Kelsey Ng

Mr. Kelsey Ng

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 October 2022 in Environmental Sciences Europe
Verified
Journal Article
Open access
PDF file
HTHiba Mohammed Taha
Hiba Mohammed Taha
RAReza Aalizadeh
Reza Aalizadeh
Nikiforos AlygizakisNikiforos Alygizakis
Nikiforos Alygizakis
JAJean-Philippe Antignac
Jean-Philippe Antignac
HAHans Peter H. Arp
Hans Peter H. Arp
ESEmma Schymanski
Emma Schymanski
Background: The NORMAN Association (https://www.norman-network.com/) initiated the NORMAN Suspect List Exchange (NORMAN-SLE; https://www.norman-network.com/nds/SLE/) in 2015, following the NORMAN collaborative trial on non-target screening of environmental water samples by mass spectrometry. Since then, this exchange of information on chemicals that are expected to occur in the environment, along with the accompanying expert knowledge and references, has become a valuable knowledge base for “suspect screening” lists. The NORMAN-SLE now serves as a FAIR (Findable, Accessible, Interoperable, Reusable) chemical information resource worldwide. Results: The NORMAN-SLE contains 99 separate suspect list collections (as of May 2022) from over 70 contributors around the world, totalling over 100,000 unique substances. The substance classes include per- and polyfluoroalkyl substances (PFAS), pharmaceuticals, pesticides, natural toxins, high production volume substances covered under the European REACH regulation (EC: 1272/2008), priority contaminants of emerging concern (CECs) and regulatory lists from NORMAN partners. Several lists focus on transformation products (TPs) and complex features detected in the environment with various levels of provenance and structural information. Each list is available for separate download. The merged, curated collection is also available as the NORMAN Substance Database (NORMAN SusDat). Both the NORMAN-SLE and NORMAN SusDat are integrated within the NORMAN Database System (NDS). The individual NORMAN-SLE lists receive digital object identifiers (DOIs) and traceable versioning via a Zenodo community (https://zenodo.org/communities/norman-sle), with a total of > 40,000 unique views, > 50,000 unique downloads and 40 citations (May 2022). NORMAN-SLE content is progressively integrated into large open chemical databases such as PubChem (https://pubchem.ncbi.nlm.nih.gov/) and the US EPA’s CompTox Chemicals Dashboard (https://comptox.epa.gov/dashboard/), enabling further access to these lists, along with the additional functionality and calculated properties these resources offer. PubChem has also integrated significant annotation content from the NORMAN-SLE, including a classification browser (https://pubchem.ncbi.nlm.nih.gov/classification/#hid=101). Conclusions: The NORMAN-SLE offers a specialized service for hosting suspect screening lists of relevance for the environmental community in an open, FAIR manner that allows integration with other major chemical resources. These efforts foster the exchange of information between scientists and regulators, supporting the paradigm shift to the “one substance, one assessment” approach. New submissions are welcome via the contacts provided on the NORMAN-SLE website (https://www.norman-network.com/nds/SLE/).

28 December 2022 in Water Research
Verified
Journal Article
Closed access
KNKelsey Ng
Kelsey Ng
Nikiforos AlygizakisNikiforos Alygizakis
Nikiforos Alygizakis
Maria Christina NikaMaria Christina Nika
Maria Christina Nika
AGAikaterini Galani
Aikaterini Galani
POPeter Oswald
Peter Oswald
JSJaroslav Slobodnik
Jaroslav Slobodnik

6 January 2023 in Antibiotics
Verified
Journal Article
Open access
PDF file
KNKelsey Ng
Kelsey Ng
Nikiforos AlygizakisNikiforos Alygizakis
Nikiforos Alygizakis
Nikolaos ThomaidisNikolaos Thomaidis
Nikolaos Thomaidis
JSJaroslav Slobodnik
Jaroslav Slobodnik
The occurrence of antibiotics in the environment could result in the development of antibiotic-resistant bacteria, which could result in a public health crisis. The occurrence of 676 antibiotics and the main transformation products (TPs) was investigated in the 48 wastewater treatment plants (WWTPs) from 11 countries (Germany, Romania, Serbia, Croatia, Slovenia, Hungary, Slovakia, Czechia, Austria, Cyprus, and Greece) by target and suspect screening. Target screening involved the investigation of antibiotics with reference standards (40 antibiotics). Suspect screening covered 676 antibiotics retrieved from the NORMAN Substance Database (antibiotic list on NORMAN network). Forty-seven antibiotics were detected in effluent wastewater samples: thirty-two by target screening and fifteen additional ones by suspect screening. An ecotoxicological risk assessment was performed based on occurrence data and predicted no effect concentration (PNEC), which involved the derivation of frequency of appearance (FoA), frequency of PNEC exceedance (FoE), and extent of PNEC exceedance (EoE). Azithromycin, erythromycin, clarithromycin, ofloxacin, and ciprofloxacin were prioritized as the calculated risk score was above 1. The median of antibiotics’ load to freshwater ecosystems was 0.59 g/day/WWTP. The detection of antibiotics across countries indicates the presence of antibiotics in the ecosystems of Europe, which may trigger unwanted responses from the ecosystem, including antibiotic resistance.

