13Solvent&VOCs

Solvent (in toxicology)

Organic compounds that are liquid, often volatile, lipophilic, non-polar, and absorbed by inhalation, ingestion, or skin.

Enzymes that metabolize ethanol

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).

Mutation in ALDH2 consequences

Leads to acetaldehyde accumulation, increasing cancer risk and ethanol toxicity.

Effects of ethanol on the brain

Acts as a GABA receptor agonist (sedative) and NMDA receptor antagonist (memory loss).

Chronic ethanol exposure effects on the liver

Can cause fatty liver, cirrhosis, and induce CYP2E1 which alters metabolism of other toxicants.

Symptoms of Fetal Alcohol Spectrum Disorder (FASD)

Learning disabilities, low birth weight, skeletal abnormalities, depression, etc.

Why is ethanol a Group 1 carcinogen?

Due to acetaldehyde mutagenicity, CYP2E1 induction, and solvent action increasing carcinogen absorption.

Signs of methanol poisoning

Blurred vision or blindness due to formate buildup.

Stages of ethylene glycol poisoning

Inebriation, cardiopulmonary issues, kidney toxicity (from calcium oxalate).

Health effects of benzene exposure

AML (acute myelogenous leukemia), reduced blood cells, and immune suppression.

How benzene is metabolized

Via CYP2E1 to toxic benzoquinones that damage DNA and proteins.

Symptoms of toluene inhalation

Confusion, memory loss, hearing/vision problems; can affect GABA, NMDA, serotonin receptors.

Syndrome associated with chronic solvent exposure

Chronic solvent encephalopathy ('painters syndrome').

Effects of carbon tetrachloride (CCl₄)

Liver damage via free radical (ROS) formation.

Health concern with tetrachloroethylene (PERC)

Liver and kidney toxicity, potential cancer risk; less toxic to humans than rats.

What is BTEX?

Common groundwater solvents: Benzene, Toluene, Ethylbenzene, Xylenes.

What are VOCs?

Volatile organic compounds that easily become vapors, often found indoors.

Indoor sources of VOCs

New furniture, electronics, air fresheners, perfumes, copiers, etc.

Ventilation rate measurement

CFM/person; higher rates improve air quality and reduce VOC exposure.