Heavy Metals Group Update

We spent many hours XRF (x-ray fluorescence) testing with our nifty handheld analyzer. Zoe focused on dinnerware and vintage toys. K085ialee tested t-shirts with screen printing as well as vinyl pool floaties. Alex focused on coins and paper currency from many countries. Barb and Alex tested many samples of eye shadows and lipsticks, mostly donated from people who didn’t want them anymore, as well as vitamins and other supplements. All the students chipped in to help prepare samples, such as grinding up vitamins and putting them in sample cups.

I’m happy to report the makeup and supplements and a few OTC medicine samples all tested free of hazardous metals. The t-shirt results have not been so clear-cut. Many screen-printed designs showed nontrivial amounts of barium–an element restricted in Europe but not in the US–and some shirts contained bromine in the fabric. Bromine is generally bad news, so we are trying to find info on why it is present in clothing.DSC07665

Alex hasn’t detected hazardous metals in paper money, but results from some of the coins are unclear. We need to examine the spectral peaks to see whether toxins are present or not. Alex surmises that money is handled so often, by so many people, it could spread metal contaminants, if present.

Ceramic dishes and old toys (mostly from the 1970s and 80s) turned up the most often with high levels of lead or cadmium. DSC07651This is expected for the dinnerware, which is commonly fired with a leaded glaze. Makers of dinnerware say the lead is bound in the glaze and poses no hazard, but they admit that old dishes with chipped or scratched glaze may cause lead to leach into food. Some cases of child lead poisoning have been traced to leaded plates.image_2

As for old toys, I personally am banning two Cadmium Barbies (those are their titles now) and a heavily leaded Fisher Price miniature bathroom set from our playroom.

We dealt with several problems this week, including a contaminated substrate: The XRF analyzer cannot distinguish between, say, a plastic toy and the material underneath it. The wooden block we initially used contained lead, thus messing up our early measurements. The students are taking all these glitches in stride.


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