NANOTECHNOLOGY SAFETY CONCERNS REVISITED

Risk characterization is the process of the qualitative/quantitative estimation of the probability of the occurrence and severity of known or potential adverse health effects in a given population based on hazard identification, hazard characterization and exposure assessment. The definition includes quantitative risk assessment, which emphasizes reliance on numerical expressions of risk, and also qualitative expressions of risk, as well as an indication of the attendant uncertainties. The introduction of nanostructured materials for biomedical and electronics applications opens tremendous opportunities for biomedical applications as therapeutic and diagnostic tools as well as in the fields of engineering, electronics, optics, consumer products, alternative energy, soil/water remediation, and others. However, very little is yet known about their potential to cause adverse effects once they are introduced into the organism—unintentionally or intentionally. The regulators are focussing their attention on the gaps in knowledge relating to the properties of NPs that might determine toxicity and in understanding the most appropriate ways both to measure this in the laboratory and to assess the real exposure in the workplace and for the consumer. Unsolved problems till remain the charcterization of the materials, the dosimetry, the transformation when included in a biological matrix, as well as which test protocol and to what extent could be applied.