Phthalate esters inhibit microbial activity in aquatic sediments

Abstract

Sediments were exposed to five concentrations of the plasticizer di(2-ethylhexyl)phthalate (DEHP) and the effects on sediments oxygen uptake were assessed. The sediments were taken from an eutrophic lake and consisted of ‘undisturbed’ sediment with overlying lake water. The community respiration in the sediment was inhibited by DEHP. The oxygen uptake from uncontaminated sediment was significantly higher than from sediments containing DEHP. The decrease in microbial activity in contaminated sediment cores was positively correlated to increasing levels of DEHP in the sediment. At concentrations of 25 μg DEHP g⁻¹ and higher the sediment respiration consisted of chemical, rather than biological, oxygen consumption.