Module 4-5 Midterm Flashcards
refers to a class of liquid organic chemicals
of variable lipophilicity and volatility, small molecular size, and lack of charge.
- Ready absorption: lung, skin, GIT
- Most are refined petroleum
- Classified according to mol. structure or functional grp
Solvent
Main Determinants of a solvent’s inherent toxicity:
C atoms
1,2,3 bonds bet. adjacent C atoms
Configuration
Halogenated
Presence of functional grp
is characterized by nonspecific symptoms (e.g., headache, fatigue, and sleep disorders) with or without changes in neuropsychological function.
CSE - chronic solvent encephalopathy
whether adverse health effects occur from solvent exposure is dependent on several
actors:
(1) toxicity/carcinogenicity
(2) exposure route
(3) amount or rate of exposure
(4) duration of exposure
(5) individual susceptibility
(6) interactions with other chemicals
reversible form of CSE, consists of symptoms only. “mild” and “severe” forms are accompanied by objective signs of neuropsychological dysfunction that may or may not be fully reversible.
neurasthenic syndrome
Types of solvents:
Inhalants
Solvent
VOC
a unique exposure situation, in that participants repeatedly subject
themselves to vapor concentrations high enough to produce effects as extreme as unconsciousness.
Solvent Abuse
they are volatile substances that can be inhaled to induce a psychoactive or mind-altering effect with vapor concentrations high enough to produce effects that resemble alcohol intoxication and may lead to unconsciousness.
Inhalants
breathed in through the nose or the mouth
“sniffing” or “snorting”
inhaling vapors from substances inside plastic or paper bags
“bagging”
solvent-soaked rag stffed into the mouth
“huffing”
occurs when the body is deprived of oxygen
Asphyxiation or suffocation
solid form but volatilize, mostly found in aerosol propellants, paint thinners, cleaners, and soil fumigants
VOC
2 important properties of solvents that govern their absorption and deposition in the
body:
Volatility & Lipophilicity
VOC
Absorption - alveoli; GIT
-> blood: air partition coefficients (PCs)
Transport, Distribution, Elimination
->Hepatic 1st-pass elimination
->Pulmonary 1st-pass elimination
Metabolism
->Bioactivation - can modulate the toxicities of solvents.
->CYP2E1 - catalyzes the oxidation
of halogenated and aromatic hydrocarbons causing cytotoxicity and/or mutagenicity.
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