Steroidal estrogens are potent endocrine-disrupting chemicals that enter natural waters through the discharge of treated and raw sewage. Because estrogens are detrimental to aquatic organisms at sub-nanogram per liter concentrations, many studies have measured so-called "free" estrogen concentrations in wastewater effluents, rivers, and lakes. Other forms of estrogens are also of potential concern because conjugated estrogens can be easily converted to potent free estrogens by bacteria in wastewater treatment plants and receiving waters and halogenated estrogens are likely produced during wastewater disinfection. However, to the best of our knowledge, no studies have concurrently characterized free, conjugated, and halogenated estrogens. We have developed a method that is capable of simultaneously quantifying free, conjugated, and halogenated estrogens in treated wastewater effluent, in which detection limits were 0.13-1.3 ng L(-1) (free), 0.11-1.0 ng L(-1) (conjugated), and 0.18-18 ng L(-1) (halogenated). An aqueous phase additive, ammonium fluoride, was used to increase the electrospray (negative mode) ionization efficiency of free and halogenated estrogens by factors of 20 and 2.6, respectively. The method was validated using treated effluent from the greater Boston metropolitan area, where conjugated and halogenated estrogens made up 60-70% of the steroidal estrogen load on a molar basis.
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http://dx.doi.org/10.1021/es402809u | DOI Listing |
Proc Natl Acad Sci U S A
December 2024
Minderoo Foundation, Perth, WA 6000, Australia.
More than 16,000 chemicals are incorporated into plastics to impart properties such as color, flexibility, and durability. These chemicals may leach from plastics, resulting in widespread human exposure during everyday use. Two plastic-associated chemicals-bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP)-and a class of chemicals-brominated flame retardants [polybrominated diphenyl ethers (PBDEs)]-are credibly linked to adverse health and cognitive impacts.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Department of Chemistry, Temple University, Philadelphia, Pennsylvania, USA. Electronic address:
Understanding how natural and engineered peptides enter cells would facilitate the elucidation of biochemical mechanisms underlying cell biology and is pivotal for developing effective intracellular targeting strategies. In this study, we demonstrate that our peptide stapling technique, fluorine-thiol displacement reaction (FTDR), can produce flexibly constrained peptides with significantly improved cellular uptake, particularly into the nucleus. This platform confers enhanced flexibility, which is further amplified by the inclusion of a D-amino acid, while maintaining environment-dependent α helicity, resulting in highly permeable peptides without the need for additional cell-penetrating motifs.
View Article and Find Full Text PDFSci Total Environ
December 2024
The Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, PR China. Electronic address:
Bisphenols, including bisphenol A (BPA) and its analogs such as bisphenol F (BPF), bisphenol S (BPS), tetrabromobisphenol A (TBBPA), tetrachlorobisphenol A (TCBPA) and tetrabromobisphenol S (TBBPS), are typical endocrine disruptors widely used in plastic production. However, until now, the occurrence mechanisms of these bisphenols in hair, a non-invasive material for human biomonitoring, have been inadequately explored. This study employed fluorescence spectroscopy and molecular docking to investigate the interactions between these 6 bisphenols and hair keratin.
View Article and Find Full Text PDFEnviron Sci Technol
November 2024
State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, Jiangsu, China.
Drinking water halogenated disinfection byproducts (DBPs) have become an increasing health concern. However, the endocrine-disrupting effects of DBPs have not been well evaluated, and the limited available data have inhibited a comprehensive understanding of their health risks. In this study, a total of 43 DBPs were evaluated for their estro-androgenic effects using two types of human breast cancer cells.
View Article and Find Full Text PDFFront Bioeng Biotechnol
October 2024
College of Textile and Clothing, Xinjiang University, Urumqi, China.
The emergence of environmental endocrine disruptor chlorobenzene (CB) in surface water and its potential environmental impacts have attracted serious global attention. It is still very difficult to achieve effective degradation of it by catalytic oxidation process under mild conditions. Here, an optimized method for degrading CB in aqueous solution using laccase and surfactant-assisted laccase-mediator (SALM) system was investigated.
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