Comment

Comment by Cea Blue on August 12, 2011 at 9:56am

Bt: Miracle Organic Pesticide or Potential Environmental Disaster?

It’s natural, it’s selective. So, what’s the problem?

• Increasingly, the types of Bt being used are rare strains that are performance-enhanced or sometimes genetically engineered. The use of Bt pesticides has spread from farms and occasional homeowner use to the spraying of millions of acres every year around the world, often over large tracts of forest land or areas with large urban populations.

• The Bt strains being used are applied at rates up to one billion times the natural levels. Often, they wipe out entire families of insects in the sprayed areas. For instance, Btk, a strain used to control moth pests such as tussock and gypsy moth, kills all insects in the Lepidoptera family (moths and butterflies). Soil biota is also affected – there is evidence to show that nematodes and predator insects (that would naturally control the pest population) are depressed also.

• Despite Bt’s purported safety for humans, no long term testing has ever been done to assure its safety. Why should you worry?
  • Bt is extremely similar (so much so it is difficult to distinguish without sophisticated testing) to two other bacteria, B. cereus, which causes food poisoning, and B. anthracis, which causes anthrax.
  •  Bt secretes many of the same toxins B. cereus does when it is growing. There is mounting evidence that spores germinate in humans and can live for extended periods of time in the respiratory and gastrointestinal tract. The effect of these low level infections is unknown, but there have been isolated reports of disease caused by Bt. One of the reasons Bt may not be seen as a common cause of sickness is that it is very hard to test for its presence – many cases diagnosed as B. cereus gastroenteritis (a fairly common form of food poisoning) may in fact be caused by Bt.
  • People with sensitive immune systems could be affected in ways we do not yet know, but immune responses are seen when Bt infections establish in humans.
  • DDT was used for thirty years and was claimed to be extremely safe for humans. The same sort of testing done to arrive at that conclusion has been done with Bt.

• Unfortunately, when Bt pesticides are formulated, a number of “inert” ingredients are added as preservatives, enhancers, and flow and wetting agents. These inerts are never revealed by manufacturers or tested for safety, and some may be toxic. For instance, Foray 48B, a common moth insecticide, probably contains the chemical BIT (1,2-benzisothiazolin-3-one) that was recently prohibited for environmental releases in the EU.

http://www.nosprayzone.org/pesticides/quickBtfacts.html