Step Of Risk Assessment Process Research Articles

Weight-of-evidence process for assessing human health risk of mixture of metal oxide nanoparticles and corresponding ions in aquatic matrices

This study proposed a framework to estimate health risks due to exposure of mixture of nanoparticles (NPs) from surface water, for the first time, as per authors’ best knowledge. The framework consisted of hazard identification, exposure assessment, dose-response assessment, risk characterization and risk management steps. Concentrations of mixture of NPs and associated ions were compiled and range of values were used for exposure estimation. The resulting concentrations of nanoparticle and metal ions in simulated digestive fluid were calculated and used to estimate exposure dose to digestive system organs during a hypothetical exposure of water during recreational activity. Exposure doses of different possible combinations of ZnO NP, CuO NP, Zn2+ and Cu2+ ions were considered. The ECHA weight-of- evidence framework was used for formulating hypotheses and collecting evidence for determining reference dose (RfD) and interaction parameter for estimating hazard interaction value (an index for risk) as per the USEPA modified weight-of-evidence method for estimating risks of binary NPs and ions. RfD values of CuO (0.0262 mg/kg/d) and ZnO NP (0.0315 mg/kg/d) were derived using information from rat-based oral toxicity studies and assumed values of uncertainty factors. The results showed that mixture of NPs under environmentally-relevant conditions do not pose any health risk. The uncertainty analysis indicated that ZnO + CuO + Zn + Cu ion suspension posed the highest risk. The switchover analysis indicated that NP concentration >0.207 mg/L resulted in risk estimate greater than 1 and pose risk. Although risk estimate was found to be smaller than 1 under the studied natural water condition, efforts should be made to continue monitoring mixture of NPs as a precautionary approach. More efforts are required to obtain data on (i)toxicity of mixture of NPs, (ii)their interaction effects, (iii)fractions of NPs reaching target organ in order to accurately predict risk. Potential benefit of this framework is in its usage for development of structure for estimating exposure risks due to mixture of NPs and ions from surface water. This can also be used to adopt methodology for gathering information on evidence required in different steps of risk assessment process, like obtaining RfD/uncertainty factor -related parameters in dose-response assessment step, deriving interaction and mixture toxicity-related parameters in risk estimation step.

Nanomaterials in Food - Prioritisation & Assessment.

Nanomaterials (NMs) are of significant economic interest and have a huge impact on many industries including the food industry. The main application in food industry includes food additives and food packaging. However, the effects of NMs on human health are highly discussed, as well as the need of harmonised analytical methods and risk assessment methodologies. In line with these discussions, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) has started in 2017 a 2‐year project focusing on NMs in food, to which the fellow was involved under the framework of the European Food Risk Assessment Fellowship Programme (EU‐FORA). This technical report contains a description of the working program, the aims and the activities to which the fellow was involved during this placement. The main aims of the programme were to be involved in different steps of risk assessment process, to improve knowledge regarding food process, analytical and toxicological methods and to learn how to conduct expert assessments. All aims were linked with different kind of activities. Gaining hands‐on experience on food risk assessment was achieved mainly by collecting occurrence data and performing exposure assessment calculations for the ‘of concern’ NMs, while scheduled visits to laboratories specialising in analytical methods of nanoparticles and toxicological studies helped to improve knowledge in these fields. Regular participation in the Working Group (GT) related to NMs in food and interaction with experts within ANSES facilitated the learning process of how to conduct collective expertise as well as to be further trained in risk assessment processes. Furthermore, apart from knowledge gained in risk assessment and NMs, the fellow was able to obtain transferable skills and knowledge that can be used to increase the scientific capacity of the fellow's home institute as well as to expand her scientific network, which could lead to collaboration opportunities in the future well beyond this fellowship.

Fuzzy Quantitative and Semi-Qualitative Risk Assessment in Projects

Before initiating a project, risks assessment, is a process that its importance has felt in past two decades and has taken a position in project activities. Project's managers apply risk assessment as a preventive method for highly possible risks having an unfavorable influence on project objectives. Risk assessment has implemented in three ways: qualitative, semi-qualitative (semi-qualitative) and quantitative. In this paper, the author reviews quantitative and semi-qualitative risk assessment methods in associated with fuzzy sets theory (FST). Moreover, considering three steps of risk assessment process, namely: definition and measurement of parameters, fuzzy inference and defuzzification, the author classified presented articles into three groups of giving opinion methods, assessment methods and defuzzification methods. It is avoided mentioning articles with same assessment methods in this paper. Although giving opinion methods and defuzzification methods have the potential to be worked on, late risk assessment surveys, demonstrate increasing attempt on developing comprehension and reality adjustment in project risk assessment methodologies.