Relative Risk Ranking Research Articles

Improved safety and quality in intravascular brachytherapy: A multi-institutional study using failure modes and effects analysis

Highlight safety considerations in intravascular brachytherapy (IVBT) programs, provide relevant quality assurance (QA) and safety measures, and establish their effectiveness. Radiation oncologists, medical physicists, and cardiologists from three institutions performed a failure modes and effects analysis (FMEA) on the radiation delivery portion of IVBT. We identified 40 failure modes and rated the severity, occurrence, and detectability before and after consideration of safety practices. Risk priority numbers (RPN) and relative risk rankings were determined, and a sample QA safety checklist was developed. We developed a process map based on multi-institutional consensus. Highest-RPN failure modes were due to incorrect source train length, incorrect vessel diameter, and missing prior radiation history. Based on these, we proposed QA and safety measures: ten of which were not previously recommended. These measures improved occurrence and detectability: reducing the average RPN from 116 to 58 and median from 84 to 40. Importantly, the average RPN of the top 10% of failure modes reduced from 311 to 172. With QA considered, the highest risk failure modes were from contamination and incorrect source train length. We identified several high-risk failure modes in IVBT procedures and practical safety and QA measures to address them.

Predicting iron exceedance risk in drinking water distribution systems using machine learning

A Machine Learning approach has been developed to predict iron threshold exceedances in sub-regions of a drinking water distribution network from data collected the previous year. Models were trained using parameters informed by Self-Organising Map analysis based on ten years of water quality sampling data, pipe data and discolouration customer contacts from a UK network supplying over 2.3 million households. Twenty combinations of input parameters (network conditions) and three learning algorithms (Random Forests, Support Vector Machines and RUSBoost Trees) were tested. The best performing model was found to be Random Forests with input parameters of iron, turbidity, 3-day Heterotrophic Plate Counts, and high priority dead ends per District Metered Area. Different exceedance levels were tested and prediction accuracies of above 70% were achieved for UK regulatory concentration of 200 µg/L. Predicted probabilities per network sub-region were used to provide relative risk ranking to inform proactive management and investment decisions.

Estimating Movement Rates Between Eurasian and North American Birds That Are Vectors of Avian Influenza.

Avian influenza (AI) is a zoonotic disease that will likely be involved in future pandemics. Because waterbird movements are difficult to quantify, determining the host-specific risk of Eurasian-origin AI movements into North America is challenging. We estimated relative rates of movements, based on long-term evolutionary averages of gene flow, between Eurasian and North American waterbird populations to obtain bidirectional baseline rates of the intercontinental movements of these AI hosts. We used population genomics and coalescent-based demographic models to obtain these gene-flow-based movement estimates. Inferred rates of movement between these continental populations varies greatly among species. Within dabbling ducks, gene flow, relative to effective population size, varies from ∼3 to 24 individuals/generation between Eurasian and American wigeons (Mareca penelope and Mareca americana) to ∼100-300 individuals/generation between continental populations of northern pintails (Anas acuta). These are evolutionary long-term averages and provide a solid foundation for understanding the relative risks of each of these host species in potential intercontinental AI movements. We scale these values to census size for evaluation in that context. In addition to being AI hosts, many of these bird species are also important in the subsistence diets of Alaskans, increasing the risk of direct bird-to-human exposure to Eurasian-origin AI virus. We contrast species-specific rates of intercontinental movements with the importance of each species in Alaskan diets to understand the relative risk of these taxa to humans. Assuming roughly equivalent AI infection rates among ducks, greater scaup (Aythya marila), mallard (Anas platyrhynchos), and northern pintail (Anas acuta) were the top three species presenting the highest risks for intercontinental AI movement both within the natural system and through exposure to subsistence hunters. Improved data on AI infection rates in this region could further refine these relative risk assessments. These directly comparable, species-based intercontinental movement rates and relative risk rankings should help in modeling, monitoring, and mitigating the impacts of intercontinental host and AI movements.

