste] Debating How Much Weed Killer (atrazine) Is Safe in Your Water Glass

[DeBiasi,Deborah]

http://www.nytimes.com/2009/08/23/us/23water.html?th&emc=th

August 23, 2009

Debating How Much Weed Killer Is Safe in Your Water Glass 

By CHARLES DUHIGG

For decades, farmers, lawn care workers and professional green thumbs
have relied on the popular weed killer atrazine to protect their crops,
golf courses and manicured lawns. 

But atrazine often washes into water supplies and has become among the
most common contaminants in American reservoirs and other sources of
drinking water. 

Now, new research suggests that atrazine may be dangerous at lower
concentrations than previously thought. Recent studies suggest that,
even at concentrations meeting current federal standards, the chemical
may be associated with birth defects, low birth weights and menstrual
problems. 

Laboratory experiments suggest that when animals are exposed to brief
doses of atrazine before birth, they may become more vulnerable to
cancer later. 

An investigation by The New York Times has found that in some towns,
atrazine concentrations in drinking water have spiked, sometimes for
longer than a month. But the reports produced by local water systems for
residents often fail to reflect those higher concentrations. 

Officials at the Environmental Protection Agency say Americans are not
exposed to unsafe levels of atrazine. They say that current regulations
are adequate to protect human health, and that the doses of atrazine
coming through people's taps are safe - even when concentrations jump. 

But some scientists and health advocates disagree. They argue that the
recent studies offer enough concerns that the government should begin
re-examining its regulations. They also say that local water systems -
which have primary responsibility for the safety of drinking water -
should be forced to monitor atrazine more frequently, in order to detect
short-term increases and warn people when they occur. 

The E.P.A. has not cautioned pregnant women about the potential risks of
atrazine so that they can consider using inexpensive home filtration
systems. And though the agency is aware of new research suggesting
risks, it will not formally review those studies until next year at the
earliest. Federal scientists who have worked on atrazine say the agency
has largely shifted its focus to other compounds.

Interviews with local water officials indicate that many of them are
unaware that atrazine concentrations have sometimes jumped sharply in
their communities. But other officials are concerned. Forty-three water
systems in six states - Illinois, Indiana, Iowa, Kansas, Mississippi and
Ohio - recently sued atrazine's manufacturers to force them to pay for
removing the chemical from drinking water.

Representatives of the E.P.A. and Syngenta, the company that
manufactures most of the atrazine sold, say that current federal
standards are based on hundreds of studies showing Americans are safe.
In a written statement, the E.P.A. said that it applied large safety
buffers in regulating atrazine and continued to monitor emerging
science. 

"The exposure that the agency allows under its atrazine drinking water
regulations is at least 300 to 1,000 times lower than the level where
the agency saw health effects in the most sensitive animal species
tested," the statement said. New studies, while raising important
issues, do not "suggest a revision to E.P.A.'s current regulatory
approach, which has been built on the review and consideration of
hundreds of studies, including animal toxicity and human epidemiological
studies dealing with atrazine," the agency said.

Syngenta said the lawsuits were baseless.

But the head of another government agency voiced apprehension. "I'm very
concerned about the general population's exposure to atrazine," said
Linda S. Birnbaum, director of the National Institute of Environmental
Health Sciences, a division of the Department of Health and Human
Services. "We don't really know what these chemicals do to fetuses or
prepubescent children."

"At a minimum, pregnant women should have access to accurate information
about what's in their drinking water," Dr. Birnbaum added. 

Critiques of the E.P.A.

Atrazine is just one example of what critics say are regulatory
weaknesses in the protections of America's drinking water. Health and
environmental advocates argue that the laws safeguarding drinking water
and policing toxins are insufficient, and that the E.P.A. is often too
slow in evaluating emerging risks, not cautious enough and too unwilling
to warn the public when health concerns arise. 

