Biodegradation Rates of Ferulic Acid Derivatives and Traditional Sunscreen Actives in Marine, Bay, and Freshwater Environments

Abstract

In recent years, concern over adverse effects of conventional organic ultraviolet (UV) absorbers on human and environmental health has grown. In particular, the time frame that such compounds are expected to remain in the environment is a topic of interest. In this work, the mineralization rates of traditional sunscreen actives octinoxate (EHMC), homosalate (HMS), and avobenzone (AVO) were compared to bioderived UV absorbers ferulic acid (FA), ethyl ferulate (ETF), feruloylated soybean oil (FSO), and feruloylated coconut oil (FCO). These rates were determined by observing CO 2 generation over time under three separate nutrient-supplemented, environment-like conditions: marine water, bay water, and freshwater. The effect of nutrient supplementation was also separately estimated through comparing mineralization rates of supplemented with nonsupplemented freshwater. The resulting mineralization rates and projected half-lives of these compounds were then compared with previous experiments performed in wastewater treatment sludge, as well as with biodegradation properties predicted by quantitative structure−activity/property relationship (QSAR) models. Across all three aquatic environments, we observed that the ferulic acid derivatives (FA, ETF, FSO, and FCO) mineralized faster than conventional UV absorbers (EHMC, HMS, AVO) by 1 to 2 orders of magnitude.