Histopathological effects of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in the gills, intestine and liver of turbot (Psetta maxima)

• Turbots exposed to BDE-47 showed several lesions in gills, intestine and liver.
• The gills showed the most severe effects among the tissues studied.
• The gills of treated fish showed lamellar fusion and blood congestion.
• BDE-47 induced hyperplasia and hypertrophy of mucous cells in gills and intestine.
• Hepatocytes showed altered morphology and nuclear vacuolization and pycnosis.

Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental pollutants because of their widespread use as flame retardants in various consumer products (plastics, textiles, electronic appliances and building materials) and their long half-life. BDE-47 (2,2′,4,4′-tetrabromodiphenyl ether) is the major PBDE congener detected in the environment and in animal tissues. In the present study, the histopathological effects are examined of BDE-47 on the gills, intestine and liver tissues of juvenile turbot (Psetta maxima).The specimens were exposed to two concentrations of BDE-47 (0.03 and 0.3 µg/L) for a period of 15 days. The histological changes were detected microscopically and evaluated with quantitative or semi-quantitative analyses. At the doses of BDE-47 assayed, the most common gill injuries were lamellar fusion, blood congestion and hyperplasia and hypertrophy of the epithelial and mucous cells. In the intestine of fish exposed to BDE-47, the alterations detected were hyperplasia and hypertrophy of mucous cells. Hepatic lesions in the liver of fish exposed to BDE-47 were characterized by circulatory disturbances, irregular morphology of hepatocytes, cellular and nuclear hypertrophy, and nuclear vacuolation and pyknosis. As BDE-47 is present in food and other material related to aquaculture systems, our results indicate that exposure to this pollutant could have serious consequences on health in turbot and other cultured fish.