1
|
Choi J, Rotter S, Ritz V, Kneuer C, Marx-Stoelting P, de Lourdes Marzo Solano M, Oertel A, Rudzok S, Ziková-Kloas A, Tralau T, Hensel A. Thresholds of adversity for endocrine disrupting substances: a conceptual case study. Arch Toxicol 2024; 98:2019-2045. [PMID: 38704806 PMCID: PMC11168997 DOI: 10.1007/s00204-024-03748-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/21/2024] [Indexed: 05/07/2024]
Abstract
For endocrine disrupting chemicals (EDC) the existence of "safe exposure levels", that is exposure levels that do not present an appreciable risk to human health is most controversially discussed, as is the existence of health-based reference values. Concerns have been especially raised that EDCs might not possess a threshold level such that no exposure level to EDCs can be considered safe. To explore whether or not threshold levels can be identified, we performed a screening exercise on 14 pesticidal and biocidal active substances previously identified as EDCs in the European Union. The respective substances are ideal subjects for case studies to review for endocrine activity and disruptive potential following well-defined regulatory assessment based on solid data to effectually establish adversity as consequence of endocrine disruption. Dimethomorph, metiram and propiconazole for which the weight of evidence demonstrating endocrine disruption was the strongest were used as subjects for further study. Epoxiconazole was additionally selected as its effects on the endocrine system are extensive. For all four substances, analysis of the toxicological data clearly indicated thresholds of adversity below which no adverse effects mediated through an endocrine mechanism were observed. Particular emphasis was placed on mechanistic considerations including homeostasis and the concept of adversity. As a proof of concept this study provides evidence that like other substances of toxicological concern EDCs have threshold levels for adversity. While for some EDCs the respective thresholds might indeed be very low this shows that, data allowing, for other EDCs sufficiently protective reference values can be derived.
Collapse
Affiliation(s)
- Judy Choi
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Stefanie Rotter
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Vera Ritz
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Carsten Kneuer
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Philip Marx-Stoelting
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | | | - Angelika Oertel
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Susanne Rudzok
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Andrea Ziková-Kloas
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Tewes Tralau
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany.
| | - Andreas Hensel
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| |
Collapse
|
2
|
Barola C, Brambilla G, Galarini R, Moretti S, Morabito S. Assessment of the combined inputs of antimicrobials from top soil improvers and irrigation waters on green leafy vegetable fields. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2024; 41:313-324. [PMID: 38295296 DOI: 10.1080/19440049.2024.2306930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/12/2024] [Indexed: 02/02/2024]
Abstract
Sustainable food systems involve the recycling of biowaste and water. This study characterizes thirty-one top soil improvers of anthropogenic, animal, and green waste origin, along with eleven irrigation waters from rivers, channels, and civil wastewater treatment plants (cWWTPs) for the presence of antimicrobials. Liquid chromatography coupled with hybrid High-Resolution Mass Spectrometry (LC-HRMS/MS) was employed to identify forty-eight drugs belonging to the classes of sulfonamides (11), tetracyclines (7), fluoroquinolones (10), macrolides (12), amphenicols (3), pleuromutilins (2), diaminopyrimidines (1), rifamycins (1) and licosamides (1). Sludge from cWWTPs, animal manure, slurry, and poultry litter exhibited the highest loads for sulfonamides, tetracyclines, fluoroquinolones and macrolides (80, 470, 885, and 4,487 ng g-1 wet weight, respectively) with nor- and ciprofloxacin serving as markers for anthropogenic sources. In compost and digestate, antimicrobials were found to be almost always below the limits of quantification. Reused water from cWWTPs for irrigation in open-field lettuce production were contaminated in the range of 12-221 ng L-1 with sulfonamides, tetracyclines, and fluoroquinolones, compared to very few detected in channels and surface waters. The Antimicrobials Hazard Index (HI), based on the Predicted No Effect Concentration for Antimicrobial Resistance (PNECAMR), was significantly >100 in contaminated topsoil improvers from urban and animal sources. Accounting for worst-case inputs from topsoil improvers and irrigation water, as well as dilution factors in amended soil, fluoroquinolones only exhibited an HI around 1 in open fields for lettuce production. The origin of topsoil improvers plays a pivotal role in ensuring safe and sustainable leafy vegetable production, thereby mitigating the risk of Antimicrobial Resistance (AMR) onset in food-borne diseases and the transfer of AMR elements to the human gut flora.
