3 ms·

My assumption in writing the above was that non-soluble elemental lead metal (the thing the sheathing is made out of, and that Roman aqueducts were made out of,

by derefr 3y ago

My assumption in writing the above was that non-soluble elemental lead metal (the thing the sheathing is made out of, and that Roman aqueducts were made out of, and the thing that soil could easily trap and filter out) is the "problem" with lead poisoning; while the lead ions in lead compounds are mostly safe. Like it is with mercury, where mercury amalgams are perfectly fine to use as dental fillings, but getting even a little metallic mercury past your skin will kill you. Looking into it, though, apparently lead metal and lead ions are both toxic, through independent mechanisms. And that the toxicity of e.g. lead-based paint is due to the toxicity of lead compounds, rather than the toxicity of metallic lead. Still: is there cause to believe that metallic lead from lead sheathing in cables, would react with something in the ground to form soluble lead compounds, rather than remaining particulate metal and therefore coming to rest in the soil? Things don't oxidize underground, right? And groundwater is usually pH-neutral enough to not create an environment amenable for reduction reactions involving e.g. chromium or sulfur, right? I say this because several people above have mentioned that there are other metallic-ion "natural pollutants" in groundwater — but I've still never heard of groundwater with high natural lead levels.

lazide 3y ago
You have mercury all wrong, and lead mostly so. Elemental mercury is very difficult to absorb, and even in vapor form the LD50 is quite high. It typically requires extended exposure to even vapor from mercury to have any issues. Even a drop of organic mercury on a glove (let alone skin) can kill. Historically, even periodically drinking liquid elemental mercury was relatively harmless and didn’t poison anyone. You’d have to do it a lot. The Louis and Clark expedition used it for its laxative effects, and it’s allowed historians to confirm which campsites were theirs or not, for instance. Most compounds and salts of mercury, especially organic compounds, are incredibly toxic. [https://emergency.cdc.gov/agent/mercury/mercorgcasedef.asp https://emergency.cdc.gov/agent/mercury/mercorgcasedef.asp] Many of those compounds form when metallic/elemental mercury is around certain microorganisms, like those in many ponds and lakes, or when man made. Lead isn’t dissimilar. Lead poisoning (or measurable uptake) from elemental lead almost always requires extended ingestion or inhalation of lead, or ingestion/exposure to a salt or compound which allows easier intake. The most common forms of lead poisoning usually involve things like habitual smoking or eating while having lead dust covered hands, or persistent ingestion of lead containing substances (like contaminated water) or breathing in of lead contaminated dust. It takes a surprising amount of persistent exposure, unless someone is really stupid. Like doing oxyacetylene cutting of lead sheet without PPE, or cleaning a shooting range then not washing their hands after.
- rightbyte 3y ago
  > cleaning a shooting range then not washing their hands after Care to elaborate? Even handling bullets should be no more posionus than handling diver weights?
  - lalopalota 3y ago
    "not washing their hands" being the key part. it isn't dangerous to handle diver weights or clean up a shooting range. if the traces aren't cleaned off your hands before touching the face/eyes, eating, smoking cigarettes, etc, the lead will get into the body and cause problems.
  - genmud 3y ago
    Also, depending on how the bullets get caught at the range (shredded tires vs sand vs steel backstops), they tend to produce a lots of fine lead dust[1]. [1] - https://youtu.be/QfDoQwIAaXg https://youtu.be/QfDoQwIAaXg
    - lazide 3y ago
      I love those slow-mo bullet impact videos! Also, be aware that most primers usually have some kind of heavy metal in them (lead azide, lead styphnate, mercury fulminate) though there are newer compositions using strontium and tetrazine starting to get traction. [https://en.m.wikipedia.org/wiki/Mercury(II)_fulminate https://en.m.wikipedia.org/wiki/Mercury(II)_fulminate] Additionally, non-jacketed bullets (common with rim fire, low power pistol, blackpowder, and some other random stuff) will blast lead off the back of the bullets at the muzzle or forcing cone and into the air. If the area is adequately ventilated it’s not really an issue. Some indoor ranges are not! Sometimes significant amounts of fine particulates can end up at shooting stations from it, or be inhaled. That said, just wash your hands and don’t hang out in ranges that get Smokey and you’ll be fine. If you’re cleaning up a range with bad ventilation, wear a respirator rated for metal dust. I’ve done all the high risk activities (including a decent amount of soldering with gasp leaded solder) for over 3 decades, have done that, and have tested ‘non-detectable’ for lead and mercury every time I felt like checking. I’ve had friends who didn’t that ended up on Chelation therapy. Don’t be like them. They’re miserable.