Expert Knowledge Elicitation to assess the ability of matrices to transmit African swine fever virus

An Expert Knowledge Elicitation (EKE) was carried out regarding the possible contamination with African swine fever virus (ASFV) of products used as pig feed, their traded/imported volumes and their use on pig farms. In addition, the EKE also concerned empty vehicles returning to ASF-unaffected areas of the EU after delivering pigs to ASF-affected areas. The EKE was carried out by three independent groups of six to eight experts each. It was carried out in three steps: assessing the likelihood of contamination of a product at origin; assessing the likelihood of the contaminated product having enough viable virus to infect a pig (the infectious dose); and assessing the volume of trade or imports of each product from an affected area in either the EU or Eurasia which would be delivered to either a small-scale or large-scale pig farm. This report presents the results of the three elicitations. The results of the EKE have been used by the AHAW Panel in a pathway model to determine the likelihood of each product to introduce ASFV into non-affected areas of the EU based on relative risk ranking.

Relative Risk Ranking and Mapping Method Using Pollutant Release and Transfer Register Data

Objectives : According to Article 12 of the Chemical Control Act, the government must publish PRTR data to satisfy people’s right to know and reduce chemical emissions from chemical facilities. However, the database and annual reports are written in text and table that it’s difficult to understand at a glance. Risk scoring, ranking and mapping for easy understanding of Pollutant Release and Transfer Register data’s meaning and relative risk is the purpose of this study.Methods : Previous cases were investigated and analyzed. Also, many chemical screening methods were investigated to develop equation. A calculation formula was developed and the relative risk score for the top emissions substances and workplace was calculated using Gyeonggi Province PRTR data, which recorded the largest population, emissions, and number of emitters nationwide. The calculated points are graded and expressed on the map to easily grasp the information visually.Results and Discussion : It was confirmed at a glance that the distribution of the top emissions companies in province is concentrated in industrial parks. It was also confirmed that most of the sites with high risk scores were distributed along the West Coast. However, due to the lack of data available for risk calculation, many parts of the formula’s development process were simplified or replaced with generic data, which limited the quantitative accuracy of the risk score.Conclusions : The PRTR data was analyzed and processed to determine the relative risk ranking using a relatively simple formula. This allows us to express the meaning of the data more accurately. In particular, by expressing it on a map, it is possible to identify chemical substance emission sites that are of priority interest. It can be used to select priority targets for related implementing projects such as monitoring.

Risk of cardiovascular disease is driven by different combinations of environmental, medical and behavioral factors: Building a conceptual model for cumulative risk assessment

The U.S. Environmental Protection Agency (EPA) and National Institute of Environmental Health (NIEHS) held a workshop in 2012 to discuss principles and applications of cumulative risk assessment (CRA). The workshop organizers chose cardiovascular disease (CVD) as an example health outcome for which cumulative risk considerations could illuminate environmental and health management strategies. To guide discussions, we developed a series of conceptual models illustrating factors influencing CVD. The CVD conceptual model represents complex processes across varying space and time scales, different causal pathways, and multiple chemical and non-chemical stressors and factors. It includes causal influences of environmental exposures and lifestyle choices, in the context of genetics and medical factors. The representation of cumulative risk as a network of interrelated nodes and arrows helps define and organize the problem and available information, determine the scope and scale, and creates a platform for analysis. It provides an interface for discussing how different entities (e.g., environmental versus health-driven organizations) can work together on different parts of the problem, and facilitates relative risk ranking and management triage. Color coding is used to distinguish categories of stressors and possible oversight responsibility. This work informs guidelines for CRA planning and assessment of factor combinations affecting real-world risk.

Evaluation of the Comparative Risk of Aerosol Generation by Tracheal Intubation and Extubation in the Operating Theatre

Background: Transmission of SARS-CoV-2 by bioaerosols is of increasing concern. The enhanced levels of personal protective equipment (PPE) and preventative measures to attenuate viral transmission during aerosol generating procedures (AGPs) are having a huge impact on healthcare provision. There is no quantitative evidence on the number and size of airborne particles produced during AGPs to inform risk assessments. Methods: Real-time, high-resolution environmental monitoring was conducted in ultraclean ventilation operating theatres. Continuous sampling with an optical particle sizer allowed characterisation of aerosol generation within the airway management zone during endotracheal intubation and extubation for urgent orthopaedic trauma or neuro-surgery. Findings: Aerosol monitoring showed a very low background particle count allowing resolution of the transient airborne particle plume produced by reference volitional coughs (maximum concentration, 1,690±140 particles.L‑1,n=38). By comparison, endotracheal intubation including mask ventilation produced negligible quantities of aerosolised particles (maximum concentration, 80±10 L‑1,n=14, P<0·001 vs cough). Extubation, particularly when the patient coughed (~50% of extubations), produced a similar size distribution of aerosolised particles to the reference cough but contained a smaller number of particles (<25%). Interpretation: Using a volitional cough as a reference we have been able to produce a relative risk ranking for endotracheal intubation and extubation as potential AGPs. The study does not support the assignation of endotracheal intubation by direct laryngoscopy with manual ventilation as AGPs in routine anaesthetic practice. Extubation does generate aerosols, particularly if the patient coughs, but these are weaker than a standard reference cough and this challenges the designation of extubation as being a higher risk event for airborne vector transmission. These findings indicate the need for urgent reappraisal of guidance on PPE and patient management for AGPs. Funding: Supported by Elizabeth Blackwell Institute with funding from the University of Bristol’s alumni and friends. BRB is supported by the Natural Environment Research Council (NE/P018459/1). Declaration of Interest: None to declare Ethical Approval Statement: Not needed

