Organic solvent toxicity

Overview of some organic solvents

	Effects
Aromatic amines	Transitional cell carcinoma of the bladder
Lindane	CNS: dizziness, vertigo, headache
Polyvinyl chloride	Hemangiosarcoma CNS: ataxia, coma Scleroderma-like skin changes
Hydrocarbons	Systemic toxicity (sensorimotor polyneuropathy, cardiac arrhythmias) If aspirated → aspiration pneumonia Benzene derivatives → methemoglobinemia

High lipid solubility

• All organic solvents are highly lipid-soluble (i.e., lipophilic), which can lead to:
  • Degreasing of the skin → eczema
  • Mucosal irritation
  • Permeation of the CNS, with symptoms based on the area affected (e.g, headache, chronic toxic encephalopathy)
  • Peripheral neuropathy (e.g., polyneuropathy )

Chronic toxic encephalopathy

• Etiology: chronic or repeated high-dose exposure (e.g,, inhalation) to organic solvents or heavy metals → cerebral, cerebellar, and brain stem atrophy
• Presentation
  • Mental conditions (e.g., personality changes)
  • Multifocal neurologic deficits (e.g., memory impairment)
• Grading

		Clinical features	Diagnosis	Prognosis
Stage I		Difficulty concentrating Poor memory Mood changes	History Psychopathological findings	Complete recovery within 2 years if no further exposure occurs.
Stage II	A	Symptoms: same as above Personality changes	Same as above Psychological evaluation to detect psychomotor retardation	Reduced healing tendency
	B	Symptoms: same as above Psychomotor deficits (e.g., ataxia)	Same as above Neurological evaluation to detect sensorimotor disturbances
Stage III		Dementia associated with pronounced memory problems and mental retardation	Detection of cerebral atrophy on cranial imaging	Improvement of symptoms rarely occurs

References:^{[1][1][1][1][2]}

• Sources of exposure: inhalation of or skin/eye contact with polyvinyl chloride, which is found in automotive parts, furniture, packaging materials, pipes, and wire coating
• Effects
  • Neurological changes (e.g., fatigue, dizziness, ataxia, visual disturbances, coma)
  • Eye, mucous membrane, and respiratory tract irritation
  • Chronic exposure: vinyl chloride disease
    • Abdominal pain
      • Liver, esophagus, and stomach injury
      • Splenomegaly
    • Malignant liver tumors (especially hemangiosarcoma)
    • Vascular changes (e.g., thrombocytopenia, Raynaud syndrome, frostbite)
    • Acroosteolysis
    • Scleroderma-like skin changes
• Diagnosis: detection of thiodiglycolic acid in urine

References:^[1]

• Classification and sources of exposure
  • Aromatic hydrocarbon : benzene
    • Found in solvents, glues, nail polishes, cigarette smoke, car emissions, paints
    • Benzene derivatives:a hydrocarbon (e.g., xylene, toluene), amine group (e.g., aniline), or a nitro-compound (e.g.,nitrobenzene) attached to a benzene ring
  • Aliphatic hydrocarbon ;: n-hexane, heptane, methane, ethane, propane, butane, octane
    • Found in gasoline or kerosene (solvents, paraffin wax, lighter fluid, furniture polishes, and lamp oil)
  • Halogenated hydrocarbon : methylene chloride, chloroform, carbon tetrachloride, trichloroethylene , tetrachloroethylene
    • From biomass burning or natural production by fungi/bacteria
    • CCl4: formerly widely used in fire extinguishers, refrigerants, dry-cleaning fluids, and propellants
  • Terpene hydrocarbon : turpentine in the form of pine/turpentine oil, which is used in the rubber, painting, or welding industries
• Effects
  • Systemic toxicity
    • Neurotoxicity (e.g., sedation, headache, blurry vision, sensorimotor polyneuropathy , chronic toxic encephalopathy, coma)
    • Cardiotoxicity (e.g., arrhythmias)
    • Nephrotoxicity (e.g., nephritis, nephrosis, and renal failure)
    • Carbon tetrachloride toxicity → centrilobular fatty change, congestion, and necrosis of the liver
    • Benzene derivatives such as aniline and nitrobenzene: methemoglobin-forming agents → methemoglobinemia
    • Chronic benzene exposure: acute or chronic myeloid leukemia, non-Hodgkin lymphoma
  • If aspirated → aspiration pneumonia
• Diagnosis: clinical
• Treatment
  • Supportive (i.e., monitoring, fluid therapy, supplemental oxygen, intubation if in respiratory failure)
  • Nasogastric lavage may be considered for patients who ingested a large amount of hydrocarbons with significant toxic potential and present within 1 hour of ingestion.

References:^[2][4]