Yu Liu | USGS Science

USGS2025

Tetrabromobisphenol S (TBBPS) causes non-negligible and multigenerational reproductive toxicity in zebrafish

Tetrabromobisphenol S (TBBPS) is one of the most extensively used brominated flame retardants detected in the environment. Despite its widespread presence, the effects of persistent environmental exposure to TBBPS on the reproductive system remain unclear, raising significant health concerns. Here, using the zebrafish ( Danio rerio ) model, we identified significant intergenerational endocrine disruption and reproductive toxicity induced by TBBPS after a life-cycle (150 days) of parental exposure to environmentally relevant concentrations of TBBPS (0.01, 0.1, 1, 10, and 100 μg/L). TBBPS interfered with hormone levels and the expression of genes within the hypothalamic–pituitary–gonadal (HPG) axis in both F0 males and females, leading to reduced embryo quality. The parental transmission of TBBPS also impacted the endocrine and reproductive systems of the F1 fish, including the increase of gonadotropin-releasing hormone 3 neuron numbers, changes in hormone levels, and a decrease in embryo numbers. F2 fish also displayed endocrine disruption, even in the absence of detectable TBBPS residues, evidenced by altered fertilization rates and vitellogenin levels. Together, our findings show that exposure to environmentally relevant concentrations of TBBPS can induce reproductive toxicity that persists across generations, weakening the endocrine system and early growth in offspring by disrupting the HPG axis. These data provide critical insight into the persistent health risks posed by TBBPS.

Environmental Science & Technology↗

USGS2015

Extreme variation of sulfur isotopic compositions in pyrite from the Qiuling sediment-hosted gold deposit, West Qinling orogen, central China: An in situ SIMS study with implications for the source of sulfur

High spatial resolution textural (scanning electron microscope (SEM)), chemical (electron microprobe (EMP)) and laser ablation-inductively coupled plasma-mass spec- trometry (LA-ICP-MS)), and sulfur isotopic (secondary ion mass spectrometry (SIMS)) analyses of pyrite from the Qiuling sediment-hosted gold deposit (232±4 Ma) in the West Qinling orogen, central China were conducted to distinguish pyrite types and gain insights into the source and evolution of sulfur in hydrothermal fluids. The results reveal an enormous variation (−27.1 to +69.6‰) in sulfur isotopic composition of pyrite deposited during three paragenetic stages. Pre-ore framboidal pyrite, which is characterized by low concentra- tions of As, Au, Cu, Co, and Ni, has negative δ34S values of −27.1 to −7.6‰ that are interpreted in terms of bacterial re- duction of marine sulfate during sedimentation and diagenesis of the Paleozoic carbonate and clastic sequences, the predom- inant lithologies in the deposit area, and the most important hosts of many sediment-hosted gold deposits throughout the West Qinling orogen. The ore-stage hydrothermal pyrite con- tains high concentrations of Au, As, Cu, Sb, Tl, and Bi and hasa relatively narrow range of positive δ34S values ranging from +8.1 to +15.2‰. The sulfur isotope data are comparable to those of ore pyrite from many Triassic orogenic gold deposits and Paleozoic sedimentary exhalative (SEDEX) Pb-Zn de- posits in the West Qinling orogen, both being hosted mainly in the Devonian sequence. This similarity indicates that sulfur, responsible for the auriferous pyrite at Qiuling, was largely derived from the metamorphic devolatization of Paleozoic marine sedimentary rocks. Post-ore-stage pyrite, which is sig- nificantly enriched in Co and Ni but depleted in Au and As, has unusually high δ34S values ranging from +37.4 to +69.6 ‰, that are interpreted to result from thermochemical reduc- tion of evaporite sulfates in underlying Cambrian sedimentary rocks with very high δ34S values. The variations in Au content and sulfur isotopic compositions across a single ore-stage py- rite grain may reflect displacement of indigenous groundwater with low δ34S values by auriferous metamorphic fluids with high δ34S values. The very low-grade metamorphism of the host rocks and the metamorphic derivation of sulfur for the ore pyrite indicate that the Qiuling sediment-hosted gold deposit is an epizonal manifestation of an orogenic gold system in the West Qinling orogen.

Mineralium Deposita↗