A Risk Framework for Munitions and Explosives of Concern in Support of U.S. Offshore Wind Energy Development

AbstractMunitions and explosives of concern (MEC) in U.S. waters can present a risk to the development and operation of offshore wind energy resources. Therefore, the U.S. Bureau of Ocean Energy Management requires offshore wind energy developers to evaluate the risk MEC poses to the development, operation, and maintenance of offshore wind energy generation and transmission systems. This article describes an MEC risk management framework consisting of the following steps: (1) MEC hazard assessment, (2) MEC risk assessment, (3) MEC risk validation, and (4) MEC risk mitigation. The MEC hazard assessment involves historical research to identify MEC potentially present in the development area. The MEC risk assessment evaluates the development activities and provides a relative MEC risk ranking for those activities. The developer determines the acceptability of these risks, and any potentially unacceptable MEC risks undergo risk validation through field surveys. The developer then considers the tolerability of the validated risks and develops and implements an appropriate MEC risk mitigation strategy based on actual site conditions. A risk framework provides a structured method to plan and operationalize the identification, evaluation, and mitigation of MEC risk throughout the development, operation, and maintenance life cycle of an offshore wind energy generation and transmission project.

Risk-based structural integrity management for offshore jacket platforms

This paper presents a method for risk assessment and inspection plan development as part of the risk-based structural integrity management of offshore jacket platforms. The method provides a global risk assessment for the whole platform's structure and local risk assessment for the platform's structural components (e.g. tubular joints). The global risk assessment uses semi-quantitative or quantitative approaches depending on the available platform's data. The semi-quantitative method is used either at a high level to perform relative risk ranking of platforms in a fleet in order to identify the platforms most at risk and which require more inspection focus or a detailed risk analysis; or at the unit level to define inspection interval and general inspection requirements. The quantitative method involves either structural analysis results (e.g. reserve strength ratio) with a dedicated metocean hazard curve or structural reliability method; and it is used at the unit level only to define inspection interval and inspection requirements. The local risk assessment uses also semi-quantitative or quantitative approach. The semi-quantitative method is used to provide local risk ranking of the structural components of a platform, which allows, if required, local inspections' scope to be defined. The quantitative method involves a probabilistic fatigue method to define inspection plans for selected tubular joints subjected to fatigue and the failures of which are critical for the overall platform structure. The inspection strategy and program, developed by the method presented in this paper, are focused on the routine underwater inspections and are based on the recommended practice of the American Petroleum Institute for the structural integrity management of fixed offshore platforms. An example of application of the method is set out by showing the results of a project carried out by Bureau Veritas.

Publisher's note

Abstract This paper presents a method for risk assessment and inspection plan development as part of the risk-based structural integrity management of offshore jacket platforms. The method provides a global risk assessment for the whole platform's structure and local risk assessment for the platform's structural components (e.g. tubular joints). The global risk assessment uses semi-quantitative or quantitative approaches depending on the available platform's data. The semi-quantitative method is used either at a high level to perform relative risk ranking of platforms in a fleet in order to identify the platforms most at risk and which require more inspection focus or a detailed risk analysis; or at the unit level to define inspection interval and general inspection requirements. The quantitative method involves either structural analysis results (e.g. reserve strength ratio) with a dedicated metocean hazard curve or structural reliability method; and it is used at the unit level only to define inspection interval and inspection requirements. The local risk assessment uses also semi-quantitative or quantitative approach. The semi-quantitative method is used to provide local risk ranking of the structural components of a platform, which allows, if required, local inspections' scope to be defined. The quantitative method involves a probabilistic fatigue method to define inspection plans for selected tubular joints subjected to fatigue and the failures of which are critical for the overall platform structure. The inspection strategy and program, developed by the method presented in this paper, are focused on the routine underwater inspections and are based on the recommended practice of the American Petroleum Institute for the structural integrity management of fixed offshore platforms. An example of application of the method is set out by showing the results of a project carried out by Bureau Veritas.

