Metals shed from Mardi Gras beads

by Dr. Ruth Carmichael/Dauphin Island Sea Lab

child holds beads

Newly published research led by a team at the Dauphin Island Sea Lab is the first to show that Mardi Gras beads could release potentially harmful metals to the environment. Some of these metals include chromium, copper, arsenic, lead, and barium. Each of which, in high concentrations, can cause ecological or human health concerns.

The study, published February 9 in the Gulf and Caribbean Research Journal, examined how Mardi Gras beaded necklaces could shed these metals.

Weathering and handling of beads can cause metals to be shed from the metallic coating on beads to the environment, and even light handling can result in a measurable release of metallic coating and comprising metals.

“This study is the first to show that metals are not only present but actually can be transferred from beads to the environment or to people,” said Dauphin Island Sea Lab Senior Marine Scientist and paper co-author Dr. Ruth H. Carmichael.

Beads are commonly dropped on the ground and may be walked on, runover by vehicles, and washed by rain and street cleaners before being swept into drains following parades, with many and longer-term opportunities for environmental or wildlife contamination.

Dr. Carmichael and the team discovered that the quantity of metals released from beads depended on the color of the beads and the type or intensity of handling.

“Metals that were shed in the highest amount were the ones at the highest concentration on the beads to begin with, and they tended to be associated with the color of the beads”, said Carmichael. “For example, we found that Chromium (Cr) and Copper (Cu) that impart green color were in higher concentrations on green beads and Barium (Ba), which is a silvery color, was in higher concentration on silver beads”

Of particular interest, Barium and Copper were released at the highest quantities from beads to water from either color of bead, and Arsenic (As) and Lead (Pb) were released from some beads to water at concentrations above the EPA maximum concentration levels set for drinking water safety.

“Just one necklace in 750 milliliters of water, which is equivalent to a wine bottle, could release Arsenic and Lead at concerning levels from the beads we tested,” Carmichael explained.

Lead concentrations were also found to be high on beads collected by the researchers at parades in Mobile, Alabama, during the 2018 Mardi Gras season.

Based on these findings, researchers suggest washing hands after handling Mardi Gras beaded necklaces, avoiding putting them in the mouth, and not giving them to children without supervision.

Carmichael and team also suggest supporting bead re-use programs to limit the addition of new beads to the environment and collecting and properly disposing of beads to minimize transport to storm drains. Distributors and consumers could also demand greater oversight of products and support using natural alternatives.

The study, Braving the Elements: Loss of Metals from Mardi Gras Beads due to Handling and Weathering, was published in the journal Gulf and Caribbean Research (Vol 35, 1-7, 2024, DOI: 10.18785/gcr.3501.01).

Of interest, the first author on this paper is a student at the Alabama School of Math and Science. The research was originally conducted as part of a two-year science fair project at Phillips Preparatory School in Mobile, Alabama.

Related: LSU biologist develops solutions to reduce plastic in the environment