Intoxication with chlorinated hydrocarbons and benzene

This article has been translated from WikiSkripta; ready for the editor's review.

benzene molecule

tetrachloromethane molecule

chloroform molecule

Acute manifestations of chloroform intoxication

Benzene

• high danger → only used to a limited extent (production of benzene derivatives, pharmaceutical industry)
• the work is under strict hygiene measures
• source: oil, coke plants (during coke production)
• lethal dose: 10–15 ml p.o.
• metabolism – it is oxidized to benzepoxide (carcinogen), reacts with DNA, approx. 15 % is excreted unchanged through the lungs ; in urine – phenol ((it is there even without exposure as a breakdown product of AMK), phenyl mercapturic acid, urine is collected at the end of the shift

Clinical picture of intoxication

1. acute intoxication – neurotoxic manifestations in the foreground
2. long-term exposure – hematotoxic – effects dominate leukopenia, trombocytopenia, anemia, pancytopenia, there is an increased level of chromosomal aberrations in peripheral lymphocytes
   • after 10–20 years AML or CML may develop

Tetrachloromethane and chloroform

• 50 % is metabolized by the liver, 50 % is exhaled unchanged
• we have little data on metabolites

Acute effects

Central Nervous

• excitation, disorientation, dizziness, drunkenness, nausea, drowsiness and even unconsciousness

Hepatotoxicity

• dominates in oral poisoning, steatosis and necrosis occur, mainly in carbon tetrachloride
• steatosis is caused by damage to the endoplasmic reticulum, which leads to disruption of lipid transport
• necrosis is conditioned by the release of lysosomal enzymes by the action of free radicals
• Thanks to cytochrome P450, CCl₄ breaks down into Cl⁻ and trichloromethyl radical, then HCl a phosgene are formed – this damages
• therefore, alcoholics are more susceptible (they have more active cytochrome P450)
• with chloroform, damage used to be observed only at high concentrations

Nephrotoxicity

• CCl₄ damages tubule cells, glomeruli are not damaged

links

Related Articles

• Organic solvents

Source

• BENEŠ, Jiří. Study materials [online]. [cit. 24.02.2010]. <http://jirben.wz.cz>.

References

• PELCLOVÁ, Daniela. Occupational diseases and intoxication. 2nd edition. Karolinum, 2006. 207 pp. ISBN 80-246-1183-X.