• Question: what is the most poisonous substance on the periodic table

    Asked by anon-253640 on 19 May 2020.
    • Photo: Matthew Alkan

      Matthew Alkan answered on 19 May 2020:

      Every element is poisonous to living organisms in the wrong amounts. I am unsure if one particular element is more toxic than another and maybe someone could elaborate, but cyanide is always very interesting in my opinion as it effects the way blood transports oxygen around the body.

      Of course when you are working in science it is very important to carry out thorough risk assessments and make sure you have the correct safety kit and safety practices before you start work as all elements could pose a risk its just a matter of managing that risk safely.

    • Photo: Daire Harvey-Carroll

      Daire Harvey-Carroll answered on 19 May 2020:

      Wow I hadn’t expected that question! I’m not a chemist but I would say one of the radioactive elements – like plutonium – would have the biggest impact on your health if you were to swallow even the tiniest amount! Luckily most radioactive elements are extremely rare in nature so its unlikely you’ll ever come across them.

    • Photo: Oli Wilson

      Oli Wilson answered on 19 May 2020:

      Ooh, this is an interesting question! This isn’t my speciality either, but I thought I’d see if I could find out. Lots of the most poisonous/toxic substances are compounds rather than elements (that is, they’re made up of atoms from different chemicals, bonded together) so they’re not on the periodic table. One of the most dangerous was described like this, in a great BBC article by Dr Michael Moseley (https://www.bbc.co.uk/news/magazine-24551945):
      “It is the most poisonous substance known to man. A couple of teaspoons would be enough to kill everyone in the UK. A couple of kilos would kill every human on earth. … a lethal dose for me would weigh less than one cubic millimetre of air.” And people inject it into themselves as a beauty treatment – it’s botox!
      Now, botox isn’t an element, but according to Wikipedia there is an element that comes close to botox’s toxicity: Polonium, specifically its heavy isotope Po-210, is about one tenth as deadly as botox. It hit the news a few years ago when it was used to murder a former Russian spy called Alexander Litvinenko in London.
      And one final thing that I find interesting – lots of incredibly toxic chemicals come from natural sources, like bacteria, fish, plants, frogs, snakes etc, but as well as causing harm they can be really important sources of potential medicines. A plant-derived toxin called curare paralyses the lungs, so indigenous people in the Amazon use it as an arrow poison for hunting animals, but that same effect also gives it a crucial role in anaesthetics – putting people to sleep for operations. I think it’s amazing how these chemicals can have such major roles in both killing and curing.

    • Photo: Jacque Cilliers

      Jacque Cilliers answered on 19 May 2020:

      Well there are a lot of elements on the periodic table that could kill – pretty easily in fact. Arsenic is a pretty bad ass poison. Mercury is also poisonous and can actually go through the skin! I think the most deadly would probably be plutonium. I say this because you can use it to make an atomic bomb, and once it goes off… the radioactive fall out will remain deadly for many years afterwards!!

      nice question!!

    • Photo: Alice Pullen

      Alice Pullen answered on 21 May 2020:

      Personally I think Mercury is the scariest. If it gets into the food chain it does this thing called ‘bioaccumulation’ i.e. a shrimp gets a small amount of mercury in them, then a fish eats 10 shrimp. That fish has even more mercury in them. Maybe a bigger fish eats 10 of those fish. That way, mercury gets concentrated up the food chain… and eventually maybe people eat the fish! This has already happened in some parts of the world.

      Not all poisons are elements, though, so not all of them show up in the periodic table. I recommend looking up neurotoxins from venomous snakes! They’re super interesting 🙂 the Horrible Science book series also has a book called ‘Painful Poisons’ if you want to do more reading on it

    • Photo: Lauren Graham

      Lauren Graham answered on 22 May 2020:

      I don’t know the exact answer to this question but my lab tests water samples for 26 different metals that could cause harm to humans and the environment if the concentrations are too high. Some of the very bad ones we look for in samples include lead, arsenic, and manganese!

Comments