Field of Science

Elemental Tales: Get the lead out!

Workers manufacturing the pigment white lead (Pb(OH)2.2PbCO3 apparently made a habit of adding dilute sulfuric acid to their drinking water to prevent lead poisoning. The reaction of the sulfate ions (SO42-) with the aqueous lead ions (Pb2+) forms an insoluble precipitate of lead sulfate, effectively removing the lead from the water (as long as you let the precipipate settle before drinking!). This risk of lead poisoning in these workers was so high that it was referred to as "painter's colic".

5 comments:

  1. Once again, many years ago one summer I did a short internship in a textile plant back in Turkey. I used to eat my lunch in a big lunch room with all the other workers. Everyday in addition to some main course, we were given yogurt. The rationale, according to my fellow workers, was that yogurt was supposed to prevent or lessen the effects of any accidental poisoning from the dyes they were using. There was probably some scientific basis for that, but I never figured what it was. Perhaps, the lactic acid in yogurt also binds lead & other metal ions & makes them less bioavailable.

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  2. So I did a little research to discover its the calcium which displaces the lead on binding sites in the gut...so I'll keep eating my good Greek yogurt!

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  3. Thanks Michelle. Very interesting!

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  4. Perhaps I'm being stupid, but doesn't it make more sense to get enough water from home and use it at the factory? I mean, it must be easier to carry lot of water than a lot of sulfuric acid!

    I'm sorry, I did not mean to be sarcastic, just thought it was an odd way to solve a problem, though I guess student of chemistry would be more keen on the sulfuric acid way of solving it.

    Interesting tidbit, though, thanks

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