Photodegradation of the endocrine-disrupting chemicals 4n-nonylphenol and triclosan by simulated solar UV irradiation in aqueous solutions with Fe(III) and in the absence/presence of humic acids

Comparison of in vitro membrane permeabilities of diverse environmental chemicals with in silico predictions

The parallel artificial membrane permeability assay (PAMPA) is widely used for estimating biomembrane permeabilities of experimental drugs in pharmaceutical research. However, there are few reports of studies using PAMPA to measure membrane permeabilities of chemicals of environmental concern (CECs) outside the pharmaceutical domain, many of which differ substantially from drugs in their physicochemical properties. We applied PAMPA methods simulating gastrointestinal (PAMPA-GIT) and blood-brain barrier (PAMPA-BBB) membranes under consistent conditions to 51 CECs, including some pharmaceuticals. A backward stepwise multivariate linear regression was implemented to explore the correlation between the differences of measured permeabilities from PAMPA-GIT and PAMPA-BBB and Abraham solute descriptors. In addition, a previously reported in silico model was evaluated by comparing predicted and measured permeability results. PAMPA-GIT and PAMPA-BBB experimental permeability results agreed relatively well. The backward stepwise multivariate linear regression identified excess molar refraction and polarizability to be significant at the 0.10 level in predicting the differences between PAMPA-GIT and PAMPA-BBB. The in silico model performed well - with predicted permeability of most compounds within two-fold of experimentally measured values. We found that CECs pose experimental challenges to the PAMPA method in terms of having lower solubility and lower stability compared to most drugs.

Advances in identifying and managing emerging contaminants in aquatic ecosystems: Analytical approaches, toxicity assessment, transformation pathways, environmental fate, and remediation strategies

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management.

MAKING WAVES: Effluent to estuary: Does sunshine or shade reduce downstream footprints of cities?

Riparian tree canopies are key components of river systems, and influence the provision of many essential ecosystem services. Their management provides the potential for substantial control of the downstream persistence of pollutants. The recent advent of new advances in mass spectrometry to detect a large suite of emerging contaminants, high-frequency observations of water quality and gas exchange (e.g., aquatic eddy covariance), and improved spatial resolution in remote sensing (e.g., hyperspectral measurements and high-resolution imagery), presents new opportunities to understand and more comprehensively quantify the role of riparian canopies as Nature-based Solutions. The paper outlines how we may now couple these advances in observational technologies with developments in water quality modelling to integrate simulation of eutrophication impacts with organic matter dynamics and fate of synthetic toxic compounds. In particular regarding solar radiation drivers, this enables us to scale-up new knowledge of canopy-mediated photodegradation processes at a basin level, and integrate it with ongoing improvements in understanding of thermal control, eutrophication, and ecosystem metabolism.

Studies of Endocrine Disruptors: Nonylphenol and Isomers in Biological Models

Certain emerging pollutants are among the most widely used chemicals globally, causing widespread concern in relation to their use in products devoted to cleaniness and asepsis. Nonylphenol ethoxylate (NPEOn) is one such contaminant, along with its degradation product, nonylphenol, an active ingredient presents in nonionic surfactants used as herbicides, cosmetics, paints, plastics, disinfectants, and detergents. These chemicals and their metabolites are commonly found in environmental matrices. Nonylphenol and NPEOn, used, are particularly concerning, given their role as endocrine disruptors chemical and possible neurotoxic effects recorded in several biological models, primarily aquatic organisms. Limiting and detecting these compounds remain of paramount importance. The objective of the present review was to evaluate the toxic effects of nonylphenol and NPEOn in different biological models. Environ Toxicol Chem 2023;00:1-12. © 2023 SETAC.

Elucidation of the photoinduced transformations of Aliskiren in river water using liquid chromatography high-resolution mass spectrometry

Aliskiren was selected as a compound of potential concern among a suspect screening list of more than 40,000 substances on a basis of high occurrence, potential risk and the absence of information about its environmental fate. This study investigated the photoinduced degradation of aliskiren in river water samples spiked at trace levels exposed to simulated sunlight. A half-life time of 24 h was observed with both direct and indirect photolysis playing a role on pollutant degradation. Its photo-induced transformation involved the formation of six transformation products (TPs), elucidated by LC-HRMS - resulted from the drug hydroxylation, oxidation and moieties loss with subsequent cyclization structurally. The retrospective suspected analysis performed on a total of 754 environmental matrices evidenced the environmental occurrence of aliskiren and two TPs in surface waters (river and seawater), fresh water, sediments and biota. In silico bioassays suggested that aliskiren degradation undergoes thought the formation of TPs with distinct toxicity comparing with the parent compound.