by derefr 3y ago

lazide 3y ago

You have mercury all wrong, and lead mostly so. Elemental mercury is very difficult to absorb, and even in vapor form the LD50 is quite high. It typically requires extended exposure to even vapor from mercury to have any issues. Even a drop of organic mercury on a glove (let alone skin) can kill. Historically, even periodically drinking liquid elemental mercury was relatively harmless and didn’t poison anyone. You’d have to do it a lot. The Louis and Clark expedition used it for its laxative effects, and it’s allowed historians to confirm which campsites were theirs or not, for instance. Most compounds and salts of mercury, especially organic compounds, are incredibly toxic. [https://emergency.cdc.gov/agent/mercury/mercorgcasedef.asp https://emergency.cdc.gov/agent/mercury/mercorgcasedef.asp] Many of those compounds form when metallic/elemental mercury is around certain microorganisms, like those in many ponds and lakes, or when man made. Lead isn’t dissimilar. Lead poisoning (or measurable uptake) from elemental lead almost always requires extended ingestion or inhalation of lead, or ingestion/exposure to a salt or compound which allows easier intake. The most common forms of lead poisoning usually involve things like habitual smoking or eating while having lead dust covered hands, or persistent ingestion of lead containing substances (like contaminated water) or breathing in of lead contaminated dust. It takes a surprising amount of persistent exposure, unless someone is really stupid. Like doing oxyacetylene cutting of lead sheet without PPE, or cleaning a shooting range then not washing their hands after.

rightbyte 3y ago
> cleaning a shooting range then not washing their hands after Care to elaborate? Even handling bullets should be no more posionus than handling diver weights?
- lalopalota 3y ago
  "not washing their hands" being the key part. it isn't dangerous to handle diver weights or clean up a shooting range. if the traces aren't cleaned off your hands before touching the face/eyes, eating, smoking cigarettes, etc, the lead will get into the body and cause problems.
- genmud 3y ago
  Also, depending on how the bullets get caught at the range (shredded tires vs sand vs steel backstops), they tend to produce a lots of fine lead dust[1]. [1] - https://youtu.be/QfDoQwIAaXg https://youtu.be/QfDoQwIAaXg
  - lazide 3y ago
    I love those slow-mo bullet impact videos! Also, be aware that most primers usually have some kind of heavy metal in them (lead azide, lead styphnate, mercury fulminate) though there are newer compositions using strontium and tetrazine starting to get traction. [https://en.m.wikipedia.org/wiki/Mercury(II)_fulminate https://en.m.wikipedia.org/wiki/Mercury(II)_fulminate] Additionally, non-jacketed bullets (common with rim fire, low power pistol, blackpowder, and some other random stuff) will blast lead off the back of the bullets at the muzzle or forcing cone and into the air. If the area is adequately ventilated it’s not really an issue. Some indoor ranges are not! Sometimes significant amounts of fine particulates can end up at shooting stations from it, or be inhaled. That said, just wash your hands and don’t hang out in ranges that get Smokey and you’ll be fine. If you’re cleaning up a range with bad ventilation, wear a respirator rated for metal dust. I’ve done all the high risk activities (including a decent amount of soldering with gasp leaded solder) for over 3 decades, have done that, and have tested ‘non-detectable’ for lead and mercury every time I felt like checking. I’ve had friends who didn’t that ended up on Chelation therapy. Don’t be like them. They’re miserable.