Publication - Enhanced lead accumulation in cassia bark linked to lichen and algae: a case study from Northern Vietnam

In 2026, ASTA collaborated with academic and industry partners in Vietnam to conduct a follow-up study expanding upon 2025 research investigating the potential role of lichen and moss present on the outermost bark layer of Vietnamese cassia in relation to heavy metal contamination. By comparing lead concentrations in bark, underlying wood, and surface-growing lichen, the study confirmed that lichen function as bioaccumulators, effectively capturing airborne dust and heavy metal particulates from the surrounding environment. These findings indicate that lead contamination is primarily a surface issue, suggesting that the issue is manageable through targeted mitigation strategies, including lichen removal prior to cassia processing. As next steps, researchers will evaluate technical approaches for lichen removal, assess seasonal variability in lead accumulation, identify potential sources of airborne lead, and support the development of enhanced pre-processing standards and best practices.

This presentation was provided at the 2020 Annual Online The presenter, Exponent Inc, presented a webinar on an exposure-based screening tool for contaminants in spices, including a brief overview of the risk characterization framework and a dietary exposure assessment, a description of the screening tool including objective, approach, framework, and data, and a tool demonstration (lead in cinnamon/cassia as a case study).