The long and short of commodity tails and their relationship to Asian equity markets

We aim to determine if the relative tail risk of commodities remains consistent over time and whether there is association between commodity tail risk and Asian equity markets. We examine the tail risk of 24 commodities over a 12year period. Tail risk is measured using Conditional Value at Risk (CVaR), which measures volatility beyond a specified threshold. We classify tails for individual commodities as long and short based on their CVaR relative to the market. Overall, livestock commodities have the lowest CVaR risk, with some of the energy and metals commodities having the highest. However, the most interesting finding is that there is no consistency in relative tail risk rankings among commodities over time, and commodities having among the shortest tails in one period can have some of the longest in another period. Thus the relative tail risk of commodities changes significantly over time. We find that measured by CvaR, commodities generally have higher risk than Asian equities and that the relationship between equities and commodities is inconsistent in both strength and direction over time.

SIMONI (Smart Integrated Monitoring) as a novel bioanalytical strategy for water quality assessment: Part II-field feasibility survey.

Because it is impossible to chemically analyze all relevant micropollutants, the implementation of bioanalytical tools is essential to estimate ecological risks of chemical mixtures in regular water-monitoring programs. The first tier of the Smart Integrated Monitoring (SIMONI) strategy, which was described in part I, is based on the combination of passive sampling and bioanalytical measurements. Bioassay responses are compared with effect-based trigger values (EBT), and an overall SIMONI score on all bioassay data was designed to indicate environmental risks. The present study is focused on analyzing the feasibility of the hazard identification tier by evaluating results of 45 field campaigns at sites with different pollution profiles near the city of Amsterdam. A Daphnia assay was performed in situ, while silicon rubber or polar organic chemical integrative sampler (POCIS) extracts were tested with 4 nonspecific (daphnids, algae, bacteria, and cell culture) and 10 specific (9 Chemical Activated Luciferase Gene Expression [CALUX] assays and antibiotics scan) bioassays. Sensitivity analyses demonstrated the relevance of 2 classification variables in the SIMONI score formula on all bioanalytical data. The model indicated increased risks for the ecosystem at surface waters in greenhouse areas and undiluted wastewater-treatment plant (WWTP) effluents. The choice of testing specific bioassays on either polar or nonpolar passive sampling extracts is cost-effective and still provided meaningful insights on micropollutant risks. Statistical analyses revealed that the model provides a relevant overall impact assessment based on bioassay responses. Data analyses on the chemically determined mixture toxic pressure and bioanalytical methods provided similar insights in relative risk ranking of water bodies. The SIMONI combination of passive sampling and bioanalytical testing appears to be a feasible strategy to identify chemical hazards. Environ Toxicol Chem 2017;36:2400-2416. © 2017 SETAC.

Ecotoxicological Assessment of Phosphate Recyclates from Sewage Sludges

Sewage sludge contains valuable plant nutrients, especially phosphorus. But unfortunately, it also contains pollutants which are hazardous for the environment. Phosphorus recovery from sewage sludge and its agricultural valorisation in recycling fertilisers based or containing recovered phosphate provides opportunities to minimise negative environmental effects caused by direct sludge application or conventional fertilisation. For validation, crystallised (struvite) and thermally treated phosphate recyclates (PRs) were chemically analysed, ecotoxicologically assessed and compared with a conventional phosphate fertiliser (triple superphosphate (TSP)). Three test species covering the environmental compartments water, sediment and soil were applied to evaluate the acute toxic effects of the phosphate fertiliser samples in laboratory tests (Lemna minor, Gammarus fossarum, Eisenia fetida). The assessment and comparison showed that TSP was more toxic than the PRs at the higher tested concentrations, probably due to a higher water solubility and not to chemical composition. Higher concentrations of the crystallised PRs caused mostly a slightly higher negative effect on tested parameters of the duckweed and the freshwater amphipod than the thermally treated PRs. Agronomical relevant application amounts of all PRs and TSP (worst-case scenario) might not have an acute toxic effect on the soil invertebrates. The PRs might have minor effects on the growth of L. minor, and TSP might negatively affect the survival of the freshwater amphipods. Recovered phosphate-containing materials (PRs), in particular struvite, proved to be of high quality and low hazard in a relative risk ranking; thus, it could be one of the future alternatives of phosphorus fertilisation in agriculture.