Collapse
Affiliation(s)
- Carolina Barola
- Centro Specialistico Sviluppo Metodi Analitici, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Perugia, Italy
| | - Gianfranco Brambilla
- Food Borne Diseases and One Health Unit, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Roberta Galarini
- Centro Specialistico Sviluppo Metodi Analitici, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Perugia, Italy
| | - Simone Moretti
- Centro Specialistico Sviluppo Metodi Analitici, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche "Togo Rosati", Perugia, Italy
| | - Stefano Morabito
- Food Borne Diseases and One Health Unit, Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| |
Collapse
|
3
|
Sapińska D, Adamek E, Masternak E, Zielińska-Danch W, Baran W. Influence of pH on the Kinetics and Products of Photocatalytic Degradation of Sulfonamides in Aqueous Solutions. TOXICS 2022; 10:655. [PMID: 36355946 PMCID: PMC9695452 DOI: 10.3390/toxics10110655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/19/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
The aims of the study were to determine the kinetics of the photocatalytic degradation of six sulfonamides in the presence of TiO2-P25 in acidic, neutral, and alkaline solutions and to identify the structures of the stable products. It was stated that the pH of the solution significantly affected the photocatalytic degradation rate of sulfonamides in acidic and alkaline environments, and the effect likely depended on the susceptibility of sulfonamides to attack by hydroxyl radicals. In the post-reaction mixture, we identified the compounds resulting from the substitution of the aromatic rings with a hydroxyl group; the amide hydrolysis products; the hydroxylamine-, azo, and nitro derivatives; and the compounds formed via the elimination of the sulfone group. Moreover, previously unknown azo compounds were detected. Some degradation products of sulfonamides may exhibit marked bacteriostatic activity and high phytotoxicity. The azo and nitro compounds formed in an acidic environment may be potentially more toxic to aquatic ecosystems than the initial compounds.
Collapse
|
4
|
Vadlamani G, Sukhoverkov KV, Haywood J, Breese KJ, Fisher MF, Stubbs KA, Bond CS, Mylne JS. Crystal structure of Arabidopsis thaliana HPPK/DHPS, a bifunctional enzyme and target of the herbicide asulam. PLANT COMMUNICATIONS 2022; 3:100322. [PMID: 35605193 PMCID: PMC9284294 DOI: 10.1016/j.xplc.2022.100322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/21/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Herbicides are vital for modern agriculture, but their utility is threatened by genetic or metabolic resistance in weeds, as well as regulatory barriers. Of the known herbicide modes of action, 7,8-dihydropterin synthase (DHPS), which is involved in folate biosynthesis, is targeted by just one commercial herbicide, asulam. A mimic of the substrate para-aminobenzoic acid, asulam is chemically similar to sulfonamide antibiotics, and although it is still in widespread use, asulam has faced regulatory scrutiny. With an entire mode of action represented by just one commercial agrochemical, we sought to improve the understanding of its plant target. Here we solve a 2.3 Å resolution crystal structure for Arabidopsis thaliana DHPS that is conjoined to 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), and we reveal a strong structural conservation with bacterial counterparts at the sulfonamide-binding pocket of DHPS. We demonstrate that asulam and the antibiotic sulfamethoxazole have herbicidal as well as antibacterial activity, and we explore the structural basis of their potency by modeling these compounds in mitochondrial HPPK/DHPS. Our findings suggest limited opportunity for the rational design of plant selectivity from asulam and indicate that pharmacokinetic or delivery differences between plants and microbes might be the best ways to safeguard this mode of action.
Collapse
Affiliation(s)
- Grishma Vadlamani
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Kirill V Sukhoverkov
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Joel Haywood
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Karen J Breese
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Mark F Fisher
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Keith A Stubbs
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Joshua S Mylne
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia; Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia.
| |
Collapse
|