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Table 2. Cases of acute pyrethroid poisoning, 1983-88.
Cause Deltamethrin Fenvalcrate Cypermethrin Others Total
Occupational 158 63 6 2 229
Accidental 167 133 39 5 344
Total 325 196 45 7 573
convulsion, pulmonary edema, and coma were seen in severe cases. To identify
acute poisoning cases, the following criteria, graded by severity were
proposed (they were adopted by the Chinese Ministry of Public Health in 1989
as the national diagnostic criteria for acute pyrethroid poisoning):
Verified exposure to pyrethroids within 3 days before onset of
symptoms.
Suspected acute poisoning - abnormal facial sensations (burning, itching,
or tingling, often exacerbated by sweating or washing with hot
water, lasting no longer than 24 h) or miliary papules and contact
dermatitis, without systemic symptoms or signs.
Mild acute poisoning - in addition to the above symptoms: dizziness,
headache, nausea, anorexia, and fatigue, as well as signs of listlessness
or muscular fasciculation in limbs requiring leave from work for more
than I day.
Severe acute poisoning - convulsive attack, pulmonary edema, or
coma in addition to the above systemic symptoms and signs.
Reasonable exclusion of other diseases (e.g., common cold, heat stroke,
food poisoning, or other pesticide poisonings).
The age of the 3 113 cotton growers studied ranged from 15 to 72 years, with
the majority between 25 and 44 years. There were twice as many males (2230)
as females (883). Of the participants, 77.8% had primary and secondary school
education.
The major kinds of pyrethroids used by the farmers were: 2.5% deltamethrin
EC (Roussel-Uclaf Company), 20% fenvalerate EC (Suimoto Company), and
10% cypermethrin EC (Shell Oil Company), which were used by 2588 farmers
(83.1%); and pyrethroids mixed with organophosphates, i.e., DDVP
(2,2-dichiorovinyl dimethyl phosphate, 9%), methamidophos (4.4%),
o-methoate (2.4%), or others, used by 525 farmers (16.9%) (Table 3). Four types
of spraying equipment were used to apply the pesticides: single-nozzle pressure
type (83.2%); bearing and mobile type (16.2%); mechanical type (0.4%);
and ultra-low-volume type (ULV, 0.2%).
Pyrethroids of a concentration higher than 1:2 000 were used by 37.7% of the
farmers; the highest concentration being 1:50 for the ULV-spraying apparatus.
The application rates were 10-30 L/h, and spraying time was no more than
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