New publication in Emerging Contaminants finds lasting microbial responses after rapid dissipation of tire-derived contaminants

6PPD, a widely used tire antioxidant, can be transformed into the highly toxic oxidation product 6PPD quinone. Both compounds are increasingly detected in aquatic environments, but their effects on sediment microbial communities remain poorly understood. The researchers used sediment-water microcosms at environmentally relevant concentrations and combined amplicon sequencing, ecological network analysis, community assembly analysis and metagenomics to investigate contaminant dissipation and microbial responses.

Both compounds dissipated rapidly, with most of the added contaminants attenuating within the first few days. Despite this, transient 6PPD exposure was associated with changes in microbial succession, network characteristics and community assembly processes. Nutrient-related conditions also changed, including increases in ammonium and sulfate concentrations. Carbon-cycling potential remained comparatively stable, while nitrogen- and sulfur-cycling potential varied more strongly across treatments and incubation periods. These responses remained detectable after substantial contaminant dissipation, highlighting the importance of considering microbial effects when evaluating tire-derived contaminants in aquatic sediments.

The study was led by Hanghai Zhou (Guest Scientist at EDGE | CEMESS, University of Vienna) and co-authored by Thilo Hofmann (EDGE | CeMESS, University of Vienna). Zhou is also affiliated with the Zhejiang Academy of Agricultural Sciences, China. The other team members of this study are Zhou Wu (Jiangnan University, China); Zhongyong Yan (Marine Ecological and Environmental Monitoring Center of Zhejiang Province, China); Zhendong Li and Lihua Zou (Southwest Forestry University, China); Lijia Jiang, Chunfang Zhang and the two corresponding authors Hua Li (Zhejiang University, China) and Jiangwu Tang (Zhejiang Academy of Agricultural Sciences, China).