2. Introduction
Organochlorines (OCs) are organic molecules with chlorine in their
structure ( chlorinated hydrocarbons)
In general they are non-volatile
solids at room temperature
Organochlorine compounds usually have a large molecular mass.
They are very stable and are moderate polarity. This makes OC easily
soluble in fats.
They were found in all environments: air, water, soil, sediments, and
biota samples.
3. Organochlorines pesticides (OCPs)
Most organochlorines have a negative temperature coefficient
meaning they are more toxic at lower temperatures. This property
makes organochlorine agents more toxic to cold-blooded
creatures like insects and mammals.
Organochlorine pesticides are used extensively from the 1940s
through the 1960s in agriculture and mosquito control.
The compounds in this group include:
DDT(dichlorodiphenyltrichloroethane), methoxychlor, toxaphene,
mirex, kepone, lindane, cyclodine, and benzene hexachloride.
As neurotoxicants, many organochlorine pesticides were banned
in the United States and other countries.
4. Signs and symptoms
CNS excitation and depression, are the primary clinical effects of acute
organochlorine toxicity; therefore, patients may present with any of the
following:
Initial euphoria with auditory or hallucinations.
Seizures
Agitation or unconsciousness
Facial paresthesia
Inability to close eyelide
Drooping the mouth Facial nerve
Facial paresthesia
5. Other signs and symptoms include the following:
Pulmonary - Cough, shortness of breath
Dermatologic - Skin rash
Gastrointestinal - Nausea, vomiting, diarrhea, and abdominal pain
Nervous system - Headache, dizziness .
.
6. Route of Exposure
There are three types of exposure: dermal, inhalation, and ingestion.
Dermal exposure is the most common type of exposure for the applicator.
the skin is easily exposed when handling pesticides.
Inhalation or breathing a pesticide into the lungs is less common, but is
still a danger to the applicator.
Ingestion exposures occur when users eat, smoke, or drink around
pesticides or forget to wash after use. other parts of the body (eyes,
abdomen, groin) absorb pesticides more quickly.
7. Ingestion produces the following manifestations:
Nausea and vomiting
Confusion, tremor, myoclonus, coma, and seizures
Respiratory depression or failure
Skin absorption or inhalation produces the following manifestations:
Ear, nose, and throat irritation
Blurred vision
Cough, Acute lung injury
Dermatitis
Eczema by pesticide
8. Organochlorines affect nerve impulse transmission by altering
membrane Na+ K+ flux, resulting in CNS hyperexcitability.
Organochlorines produces myocardial irritability and cardiac
arrhythmias.
Mechanism of Toxicity
DDT(dichlorodiphenyltrichloroethane) and related compounds
act on sodium channel and sodium conductance across the
neuronal membrane, especially of axones.
Cyclodine and Lindane appear to inhibit the GABA mediated
chloride channels in CNS.
9.
10. An oral median lethal dose (LD50) is higher than 50 mg/kg in animal studies. The
estimated approximate minimum lethal dose for humans is 2-7 g
LD50 and toxicity rating
LD50 in the rats
113-800 mg/kg
DDT
88-190 mg/kg
lindane
100-210 mg/kg
cyclodine
11. Toxicity tests
The normal range for blood chlorine in most laboratories is 96 to
106 milliliters per liter. Diagnostics may use a chlorine meter to
determine the level of chloride in the blood.
If chloride level in the blood is more than 106 it will cause
hyperchloremia.
12. No specific antidotes are available for organochlorine poisoning.
Decontamination may be indicated to prevent continued absorption, as
well as exposure of health care personnel. For dermal decontamination,
remove clothing and wash skin with soap and water. This is best
performed in the field.
the medications used in relieve symptomes include gastrointestinal
decontaminants, beta-blockers, vasopressors, and benzodiazepines and
other anticonvulsants.
Antidote and treatment