Removal and biotransformation of 4-nonylphenol by Arthrospira maxima and Chlorella vulgaris consortium

4-Nonylphenol (4-NP) is an anthropogenic contaminant found in different environmental matrices that has an effect over the biotic and abiotic factors within the environment. Bioremediation by microorganisms can be used as a potential treatment to remove this pollutant. In this work, a consortium of two microorganisms, Arthrospira maxima and Chlorella vulgaris, was employed to remove 4-NP from water. The parameters analyzed included cell growth, removal of 4-NP, and 4-NP remnant in the biomass. In addition, the metabolites produced in the process by this consortium were identified. It was found that C. vulgaris is more resistant to 4-NP than A. maxima (cell growth inhibition by 4-NP of 99%). The consortium used in this study had an IC₅₀ greater than any strain of microalgae or cyanobacteria reported for 4-NP removal (9.29 mg/L) and reduced up to 96% of 4-NP in water in the first 48 h of culture. It was also observed that there is a bio-transformation of 4-NP, comparable with the process carried out by another bacterium, in which three similar metabolites were found (4-(1-methyl-octyl)-4-hydroxy-cyclohex-2-enone, 4-nonyl-4-hydroxy-ciclohexa-2,5-dienone and 4-nonyl-4-hydroxy- ciclohex-2-enone) and one that is similar to plant metabolism (4-nonyl-(1-methyl,6,8-metoxy)-hydroxybenzene). These results indicate that microalgae and cyanobacteria consortium can be used to remove 4-NP from water.

Removal of Nonylphenol by using Fe-doped NaBiO3 compound as an efficient visible-light-heterogeneous Fenton-like catalyst

Fe-doped NaBiO₃ nanoscaled compounds were prepared by hydrothermal method and evaluated as a highly efficient photo-Fenton-like catalyst under visible light irradiation. The Fe-doped NaBiO₃ compound had a specific surface area of 41.42 m² g^-1, which is considerably larger than that of NaBiO₃ nanoparticles (28.81 m² g^-1). The compound exhibited an excellent visible light-Fenton-like catalysis activity, which is influenced by the iron content of the compound and the pH value of the solution. Under the optimal conditions, the Fe-doped NaBiO₃ compound led to fast degradation of Nonylphenol with an apparent rate constant of 5.71 × 10^-2 min^-1, which was 8.23-fold of that achieved by using NaBiO₃. The significantly enhanced visible light-Fenton-like catalytic property of the Fe-doped NaBiO₃ was attributed to the large surface area and the high adsorption capacity of the compound, and the Fenton catalytic ability of iron in the compound.

Solar photodegradation of carbamazepine from aqueous solutions using a compound parabolic concentrator equipped with a sun tracking system

The primary purpose of this study was to investigate the efficiency of a Compound Parabolic Concentrator (CPC) equipped with a sun tracking system in the photolysis of carbamazepine as a refractory organic compound. The natural sunlight experiments were accomplished during the period May–July 2017 in Tehran, Iran. The intermediate by-products of the process of solar photodegradation of carbamazepine (CBZ) were characterized using LC–MS. The results showed that increasing the reactor temperature did not significantly change CBZ degradation efficiency. However, the solution pH played a comparatively important role in CBZ solar photo degradation: removal efficiency increased considerably with pH from about 49% at pH 7 to almost 61% at pH 9. According to our findings, using a CPC reactor equipped with a sun tracker system promotes the solar photo-transformation rate of CBZ by 2-3 fold. In addition, LC/MS analysis showed that eight main intermediates were formed in the treated solution after solar photodegradation of CBZ. Therefore, complete mineralization of CBZ was not accomplished.

