SOLVENTS
PHYSICAL AND CHEMICAL PROPERTIES:
SolubilityFlammability
VolatilityChemical structure
PHARMACOKINETICS OF SOLVENTSRoute of exposure:
1-pulmonary 2-percutaneous
Distribution :Metabolism:
1-toxification 2-detoxification
Excretion: 1-expiration
2-urine
BIOLOGICAL MONITORING
Less value for solvents because of:
1-rapid absorption and excretion
2-acute high brief exposure is more important than accumulation exposure.
HEALTH EFFECTS OF SOLVENTS
Skin disorders:20% of occupational dermatitis.
Defatting property.Concentration and time of exposure.Clothing and gloves.
Finding: irritation, dryness, scaling, tingling,
itching . patch test in a few instances.
Treatment & prevention: emollient, topical steroid,
good hygiene, education, engineering control.
central nervous system:
acute effects: euphoria, anesthetic, headache, confusion, disorientation,
drowsiness…, symptoms resolved under 24 hours.
chronic effects: neurobehavioral disorders, cortex atrophy, Alzheimer, vestibulo-oculomotor disorder.
diagnosis: 1- Hx of exposure 2-clinical finding 3- role out of other disease
PERIPHERAL NERVOUS SYSTEM
Sensorymotor nuropathy:symmetric, ascending, distal axonopathy.
Common cause:
CS2, n,hexan, methyl n buthyl ketone.
Others:
Terigeminal anesthesia = TCESensory neural HL= styreneVisual disorder = tuloene, styrene.
Diagnosis: NCV, EMG, nerve biopsy, clinical findings.
DDx: diabetes mellitus, alcoholism, drugs
Treatment: cut of exposure.
Prognosis: depends on damage and removal time.
Respiratory system:Findings: mucosal irritation, cough, pulmonary edema, hypoxia.
Heart:cardiac sensitization to epinephrine effects.methylene chloride acts on heart like as CO.
Liver: hepatotoxicity of halogenated hydrocarbons.
Finding: RUQ pain, nausea, vomiting, icter. Serum bile acid rising. Antipyrine metabolism rising.
DDx: alcoholic hepatitis.
kidney: TCC= acute tubular necrosis.
toluene= distal RTA.
ethylene glycole= renal stone.
RPGN in case reports.
Findings: polyuria, proteinuria, glucosuria, RTA.
Blood: aplastic anemia= benzen, chlorinated
hydrocarbons.
hemolytic anemia= glycol ethers.
Cancer potential:benzen, halogenated hydrocarbons, mixed solvents.
Reproductive system: increased risk of SA, malformation, time of fertility,
FAS, oligospermia & azospermia(in exposed men)
PREVENTION OF SOLVENT TOXICITY
1 -selection & substitution of solvent.
2-engineering controls.
3-personal protection.