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BRIEF: I am looking for information reguarding ricin...


QUESTION:
I am looking for information regarding ricin. I have seen it referenced as one of the top three most toxic substances known to man, however, it is listed as 12th on the following list: Botulin 0.001 Shiga 0.002 Tetanus 0.002 Abrin 0.04 Diptheria 0.10 Maitotoxin 0.10 Palytoxin 0.15 Ciguatoxin 0.40 textilotoxin 0.60 C. perfringens 0.1-5.0 Batrachotoxin 2.0 Ricin 3.0 Can you tell me why the differences? Are those listed above all substances or are diseases? If not all are substances, is this the reason for the discrepency? Is ricin in fact third on a list of the most toxic SUBSTANCES known to man?

ANSWER:

Some of those listed are toxins produced by pathogenic bacteria and represent the mechanism by which these bacteria cause disease (Botulinin, shigatoxin, tetanus, diptheria, C. Perfringens). Several of the marine toxins listed are actually bacterial or dinoflagellate toxins, too. What are the units for the list? (ug, mg, per kg BW, per lb, per head?) What is the definition of toxicity? Death? illness? rash? Is this the dose to kill all subjects? 50% of a population (LD50)? What species (human, mice, chicken?) Is this by injection, ingestion or touch? Is this experimental data, or from poisoning cases? Changes in any one of these parameters can scramble the list, so to judge what is going on, you need to define this list by answering all of those questions. A dose of ricin at 0.00000001 % (or 0.0000000001 as a fraction) of the body weight is lethal in some cases, if injected. I would place ricin a little closer to abrin than this, but, it all depends on how you define the list. Calculating the dose from dead people or animals accidentally poisoned is difficult and tends to underestimate toxicity. Many poisons that are deadly by injection are much less so if eaten and are harmless if merely handled, so tell me more about this list...