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Lethal Doses of Water, Caffeine and Alcohol
Today’s graphic is a whimsical look at lethal doses of chemicals we consume on a regular basis. Whilst it may be more common to view chemicals in a black and white framing of ‘toxic’ or ‘non-toxic’, the reality is more of a sliding scale of toxicity. The admission of too much of any chemical into the body can cause toxic effects, and even death – the only variant from chemical to chemical is how much is ‘too much’. For some chemicals, the amount will be very low, whilst for others, it may be almost impossibly high.
So, how can we compare the toxicities of differing chemicals, when they can all produce varying effects, and these effects all require the intake of differing amounts? One of the most commonly quoted figures when discussing the toxicity of chemicals is the LD50, which stands for ‘lethal dose 50%’, or ‘median lethal dose.’ This is the amount of a chemical required to cause death in 50% of the animals in the group it is tested on. The figures can be given for when the chemical is given orally, when it is applied to the skin, or when it is injected into the animal. The results of these tests can then be converted into figures for humans, and expressed in milligrams per kilogram of body weight. The smaller the lethal dose, the more toxic the chemical; thus, the LD50 provides a way of comparing the toxicities of all chemicals.