In January, a Government Accountability Office report said that the
E.P.A.'s system for assessing toxic chemicals was broken, and that the
agency often failed to gather adequate information on whether chemicals
posed health risks. 

Forty percent of the nation's community water systems violated the Safe
Drinking Water Act at least once last year, according to a Times
analysis of E.P.A. data, and dozens of chemicals have been detected at
unsafe levels in drinking water. 

In interviews, some E.P.A. officials conceded that they were frustrated
by the limitations they face in scrutinizing chemicals like atrazine. An
estimated 33 million Americans have been exposed to atrazine through
their taps, according to data from water systems nationwide.

"The public believes that the E.P.A. has carefully reviewed all the
chemicals that are used and has the authority it needs to deal with
risks, but that's often not the case," said Erik D. Olson, director of
food and consumer product safety at the Pew Charitable Trusts, and a
former lawyer at the E.P.A. and for the Senate Committee on the
Environment and Public Works.

"The E.P.A. is working with weak laws, basic research at the agency is
often seriously underfunded, and in some cases there's institutional
inertia against change," he added. "That's contributed to a sense that
the agency is often slow to react to new science showing risks."

Though the hazards posed by atrazine are far from clear, some scientists
and health advocates argue that the chemical deserves special scrutiny
because it is so widely used. The European Union, for instance, has
banned atrazine as part of a precautionary policy that prohibits
pesticides that easily contaminate groundwater. (European regulators did
not evaluate the chemical's health risks.) 

Atrazine, which is sold under various brand names including AAtrex, is
most commonly used on corn in farming states. But it can also be found
on lawns, gardens, parks and golf courses. Sometimes, the only way to
avoid atrazine during summer months, when concentrations tend to rise as
cropland is sprayed, is by forgoing tap water and relying on bottled
water or using a home filtration system.

E.P.A. officials note that anyone using atrazine must complete a short
training course and is warned to wear long-sleeve shirts and pants, as
well as chemical-resistant gloves and shoes, when spraying. The chemical
cannot be applied near lakes, reservoirs or other bodies of water. And
local water systems must produce an annual report detailing the highest
concentrations of atrazine and other chemicals detected over the
previous year.

Some high-ranking E.P.A. officials say there are concerns over atrazine,
and that it, among other chemicals, is likely to be closely re-examined
by the new E.P.A. administrator, Lisa P. Jackson.

"Atrazine is obviously very controversial and in widespread use, and
it's one of a number of substances that we'll be taking a hard look at,"
said Stephen A. Owens, who was recently confirmed as the E.P.A.'s
assistant administrator for prevention, pesticides and toxic substances.


He went on: "I can't say whether the outcome will be any different, but
Administrator Jackson has made clear that we need to take a close look
at decisions made in the previous administration, and be certain about
the science behind those judgments."

The New Science

Some of the current regulations governing atrazine in drinking water
were established in the 1990s. Critics say that science has changed
since then - but that the regulations have not.

Recent studies suggest that when adults and fetuses are exposed to even
small doses of atrazine, like those allowed under law, they may suffer
serious health effects. In particular, some scientists worry that
atrazine may be safe during many periods of life but dangerous during
brief windows of development, like when a fetus is growing and pregnant
women are told to drink lots of water. 

"There are short, critical times - like when a fetus's brain is
developing - when chemicals can have disastrous impacts, even in very
small concentrations," said Deborah A. Cory-Slechta, a professor at the
University of Rochester in New York who has studied atrazine's effects
on the brain and serves on the E.P.A.'s science advisory board. "The way
the E.P.A. tests chemicals can vastly underestimate risks."

"There's still a huge amount we don't know about atrazine," she added.

In recent years, five epidemiological studies published in peer-reviewed
journals have found evidence suggesting that small amounts of atrazine
in drinking water, including levels considered safe by federal
standards, may be associated with birth defects - including skull and
facial malformations and misshapen limbs - as well as low birth weights
in newborns and premature births. Defects and premature births are
leading causes of infant deaths.

