New Research: Herbicide Atrazine Linked to Cancer, Birth Defects, Endocrine Disruption, and Endangered Species Impacts

New research
on birth defects at extremely low concentrations and documentation of widespread
ground- and drinking-water contamination has strengthened the case for banning
the toxic compound atrazine, the most commonly used herbicide in the United
States. Atrazine is a widely used weed killer that chemically castrates male
frogs at extremely low concentrations and is linked to significant human and
wildlife health concerns, including endocrine disruption, birth defects,
fertility problems, and certain cancers.

"It's time to ban atrazine to
protect our drinking water and our most imperiled wildlife," said Jeff Miller, a
conservation advocate with the Center for Biological Diversity. "There is no
reason to continue use of this poisonous contaminant given the building evidence
of harm to humans and endangered species."

Atrazine is a potent chemical that
is the most common contaminant of ground-, surface, and drinking water
nationwide. Recent research published in peer-reviewed journals suggests that
small amounts of atrazine in drinking water can be harmful at much lower
concentrations than federal standards, and link the pesticide to birth defects,
low birth weights, premature births, and menstrual problems. Previous research
has provided evidence linking atrazine to prostate cancer and decreased sperm
count in men, and higher risk of breast cancer in women.

Articles this week in the New York Times, Washington Post, and Huffington Post discuss how the Environmental
Protection Agency is ignoring unsafe atrazine contamination levels in surface
and drinking water in the Midwest and South. Agency documents show that numerous
watersheds and drinking-water systems are contaminated with atrazine, which was
banned by the European Union and in Switzerland, the
home country of its parent company Syngenta, because of dangers to both people
and wildlife.

Atrazine is linked to declines of
endangered amphibians and fish in California such as the California red-legged
frog, California tiger salamander, Delta smelt, coho and chinook salmon, and
steelhead trout. Atrazine also harms many other endangered species throughout
the country, including sea turtles in Chesapeake Bay, Barton Springs salamanders
in Texas, endangered mussels in Alabama, shortnose sturgeon in Midwest waters,
the Wyoming toad, and the Illinois cave amphipod.

Numerous studies have definitively
linked pesticides and herbicides with significant developmental, neurological,
and reproductive damage to amphibians. Pesticide contamination can cause
deformities, abnormal immune system functions, diseases, injury, and death.
Studies by Dr.
Tyrone Hayes at the University of California show that atrazine is an
endocrine disruptor that interferes with reproduction and "assaults male sexual
development." Dr. Hayes demonstrated that atrazine chemically castrates and
feminizes male frogs at concentrations 30 times lower than levels allowed by the
Environmental Protection Agency. Although exposure levels as low as 0.1 parts
per billion (ppb) result in frog hermaphrodites, the agency's atrazine criterion
for the "protection of aquatic life" is 12 ppb.

Conservationists sued the
Environmental Protection Agency in 2003 for failing to review the impacts of
atrazine on several endangered species. The registration for atrazine was
revised later that year, revealing the agency's obeisance to the agrochemical
industries it was intended to regulate. Despite numerous studies and
overwhelming evidence linking atrazine to significant human and wildlife health
concerns, the agency imposed no new restrictions on its
use.

The Center for Biological Diversity
has mounted a Pesticides Reduction Campaign to hold the Environmental
Protection Agency accountable for pesticides it registers for use and to cancel
or restrict use of harmful pesticides within endangered species' habitats. Our
2004 report, Silent Spring Revisited: Pesticide Use and Endangered
Species, details the decades-long failure of the agency to
regulate pesticides harmful to endangered species. In 2006 the Center published Poisoning
Our Imperiled Wildlife: San Francisco Bay Area Endangered Species at
Risk from Pesticides, a
report analyzing the agency's dismal record in protecting Bay Area
endangered species and the agency's ongoing refusal to reform pesticide
registration and use in accordance with scientific
findings.

We and our allies have filed
numerous lawsuits to force assessment of pesticide impacts on endangered species
and prohibiting use of such chemicals within endangered species habitats until
formal consultations with the U.S. Fish and Wildlife Service have been
completed. In 2005, our lawsuit forced the Environmental Protection Agency to
assess impacts of atrazine and five additional pesticides on the Barton Springs salamander in Texas. In 2006, we reached
a settlement agreement that prohibits the use of 66 toxic pesticides in and near
core California red-legged frog habitats. In 2009 we reached
a proposed agreement restricting the use of 74 pesticides and
evaluation of their impacts on 11 endangered species in the San Francisco Bay
Area.

Although required by court order in
2003 to further assess atrazine, the Environmental Protection Agency entered
into a private deal whereby the atrazine manufacturer Syngenta was allowed to
conduct contaminant monitoring, assessing a mere 3 percent of the watersheds
identified as "at risk" of atrazine contamination. A recent report by
conservationists analyzing agency monitoring data reveals that the agency has
been ignoring the atrazine contamination problem, and that the monitoring is misleading and its regulation
insufficient. The monitoring programs were not designed to find the
biggest problems, the screening levels are too permissive, and the monitoring
ignores more than 1,000 vulnerable watersheds.

Resources on
Atrazine:

Atrazinelovers - Dr. Tyrone Hayes' web site
informing
the public about the dangers of atrazine

Hayes et al.
2006 - Pesticide
Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimating
the Impact 

Hayes 2004 -There
Is No Denying This: Defusing the Confusion about
Atrazine

Harper's
Magazine, August 2006 - US:
It's Not Easy Being Green: Are Weed-Killers Turning Frogs into
Hermaphrodites?

Innovations
Report, February 2006 - Pesticide
Combinations Imperil Frogs

Sierra
Magazine, 2004 - A
Frog Biologist Battles an Agrichemical Giant