Assessment of Nanopollution from Commercial Products in Water Environments

Catching nano: Evaluating the fate and behaviour of nano-TiO2 in swimming pools through dynamic simulation modelling

Engineered titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreens widely used by swimmers in aquatic settings have raised concerns about their potential adverse impact on ecosystems and human health due to their small size and unique physicochemical properties. Therefore, this research paper aims to investigate the fate and behaviour of nano-TiO2 from sunscreens in swimming pools using System Dynamics Modelling. The study developed a dynamic simulation model that considers various factors, including weather conditions, sunscreen and pool usage behaviour, filtration efficacy, pool maintenance, water chemistry, pool chemicals, and TiO2 concentration levels, which can affect exposure levels for different scenarios. The study considered non-linear interdependent relationships, feedback structures, and temporal changes and dealt with parameter uncertainties through Monte Carlo analyses. The results reveal that the regular use of sunscreen leads to nano-TiO2 concentrations ranging from 0.001 to 0.05 mg/L within a year, reflecting seasonal and pool usage variations. The study also found that changes in the weight percentage of TiO2 in the sunscreen formulation and the filtration duration per day are the most sensitive factors affecting TiO2 concentrations. Scenario analyses exploring different nano-TiO2 removal strategies suggested that one daily turnover is necessary for sufficient removal. Regular manual pool maintenance and monthly use of a pool clarifier are recommended for enhanced and accelerated removal without substantial additional costs. The study is novel in its integrated approach, combining empirical work with dynamic simulations, resulting in a novel approach to model the environmental fate and behaviour of nano-TiO2. The study makes important methodological contributions to the field and has initiated an interdisciplinary collaboration to create more accurate models. This study is of great significance as it presents a pioneering analysis of the impact of sunscreen properties, user behaviour, and environmental stressors on the fate and behaviour of nano-TiO2 in swimming pools.

Neurotoxicity and Oxidative Stress Development in Adult Atya lanipes Shrimp Exposed to Titanium Dioxide Nanoparticles

Titanium dioxide is a type of nanoparticle that is composed of one titanium atom and two oxygen atoms. One of its physicochemical activities is photolysis, which produces different reactive oxygen species (ROS). Atya lanipes shrimp affect detrital processing and illustrate the potential importance of diversity and nutrient availability to the rest of the food web. It is essential in removing sediments, which have an important role in preventing eutrophication. This study aimed to determine the toxic effect of changes in behavior and levels of oxidative stress due to exposure to titanium dioxide nanoparticles in Atya lanipes and to determine the effective concentration (EC50) for behavioral variables. The concentrations of TiO2 NPs tested were 0.0, 0.50, 1.0, 2.0, and 3.0 mg/L with the positive controls given 100 µg/L of titanium and 3.0 mg/L of TiO2 NPs ± 100 µg/L of titanium. After 24 h of exposure, significant hypoactivity was documented. The EC50 was determined to be a concentration of 0.14 mg/L. After the exposure to 10 mg/L of TiO2 NPs, oxidative stress in gastrointestinal and nervous tissues was documented. The toxic effects of this emerging aquatic pollutant in acute exposure conditions were characterized by sublethal effects such as behavior changes and oxidative stress.

Nanoparticles in the Environment and Nanotoxicology

Nanomaterials, including engineered nanoparticles and microplastics/nanoplastics, have attracted increasing concern as they might potentially release into the environment, leading to potential risks to ecosystems [...].

A BaTiO3/WS2 composite for piezo-photocatalytic persulfate activation and ofloxacin degradation

Piezoelectric fields can decrease the recombination rate of photogenerated electrons and holes in semiconductors and therewith increase their photocatalytic activities. Here, a BaTiO₃/WS₂ composite is synthesized and characterized, which combines piezoelectric BaTiO₃ nanofibers and WS₂ nanosheets. The piezo-photocatalytic effect of the composite on the persulfate activation is studied by monitoring Ofloxacin (OFL) degradation efficiency. Under mechanical forces, LED lamp irradiation, and the addition of 10 mM persulfate, the OFL degradation efficiency reaches ~90% within 75 min, which is higher than efficiencies obtained for individual BaTiO₃, WS₂, or TiO₃, widely used photocatalysts in the field of water treatment. The boosted degradation efficiency can be ascribed to the promotion of charge carrier separation, resulting from the synergetic effect of the heterostructure and the piezoelectric field induced by the vibration. Moreover, the prepared composite displays good stability over five successive cycles of the degradation process. GC-MS analysis is used to survey the degradation pathway of OFL during the degradation process. Our results offer insight into strategies for preparing highly effective piezo-photocatalysts in the field of water purification.