Some of those studies suggest that as atrazine concentrations rise, the
incidence of birth defects grows. One study - by researchers at Purdue
University, published in the journal Environmental Health Perspectives -
suggests that concentrations as small as 0.1 parts per billion may be
associated with low birth weights. 

The E.P.A. generally does not require water systems to notify residents
unless the yearly average of atrazine in drinking water exceeds 3 parts
per billion, and under a determination made earlier this decade, the
agency considers one-day exposures of up to 297 parts per billion safe.

Another study suggests that concentrations of atrazine in drinking water
below the E.P.A. thresholds may disrupt menstrual cycles.

Many of those studies examined large populations that are already
exposed to atrazine and sought to exclude the effects of other
contaminants and environmental or health factors. However, such
epidemiological studies cannot prove that atrazine causes specific
diseases. Definitive scientific proof would probably require unethical
experiments, like exposing pregnant women to the chemical in controlled
settings. Some research found that other pesticides may have also
contributed to health problems.

Agency and Industry Rebuttal

In written statements, the E.P.A. and Syngenta argued there were
problems with all of the studies suggesting health risks from low doses
of atrazine. 

Agency officials pointed out that epidemiological findings cannot fully
differentiate between multiple influences, and that they only highlight
associations, and do not demonstrate a cause-and-effect relationship,
and that the "E.P.A. has required and extensively reviewed laboratory
studies on atrazine and developmental effects."

"Data from these studies," the E.P.A. said, "do not suggest that birth
defects, small-for-gestational-age, or effects on limb development would
occur as a result of exposure to levels of atrazine found in the
environment." Officials added that the agency evaluates all studies as
they appear and takes appropriate actions.

Syngenta said in a written statement that "the evidence is overwhelming
that atrazine does not cause adverse health effects at levels to which
people are normally exposed," and that "studies have shown that atrazine
does not cause birth defects and does not cause reproductive effects."

But six researchers asked by The Times to review the epidemiological
studies said the results were troubling. "These suggest real reasons for
concern," said Melissa Perry, an associate professor at the Harvard
School of Public Health. "The results need to be replicated, but they
suggest there are real questions for policy makers about what
constitutes safe levels of atrazine."

Concerns have also been raised by researchers at the E.P.A. itself.
Since 2003, for instance, research published by agency scientists in
journals like Toxicology and Applied Pharmacology has shown that when
rats are exposed to brief doses of atrazine as fetuses, some experience
delayed puberty and their mammary glands change in ways that could make
them more vulnerable to cancer later in life. 

"The morphological changes we see look similar to those caused by other
compounds that make tissue more susceptible to carcinogens," said
Suzanne Fenton, an E.P.A. scientist who has written about atrazine.
"This theory hasn't been tested for atrazine. There's still a lot that
we don't know."

E.P.A. and Syngenta representatives said that experiments showing
changes in rats used higher doses than found in drinking water and that
those studies did not provide the scientific confidence required for
regulation. Outside scientists, in interviews, said other research
suggested that similar effects could be observed at lower doses. 

Dr. Fenton says she is no longer working on atrazine. Other E.P.A.
employees also said they had been encouraged to redirect their energies
to other chemicals, because of insufficient resources and competing
priorities. 

E.P.A. officials said that other researchers were currently working on
atrazine and that the agency intended to convene a panel by 2011 to
evaluate epidemiological and other studies.

Below the Radar

The federal Safe Drinking Water Act was created, in part, with cities
like Piqua, Ohio, in mind. A town of 20,500, it has its own water
system, and thanks to federal right-to-know laws created to warn
residents about chemicals in their drinking water, Piqua's officials
must test for atrazine and other substances and inform people of the
highest concentrations detected.

But when spikes in atrazine occur in Piqua and elsewhere, residents
often do not learn of them, a review of E.P.A. and state data shows. 

