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Comment by OopsCriticality | Hacker News Reader

> that still leaves 24 million pounds of lead each year from car batteries that don't get recycled

Is that actually a lot? Similar statements are made with respect to nuclear waste, but frankly, I've regarded these statements in units of mass as deliberately misleading due to nuclear waste (or lead in this case) to be uniquely dense relative to what we are accustomed to dealing with on a daily basis.

Siri, via Wolfram Alpha, says that 24 million pounds of lead is about 33,900-ft3, or a cube of 32-ft a side. If correct, that doesn't feel like a lot considering this is framed as a the global lead acid car battery recycling waste.

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All of the mined gold in the world is a cube about 70 ft on a side. Big cubes are hard to intuitively reason about.

Lead is also pretty bad for people. From some research on Wikipedia and with GNU units, an adult can get clinically significant lead poisoning by absorbing about half a milligram of lead into their bloodstream. (You would have to eat, breathe, or touch more than that in order to get it into the blood.)

If you took all of that non-recycled car battery lead waste and distributed it evenly across the whole U.S. population, you would have 6 orders of magnitude more than the absorbed dose required to give everyone in the country clinical lead poisoning.

(Obviously most of that waste has no likelihood of being absorbed into someone's body, so this calculation isn't necessarily that meaningful.)

In the more familiar unit of "swimming pools", it looks like it might be around 10.

Actually I get substantially less than that.

Olympic sized pool = 164ft x 82ft x 9ft 10 inches = 132, 300ft^3. Density of lead: 709 lbs per ft^3.

So a single Olympic-sized pool would weight almost 94,000,000 lbs if filled with lead.

(If you really want to blow your mind, that same pool would weight almost 200 million lbs if filled with Osmium, the most dense element. Of course, that's WAY WAY more than the amount of Osmium that exists...I can't find a world wide figure but US production is only about 250 lbs per year)

I have always been surprised how cheap osmium is given how rare it is ($400 an oz). I have wanted to buy some, but it is not the nicest metal to play with [1].

1.https://en.wikipedia.org/wiki/Osmium

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