Thursday, November 19, 2009

What Do Jewelry and E-waste Have In Common?

This week in our environmental epidemiology class one of the main topics of discussion was lead. Our instructor brought up a very interesting source of exposure: lead jewelry. The discussion included a talk about how e-waste is contributing to this problem.

I came across two well-known stories from the United States that demonstrate this issue. In 2003, in Oregon, a 4 year old boy died after swallowing a piece of jewelry bought from a vending machine. Later it was discovered that the toy medallion consisted of 38.8% lead [CDC report, 2004]. More recently, in 2006, another child died from acute lead poisoning in Minnesota, after ingesting a metallic heart-shaped charm. The charm was a gift with purchase from Reebok, which was almost entirely made from lead (99.1%) [CDC report, 2006]. In both instances, the product responsible was imported from abroad. The Consumer Product Safety division of Health Canada, and the Consumer Product Safety Commission in the US, are responsible for ensuring that tragedies like this never happen but evidently things are missed.

How this relates to e-waste:
In my literature search I came across a paper by Weidenhamer and Clement looking at e-waste as a possible source for lead contaminated jewelry. These researchers took note of the movement of e-waste from North American to Asian countries, and hypothesized that recycled circuit boards were being used to produce these heavily leaded jewelry items sold in the US. They took sixteen jewelry items that were previously known to contain 20-80% lead, and analyzed the items for lead, copper and tin content. In addition, lead-tin solders (what's used to join two pieces of metal together) from workshops in China were looked at, which are typically 60% tin/40% lead or 63% tin/37% lead by weight [Geibig & Socolof, 2005]. The main source of lead in electronic goods is in these lead-tin solders and also leaded glass of cathode ray tubes (the big tubes found in older computer screens and tvs) [Ernst et al., 2003].

Eight samples of the solder used in workshops in Taizhou, China (a major e-waste recycling area) were retrieved for a comparison to the contents found in the jewelry samples. After analyzing and comparing the lead-tin content in all 16 jewelry samples, 6 samples contained suspicious amounts of tin, and 5 of these samples contained suspicious amounts of copper. Because copper is normally only a trace component of electronic solders, the heating of circuit boards in molten solder, as observed in e-waste recycling workshops, has the potential to transfer a significant amount of copper into the solder. This supports their hypothesis that at least some of the leaded jewelry may be manufactured from scrap solder materials.

This study did not look at heavily leaded jewelry (>80% lead by weight). So the question of where these highly leaded jewelry items are coming from still remains a mystery.

Here are some things to look out for when purchasing jewelry, as recommended by Health Canada:
  • Pure lead is heavy, soft, dark bluish grey in colour and has a dull surface.
  • Jewelry with a very high lead content tends to be: thicker and leave a greyish mark when wiped on a white piece of paper.
  • Check with the retailer before buying an item. If they cannot provide assurance, don't buy it.
  • For Children: don't allow them to wear adult jewelry, suck or chew on jewelry, and if items are swallowed contact emergency medical services if you think the item may have contained lead.

1 comment:

  1. Intriguing detective work, tracing the mix of metals back to e-waste - would be good to have a metallurgist comment on the methods.

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