Alternative Asian medicine containing Australian marine life caught off the central Queensland coast may contain toxins, according to a University of Queensland (UQ) study.
The biggest concern was medicines which contain traces of devil and manta rays and are used to treat various ailments, including acne and cancer.
Dr Kathy Townsend, of the School of Biomedical Sciences and UQ's Moreton Bay Research Station, said the studies identified the presence of toxic substances in the rays.
"Devil and manta rays are some of the world's most biologically vulnerable fishes, and their dried gill plates have become a valued commodity in alternative medicine markets," Dr Townsend said.
"Vendors recommend gill plates for ailments ranging from acne to cancer, and as a general health tonic, even though it is a new addition to traditional medicine literature and rarely prescribed."
Dr Townsend said Chinese, Indonesian, Vietnamese, Sri Lankan and Indian waters were most reported as gill plate sources.
However, larger rays from Australian waters were regarded as a high-end product despite a 2015 study, involving Dr Townsend, that reported a quarter of live devil rays caught near Lady Elliott Island in Queensland displayed lead levels exceeding international food safety standards.
"It could be linked to the large-scale mining activities in Queensland, inland from the Great Barrier Reef," Dr Townsend said.
"Australia is one of the world's largest producers of lead, and lead mining has been identified as a major cause for concern for environmental contamination.
"Other marine organisms in the Great Barrier Reef have been found to be similarly affected by high lead levels, including in the adjacent Townsville harbour."