Degradation of 4-nonylphenol in marine sediments by persulfate over magnetically modified biochars

In this study, an environmentally friendly and economically viable bamboo biochar (BB) was modified by Fe₃O₄ and was applied for the treatment of real river sediments containing the endocrine disruptor chemical (EDC) 4-nonylphenol (4-NP). The microporosity of Fe₃O₄-BB was clearly observed from the N₂ adsorption isotherms. The catalytic performance of Fe₃O₄-BB is highly dependent on pH and the catalyst dosage. The degradation efficiency of 4-NP (85%) was achieved at pH 3.0 using an initial dosage of 3.33 g L^-1 Fe₃O₄-BB and 2.3 × 10^-5 M persulfate (PS) in a biochar-sediment system. The kinetic behavior of 4-NP degradation with catalysis can be accounted by using the Langmuir-Hinshelwood type kinetic model. The MTT assay results indicated that Fe₃O₄-BB has a low potent cytotoxic effect and is therefore suitable for application in remediation of contaminated sediment.

Zinc Porphyrin-Functionalized Fullerenes for the Sensitization of Titania as a Visible-Light Active Photocatalyst: River Waters and Wastewaters Remediation

Zinc porphyrin-functionalized fullerene [C60] derivatives have been synthesized and used to prepare titania-based composites. The electrochemical properties and HOMO and LUMO levels of the photosensitizers were determined by electrochemical measurements. Raman and IR techniques were used to study chemical groups present on the titania surface. Absorption properties of the composites were measured in the solid state by diffuse reflectance UV-Vis spectra (DRS). The zeta potential and aggregate sizes were determined using dynamic light scattering (DLS) and electrophoretic light scattering (ELS) techniques. Surface areas were estimated based on Brunauer–Emmett–Teller (BET) isotherms. The photocatalytic activity of the photocatalysts was tested using two model pollutants, phenol and methylene blue. The composite with the highest photocatalytic potential (1/TiO₂) was used for river and wastewater remediation. The photodegradation intermediates were identified by LC-UV/Vis-MS/MS techniques.

Aquatic organic matter: Classification and interaction with organic microcontaminants

Organic matter (OM) in aquatic system is originated from autochthonous and allochthonous natural sources as well as anthropogenic inputs, and can be found in dissolved, particulate or colloidal form. According to the type/composition, OM can be divided in non-humic substances (NHS) or humic substances (HS). The present review focuses on the main groups that constitute the NHS (carbohydrates, proteins, lipids, and lignin) and their role as chemical biomarkers, as well as the main characteristics of HS are presented. HS functions, properties and mechanisms are discussed, in addition to their association to the fate, bioavailability, and toxicity of organic microcontaminants in the aquatic systems. Despite the growing diversity and potential impacts of organic microcontaminants to the aquatic environment, limited information is available about their association with OM. A protective effect is, however, normally seen since the presence of OM (HS mainly) may reduce bioavailability and, consequently, the concentration of organic microcontaminants within the organism. It may also affect the toxicity by either absorbing ultraviolet radiation incidence and, then, reducing the formation of phototoxic compounds, or by increasing the oxygen reactive species and, thus, affecting the decomposition of natural and anthropogenic organic compounds. In addition, the outcome data is hard to compare since each study follows unique experimental protocols. The often use of commercial humic acid (Aldrich) as a generic source of OM in studies can also hinder comparisons since differences in composition makes this type of OM not representative of any aquatic environment. Thus, the current challenge is find out how this clear fragmentation can be overcome.

Effect of triclosan and its photolysis products on marine bacterium V. fischeri and freshwater alga R. subcapitata

The use of antibacterial agents in consumer products may lead to adverse effects in waters receiving treated wastewater. Triclosan is one of the antibacterial agents used widely in the world and its high usage leads to relatively high concentrations in wastewater effluents. In this study, the probable effect of triclosan in receiving waters was assessed using different organisms. The EC50 values were 668 ± 80 μg/L and 7.8 ± 0.1 μg/L, for Vibrio fischeri and Raphidocelis subcapitata, respectively, indicating the higher sensitivity of the alga. The toxicity of triclosan upon exposure to UV light decreased for both species, as suggested by the increase in EC50 values (1300 ± 50 μg/L and 8.7 ± 0.6 μg/L for V. fischeri and R. subcapitata, respectively). The effect of photolysis on toxicity reduction was higher for V. fischeri and the EC50 values were similar for direct and indirect photolysis. LC-MS/MS analysis of samples with and without UV exposure suggested a decrease in triclosan concentration as well as formation of photolysis byproducts upon photolysis.