4 February 2023 in Water
Verified
Journal Article
Open access
PDF file
Nikiforos AlygizakisNikiforos Alygizakis
Nikiforos Alygizakis
KNKelsey Ng
Kelsey Ng
NMNiki Maragou
Niki Maragou
SASylvana Alirai
Sylvana Alirai
PBPeter A. Behnisch
Peter A. Behnisch
JSJaroslav Slobodnik
Jaroslav Slobodnik
Wastewater treatment plants (WWTPs) represent an important input of contaminants in the environment. Therefore, it is critical to continuously monitor the performance of WWTPs to take appropriate action and avoid an influx of contaminants in the environment. In this study, a battery of seven in vitro bioassays covering a selected spectrum of toxicity effects is proposed for quality control of wastewater effluents. The bioassays address mixture toxicity, which is the combined adverse effect of multiple contaminants and can act as an early warning system. The proposed battery was applied to samples from 11 WWTPs of representative technology from the Danube River Basin (DRB). The order of toxic effects in terms of extent of exceedance of effect-based trigger values (EBTs) was PAH (PAH activity) > PXR (xenobiotic metabolism) > ERα (estrogenic activity) > PPARγ > Nrf2 (oxidative stress) > anti-AR > GR. A mitigation plan for WWTP operators based on EBT exceedance is proposed. This study demonstrates that the proposed effect-based monitoring battery is a complementary tool to the chemical analysis approach. A regular application of such time- and cost-effective bioanalytical tools in the WWTPs of the DRB is proposed to provide a ‘safety net’ for aquatic ecosystems.

13 June 2025 in Journal of Environmental Exposure Assessment
Verified
Journal Article
Open access
PDF file
Nikiforos AlygizakisNikiforos Alygizakis
Nikiforos Alygizakis
KNKelsey Ng
Kelsey Ng
Georgios GkotsisGeorgios Gkotsis
Georgios Gkotsis
Maria Christina NikaMaria Christina Nika
Maria Christina Nika
KVKonstantinos Vasilatos
Konstantinos Vasilatos
JSJaroslav Slobodnik
Jaroslav Slobodnik
A holistic investigation of legacy persistent organic pollutants and contaminants of emerging concern was conducted for 14 biota samples collected from Antarctica between 2018 and 2020. The sample set included sea stars, sea urchins, macrophytes, fish muscle, seal muscle and placenta, and penguin muscle and eggs. The four Water Framework Directive heavy metals (lead, cadmium, nickel, and mercury) were present in all samples. Organophosphorus flame retardants and brominated flame retardants were detected sporadically at low concentration levels (below 0.7 ng/g ww). Isomers of Dechlorane Plus were not detected (< 0.01 ng/g ww). In contrast, dioxins, polybrominated diphenyl ethers (PBDEs) and polychlorinated bisphenols (PCBs) were frequently detected. The highest concentration was observed for PCBs, specifically PCB118 (up to 2,478 ng/g ww) and PCB105 (up to 977 ng/g ww). Wide-scope target screening of 2,236 compounds and suspect screening of 65,591 compounds were performed. Thirty-three contaminants from various chemical classes were detected through wide-scope target screening, of which 42% were pharmaceuticals and personal care products (PPCPs) and 30% were industrial chemicals (ICs) and their transformation products. An additional 55 compounds were identified through suspect screening, with PPCPs and ICs each accounting for 26 compounds. Most of the identified compounds are registered as REACH substances by the European Chemicals Agency, with some produced in very high volumes, exceeding 1,000,000 tonnes. Contaminant levels in Antarctic biota samples were lower than those reported in similar European studies, such as those conducted in the Danube River Basin.

12 November 2021
Verified
Book Chapter
Closed access
FVFelicity Veal
Felicity Veal
KNKelsey Ng
Kelsey Ng