Ubiquity and ecological risks of conjugated steroids cannot be overlooked: First evidence from estuarine sediments.

Steroids, renowned for endocrine-disrupting capabilities, have garnered significant research interest, predominantly centered on their parent forms. This study was the first to explore the composition, spatiotemporal characteristics, sources, mass inventories, and ecological risks of steroids in free and conjugated forms in estuarine sediments. Seventeen steroids were identified in sediments with the total levels of 1.

Organophosphate flame retardants and their metabolites in the Pearl River Estuary: Occurrence, influencing factors, and ecological risk control strategies based on a mass balance model.

Estuaries serve as crucial filters for land-based pollutants to the open sea, but there is a lack of information on the migration and fate of organophosphate flame retardants (OPFRs) within estuaries. This study focused on the Pearl River Estuary (PRE) by examining the co-occurrence of OPFRs and their metabolites and quantifying their transport fluxes using a mass balance model. The seawater concentrations of OPFRs and their metabolites exhibited significant seasonal variations (p < 0.

First insights into the bioaccumulation, biotransformation and trophic transfer of typical tetrabromobisphenol A (TBBPA) analogues along a simulated aquatic food chain.

Tetrabromobisphenol A (TBBPA) analogues have been investigated for their prevalent occurrence in environments and potential hazardous effects to humans and wildlife; however, there is still limited knowledge regarding their toxicokinetics and trophic transfer in aquatic food chains. Using a developed toxicokinetic model framework, we quantified the bioaccumulation, biotransformation and trophic transfer of tetrabromobisphenol S (TBBPS) and tetrabromobisphenol A di(allyl ether) (TBBPA-DAE) during trophic transfer from brine shrimp (Artemia salina) to zebrafish (Danio rerio). The results showed that the two TBBPA analogues could be readily accumulated by brine shrimp, and the estimated bioconcentration factor (BCF) value of TBBPS (5.

Steroid metabolites as overlooked emerging contaminants: Insights from multimedia partitioning and source-sink simulation in an estuarine environment.

Steroids have been attracting global attention given potential carcinogenic and endocrine-disrupting effects, yet the environmental status of steroids, especially their metabolites, in estuarine environment remain largely unexplored. This study investigated 31 steroids and metabolites in suspended particulate matter (SPM), water phase and sediments of the Pearl River Estuary (PRE) during the dry and wet seasons to elucidate their spatiotemporal patterning, partitioning behavior, and environmental fate. The results showed that natural steroids predominated in SPM and sediments while the metabolites predominated in water.

Expanded polystyrene buoys as an important source of hexabromocyclododecanes for aquatic ecosystem: Evidence from field exposure with different substrates.

The production and use of hexabromocyclododecanes (HBCDs) have been strictly limited due to their persistence, toxicity and bioaccumulation. However, the release of HBCDs from related products and wastes would continue for a long time, which may cause many environmental problems. In this study, we investigated the occurrence and distribution of HBCDs and microplastics (MPs) in aquatic organisms inhabiting different substrates.

Contamination and ecological risks of steroid metabolites require more attention in the environment: Evidence from the fishing ports.

Due to strong endocrine disrupting effects, steroids in the environment have attracted substantial attention, with studies mostly focusing on the parent steroids. Here, we conducted the first investigation on the contamination profiles, possible sources, mass inventories, and ecological risks of 27 steroids and their metabolites in 15 typical fishing ports in Southeast China. Twelve steroids were detectable in the sediment samples with the total mean concentrations of 4.

[The fluorescence characteristics of dissolved organic matter (DOM) in the seagrass ecosystem from Hainan by fluorescence excitation-emission matrix spectroscopy].

The fluorescence characteristics of dissolved organic matter (DOM) were determined in the seagrass ecosystem collected in Xincun Bay of Hainan Island in late January, 2013, using fluorescence excitation-emission matrix spectroscopy (EEMs). EEMs spectra showed 2 types of fluorescence signals in DOM samples, three hurnic-like fluorescence peaks and two protein-like fluorescence peaks, respectively. The former included UVC peak A (Ex/Em: 230/430 nm), UVA peak C (Ex/Em: 350/440 nm), and UVA peak M (Ex/Em: 300/380-400 nm), while the latter included tryptophan-like peaks R (Ex/Em: 230/355 - 375 nm) and N (Ex/Em: 280-300/365-380 nm).

[Study on optical characteristics of chromophoric dissolved organic matter (CDOM) in rainwater by fluorescence excitation-emission matrix and absorbance spectroscopy].

The optical characteristics of chromophoric dissolved organic matter (CDOM) were determined in rain samples collected in Xiamen Island, during a rainy season in 2007, using fluorescence excitation-emission matrix spectroscopy associated with UV-Vis absorbance spectra. Results showed that the absorbance spectra of CDOM in rain samples decreased exponentially with wavelength. The absorbance coefficient at 300 nm [a(300)] ranged from 0.

[Characterization of photobleaching of chromophoric dissolved organic matter in Xiamen Bay by excitation emission matrix spectroscopy].

Fluorescence excitation-emission matrix spectroscopy (EEMs) was applied to study the photobleaching of chromophoric dissolved organic matter (CDOM) in two surface water samples from Xiamen Bay exposed to natural sunlight between 10:00-16:00 during September 12-18, 2007. Both samples were collected from the lower and middle salinity areas in Jiulong Estuary of Xiamen Bay, and then filtered by 0.2 microm polycarbonate filters before the photobleaching incubation experiment.

[Photodegradation of chromophoric dissolved organic matter from Jiulong River Estuary under natural solar radiation].

Low salinity water sample collected from Jiulong River Estuary filtered using 0.2 microm Millipore filter was exposed to natural solar radiation from 10:00 to 16:00 each day during one week period in early and late May, 2005. Photodegradation of fluorescence and absorption properties of CDOM (chromophoric dissolved organic matter) was observed.