February 2023

In this VETgirl online veterinary continuing education blog, Dr. Justine Lee, DACVECC, DABT talks about the toxicity dangers of vinyl chloride and what you need to know about your veterinary patients exposed to the recent Ohio train derailment releasing dangerous chemicals in East Palestine, Ohio.

By Dr. Justine Lee, DACVECC, DABT
Director of Medicine / CEO, VETgirl

The toxicity of vinyl chloride

On February 3, 2023, a train derailment carrying several potentially toxic chemicals derailed in East Palestine, OH. So, what toxic chemicals were released, and what dangers do these pose to our veterinary patients, farm animals, wildlife, and insects? Supposedly, 3,500 fish died off in nearby streams, and for me, this is often the canary in the coal mine.

Some of these toxic chemicals either burned or were leaked during the derailment and included (listed alphabetically):

    • benzene
    • butyl acrylate
    • ethyl hexyl acrylate
    • ethylene glycol monobutyl ether
    • propylene glycol*
    • vinyl chloride

So, what do we need to know about these, with vinyl chloride and benzene being ones I’m most concerned about?

* Propylene glycol is commonly used in cosmetics, lotions, as a carrier for diazepam and generally not of concern for me.

Vinyl chloride is highly flammable. The biggest danger is vinyl chloride monomer (VCM) gas, which can primary result in central nervous system (CNS) signs, respiratory signs, and severe irritation (e.g., ocular, dermal, mucous membranes, etc.). Unfortunately, there is a “long latent period bewteen exposure and symptom onset.”

Clinical signs of vinyl chloride in both humans and animals include:

    • CNS
      • Lethargy/weakness
      • Ataxia
      • Headache (human)
      • Narcolepsy (human)
      • Numbness/tingling of the extremities
      • Seizures
      • Death
    • Cardiovascular/Respiratory
      • Arrhythmias
      • Dyspnea
      • Asthma
    • Gastrointestinal (GI) signs
      • Abdominal pain
      • Vomiting
      • Diarrhea
      • GI bleeding

train

In humans, chronic exposure to vinyl chloride has been associated with the following:

    • Organ changes (e.g., hepatomegaly, hepatic fibrosis, splenomegaly)
    • Pulmonary (e.g., chronic interstitial pulmonary changes)
    • CNS changes (e.g., neuropathy, polyneuropathy)
    • Dermal changes (thickening of skin, collagen deposition)
    • Bone marrow changes (e.g., thrombocytopenia)
    • Cancer (as vinyl chloride is a known human carcinogen and classified as group 1 by the International Agency for Research on Cancer (carcinogenic to humans) and has reported caused hepatic angiosarcoma with heavily exposed workers)
    • Reproductive (e.g., decreased sperm count/libido, congenital malformations in animals

As for benzene, this is a chemical commonly used to make plastics, resins, adhesives and polymers. I had to do my undergraduate research with benzene under a chemistry hood, and have always had a healthy respect for it as it smells and is carcinogenic (Also listed as a Class 1 carcinogen). How is benzene poisonous? Benzene metabolites (e.g., phenol, hydroquinone, catechol, etc.) results in systemic toxicosis, including bone marrow suppression and potential mutagenesis. It can also have CNS affects. Honestly, there probably isn’t a lot of research in benzene ACUTE exposures such as the train derailment, as it’s usually through chronic exposure; benzene is found in higher levels in smokers and is also found as an air pollutant.

Clinical signs of benzene in both humans and animals are similar to above:

    • Local irritation (e.g., oral, dermal, ocular)
    • CNS
      • Lethargy/weakness or excitement
      • Ataxia
      • Euphoria
      • Headache (human)
      • Seizures
      • Coma
      • Death
    • Cardiovascular/Respiratory
      • Tachycardia
      • Cough
      • Pallor
      • Tachypnea/Dyspnea
      • Hoarseness
      • Bronchial reaction
      • Chemical pneumonitis
      • Pulmonary edema
    • Gastrointestinal (GI) signs
      • Burning sensation to mucous membranes
      • Nausea
      • Vomiting
      • Abdominal pain

In humans, chronic exposure to benzene has been associated with the following:

    • Bone marrow changes (e.g., myeloid dysplasia, anemia, leukemia)
    • Reproductive change (e.g., stillbirth, miscarriage/abortion, irregular cycle)

As a toxicologist and veterinarian, I’m concerned about the secondary exposure not only to humans and animals/pets, but also to the wildlife and environment. When in doubt, symptoms should be treated supportive and symptomatically, as it’s too late for decontamination. As for diagnostic work up, I would start with a thorough physical examination and history, and perform routine blood work (e.g.,  CBC, biochemistry). Depending on the symptoms of the patient, radiographs may be warranted.

To be safe, I would recommend educating pet owners about using safety precautions below. Unfortunately, who knows for how long – if it was personally me, I would implement these recommendations for at least a few months:

    • If you are able to get you, I would recommend moving your two-legged and four-legged away from the environment for long periods of time (e.g., sheltering elsewhere out of town, moving to a different pasture as far away from the site as possible)
    • Use bottled water only
    • Do not consume garden items, fish or meat sources (e.g., venison, etc.)
    • Do not use collected rain water (e.g., rain barrels) on food sources from the garden
    • Keep the house closed up (e.g., do not open windows)
    • Use of a HEPA air purifier
    • Avoid letting your cats / pets outside if possible
    • Avoid walking your dog(s) outside for longer than necessary for a few weeks
    • Move outdoor fish (from a koi pond) inside into an appropriate tank for a few weeks

When in doubt, contact the ASPCA Animal Poison Control Center or the National Poison Control Center for further information.

  1. Are your recommendations above for a specific region/time frame? Living about 75 miles away, I have been apprehensive to say the least…

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