Toxicants residue in food and cancer risk: Captan (C9H8Cl3NO2S)

Toxicants residue in food and cancer
risk: Captan (C9H8Cl3NO2S)

Environmental Toxicology
Group 14

5/28/16


content
Captan
Residue in food
Exposure

D-R, exposure
Acute toxicity
Chronic toxicity
Human health effects

Distribution and excretion

Cancer risk

Characterization
Toxicity on animal
Toxicity to human
Cancer risk
Notes


Captan introduction

1,2,3,6-tetrahydro-N- (trichloromethylthio) phthalimide

C9H8Cl3NO2S

A white solid
agricultural fungicide
Target pests:
numerous fungi and
microbial


Residue in food
Captan is highly recommended for preventing and controlling fungal diseases on:
Fruits
Apples, Grapes, Peaches and Strawberries

Vegetables
Seed Treatment Only
Apple scab

Bulbs
Preplan Treatment - Gladioli and Tuberous Begonias

Lawns and turf
Ornamentals
Azaleas, Carnations, Chrysanthemums, and Roses

Oil farm

Peach scab


Exposure

Pathways
Food
Air
Water

Routs
Inhalation
Ingestion
Eyes contact
Skin contact


Distribution and Excretion
Distribution
Administered to rats orally, activity was recovered as follows:
 51.8% urine
 22.8% expired air
 15.9% feces

 0.6% tissues

Excretion



first 24 hours, more than 90%  excreted in the urine and feces,



during the next two days  almost all the rest was excreted



Only 0.01-0.05% was deposited in the organs


Dose and response, exposure

Acute toxicity

Chronic toxicity

Human health effects


Acute toxicity
The mechanism of action may involve the degradation of captan into the short-lived thiophosgene, which is a highly reactive with thiols and
other functional groups.

Test

Results

Oral LD50 - rat

LD50 = 9 g/kg (M)

Dermal LD50 – rat

LD50 > 2 g/kg

Inhalation LC50 – rat

Eye Irritation – rabbit

LC50 = 0.72 mg/L (M)
LC50 = 0.87 mg/L (F)
Irreversible corneal opacity
at 21 days in unwashed eyes

Dermal Irritation -rabbit

Not an irritant at 3 days

Dermal Sensitization -guinea pig

Moderate skin sensitizer

Data extract from Captan technical fact sheet, US national pesticide information


Chronic toxicity
Reproduction
In a three-generation rat reproduction study:

 at 1000 mg/kg diet (50 (mg/kg)/day) 

lowered lactation in 3

rd

generation (only

effects)

 at 500 mg/kg (5 (mg/kg)/day)  no effects

Teratogenicity
Rabbit: No malformed fetuses were observed from rabbits given up to 75 mg/kg of captan orally on days 6-18 of gestation.
Monkey: no fetal malformations from monkeys given up to 75 mg/kg on days 21-34 of gestation.


Human health effects

Acceptable daily intake for man: 0 - 0.1 mg/kg
Signs of Toxicity – Humans:
Individuals working with captan or in fields where captan was applied reported eye and skin irritation.
Investigators conducted patch tests with 0.1 to 1.0% captan which they placed on the upper backs of 279 to 442 individuals who were currently, one
time, or never employed in agriculture:





Out of the 442 people tested,

13 individuals at the highest dose experienced irritant reactions.
17 experienced allergic reactions.


Human health effects
Case report
acute

17 years old woman (suicide)

7.5 g of Captan

after 3 hours: headache, nausea, weakness, numbness of upper limbs,
and substernal pain

chronic

A 73-yr old retired fruit grower

Workers

spraying operations using captan

captan in air (5 mg/m3)
(high concentration)

persistent erythema, itching, & desquamation of the face & backs of
hands

eye irritation including burning, itching and tearing


Cancer risk
The U.S. EPA has assigned captan a carcinogenicity classification of B2, probable human carcinogen
(B2: Sufficient evidence of carcinogenicity from animal studies with inadequate or no data from epidemiologic studies in

humans.)

From PAN pesticide
database


cancer risk
Test
Charles River CD rats were fed 25 to 250 mg/kg/day captan for 2 years.


Males
- exhibited hepatocellular hypertrophy and significant trends of adenomas and carcinomas in the kidney at 100 mg/kg/day.

- increased relative organ weight for heart, brain, liver, and thyroid/parathyroid.

Both sexes
- showed an increased relative kidney weight and a decreased body weight.

- The lowest observable effects level (LOEL) was determined to be 100 mg/kg/day


cancer risk

Captan residues on apples, cantaloupe, cucumbers, grapefruit, lemons, lettuce, oranges, squash, strawberries, and spinach is substantially
reduced by washing and almost non-detectable after peeling.

Captan residues in celery, cucumbers, squash, and spinach is almost non-detectable after cooking.

Residential Exposure Activity

Primary handler - Mixing/loading/applying
wettable powders to fruit trees

Residential

Food

Aggregate

DWLOC cancer

Cancer

Cancer

Food and

ppb

Risk

Risk

Residential

6.5x10

Secondary handler - Painting with a brush

8.5x10

Post application - Ornamentals

4.2x10

-7

-8
-8

1.3x10

1.3x10
1.3x10

-7

-7
-7

7.8x10

2.2x10

1.7x10

-7

-7
-7

3.2

11
12

Aggregate Cancer Risks for Captan, EPA
DWLOC: drinking water levels of comparison


Characterization
Toxicity on animal

Toxicity to human










low in toxicity if eaten by
low in toxicity if breathed in

skin irritation
allergic reactions

low in toxicity if contacted with skin
highly toxic to the eyes
Decrease immune function with large amount used

Cancer risk




Rats and mice developed various types of cancers
B2 category to human by US EPA


Notes within captan residues in food

Many fruits and vegetables may contain captan residues but it can be easily washed.
Cooking eliminates captan residues.
Do the following if you experience any:
Route of Exposure

Symptoms

Inhalation

First Aid

Fresh air rest. Refer for medical attention.

Skin

MAY BE ABSORBED! Redness

Eye

Redness. Pain. Blurred vision

Ingestion

Diarrhea. Vomiting.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for
edictal attention.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible)
then take to a doctor.

Rinse mouth. Refer for medical attention.


Thank you
We welcome any question or comment.