Lead and Antimony Contamination from Lead Shot Weight Belt

[cmburch]

My lead shot weight belt soaked in about 2 gallons of water overnight came to about 0.17 mg/L of lead. Which is reasonable considering the greater surface area of lead shot and rubbing. Is this significant, 0.17 parts-per-million? So less than 1/4 ppm. Well yes, if one was to drink the bucket of water. Is it against the law to dump this bucket of water down my drain? No the local level is 2 ppm for discharging into the sewer system. I guess someone else will have to look into this and determine can this level be harmful to children around the home if there was a possibility of contamination. (The dog drinking from the weight rinsing bucket?)

What I also noticed was almost 0.5 ppm antimony.

I get my lead for free from a buddy that cleans it out of indoor shooting ranges. My lead is not coated with graphite.

I am going to switch back to my coated lead weights, so I have less to worry about the possibility of contaminating my home and the environment even if these levels are not significant.

[No Misses]

Wow. You really had some time on your hands.

Thanks for the info.

[ChrisA]

Originally Posted by cmburch

My lead shot weight belt soaked in about 2 gallons of water overnight came to about 0.17 mg/L of lead.

Thanks for putting a number on this. How did the water in the bucket look? Could you see the lead in the water?

I'm guessing what you measured was only the desolved lead and your test could not detect lead particles suspended in the water. For example if you took a liter of water and added one full gram of lead powder you'd have 1000mg/L of lead but the test might only show .2mg/L because all the power sinks. I actually thing this is what what happens because I know desolved lead is not visable put particel are and I see enough particle that the rinse water is grey.

One more thing. The typical diver usage is not like your test. A diver will first soak the lead shot in saltwater (which is corrosive) and then he will soak the lead in his rinse bucket. I think lead which has become porus and slightly corroded may act difertn them new shinny shoot.

and then what about al th lead that goes directly to the ocean durring your typical 45 minute to one hour dive?

I'm not arguing. I'm curious too if it really matters. I still have and use some soft weights

[cmburch]

I had to rinse the saltwater off my gear anyway. The ICP-MS instrument can analyze most elements on the periodic table from mass 2 He to mass 260 No. To analyze 1 sample for lead and antimony takes less than 3 sec each element. So the instrument will crank out over a hundred water samples a day - 250+ if running overnight. I actually looked at about 20 elements from Be (9) to U (238). It took more time to write the post. I had the the torch operating at about 7000K - Surface of the sun about 6000K - so particles of Pb will ionize. The water was slightly turbid, but sub-ppm level can not be even seen with a turbidimeter much less the naked eye, so the turbidity was probably related to organic molecules from the ocean. I use a white bucket. There are no particles visible.

The test could easily be run with instant ocean at the right concentration. I am not so sure if lead/antimony alloys are more susceptable to saltwater. I think what we are seeing is lead dust so it is probably not dissolved. I can easily filter the lead contaminated water through a 0.45u filter to test this. The filtrate will be clean - little or no lead - the lead will be stuck to the filter.

Since I freedive, I spend about 3 hrs in the water. So overnight in instant ocean should do the trick. I don't think it will make a difference though. Next week after diving if the weather is nice. This weekend it's suppose to blow.

[CompuDude]

I don't use soft weights for this very reason. Whether or not the lead dust is within Federal exposure limits is pretty irrelevant to me... I just don't want any part of it.

There is little or no lead given off by my coated hard weights. And in a good pocket weight belt, they're not uncomfortable, either.

[scubasamurai]

nest study, but i still believe you probably absorb more lead that is in paint in old buildings and construction materials that haven't been cleaned up. i mean how much do you handle those weights?? and the contact you have , you need to actually ingest the lead itself, breathing in dust is a possiblilty but being that they are cleaned reduces the risks, washing your hands is the biggest factor in reducing the lead exposure. most of the studies with kids are done from being in constant contact with lead ie in dinnerware (plates) and on walls painted with lead based paint ( now outlawed but still in older homes) you really don't hold that lead weight in your hands 24/7 do you

[cmburch]

Yes, much of this has already been discussed.
See link dive weights

[Penguino]

Over time, does this mean that soft weights become lighter?

[cmburch]

At parts-per-million loss it may be 50 to 100 years to notice the loss. For an exact time and amount lost we should get Cummings66 in on this.

[cummings66]

My slide rule is at work. Suffice it to say it'd be long after my body has turned to dust. 2.2 lbs to a kilogram. So, if we lose .17 mg per day.

Just a quick mental note, that doesn't seem right at all. I've seen lead weight pouches on the bottom that have been there for years and still had almost the entire mass intact. I think there's an error here, somethings off. What I've seen does not even start to agree with the math. If you want to know how many days it would take simple math to convert .17 mg to grams would tell you, but the time frame is much to short.