Occurrence, effects and environmental risk of antifouling biocides (EU PT21): Are marine ecosystems threatened?

Abstract

This review presents a comprehensive compilation of toxicological and environmental data, further used to assess the ecological risk (ERA) of the 11 EU approved antifouling biocides (PT21). Diuron, chlorothalonil, DCOIT, and pyrithiones are amongst the most toxic biocides toward producer species, while, CuSCN, medetomidine, and zineb showed higher toxicity toward consumers. In addition, medetomidine, CuSNC, zineb, Cu₂O, and chlorothalonil are up to 400-fold more toxic to non-target organisms than target organisms highlighting their potential threat for marine ecosystems. Biocides hazard, which was assessed based on the marine PNEC_{probabilistic} for biocides having enough and reliable ecotoxicological data, can be summarized in the following order: ZnPT (more hazardous) > CuPT > DCOIT > diuron > chlorothalonil > dichlofluanid > tolylfluanid. For the remaining biocides, the marine hazard was calculated based on the PNEC_{deterministic} as follows: CuSCN (more hazardous) > Cu₂O > medetomidine > zineb. The risk assessment indicates that the following biocides poses risk (quotient >1) for the coastal ecosystems: DCOIT, diuron, dichlofluanid, chlorothalonil, CuSCN, Cu₂O, medetomidine and zineb. In order to protect the services and functions of coastal environments, a systematic and continuous monitoring of these biocides in coastal areas are highly recommended. Current regulatory framework and the replacement of state-of-the-art biocides by safer alternative is also critically discussed.

Graphical abstract

Keywords:

• Biofouling
• hazard assessment
• regulation
• risk assessment
• species sensitivity distribution (SSD)
• predicted no effect concentration (PNEC)

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Thanks are due to the financial support to São Paulo Research Foundation (FAPESP) under Grant FAPESP: 2019/19898-3 and FAPESP: 2017/10211-0 and to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020), through national funds. Dr. Roberto Martins is funded by national funds (OE), through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19 (CEECIND/01329/2017). This project was also carried out in the framework of the bilateral project “Exposure and bioaccumulation assessment of anti-fouling nanomaterials in marine organisms from temperate and tropical waters” funded by FCT and CAPES (ref. 4265 DRI/FCT) and the project NANOGREEN (CIRCNA/BRB/0291/2019) funded by national funds (OE), through FCT.