Photodegradation of some brominated and phenolic micropollutants in raw hospital wastewater with CeO2 and TiO2 nanoparticles

In this study, the degradations of 2,3,4,5,6-pentabromotoluene (PBT), 2,3,4,5,6-pentabromoethyl benzene (PBEB), triclosan (TCS) and gemfibrozil (GFZ) in raw hospital wastewater were investigated with cerium (IV) oxide and titanium (IV) oxide nanoparticles considering the mechanisms of adsorption, photolysis, and photocatalysis with UV-C lamps. The effects of nano-CeO₂ and nano-TiO₂ concentrations, irradiation times, UV light powers and hospital wastewater pH on the photodegradation yields of micropollutants namely PBT, PBEB, TCS and GFZ were investigated throughout photocatalysis. The nano-TiO₂ produced had an anatase phase with crystalline shape with a surface area of 205 m² g^-1 and an average size of 11.50 nm. The CeO₂ nanoparticles had a spherical shape with a higher surface area (302 m² g^-1) than that of TiO₂ and a lower average size (8.11 nm). It was found that the removals of PBT, PBEB, TCS and GFZ with adsorption (5.7%-17.1%) and photolysis (9.0%-15.9%) were not significant for both nanoparticles. The photodegradation of PBT (92%), PBEB (90%), TCS (97%) and GFZ (95%) with nano-CeO₂ gave better results than nano-TiO₂ (90%, 87%, 94% and 93% for PBT, PBEB, TCS and GFZ, respectively) under optimum experimental conditions (0.50 g L^-1 nano-CeO_2, 45 min irradiation time, 25 °C temperature, pH = 8.50, 210 W UV light power). Both nanoparticles were reused effectively after photo-removals of the micropollutants from the hospital wastewater. The lowest photodegradation yields were 80%, 78%, 75% and 74% for TCS, GFZ, PBT and PBEB, respectively, with nano-TiO₂ after six sequential treatments. The lowest photodegradation yields were 86%, 83%, 80% and 79% for the same micropollutants, respectively, with nano-CeO₂ after six sequential treatments. The cost to treat 1 m³ raw hospital wastewater were 8.70 € and 2.28 €, for the photocatalytic treatments with nano-TiO₂ and nano-CeO₂, respectively.

Direct and indirect photolysis of seven micropollutants in secondary effluent from a wastewater lagoon

The photodegradation of seven micropollutants commonly found in municipal wastewater, namely caffeine, carbamazepine, diuron, simazine, sulfamethoxazole, triclosan and 2,4-D, was investigated in pure water and secondary effluent to understand the direct and indirect photolysis of these compounds under natural sunlight irradiation. Sulfamethoxazole and triclosan were readily photodegraded with half-lives of 5.8 and 1.8 h, respectively, whilst the others were relatively resistant towards sunlight irradiation. Enhanced degradation was observed in secondary effluent compared with in the pure water matrix for all compounds, except for triclosan. It was confirmed that hydroxyl radicals played an important role in the photodegradation of the micropollutants while singlet oxygen may also play a role. The contribution of hydroxyl radical to the overall degradation of the five compounds that were resistant to direct sunlight accounted for 32%-70%. The impact of humic acid and nitrate, two known photosensitisers and wastewater components, on the photodegradation of the seven micropollutants in pure water was investigated under simulated solar radiation. The presence of nitrate promoted the photochemical loss of all seven micropollutants, however, humic acid caused promotion or inhibition, depending on the characteristics of the micropollutant. Humic acid enhanced the photolytic degradation of caffeine, sulfamethoxazole and diuron, while it hindered the photodegradation of the other four compounds by absorbing the available irradiation energy and/or reforming the parent compound. Furthermore, it was shown that there was only a small increase (up to 15%) in photodegradation of the compounds at 25 °C compared with that at 10 °C in the simulated system.

Triclosan exposure, transformation, and human health effects

Triclosan (TCS) is an antimicrobial used so ubiquitously that 75% of the US population is likely exposed to this compound via consumer goods and personal care products. In September 2016, TCS was banned from soap products following the risk assessment by the US Food and Drug Administration (FDA). However, TCS still remains, at high concentrations, in other personal care products such as toothpaste, mouthwash, hand sanitizer, and surgical soaps. TCS is readily absorbed into human skin and oral mucosa and found in various human tissues and fluids. The aim of this review was to describe TCS exposure routes and levels as well as metabolism and transformation processes. The burgeoning literature on human health effects associated with TCS exposure, such as reproductive problems, was also summarized.

