July 06, 2012
BURLINGTON – Low levels of two herbicides, clopyralid and picloram, have been detected in some samples of compost made at Chittenden Solid Waste District facilities.
These herbicides are not widely used on food crops in Vermont. They are intended for use on non-residential turf or rangeland situations to control thistle, clover and other weeds.
The Health Department has analyzed lab test results provided by CSWD. Levels of herbicides detected in the compost are far lower than levels that would increase risk of harm to human health, but are enough to affect some growing plants such as tomatoes, potatoes and beans.
Other fruits and vegetables grown in the same compost may not show signs of damage, but could still contain these herbicides.
“With the information we have so far, we would not expect that these low levels of herbicides would cause consumers any harm,” said the Health Department’s State Toxicologist Sarah Vose, PhD. “But we want gardeners to be aware and to make their own informed decision about consuming produce grown in the affected compost.”
Both herbicides show very low toxicity in animal studies. The United States Environmental Protection Agency classifies both as unlikely to be carcinogenic to humans. Studies do not indicate any harm to the developing fetus in animals exposed to these herbicides.
Home gardeners who have concerns about health can call the Health Department weekdays at 800-439-8550. Commercial growers can call the Agency of Agriculture at 802-828-6531 with questions. Produce destined for the marketplace will be evaluated on a case-by-case basis.
Many gardeners have reported that some plants grown in some of the compost products have damage characteristic of these herbicides: cupped leaves, twisted stems, distorted growing points and reduced fruit set.
The Agency of Agriculture is investigating to determine the source of the contamination. “Based on the current lab results, and the combination of different herbicides in the different compost ingredients, nothing becomes immediately apparent as the source of contamination,” said Cary Giguere, agrichemical management chief. “Looking at the reported commercial pesticide usage data collected by the Agency, I see nothing to suggest that contamination is the result of any legal use here in Vermont.”
The Agency of Agriculture and the Health Department advise Vermonters who have experienced “leaf curl” or similar damage to their plants, and have used compost products from CSWD, to consult with UVM Extension Service, Plant Diagnostic Clinic at 802-656-0493 or http://pss.uvm.edu/pd/pdc/ .
Source: Agency of Agriculture, Food and Markets
Last Updated at: July 06, 2012 08:27:23