PESTICIDES

Alexander V. Lyubimov, M.D., Ph.D.Director

Toxicology Research LaboratoryDepartment of Pharmacology

University of Illinois at Chicago

Pesticide is a substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest (US EPA).

Pest includes harmful, destructive, or troublesome animals, plants, or microorganisms.

APPLICATORS ONLY?

Are there ANY other populations

(besides occupationally exposed) who can be poisoned by

PESTICIDES?

HOW WE CAN SURVIVE IT?

NO-EFFECT-LEVEL (NOEL) in animals

is used to determine:Residue Tolerance Limits

maximum safe levels of pesticide in food

PESTICIDES CLASSIFICATION1.Insecticides

1.1 Organophosphates (most are actually thiophosphates)1.2 Carbamates1.3 Organochlorines1.4 Botanical compounds

2.Herbicides2.1 Chlorophenoxy compounds2.2 Bipyridyl compounds2.3 Miscellaneous compounds

3. Rodenticides* Continued

* Continued

4. Fungicides

4.1 HCB

4.2 Organomercurials

4.3 PCP

4.4 Phthalimides

4.5 Dithiocarbamates (EBDC)

* Continued

* Continued

5. Fumigants

5.1 Phosphine

5.2 Ethylene Dibromide / Dibromochloropropane (DBCP)

BIPYRIDYL DERIVATIVEParaquat

LD50 ≈ 22 – 262 mg/kg, moderately toxic

Target Organ : Lung in all species

Mechanism of action :

Free Radical superoxide anion, O2-

Lipid peroxidation

Treatment :

Gastric lavage

mineral adsorbents

hemoperfusion

No hyperbaric oxygen!

FUNGICIDES

Low acute toxicity

LD50 ~ 800 – 10,000 mg/kg.

Cytotoxic

Mutagenic

(mechanism of action to fungus)

Teratogenic

Carcinogenic ~ 90% in animal models.

HCB

Immunosuppression

Hepatic and thyroid tumors (animals)

Teratogen

(transplacental and milk acquisition)

DITHIOCARBAMATES (EBDC)

Low toxicity

(Biotransformation Ethylene Thyourea (ETU)

in animals is well known to produce:Mutagenicity, Carcinogenicity

Teratogenicity, Embryotoxicity

FUMIGANTS

Phosphine

(ALP PH3)

Ethylene Dibromide / Dibromochloropropane (DBCP)

produce:

gastric carcinomas

DBCP – sterility in humans