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<br />JOURNAL OF PESTICIDE REFORMI FALL 1994 · VOL.14, NO.3
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<br />Figure 2
<br />Uses of B.t. in Califomla
<br />
<br />artichokes
<br />apples
<br />nectarines
<br />plwns
<br />broccoli
<br />cantaloupe
<br />peppers
<br />almonds
<br />alfalfa
<br />
<br />.:':",
<br />
<br />public health
<br />
<br />Figure 3
<br />Crops Frequently Treated with B.t.
<br />
<br />
<br />Spinach (processing)
<br />
<br />Celery
<br />
<br />Raspberries
<br />
<br />Cabbage (fresh)
<br />
<br />Bell peppers
<br />
<br />
<br />o 10 20: 30 40 50 60 70 80 90 100
<br />(Percent of crop treated with B.t.)
<br />Sources:.''':''.''. '
<br />U.S. Depl of Agriculture. NatiOnal Agricultural Statistics Service. Economic Research
<br />Service. 1993. Agricultural chemical usage: Vegetables 1992 summary. Washington,
<br />D.C. (June.) ',. . -
<br />U.S. Oept. of Agriculture. National Agricultural Statistics Service. Economic Research
<br />Service. 1992. Agricultural chemical usage: 1991 fruits and nuts summary. Washington.
<br />D.C. (June.) '" . ,
<br />
<br />Source: Califomia Environmental Protection Agency. Dept. of
<br />Pesticide Regulation. 1993. Summary of ~cide use report data:
<br />Annual 1991. Indexed by chemical. Sacramento. CA. (Janu~.)
<br />
<br />
<br />In Califomla, where pesticide use reporting is more comprehensive than in other states, almost 52,000 pounds of B.t. were u~ on diverse crops in
<br />1991. Grapes, lettuce, and tomatoes account for almost half the B.t. used in Califorllla (left). B.t.is extensively used nationawide In the production of
<br />certain fruit and vegetable crops (right).' . '
<br />
<br />ralysis, followed by dearh wirhln 12 hours.
<br />When rhe same dosage was injec;:ted under
<br />rhe skin of suckling mice, dearh occurred
<br />in 2-3 hours. The delta-endotoxin also
<br />'Caused destruction of rat, mouse, sheep,
<br />horse, and human red blood celIs.19 When
<br />a small protein isolated from the endotoxin
<br />was administered to mice at sublethal lev-
<br />els, mice suffered from'severe hypothermia
<br />and rheir hean beat slowed. 20
<br />
<br />Acute Toxicity to Humans
<br />
<br />Bacillus thuringiensis var. kurstaki:
<br />There have been few experimental studies
<br />assessing rhe toxicity of B.t.k. to humans.
<br />Most information comes from occupational
<br />exposures, or from exposures occurring dur-
<br />ing large-scale B.t.k. programs.
<br />One case ofB.t.k. infection resulted from
<br />a farmer splashing a B.t.k. formulation,
<br />Dipd, in his eye. The man developed an
<br />ulcer on his cornea from which positive
<br />B.t.k. cultures were taken.21 Another man
<br />working on a spray program splashed B.t.k.
<br />on his face and eyes. He then developed
<br />skin irritation, burning, swelling, and red-
<br />ness. B.t.k. was cultured from a sample taken
<br />from his eye.22 Ground-spray applicators
<br />using Foray 48B reported symptoms of eye,
<br />
<br />,. -"
<br />
<br />nose, rhro~t. andrcspiratory irritation. The
<br />frequency orrheir complaints was found to
<br />be related to rhe degree of exposure. Work-
<br />ers wirh similar preexisting healrhproblems
<br />were more likely to report adverse effects
<br />from rhe ground spray.:l3
<br />A woman exposed to an B.t.k. formula-
<br />tion as a result of drift went to rhe hospital
<br />due to burning, itching and swelling of her
<br />face and upper chest. She later exhibited a
<br />fever, altered consciousness, and suffered
<br />seizures.24 No B.t. was cultured from tissue
<br />, samples, but her doctor believed that B.t.
<br />was rhe cause of rhe clinicai symptoms.25
<br />Monitoring studies following large-scale
<br />B.t. spray' programs have showri that ex-
<br />posed people carty B.t. in their tissues. For
<br />example, more than 11 perCent of nasal
<br />swab samples taken from patients surveyed
<br />by doctors in Vancouver (Canada) follow-
<br />ing a gypsy moth spray program were found
<br />to contain B.t.k. 23 B.t. was also found ip
<br />cultures taken from patients in Lane
<br />County, Oregon following a gypsy morh
<br />spray program there. Monitoring stUdies also
<br />show that exposed people report a variety
<br />of healrh problems that they believe to be
<br />associated with B.t. exposure. 22 For example,
<br />during rhe ,Vancouver spray program, al-
<br />
<br />'most 250 people reported healrh problems,
<br />mostly allergy-like or flu-like symptoms,
<br />During a Washington gypsy morh. spray
<br />program, -over 250 people reported health
<br />problems and 6 were treated in emergency
<br />rooms for allergy or asthma problems.26
<br />Physicians have so far been wiable to de-
<br />finitivdy link B.t. exposure to these healrh
<br />problems.22.23.26
<br />Bat:iIJus thuringiensis var, israelensis:
<br />There has only been one ~ of docu-
<br />mented adverse effects ofB.t.i. on humans.
<br />This case involved a researcher who acci-
<br />dentally injected him.seif w~ill a mixture of
<br />B.t.i. and anorher kind of baaeria com-
<br />monly found on human skin. 20 He suf-
<br />fered from a toxic reaction and irritated
<br />lymph vessels. When these two baaeria were
<br />later injected into rodents the combination
<br />was consistently lethal, but each bacteria
<br />injected separately caused only slight
<br />inflammation.8
<br />
<br />Special Concems about. B.t.
<br />Toxicity
<br />
<br />Exotoxins: The earliest tests done re-
<br />garding B.t.'s toxicity were conduaed us-
<br />ing B.t. var. thuringimsis. a B.t. strain known
<br />to contain a second toxin called beta-ex:o-
<br />
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