Metals in paints on chopsticks: Solubilization in simulated saliva, gastric, and food solutions and implication for human health

Environ Res. 2018 Nov:167:299-306. doi: 10.1016/j.envres.2018.07.036. Epub 2018 Jul 29.

Abstract

Paints are often used on chopsticks, however, a paucity of studies has assessed metals in the paints and the associated health risk. In this study, total Pb, Cd, Cr, Co, and Ni concentrations in paints were assessed for 72 wood and 29 stainless steel chopsticks with different colors while metal solubilization from paints in simulated saliva, 0.07 M HCl, and 1% citric acid solutions was measured for 9 samples having total Pb > 90 mg kg-1, representing exposure scenarios of mouthing, incidental paint ingestion, and metal migration in food. Results showed that Pb (0.12-500,000 mg kg-1), Cd (0.002-120,000 mg kg-1), Cr (2.2-8400 mg kg-1), Co (0.004-2600 mg kg-1), and Ni (0.10-150,000 mg kg-1) concentrations varied considerably among paint samples. Most samples showed low metal concentrations, however, high metal concentrations were observed in red and green paints on stainless steel chopsticks, while paints on wood chopsticks showed lower metal concentrations. Estimation of daily metal intakes incorporating metal solubilization data in saliva, 0.07 M HCl, and 1% citric acid solutions suggested that the health risk via saliva contact was negligible, while unacceptable health risk was observed for Pb and Cd via their solubilization in 0.07 M HCl and 1% citric acid solutions from paints with high Pb and Cd concentrations. To avoid Pb and Cd exposure, use of metal-based paints on chopsticks should be banned, particularly in countries where food is regularly consumed with chopsticks.

Keywords: Chopsticks; Metal migration; Paint; Risk assessment; Toxic metals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cooking and Eating Utensils*
  • Dietary Exposure / analysis*
  • Humans
  • Metals, Heavy / analysis*
  • Paint / analysis*
  • Saliva*

Substances

  • Metals, Heavy