 |
Pesticide Action
Network Updates Service (PANUPS)
See PANUPS
updates service, for
complete information.
Compost Contaminated
with Clopyralid
December 11, 2001
For the second year in a row, the persistent herbicide clopyralid has
contaminated compost at two composting facilities in the U.S. state of
Washington. Produced exclusively by Dow AgroSciences and available commercially
under the name Confront, Clopyralid has recently contaminated compost
in New Zealand and in the U.S. state of Pennsylvania, according to the
U.S. Composting Council.
Confront is used on lawns to kill dandelions, clover and other broadleaf
plants. Although most herbicides are considered to break down during composting,
clopyralid and others in the pyridine carboxylic acid group break down
extremely slowly, especially during composting.
In Washington, plants treated with
Confront have contaminated compost at local composting facilities with
levels of clopyralid high enough to cause damage to compost users' crops,
including those at local gardens and nurseries. Publicly available studies
show low acute toxicity to humans and animals, but no data on reproductive
effects, developmental effects or cancer are available. Clopyralid is
quite soluble in water, mobile in soil and extremely toxic to certain
plants. Sunflowers, legumes, tomatoes and potatoes can be affected by
clopyralid at levels of 10 parts per billion (ppb) or less.
Clopyralid contamination has prevented the Spokane Regional Composting
Facility in Washington from selling compost to the general public this
year, and 25,000 cubic yards of compost remain unsold from last year.
Tests in May 2001 at the facility revealed clopyralid residue levels of
73 and 80 ppb. At Washington State University, loss of revenue, settling
claims, testing and additional labor due to clopyralid contamination has
cost the facility about US$250,000 over the past two years.
Critics charge that the contamination
undermines the investment of millions of dollars in public and private
composting facilities and threatens consumer confidence in composting
facilities' reputation for providing quality products.
"Confront
is totally contradictory to all of our goals for recycling, resource conservation
and sustainability... Dow must follow the precautionary principle and
withdraw Confront immediately until it can be proven safe for organics
recycling," commented Ann Morse, president of GrassRoots Recycling
Network in Georgia. "Dow must take full responsibility for damage
caused by its products," she added.
In April 2001, the city and county
of Spokane, Washington asked Dow to stop distributing clopyralid temporarily
in their local area. The company agreed to do so for residential uses,
but the herbicide will still be used on golf courses whose grass is not
taken to composting facilities. The city has also begun a campaign to
educate people about why herbicide treated grass cannot be composted.
Washington State University has responded by certifying vendors of straw
and hay--the main crops suspected of carrying clopyralid. Vendors will
have to guarantee that their crops are herbicide free.
Fearing that the contamination may be more widespread than several isolated
incidents, the Washington Organics Recycling Council has asked all composting
facilities in the state to start monitoring for clopyralid.
Public utilities in the U.S. states of Washington and Oregon urged the
U.S. Environmental Protection Agency (EPA) to reconsider its registration
and re-registration criteria for herbicides to include the requirement
that no residual herbicides remain after a normal 60 to 90 day composting
cycle. The utilities emphasized that herbicide manufacturers, not composting
facilities, should be held responsible for the residues.
The U.S. Composting Council and other groups have called for Dow to work
with the EPA to develop clearer warning labels on clopyralid products.
Currently, the labels warn not to use compost containing grass clippings
that were sprayed with clopyralid during the same season as spraying occurred.
However, the two cases in Washington show that contamination can persist
beyond a single season.
The Council has called upon Dow
to buy the contaminated compost, compensate organic growers for lost produce,
compensate composters for costs of remediating clients' land and fund
an independent study into the effects of clopyralid--including testing
the amount of clopyralid that passes through to the urine of animals and
humans who consume treated grain, asparagus, beets or their byproducts.
In 2000, Dow was the fifth largest agrochemical company in the world with
sales of over US$2.2 billion dollars.
Sources: Bezdicek, David,
Mary Fauci, Dan Caldwell, Rick Rinch and Jessie Lang, "One Year Later:
Persistent Herbicides in Compost," BioCycle: Journal of Composting
and Organics Recycling July 2001; Joe Truini, "Composting Council
says Dow's Herbicide Product Poisons Compost" Waste News, November
12, 2001; Washington State University press release, June 13, 2001; Agrow:
World Crop Protection News, Janurary 5, March 2 and April 13, 2001.
Contact: PANNA.
PANUPS is a weekly email news
service providing resource guides and reporting on pesticide issues that
don't always get coverage by the mainstream media. It's produced by Pesticide
Action Network North America, a non-profit and non-governmental organization
working to advance sustainable alternatives to pesticides worldwide.
You can join our efforts! We gladly
accept donations for our work and all contributions are tax deductible
in the United States. Visit http://www.panna.org/donate.
|
Printer-friendly version