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depends on the metal and the cleaning chemicals
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even water is poison if too much, you drown. you can allow millions of gallons of water to dry and its toxicity increases. farm irrigation poisoning land over decades with selenium from water is common
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many do not know but when talking parts per billion you inhale and drink and eat many things like asbestos, selenium, mercury many things in the air, water and food just staying in a house or hotel room. many modern plastics, rubber, plywood, insulation is giving off fumes like formaldehyde fumes.
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and nature with plants growing many like poison ivy are poisonous just touching. many plants if you ate them will also poison you like mushrooms
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literally sitting in a chair you can be inhaling asbestos that naturally in the air. some parts of the country parasite eggs in dried dirt go air borne in dry times and you can inhale parasite eggs that grow worms in you lungs. some countries give their kids a pill once a year so the worms or parasite come out. many people have parasite in them they do not even realize as some take years to have a big effect