Quote:
Originally Posted by Bazz4CQJ
On the subject of toxicity of chemicals, I was listening on the radio to a scientist talking about lead. At the start of his career (in the US), it was thought that there was a 'safe' level of lead in human blood and that it was around 50 units
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Some of the level-setting was expedient.
The USA had huge swathes of industrial land until the 1920-s to 30's. There were foundries everywhere, as well as chemical plants using lead to make paint. Later on, that deeply contaminated land became used for building projects for the poor.
Soil levels of lead in the yards of these houses still spiked out test equipment well into the turn of this century. There were a number of civil lawsuits filed for health problems relating to the unwitting ingestion of lead from these places. If permitted levels were lowered, these would have proliferated hugely.