The Secret Service and the FBI are investigating an envelope that was mailed to U.S. President Donald Trump. The envelope tested positive for the deadly poison ricin, according to officials on September 19.

What is ricin?

The envelope containing the poison was shipped from Canada, and a field test showed that the poison in it is ricin.

Ricin can be made from castor beans, but its effectiveness as a poison depends on the care with which it is made. In some past ricin letters, the material was not concentrated enough to be deadly.

The FBI's Washington Field Office said in a statement that federal agents are currently investigating a suspicious letter that was received at a U.S. government mail facility. The statement added that there is no known threat to public safety as of this time.

Officials stated that the U.S Postal Inspection Service is also investigating the incident. The mail addressed to the White House is pre-screened, and it is tested for dangerous substances at an off-site mail facility.

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There have been numerous cases of ricin in the mail sent to the White House in the past decade. One instance was back in 2013 in which a man in Mississippi sent a letter with ricin to President Barack Obama as part of a strange plot to frame an Elvis impersonator with whom he was feuding, according to Washington Post.

Ricin can be deadly if it is ingested or inhaled, but touching it is unlikely to be fatal. Ricin has no antidote, and symptoms of ricin poisoning include fever, difficulty breathing, diarrhea, and vomiting.

Letter came from Canada

On September 19, the RCMP said that it is working with the FBI after federal U.S. officials intercepted an envelope addressed to the White House that has the poison ricin.

Spokesperson Dan Brien told CBC News that the RCMP could confirm that it has received a request for assistance from the FBI in connection with a suspicious letter sent to the White House.

Brien stated that the initial information from the investigation suggests that the letter originated in Canada. He said that he could not offer more details at this time.

A spokesperson for Public Safety Minister Bill Blair said that his department was aware of the reports. The FBI, Secret Service, and the U.S Postal Inspection Service were leading the investigation.

Deaths connected to ricin

Several deaths have resulted after a victim was injected with ricin. People have been poisoned from eating castor beans, but most of the cases that involve eating castor beans do not result in poisoning because it is difficult for the digestive system to release the ricin from the beans.

This means that ricin is not as well absorbed through the gastrointestinal tract, compared with inhalation or injection.

The first known case of ricin poisoning happened in 1978 in London, UK, when Bulgarian dissident Georgi Markov was jabbed in the leg in public on Waterloo Bridge in the middle of London by a man using a weapon built into an umbrella.

The last recorded case of ricin was in 2018 when police raided an apartment in central Cologne and found a massive amount of Castor Beans and ricin powder and paste, according to The Telegraph.

The investigators had found three mobile phones among the possession of the suspect, in one of which many messages along with instructions on how to make a bomb were found. The suspect had also acquired the means to make ricin poison from castor beans.

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