Rhubarb Toxicity

Here is a brief video on rhubarb and its uses:

History:

During World War I rhubarb leaves were recommended as a substitute for other veggies that the war made unavailable. Apparently there were cases of acute poisoning and even some deaths. Some animals, including goats and swine, have also been poisoned by ingesting the leaves.

Source:

Toxic effects originate from the leaves of rhubarb plants rather than the edible stalk part. The plant contains oxalic acid, known to be toxic, and Anthraquinone glycosides which are suspected to be toxic. Oxalic acid can also be found in spinach, brussel sprouts, cauliflower, and broccoli but in lower concentrations.

Information above derived from here.

Oxalic acid is found in rhubarb leaves with a high content of around 0.5 grams per 100 grams of leaves. This is present in the form of oxalic acid, and also in the form of calcium and potassium oxalate salts, and is at a level much higher than that found in other portions of the plant such as the stem. The suggested lethal dose of oxalic acid is in the region of 15-30 grams, meaning you’d have to eat a fair few kilograms of the leaves to reach this dose, but lower doses can still cause nausea and vomiting.

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Anthraquinones are contributors to the colour of rhubarb, although not major contributors – that part is played by compounds called anthocyanins, common causes of colour in plants. The major anthocyanin in rhubarb is cyanidin-3-glucoside. A range of anthraquinones are also present, including emodin (orange), chrysophanol (yellow), physcion (red-orange), and rhein (red). Besides their colour contribution, these compounds and their derivatives also give rhubarb a laxative effect.

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The compounds of interest as far as these effects go are the sennosides, derivatives of anthraquinones. During digestion, these compounds are hydrolysed into a number of smaller molecules, including rheinanthrone. It’s rheinanthrone that is thought to be the primary compound behind rhubarb’s laxative effect. Sennosides are also found in the senna plant (hence the name), and are commonly used in laxative medications. They’re included in the World Health Organisation’s list of the essential medicines.

Symptoms (of oxalic poisoning):

• weakness
• burning in the mouth
• death from cardiovascular collapse
• difficulty breathing
• burning in the throat/mouth
• abdominal pain
• nausea
• vomiting
• diarrhea
• convulsions
• coma
• kidney stones
• red-colored urine
• eye pain

Symptoms (of anthrquinone poisoning):

• skin irritation
• eye irritation
• discoloration of urine

Carcinogenicity:

No current research supporting the carcinogenicity of oxalic acid or anthroquinones.

No specific acute or chronic exposure distinctions have been made.

Treatment:

• Activated charcoal
• Breathing support
• Fluids by IV
• Laxatives
• gastric lavage
• symptoms may last 1 to 3 days and may require hospital stay

Diesel Exhaust

Photo found here

Sources:

The obvious, and most common sources of diesel exhaust include large trucks such as semis, buses, fire trucks, aircraft, and construction equipment. Other sources of diesel exhaust include diesel powered cars, boats, farm equipment, generators, and railway locomotives.

• The gas portion of diesel exhaust is mostly carbon dioxide, carbon monoxide, nitric oxide, nitrogen dioxide, sulfur oxides, and hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs).
• The soot (particulate) portion of diesel exhaust is made up of particles such as carbon, organic materials (including PAHs), and traces of metallic compounds.

Exposure:

–People with some of the highest work exposures include truck drivers, toll booth workers, miners, forklift drivers and other heavy machinery operators, railroad and dock workers, and garage workers and mechanics. Some farm workers also spend a lot of time around diesel exhaust.

-At home if near major highways or large cities

-During commutes or traveling

Carcinogenicity:

It has proven difficult to study the potential cancer risk of diesel exhaust exposure due to peoples varying exposure levels and other unknown and unrelated cancer factors. However,

The International Agency for Research on Cancer (IARC) recognizes diesel exhaust as carcinogenic to humans.

The National Toxicology Program (NTP) comprised of the CDC, FDA, and NIH recognize diesel exhaust exposure as “reasonably anticipated to be a human carcinogen”

and the

National Institute for Occupational Safety and Health (NIOSH) recognizes diesel exhaust as a potential occupational carcinogen.

Target organs:

Lungs

Heart failure and increased risk of heart attack associated with diesel exposure.

Mechanism of Action

• Oxidative stress and inflammation are considered important mechanisms of action for particle-generated cardiovascular diseases and cancer, with the latter also believed to be partially attributed to polycyclic aromatic hydrocarbons (PAHs)

Signs and symptoms of acute exposure

-Diesel exhaust can irritate the eyes, nose, throat and lungs, and it can cause coughs, headaches, lightheadedness and nausea. In studies with human volunteers, diesel exhaust particles made people with allergies more susceptible to the materials to which they are allergic, such as dust and pollen. Exposure to diesel exhaust also causes inflammation in the lungs, which may aggravate chronic respiratory symptoms and increase the frequency or intensity of asthma attacks.

Preventative measures:

– particulate filters

-aid in removing particulate matter from exhaust to prevent inhalation.

– exhaust removal systems

-transfer exhaust from enclosed spaces to open air.