Organic ultraviolet filters in Irish sediments and biosolids

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Environmental Monitoring

Background:

• Ultraviolet filters (UVFs) are widely used in personal care products and can enter aquatic environments through wastewater.
• Limited data exist on UVF concentrations in Irish sediments and biosolids, and their potential ecotoxicological risks.
• Wastewater treatment plants (WWTPs) are a significant source of UVF release into the environment.

Purpose of the Study:

• To establish baseline data on the concentrations of five key UVFs (4-methylbenzylidene camphor, benzophenone-3, 2-ethylhexyl-4-methoxycinnamate, homosalate, and Octocrylene) in Irish sediments and biosolids.
• To assess the potential ecotoxicological risks posed by these UVFs based on measured environmental concentrations.
• To compare Irish UVF levels with international data and inform future environmental management strategies.

Main Methods:

• Analysis of 81 inland and transitional sediment samples and 21 agricultural biosolid samples from seven WWTPs across Ireland.
• Quantification of five specific UVFs: 4-methylbenzylidene camphor (4-MBC), benzophenone-3 (BP-3), 2-ethylhexyl-4-methoxycinnamate (EHMC), homosalate (HMS), and Octocrylene (OC).
• Calculation of mean and 95th percentile concentrations (MEC95) to evaluate ecotoxicological risk.

Main Results:

• Mean sediment concentrations (ng/g): OC (3.66), HMS (2.35), 4-MBC (1.87), BP-3 (0.19), EHMC (0.04).
• Mean biosolid concentrations (ng/g): OC (666), HMS (453), 4-MBC (13.9), EHMC (12.7), BP-3 (1.28).
• HMS, EHMC, and 4-MBC in sediments posed moderate ecotoxicological risks; overall Irish UVF levels were low internationally.

Conclusions:

• Irish UVF concentrations in sediments and biosolids are generally low compared to international findings.
• Homosalate (HMS) concentrations in WWTP biosolids are reported for the first time, indicating a need for global assessment.
• Ongoing monitoring of HMS and 4-MBC is crucial due to EU restrictions, while OC, EHMC, and BP-3 require further risk evaluation.