The role of Fe(III) on phosphate released during the photo-decomposition of organic phosphorus in deionized and natural waters

The photo-decomposition of organic phosphorus is an important route for the phosphorus cycle by which phosphate is regenerated in the aquatic environment. In this study, the role of Fe3+ as a natural photosensitizer toward the decomposition of organic phosphorus to release phosphate was examined in deionized and natural waters under UV and sunlight irradiation using glyphosate as the organic phosphorus model. The results showed that the concentration of glyphosate decreased with irradiation time in the Fe3+/UV and Fe3+/sunlight systems and TOC gradually decreased, which confirmed that glyphosate was degraded by Fe3+. The amount of phosphate released from the photo-decomposition of glyphosate was higher in the presence of Fe3+ than that of the control experiment under UV and sunlight irradiation conditions, and the generation rate of phosphate also increased with increasing Fe3+concentrations. The formation of hydroxyl radicals (·OH) in the Fe3+/UV and Fe3+/sunlight systems was identified according to the photoluminescence spectra (PL) using coumarin as the trapping molecule, and the steady-state concentrations of ·OH for the Fe3+/UV and Fe3+/sunlight systems were 1.06 × 10-14 M and 0.09 × 10-14 M, respectively. When natural water was spiked with glyphosate and Fe3+, the phosphate that was released in the Fe3+ was higher than that of the control, and the phosphate that was released was inhibited when isopropanol was added to the reaction. All of these results demonstrate that the photochemical activity of Fe3+ has significantly impact in the release of phosphate from the photo-decomposition of organic phosphorus.

Photodegradation of the novel fungicide fluopyram in aqueous solution: kinetics, transformation products, and toxicity evolvement

The aqueous photodegradation of fluopyram was investigated under UV light (λ ≥ 200 nm) and simulated sunlight irradiation (λ ≥ 290 nm). The effect of solution pH, fulvic acids (FA), nitrate (NO3 (-)), Fe (III) ions, and titanium dioxide (TiO2) on direct photolysis of fluopyram was explored. The results showed that fluopyram photodegradation was faster in neutral solution than that in acidic and alkaline solutions. The presence of FA, NO3 (-), Fe (III), and TiO2 slightly affected the photodegradation of fluopyram under UV irradiation, whereas the photodegradation rates of fluopyram with 5 mg L(-1) Fe (III) and 500 mg L(-1) TiO2 were about 7-fold and 13-fold faster than that without Fe (III) and TiO2 under simulated sunlight irradiation, respectively. Three typical products for direct photolysis of fluopyram have been isolated and characterized by liquid chromatography tandem mass spectrometry. These products resulted from the intramolecular elimination of HCl, hydroxyl-substitution, and hydrogen extraction. Based on the identified transformation products and evolution profile, a plausible degradation pathway for the direct photolysis of fluopyram in aqueous solution was proposed. In addition, acute toxicity assays using the Vibrio fischeri bacteria test indicated that the transformation products were more toxic than the parent compound.

Triclosan in water, implications for human and environmental health

Triclosan (TCS) is a broad spectrum antibacterial agent present as an active ingredient in some personal care products such as soaps, toothpastes and sterilizers. It is an endocrine disrupting compound and its increasing presence in water resources as well as in biosolid-amended soils used in farming, its potential for bioaccumulation in fatty tissues and toxicity in aquatic organisms are a cause for concern to human and environmental health. TCS has also been detected in blood, breast milk, urine and nails of humans. The significance of this is not precisely understood. Data on its bioaccumulation in humans are also lacking. Cell based studies however showed that TCS is a pro-oxidant and may be cytotoxic via a number of mechanisms. Uncoupling of oxidative phosphorylation appears to be prevailing as a toxicity mechanism though the compound's role in apoptosis has been cited. TCS is not known to be carcinogenic per se in vitro but has been reported to promote tumourigenesis in the presence of a carcinogen, in mice. Recent laboratory reports appear to support the view that TCS oestrogenicity as well as its anti-oestrogenicity play significant role in cancer progression. Results from epidemiological studies on the effect of TCS on human health have implicated the compound as responsible for certain allergies and reproductive defects. Its presence in chlorinated water also raises toxicity concern for humans as carcinogenic metabolites such as chlorophenols may be generated in the presence of the residual chlorine. In this paper, we carried out a detailed overview of TCS pollution and the implications for human and environmental health.