Understanding forest fire patterns and risk in Nepal using remote sensing, geographic information system and historical fire data

Forest fire is one of the key drivers of forest degradation in Nepal. Most of the forest fires are human-induced and occur during the dry season, with ~89% occurring in March, April and May. The inaccessible mountainous terrain and narrow time window of occurrence complicate suppression efforts. In this paper, forest fire patterns are analysed based on historical fire incidence data to explore the spatial and temporal patterns of forest fires in Nepal. Three main factors are involved in the ignition and spread of forest fires, namely fuel availability, temperature and ignition potential. Using these factors a spatially distributed fire risk index was calculated for Nepal based on a linear model using weights and ratings. The input parameters for the risk assessment model were generated using remote sensing based land cover, temperature and active fire data, and topographic data. A relative risk ranking was also calculated for districts and village development committees (VDCs). In total, 18 out of 75 districts were found with high risk of forest fires. The district and VDC level fire risk ranking could be utilised by the Department of Forest for prioritisation, preparedness and resource allocation for fire control and mitigation.

Proposal for a risk banding framework for inhaled low aspect ratio nanoparticles based on physicochemical properties

We present a conceptual framework that can be used to assign risk bands to inhaled low aspect ratio nanoparticles starting from exposure bands assigned to a specific exposure situation. The framework mimics a basic physiological scheme that captures the essential mechanisms of fate and toxicity of inhaled nanoparticles and is composed of several models and rules that estimate the result of the following processes: the deposition of particles in the respiratory tract, their (de-)agglomeration, lung burden and clearance, their diffusion through the lung mucus layer, translocation and cellular uptake and local and systemic toxicity. Each model is based on a set of particle’s physicochemical properties, including the size and size distribution(s), the zeta potential (or net charge at a specific pH), the surface hydrophobicity or hydrophilicity, the conduction band energy (for metals, metal oxides, quantum dots, etc.) and the solubility at a specific pH. The framework takes the exposure bands as input and predicts, using the above-mentioned models, an internal dose band (module 1). Module 2 assigns a relative hazard ranking depending on the region of particle deposition in the respiratory tract, the likelihood of uptake and whether the toxicological effects are assumed to be local and/or systemic. By combining the results of Module 1 and 2, the framework provides a relative risk ranking.

PROMETHEE를 이용한 도시 하수관거시스템 침수위험순위 평가

In this study, Entropy method and PROMETHEE(Preference Ranking organization METHod for Enrichment Evaluations) which is one of the multi criteria decision making methods are applied to estimate the relative inundation risk ranking of the urban sewer systems. Then, the evaluation factors were selected considering two main items to estimate the inundation risk using Entropy and PROMETHEE. In the first item considering topographical and environmental factor, average elevation, average slope, width of area, population, density of conduit were selected as the detailed factors of first item which have influence of the overflow occurrence and damage scale in urban sewer system. And, the relative reliability of sewer network was considered as the second item which can quantify the inundation appearance. Then, the reliability is estimated considering the number of overflow nodes and overflow volume simultaneously. Therefore, the suggested inundation risk evaluation method can be used as the evaluation index for sewer networks and contribute to decision making for the sewer rehabilitation policy.

