Pesticide intoxication
- Pesticides are substances against harmful organisms
- mainly against insects (insecticides), rodents (rodenticides), molluscs (molluscicides), weeds (herbicides), fungi (fungicides) ...
- systemic pesticides - penetrate plants, protect more effectively (organophosphates)
- contact pesticides - kill organisms only in affected areas
- the most toxic are some insecticides, molluscicides and herbicides
- The most common intoxication is rodenticides - it is not so severe
Organophosphate insecticides[edit | edit source]
Character noxy[edit | edit source]
Organophosphates are esters of phosphoric acid , either containing sulfur (suffix -thion) and cyp450 metabolizes them to an active derivative containing oxygen (-oxone), or have equal oxygen in the molecule;
- high acute toxicity ,
- the spectrum of preparations does not contain highly toxic organophosphates,
- they do not accumulate in the environment, they are low in adipose tissue, they are not significantly carcinogenic ,
- representatives - fenitrothion (Sumithion), diazinon , etc.
Professional exposure[edit | edit source]
The risk of intoxication arises during production, less so during further processing;
- in addition, they contain solvents and other additives.
Etiopathogenesis[edit | edit source]
Irreversible acetylcholinesterase (ACHE) inhibition - ACH → ACH degrading enzyme accumulates;
- the accumulation of ACH can explain most of the symptoms of intoxication, a disorder of cholinergic transmission,
- the synthesis of the new ACHE takes 60 days ,
- as a late consequence, neuropathy is due to degeneration of PNS axons.
Toxicity[edit | edit source]
depends on the ability to inhibit ACHE, on the concentration ...
Clinical picture[edit | edit source]
First symptoms:
- with a decrease in ACHE activity below 70% (reduction below 20% - severe poisoning),
- life-threatening poisoning - activity is immeasurable,
- depends on the speed of boarding ...
- acute - accumulating ACH affects two types of receptors (muscarinic - vegetative motor, nicotine - neuromuscular discs), then it is also a mediator in the CNS ,
- muscarinic symptoms - tearing, salivation, sweating, miosis, vomiting, abdominal pain, diarrhea, bronchial hypersecretion, bronchospasm, bradycardia (as if parasympathetic),
- the preganglial innervation of the sympathetic nervous system is also affected by ACH → in mild poisoning, the symptoms are expressed differently ( the sympathetic nervous system may antagonize this),
- nicotine symptoms - fasciculations, tremor, convulsions, paralysis of the respiratory muscles,
- CNS symptoms - disorientation, headaches , convulsions, respiratory depression, coma .
- The cause of death is respiratory failure (all systems are comprehensively involved) and cardiac arrhythmias
- chronic - accumulation may occur rarely, symptoms such as acute,
- late neuropathy - not due to ACH , about 7-21 days after severe poisoning - calf cramps, numbness, paraesthesia in the legs, weakness.
Investigation methods[edit | edit source]
- For monitoring professional exposure - erythrocyte ACHE,
- we examine neuropathy with EMG .
Differential diagnosis[edit | edit source]
Heavier exposures may resemble a stroke , a milder infectious disease.
Therapy[edit | edit source]
Pharmacological antidote is atropine - blocks muscarinic symptoms (not nicotine), before administration of atropine it is necessary to correct respiratory and cardiovascular disorders (give oxygen ) - doses are controlled by mucosal humidity, in severe poisoning - biochemical antidote - oxime - ACHE reactivator (eg obidoxime) ), comprehensive care for vital functions, in case of convulsions - diazepam (in low doses).
Carbamate insecticides[edit | edit source]
Characteristics of noxy[edit | edit source]
Carbamic acid derivatives, directly inhibiting ACHE (without activation), representatives - pirimicarb (Pirimor®), etc., also include neostigmine (Syntostigmine®) and physostigmine (natural alkaloids, indirectly acting, parasympathomimetic , used in glaucoma ... ).
Professional exposure[edit | edit source]
In agriculture, due to the lower toxicity they are in preparations for gardeners !; in industry they are used for the production of plastics.
Etiopathogenesis[edit | edit source]
They enter through all gateways, they inhibit ACHE but reversibly !!!, spontaneous reactivation occurs quite quickly, they do not settle.
Clinical picture[edit | edit source]
Acute symptoms - as with organophosphates, but they occur earlier, have a milder and shorter course, chronic poisoning - are not known (max. Dermatitis).
Investigation methods[edit | edit source]
ACHE determination is important only after intoxication (inhalation goes too fast).
Differential diagnosis[edit | edit source]
It can resemble an infectious disease, it is important to distinguish between organophosphate poisoning, neuropathy does not occur.
Therapy[edit | edit source]
Atropine is enough, then symptomatically and supportively.
Rodenticides[edit | edit source]
- The most commonly used anticoagulants - warfarin (Kumatox), brodifacoum (Volid, Talon) ...,
- they are small in granules, have a delayed effect, usually potentiated by repeated consumption of poison by rats,
- delayed toxicity does not deter rats from eating, moreover, it does not vomit rats,
- low toxicity to humans is also an important condition (they just lie on the ground, they can be ingested by children ...),
- occupational exposure - does not pose a risk.
Etiopathogenesis[edit | edit source]
It is well absorbed from the GIT (worse through the skin), they are vit.K antagonists → they block the synthesis of coagulation factors II (prothrombin), VII, IX and X lethal doses contain up to kilograms of the product.
Clinical picture[edit | edit source]
- Acute - most often in young children, ingestion of a few grains does not manifest itself, with a larger amount Quick is prolonged, bleeding symptoms are usually only in suicidal attempts (suicide is usually unsuccessful),
- chronic - very rare.
Investigation methods[edit | edit source]
Monitoring of INR value.
Therapy[edit | edit source]
Specific antidote - vitamin K ( Kanavit ) - indicated after ingestion of a large dose.
Links[edit | edit source]
[edit | edit source]
Source[edit | edit source]
- BENEŠ, Jiří. Study materials [online]. © 2007. [feeling. 2010]. < http://www.jirben.wz.cz/ >.
Reference[edit | edit source]
Categorie:Hygiene Categorie:Occupational medicine Categorie:Toxicology Categorie:Pathobiochemistry