The mechanism study of efficient degradation of hydrophobic nonylphenol in solution by a chemical-free technology of sonophotolysis

Nonylphenol is a hydrophobic endocrine disrupting compound, which can inhibit the growth of sewage bacteria in biological processes. This study investigated the degradation of 4-n-nonylphenol (NP) in water by a chemical-free technology of sonophotolysis with emphasis on the impacts of several important parameters, including light intensity, solution pH, two commonly seen inorganic ions (i.e. NO3(-) and HCO3(-)), and principally on the examination of degradation mechanisms. It was found that, solution pH could significantly influence both NP degradation efficiency and the synergistic effect of sonophotolytic process, where higher synergistic effect was obtained at more acidic condition. In addition, the presence of NO3(-) accelerated NP degradation by both acting as a photosensitizer and providing NO2˙ radicals, while HCO3(-) had little effect on NP degradation. Identification of intermediates of NP degradation indicated that NP sonophotolysis was mainly initiated by the formation of hydroxy-NP, and a new intermediate di-hydroxy-NP was identified for the first time ever in this study. Through thermodynamic analysis, results indicated that both ortho- and meta-hydroxy-NP species can coexist in the solution but the ortho-4-NBZQ (4-nonyl-benzoquinone) is dominant. In addition, the mechanism of ortho-hydroxy-NP formation was suggested by the addition of HO˙ and H˙ radicals.

Bisphenol A, nonylphenols, benzophenones, and benzotriazoles in soils, groundwater, surface water, sediments, and food: a review

Contaminants of emerging concern (CECs) are not commonly monitored in the environment, but they can enter the environment from a variety of sources. The most worrying consequence of their wide use and environmental diffusion is the increase in the possible exposure pathways for humans. Moreover, knowledge of their behavior in the environment, toxicity, and biological effects is limited or not available for most CECs. The aim of this work is to edit the state of the art on few selected CECs having the potential to enter the soil and aquatic systems and cause adverse effects in humans, wildlife, and the environment: bisphenol A (BPA), nonylphenol (NP), benzophenones (BPs), and benzotriazole (BT). Some reviews are already available on BPA and NP, reporting about their behavior in surface water and sediments, but scarce and scattered information is available about their presence in soil and groundwater. Only a few studies are available about BPs and BT in the environment, in particular in soil and groundwater. This work summarizes the information available in the literature about the incidence and behavior of these compounds in the different environmental matrices and food. In particular, the review focuses on the physical-chemical properties, the environmental fate, the major degradation byproducts, and the environmental evidence of the selected CECs.

Sonoelectrochemical degradation of triclosan in water

The sonoelectrochemical degradation of triclosan in aqueous solutions with high-frequency ultrasound (850kHz) and various electrodes was investigated. Diamond coated niobium electrode showed the best results and was used as standard electrode, leading to effective degradation and positive synergistic effect. The influence of different parameters on the degradation degree and energy efficiency were evaluated and favorable reaction conditions were found. It could be shown that 92% of triclosan (1mgL(-1) aqueous solution) was degraded within 15min, following pseudo-first order kinetics.

Neurodevelopmental and behavioral effects of nonylphenol exposure during gestational and breastfeeding period on F1 rats

Nonylphenols (NP) are endocrine-disruptors known to be widely present in our environment. This study evaluated the effects of 4-n-NP on neurobehavioral development and memory capacity after perinatal exposure on the offspring rats. Dams were gavaged with 4-n-NP (0, 50 and 200mg/kg/day) from gestational day 5 to postnatal day (PND) 21. Dams exposed to the higher dose lost weight during gestation and had a longer gestational duration. Juvenile female pups of the 200mg 4-n-NP/kg/day group were lighter. Their thyroid somatic index (TSI) was also affected. For male pups, a decrease of TSI at weaning for the 200mg 4-n-NP/kg/day group and an increase of GSI for the 50mg 4-n-NP/kg/day group were observed. Physical maturation (incisives and eyes) were likewise affected. In open field (OF) tests, females were more active than males. In the first OF (PND 36), a treatment effect was observed only for males, particularly for the high dose group, which became as active as females. The second OF (PND 71) showed few differences between groups (treated vs control), the gender difference whatever the dose was not abolished. In the Morris Water Maze test, the study of the first 30s showed that females (200mg/kg/day) were mainly affected. Their performances were improved by 4-n-NP. These effects were particularly important for the first short-term memory test and observed to a lesser extent in the second evaluation of the long-term memory (PND 69). These data showed that perinatal 4-n-NP exposure induced behavioral and neuro-developmental impairments from 50mg/kg/day.