Please find below a report by Debora Mackenzie in the May 99 Issue of The
New Scientist on the problems caused by Bt application. I believe that
will provide you more clues on your quest. I am especially amazed on the
last paragraph. Sounds familiar with recommendations on the use of other
Red flag for green spray
BACTERIAL SPORES sprayed on organic crops as a pesticide may damage the
health of people who inadvertently breathe them in. French researchers
have found that inhaling the spores can cause lung inflammation, internal
bleeding and death in laboratory mice.
Bacillus thuringiensis, or Bt, produces a toxin that kills insects. The
dried spores of the bacteria have been used as a pesticide for more than
30 years and are one of the very few insecticides sanctioned for use on
organic crops in Europe. Bt is also widely used to combat pest such as
the spruce budworm, a caterpillar that attacks trees.
Last year, French scientists isolated a strain of Bt that destroyed tissue
in the wounds of a French soldier in Bosnia. The strain, known as H34,
also infected wounds in immunosuppressed mice (This Week, 30 May 1998, p
7). Now the same team has found that H34 can kill mice with intact immune
systems if they inhale the spores.
FranE7oise Ramisse of le Bouchet army research laboratories near Paris and
her colleagues found that healthy mice inhaling 108 spores of Bt H34 died
within eight hours from internal bleeding and tissue damage. Spores from
mutants of the same strain which did not produce the insecticide were
equally lethal to mice, suggesting that it was not to blame. Ramisse and
her colleagues presented their results at a conference in Paris last month.
The researchers think that the symptoms are caused by other toxins. The
bacterium's close cousin, Bacillus cereus, produces a toxin that ruptures
cell membranes. And in 1991, Japanese researchers showed that B.
thuringiensis produces the same toxin. In fact, when the French
researchers ran samples from the soldier from Bosnia through an automated
medical analyser, it seemed to show that the bacterium was B. cereus.
Ramisse suggest that companies producing Bt spores might make them safer
by deleting the promoter sequence that activates the gene for the
Although H34 is not used as a pesticide, commercial strains of Bt tested
by the researchers also killed some mice or caused lung inflammation when
inhaled. The team obtained these strains from Abbott Laboratories, a major
supplier of Bt based in Chicago. Ramisse points out that the strains are
sprayed on forest pests at concentrations of 1011 spores per square
metre--and so might pose a danger to people in the immediate vicinity. But
Abbott maintains that Bt is safe. "We stand by our products," says Lind a
Gretton, a company spokeswoman. The French researchers have not yet tested
strains made by other companies.
"I suspect Bt infection is more widespread than we realise," says Ramisse.
Recorded infections by Bacillus pathogens are comparatively rare. Known
pathogenic species can have very distinctive symptoms. Anthrax, for
instance, is caused by B. anthracis. But where such tell-tale signs are
absent, Ramisse suspects that doctors often fail to recognise that the
bacteria are responsible, dismissing any Bacillus in patients' cultures
as contamination. Consequently, the cultures are often discarded. "I wish
they would start keeping them so we could check for Bt," she says.
When Bt was sprayed in towns in Oregon in 1991 to combat gypsy moths, the
bacterium was found in clinical samples from 55 patients who had
beenadmitted to hospital for a variety of other reasons.
Robert Haward of the Soil Association, which represents Britain's organic
farmers, says that they may have to use masks and take more care when
spraying the spores on crops.
From New Scientist, 29 May 1999
Date: Aug 09 2000 09:17:52 EDT
From: Andrew Apel
Subject: Sprayable Bt & Illness
A while back, as I recall, someone posted here that they had information
to the effect that farm workers experienced respiratory distress as a
result of being exposed to sprayable Bt products. All I have been able
to find in the literature is (a) a recommendation that workers not be
allowed into a Bt-sprayed field until 24 hours after application and (b)
(parenthetically) that Bt spray is toxic to butterflies and their larvae.
Does anyone out there know where the human-illness Bt claim comes from?
Subj: Re: AGBIOVIEW: Bt illness, manure
Date: Wed, 9 Aug 2000 12:02:18 PM Eastern Daylight Time
From: Abigail Salyers
I don't know the literature reference (if any) on cases of respiratory
arrest due to sprayed Bt, but adverse effects of spraying intact bacteria
are conceivable. Gram positve bacteria like Bacillus contain toxic
compounds in their cell walls that can be very dangerous if they enter the
bloodstream. Fortunately, Bt does not seem to survive well if it gets
into the human bloodstream through cuts but inhaling a massive dose could
well cause some problems. This has nothing to do with the Bt toxin,
Subj: France, et. al. in perspective
Date: Wed, 9 Aug 2000 1:25:39 PM Eastern Daylight Time
From: Andrew Apel
An earlier posting attempted to explain the French persona with respect to
GMOs. Consider this: 97 percent of the French want GMOs labeled. Two
French poultry producers sunk millions last year into creating (and
labeling) lines of poultry which had not been fed GMOs. The French,
supposely fearful of GMOs
and supportive of labeling, didn't care, it had no effect on poultry
sales, and the whole enterprise lost money as a result.
The same thing recently cropped up in Japan. Most Japanese say they are
"very concerned" about GMOs, but supermarkets and restaurants are saying
they find that consumers "don't care" and don't differentiate between GMO
I am becoming convinced that consumer polls which rate how "concerned"
people are about GMOs don't give the whole picture; those that do, find
that consumers "greatly concerned" about GMOs still rank those concerns
far below others...such as bacterial contamination, pesticides and cost.
Subj: Re: New York State Bill A09871
Date: Wed, 9 Aug 2000 12:26:44 PM Eastern Daylight Time
From: milton zaitlin
LEGISLATION ABOUT BIOTECHNOLOGY IN NEW YORK STATE:
I am not sure what this Sept 21 hearing deals with, but the legislation
proposing a moratorium on planting and growing 'genetically-modified'
crops in New York State is dead. Legislative committees killed it.
Yesterday I asked a staff person associated with the State Senate, who
told me he had no information about that hearing.