An index-based risk assessment model for hydrogen infrastructure

This study focuses on the development of a risk assessment model associated with the safety of a hydrogen infrastructure system. The safety of hydrogen infrastructure is one of the crucial pre-requisites for a sustainable economy and accordingly, its design should be made based upon the performance to investigate and evaluate the risks from or out of the required infrastructure. In order to support strategic decision-making for safe hydrogen infrastructure, this study proposes an appropriate index-based risk assessment model. The model evaluates the hydrogen infrastructure using the relative risk ranking of the hydrogen activities such as hydrogen production, storage and transportation, and the relative impact levels of regions. The relative risk rankings of the hydrogen activities are rated a quantitative risk analysis, whereas the relative impact level of regions is rated based on the regional characteristics such as population density. With consideration of regional characteristics, the proposed model makes it possible not only to assess the risks of processes and technologies associated with hydrogen but also to compare the relative safety levels of the hydrogen infrastructures made up with various hydrogen activities. In order to show the features and capabilities of the model, four future hydrogen infrastructure scenarios in Korea are examined in the study. The result shows that distributed production, and mass storage and transportation via liquefied hydrogen facility are relatively safer than centralized production, and compressed-gaseous hydrogen storage and transportation, respectively.

Qualitative Risk Assessment of the Acquisition of Meticillin-Resistant Staphylococcus aureus in Pet Dogs

This article presents a qualitative risk assessment of the acquisition of meticillin-resistant Staphylococcus aureus (MRSA) in pet dogs, representing an important first step in the exploration of risk of bidirectional MRSA transfer between dogs and humans. A conceptual model of the seven potential pathways for MRSA acquisition in a dog in any given 24-hour period was developed and the data available to populate that model were considered qualitatively. Humans were found to represent the most important source of MRSA for dogs in both community and veterinary hospital settings. The environment was found to be secondary to humans in terms of importance and other dogs less still. This study highlights some important methodological limitations of a technique that is heavily relied upon for qualitative risk assessments and applies a novel process, the use of relative risk ranking, to enable the generation of a defensible output using a matrix combination approach. Given the limitations of the prescribed methods as applied to the problem under consideration, further validation, or repudiation, of the findings contained herein is called for using a subsequent quantitative assessment.

A Relative Risk Ranking of Selected Substances on Canada's National Pollutant Release Inventory

ABSTRACT The National Pollutant Release Inventory (NPRI) provides pollutant release and transfer data from point sources to various media in the Canadian environment. While the inventory serves as Canada's community right-to-know program, the growing number of listed substances and reporting facilities makes it exceedingly difficult for the public to discern which substances are of greatest concern in their respective communities. A chemical's impact is best characterized when its environmental release data are combined with its toxicity and environmental fate properties. Presently, the NPRI does not provide a synthesis of this critical information and there is a need to provide more context with NPRI data to increase its usability. To help deliver this context, a relative risk ranking was compiled for a subset of NPRI substances using a modified Chemical Hazard and Evaluation Management Strategies (CHEMS-1) model. The model combines toxicity, chemical fate properties, and NPRI release data to yield a risk score for each substance. The resulting risk scores are ranked accordingly to provide a priority ranking of the substances. In addition to contextualizing the NPRI release data with hazard information, the ranking can also help set priorities for future risk assessment and evaluation by the Canadian government and scientific community. Limitations included the reliance on modelled data and default values to fill data gaps and uncertain reliability in reported NPRI data. In spite of its limitations, the CHEMS-1 model is a useful tool for prioritizing NPRI substances.

Identification of Risks in the Life Cycle of Nanotechnology‐Based Products

SummaryIn order to realize the projected market potential of nanotechnology, the environmental, health, and safety (EHS) uncertainties posed by a nano‐product (i.e., a nanotechnology‐enabled product) need to be characterized through the identification of risks and opportunities in early stages of product development. We present a methodology to identify risks from nano‐products using a scenario analysis approach that allows for expert elicitation on a set of preidentified use and disposal scenarios and what we have labeled “risk triggers” to obtain scores on their likelihood of occurrence and severity. Use and disposal scenarios describe product life‐cycle stages that could result in risk attributed to the nano‐product, whereas risk triggers are particular to nanoparticle properties. These are potential risks, as the risk assessment community is currently debating the specific risks attributed to nanotechnology. Through such a framework, our goal is to identify which products pose greater risks, where these risks occur in the product life cycle, and the impacts of these environmental risks on society. The comparison of risk triggers across nano‐products allows relative risk ranking on axes of exposure‐ and hazard‐related risk triggers. For the specific case of air fresheners, areas of acute risks resulted from bioavailability of nanoparticles in air release and water entrainment exposure scenarios; catalytic activity of nanoparticles in inhalation and air release exposure scenarios; the harmful effects due to the antibacterial property on useful bacteria particularly in susceptible populations; and, finally, risks from the lack of nanoparticle coating stability in air release scenarios.