Microplastics found in tuna, including edible muscle
What it found
Across 19 studies, tuna caught in several oceans and seas contained microplastics, mostly fibres and fragments of polyethylene and polypropylene.
The highest levels were in tuna from the Bay of Bengal and the Persian Gulf.
What they found
Animal and lab studies
Levels in the Bay of Bengal
Bigeye tuna from the Bay of Bengal had the highest levels recorded, at 42.13 plus or minus 13.58 microplastic particles per fish. This was the top value among all the studies reviewed.
Levels in the Persian Gulf
Longtail tuna from the Persian Gulf contained 5.71 microplastic particles per fish. This shows significant contamination in that region too.
Common plastics and shapes
Polyethylene and polypropylene were the plastics found most often. Most particles were fibres and fragments, and the dominant size range was 0.5 to 2.5 mm.
Microplastics in edible tissue
Microplastics were found in muscle tissue, which is the part people eat. The authors say this raises concerns about possible health risks for people who eat tuna.
Regional differences
Levels varied widely by location. Tuna from South and Southeast Asia tended to have higher levels, while samples from Europe showed lower levels, which the authors link to differences in waste management and industry.
Other findings
Where studies were done
Most studies came from Asia, especially Indonesia. No published studies were available from North America, Africa or Australia.
What the authors conclude
“The presence of MPs in edible tissues raises concerns about potential health risks for both marine life and human consumers.”
Also in their conclusions
- They say future research should expand geographical coverage and look into the ecological and health impacts of microplastics taken in.
- They advise that long-term monitoring and international collaboration are essential to tackle this global environmental challenge.
- They also call for studies on farmed tuna to see how feed, water quality, age, size and the enclosed environment affect microplastic uptake and build-up.
How it was done
Tuna are top predators that migrate widely and eat a lot, so they build up pollutants from many places. The authors wanted to pull together what is known about how microplastics get into tuna and what that might mean for marine life and people who eat seafood.
They searched three databases for studies published from 1 January 2000 to 26 February 2025 and found 277 records. After screening, 19 studies met their criteria and were included. These studies looked at microplastics in tuna organs such as gills, muscles and gastrointestinal tracts.
What it can’t tell you
- This review pulls together findings from different studies that used different methods and looked at different species and locations, so the numbers are not directly comparable.
- It cannot show what level of microplastics in tuna might mean for a person's health over time.
- It cannot say whether microplastics build up as they move up the food chain to tuna, because the evidence on this is still debated.
Who paid
- Funding
- Funded by Recep Tayyip Erdogan University Development Foundation (from the PubMed record).
- Conflicts
- The authors have no relevant financial or non-financial interests to disclose.
- Authors work at
- Tehran University of Medical Sciences, Iran; Kermanshah University of Medical Sciences, Iran; Ahvaz Jundishapur University of Medical Sciences, Iran
The paper
- Title
- A Systematic Review of Microplastic Contamination in Tuna Species: General Pathways into the Food Chain with Ecotoxicological and Human Health Perspectives
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Peivasteh-Roudsari L, Javanmardi F, Shavali Gilani P, et al (2025). A Systematic Review of Microplastic Contamination in Tuna Species: General Pathways into the Food Chain with Ecotoxicological and Human Health Perspectives. Foods (Basel, Switzerland). doi:10.3390/foods14203547Free full textPubMed 41154083DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error