Meta-analysis evaluates toxicity of PFAS to microalgae: Mechanisms and ecological risks

Area of Science:

• Environmental Science
• Ecotoxicology
• Microbiology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are widespread emerging contaminants with bioaccumulation potential.
• Microalgae, vital primary producers and water quality indicators, are exposed to PFAS in aquatic environments.
• Understanding PFAS impacts on microalgae is crucial for ecological risk assessment and management.

Purpose of the Study:

• To meta-analyze the effects of PFAS on microalgal growth, photosynthesis, and cell integrity.
• To investigate the influence of PFAS properties (chain length, functional groups) and exposure duration on microalgae.
• To assess the efficacy of microalgae in PFAS removal.

Main Methods:

• Meta-analysis of 1681 data points from 45 peer-reviewed studies.
• Statistical analysis of relationships between PFAS concentration, chain length, functional groups, and microalgal responses.
• Comparative analysis of PFAS toxicity across different microalgal groups (Chlorophyta, cyanobacteria).

Main Results:

• PFAS significantly inhibit microalgal growth and photosynthesis, increase oxidative stress, and damage cell membranes.
• Chlorophyta exhibit greater membrane damage than cyanobacteria.
• A negative correlation exists between microalgal biomass and PFAS concentration, with diminishing effects over time.
• PFAS with -COOH functional groups are more toxic than those with other groups at similar chain lengths.
• Microalgae show limited efficiency for PFAS removal.

Conclusions:

• PFAS pose a significant risk to aquatic primary producers, potentially leading to algal toxin release.
• PFAS toxicity is influenced by chemical structure and exposure duration.
• Microalgae alone are not a sufficient solution for PFAS remediation.
• Findings provide a theoretical basis for PFAS risk assessment and management strategies.