Poisonous Effects of Castor Beans

The seeds of the castor or castor bean plant contain high concentrations of ricin, one of the most toxic chemicals known, so deadly that it has been widely used as a biological weapon and is classified as a weapon of mass destruction. As tall as 12 feet high and with broad seven-digit leaves of green and sometimes purple, many who plant this attractive annual in their gardens have no idea how deadly it can be.

Cellular Effect

• Ricin interferes with cellular protein synthesis, which causes them to die rapidly. This affects all of the cells in the body, including nerve and brain cells, though it initially attacks the cells of the digestive tract.

Lethal Dosage

• As few as two castor seeds can kill an adult human. The seed hull must be broken to allow water to enter and activate the ricin; otherwise, they may pass through the body undigested with no ill effects.

Susceptibility

• Most animals react similarly to ricin ingestion (mammals, birds and insects chiefly). In addition to humans, farm animals in particular have fallen victim to castor poisoning, including poultry, sheep, cattle, rabbits, pigs and pets such as cats and dogs.

Symptoms

• Initial onset of symptoms usually occurs within a few hours of ingestion, sometimes as much as six hours. These include severe stomach pain, vomiting and diarrhea (sometimes streaked with blood). Additional indicators may include seizures, hematuria (bloody urine) and delirium. If untreated, the symptoms worsen to include severe dehydration, decreased urine flow and a dangerous drop in blood pressure because of fluid loss, usually within three days. Failure of the liver, kidneys and spleen may follow, leading to death.

Treatment

• There is no antitoxin for ricin, though medical support may avert death. Fluid replacement (intravenous feeding), ventilation support if necessary and medications to balance blood pressure have proven successful. If ingested recently, a stomach flush with activated charcoal may counteract the poison to a degree.

Prevention

• Although the entire castor plant is toxic, the seeds are where the ricin is concentrated. In most areas of the United States, castor is an annual; in the South and the Southwest, where it is warmer, it can be a perennial. To keep the plant from seeding, cut it back when it begins to flower.