World Rainforest Movement

Glyphosate in tree plantations is harmless: true or false?

“Glyphosate is less harmfull than table salt”, stated one of Aracruz Celulose’s managers at a public meeting in Brazil. Artur Duarte Branco, leader of the company workers’ trade union SINTICEL, offered to drink there and then a large glassfull of water with table salt if Aracruz’s manager drank himself a small glass of glyphosate. The man’s loyalty to the company did not go as far as that and he laughed away the challenge. Which was a wise move on his part.

The herbicide glyphosate (or Roundup) is widely used in plantation forestry, both to eliminate weeds during the initial period and to kill the trees themselves (in the case of eucalyptus plantations) after the second harvest. The “table salt” argument is used as a means to neutralize the growing environmental concerns over the wide use of Roundup in entire regions being converted to large-scale tree monocrops. However, such publicity has been shown false by independent studies which have concluded that:

1. Glyphosate can be persistent. In tests conducted by Monsanto, manufacturer of glyphosate-containing herbicides, up to 140 days were required for half of the applied glyphosate to break down or disappear from agricultural soils. At harvest, residues of glyphosate were found in lettuce, carrots, and barley planted one year after glyphosate treatment.

2. Glyphosate can drift. Test conducted by the University of California, Davis, found that glyphosate drifted up to 400 meters (1300 feet) during ground applications and 800 meters 12600 feet) during aerial applications.

3. Glyphosate is acutely toxic to humans. Ingesting about 3/4 of a cup can be lethal. Symptoms include eye and skin irritation, lung congestion, and erosion of the intestinal tract. Between 1984 and 1990 in California, glyphosate was the third most frequently reported cause of illness related to agricultural pesticide use.

4. Glyphosate has shown a wide spectrum of chronic toxicity in laboratory tests. The National Toxicology Program found that chronic feeding of glyphosate caused salivary gland lesions, reduced sperm counts, and a lengthened estrous cycle (how often an individual comes into heat). Other chronic effects found in laboratory tests include an increase in the frequency of lethal mutations in fruit flies, an increase in frequency of pancreas and liver tumors in male rats along with an increase in the frequency of thyroid tumors in females, and cataracts. (the fruit fly study used Roundup; the other studies used glyphosate.)

5. Roundup contains toxic trade secret ingredients. These include polyethoxylated tallowamines, causing nausea and diarrhea, and isopropylamine, causing chemical pneumonia, laryngitis, headache, and bums.

6. Roundup kills beneficial insects. Tests conducted by The International Organization for Biological Control showed that Roundup caused mortality of live beneficial species: a Thrichgramma, a predatory mite, a lacewing, a ladybug, and a predatory beetle.

7. Glyphosate is hazardous to earthworms. Tests using New Zealand’s most common earthworm showed that glyphosate, in amounts as low as 1/20 of standard application rates, reduced its growth and slowed its development.

8. Roundup inhibits mycorrhizal fungi. Canadian studies have shown that as little as 1 part per million of Roundup can reduce the growth or colonization of mycorrhizal fungi.

9. Glyphosate reduces nitrogen fixation. Amounts as small as 2 parts per million have had significant effects, and effects have been measured up to 120 days after treatment. Nitrogen- fixing bacteria shown to be impacted by glyphosate include a species found on soybeans and several species found on clover.

10. Roundup can increase the spread or severity of plant diseases. Treatment with roundup increased the severity of Rhizoctonia root rot in barley, increased the amount and growth of take-all fungus, a wheat disease), and reduced the ability of bean plants to defend themselves against anthracnose.

Source: Compilation by Caroline Cox, Northwest Coalition for Alternatives to Pesticides- (NCAP), from an article published in NCAP’s Journal of Pesticide Reform. Copies of the article, with complete references for all of .the information presented, are available from NCAP for $2.00. NCAP, PO Box 1391; Eugene, OR 97440;