Since local water systems test for atrazine as infrequently as once a
year, the E.P.A. has required that the companies manufacturing the
chemical, primarily Syngenta, monitor the drinking water of a sample of
towns - as many as 154 communities - as often as once a week. The
companies submit that data to federal officials. The E.P.A. says those
tests indicate that few towns have violated Safe Drinking Water limits
for atrazine.

However, a Times review of Syngenta's data shows that some communities
had large spikes of atrazine in their drinking water, sometimes for
months at a time. But residents were not warned. 

For instance, in April 2005, the drinking water in Piqua contained
atrazine concentrations of 59.57 parts per billion. The residents of
Piqua were also exposed to elevated concentrations of atrazine in 2004
and 2007. Data shows similar patterns in dozens of other cities, like
Versailles, Ind., and Evansville, Ill.

But the people of Piqua never learned about those spikes from local
water officials or the E.P.A. City officials test for atrazine only once
a month in the spring, and the annual report sent to residents in 2005
said the highest level of atrazine detected was only 11.6 parts per
billion - 80 percent lower than the peak measured by Syngenta. Residents
were also not told when peaks had occurred or how long they lasted or
whether there were multiple spikes.

Syngenta said the company regularly provided city officials with testing
results. Piqua officials were largely unaware of or did not use those
notifications.

"I didn't know that we got any information about atrazine besides our
own testing," said Frederick E. Enderle, Piqua's city manager since
2005. "I'm not even sure what we would do with it."

Some residents are angry.

"This makes my blood boil," said Jeff Lange, a Piqua resident and
environmental activist. "I have friends and family drinking this water.
How are pregnant women or sick people supposed to know when to avoid
it?"

Drinking water experts say atrazine spikes most likely occur in many
other towns that are not monitored by Syngenta. In those areas, there is
essentially no way for residents or officials to monitor how high levels
go.

E.P.A. officials said that under the Safe Drinking Water Act, the data
collected by third parties, like Syngenta, did not fall under
right-to-know provisions and that Piqua was required only to notify
residents based on the city's testing.

But residents, including Mr. Lange, said Syngenta's findings should have
at least prompted the city to test more frequently, or led the E.P.A. to
tell the city to change its testing schedule.

E.P.A. officials also said they do not believe that atrazine spikes like
those in Piqua are dangerous. "A one-time reading of 59 parts per
billion in finished water does not pose a risk to human health," the
agency wrote.

However, studies like the one at Purdue suggest there are health risks
at much smaller concentrations, and other studies suggest those risks
rise as exposures grow.

Critics contend that atrazine is just one of the many chemicals the
E.P.A. has not regulated with sufficient caution.

The Natural Resources Defense Council, an environmental advocacy group,
is expected to release a report on Monday saying that weak E.P.A.
regulation of atrazine poses risks to humans and the environment. Other
organizations have made similar charges about a variety of chemicals,
including fuel additives, dry cleaning and manufacturing solvents, and
industrial waste dumped into water supplies.

"There's pretty broad consensus that the laws regarding toxic substances
need to be modernized and overhauled, and that the E.P.A. needs more
resources," said Mr. Olson of Pew, who added that the agency's new
leadership had begun addressing many issues. 

"But in the meantime, people are getting exposed to dangerous
chemicals," Mr. Olson said. "And the E.P.A. isn't responding swiftly
enough."



Deborah L. DeBiasi 
Email:   Deborah.DeBiasi at deq.virginia.gov (NEW!)
WEB site address:  www.deq.virginia.gov 
Virginia Department of Environmental Quality 
Office of Water Permit Programs 
Industrial Pretreatment/Toxics Management Program 
PPCPs, EDCs, and Microconstituents 
Mail:          P.O. Box 1105, Richmond, VA  23218 (NEW!) 
Location:  629 E. Main Street, Richmond, VA  23219 
PH:         804-698-4028 
FAX:      804-698-4032