Mapping the Complex Journey of Swimming Pool Contaminants: A Multi-Method Systems Approach

Swimming pool owners worldwide face the challenging task of keeping their pool water balanced and free from contaminants. However, swimming pool water (SPW) quality management is complex with the countless processes and interactions of interlinked system variables. For example, contamination with sunscreen residues is inevitable as users apply sunscreen to protect their skin from damaging ultraviolet (UV) radiation. Nanoparticulate titanium dioxide (nano-TiO2) is one such residues that have received criticism due to potential human health and environmental risks. Despite ongoing research studies, management strategies of nano-TiO2 in swimming pools are still limited. Therefore, this paper focuses on developing a multi-method approach for identifying and understanding interdependencies between TiO2 particles and an aquatic environment such as a swimming pool. Given the complexity of the system to be assessed, the authors utilise a systems approach by integrating cross-matrix multiplication (MICMAC) and Systems Thinking techniques. The developed conceptual model visually depicts the complex system, which provides users with a basic understanding of swimming pool chemistry, displaying the numerous cause-and-effect relationships and enabling users to identify leverage points that can effectively change the dynamics of the system. Such systems-level understanding, and actions will help to manage nano-TiO2 levels in an efficient manner. The novelty of this paper is the proposed methodology, which uses a systems approach to conceptualise the complex interactions of contaminants in swimming pools and important pathways to elevated contaminant levels.

Following the Occurrence and Origin of Titanium Dioxide Nanoparticles in the Sava River by Single Particle ICP-MS

Titanium dioxide nanoparticles (TiO2NPs) are widely produced and used NPs in different applications. To evaluate the risk from anthropogenic TiO2NPs, more information is needed on their occurrence in the environment. For the first time, this study reports the levels of TiO2NPs in waters and sediments at selected sampling sites along the Sava River using inductively coupled plasma mass spectrometry in single particle mode (spICP-MS). The highest concentrations of TiO2NPs were determined in river water at Vrhovo (VRH), Jasenovac (JAS), and Slavonski Brod (SLB) sampling locations impacted by urban, agricultural, and/or industrial activities, suggesting that these NPs are likely of anthropogenic origin. The results further showed that hydrological conditions and sediment composition significantly influence the levels of TiO2NPs in river water at most locations. Moreover, the Ti/Al elemental concentration ratios of NPs in water and sediments at JAS were higher than the natural background ratios, further confirming their anthropogenic origin. The outcome of this study provides first information on the presence of (anthropogenic) TiO2NPs in different environmental compartments of the Sava River, contributing to more reliable risk assessments and better regulation of TiO2NPs emissions in the future.

Aquatic Toxicity Effects and Risk Assessment of 'Form Specific' Product-Released Engineered Nanomaterials

The study investigated the toxicity effects of 'form specific' engineered nanomaterials (ENMs) and ions released from nano-enabled products (NEPs), namely sunscreens, sanitisers, body creams and socks on Pseudokirchneriella subcapitata, Spirodela polyrhiza, and Daphnia magna. Additionally, risk estimation emanating from the exposures was undertaken. The ENMs and the ions released from the products both contributed to the effects to varying extents, with neither being a uniform principal toxicity agent across the exposures; however, the effects were either synergistic or antagonistic. D. magna and S. polyrhiza were the most sensitive and least sensitive test organisms, respectively. The most toxic effects were from ENMs and ions released from sanitisers and sunscreens, whereas body creams and sock counterparts caused negligible effects. The internalisation of the ENMs from the sunscreens could not be established; only adsorption on the biota was evident. It was established that ENMs and ions released from products pose no imminent risk to ecosystems; instead, small to significant adverse effects are expected in the worst-case exposure scenario. The study demonstrates that while ENMs from products may not be considered to pose an imminent risk, increasing nanotechnology commercialization may increase their environmental exposure and risk potential; therefore, priority exposure cases need to be examined.

Aquatic Environment Exposure and Toxicity of Engineered Nanomaterials Released from Nano-Enabled Products: Current Status and Data Needs

Rapid commercialisation of nano-enabled products (NEPs) elevates the potential environmental release of engineered nanomaterials (ENMs) along the product life cycle. The current review examined the state of the art literature on aquatic environment exposure and ecotoxicity of product released (PR) engineered nanomaterials (PR-ENMs). Additionally, the data obtained were applied to estimate the risk posed by PR-ENMs to various trophic levels of aquatic biota as a means of identifying priority NEPs cases that may require attention with regards to examining environmental implications. Overall, the PR-ENMs are predominantly associated with the matrix of the respective NEPs, a factor that often hinders proper isolation of nano-driven toxicity effects. Nevertheless, some studies have attributed the toxicity basis of observed adverse effects to a combination of the released ions, ENMs and other components of NEPs. Notwithstanding the limitation of current ecotoxicology data limitations, the risk estimated herein points to an elevated risk towards fish arising from fabrics' PR-nAg, and the considerable potential effects from sunscreens' PR-nZnO and PR-nTiO2 to algae, echinoderms, and crustaceans (PR-nZnO), whereas PR-nTiO2 poses no significant risk to echinoderms. Considering that the current data limitations will not be overcome immediately, we recommend the careful application of similar risk estimation to isolate/prioritise cases of NEPs for detailed characterisation of ENMs' release and effects in aquatic environments.