Environmental Nanoparticle Detection (ENPD): Development of a novel sensor to measure environmental nanoparticle exposure

This project aims to characterise and monitor the exposure to environmental manufactured nanoparticles (MNP) by developing a novel real-time sensor platform. A PhD student, working with staff at Cranfield University and Casella Measurement Ltd, will develop and evaluate a technology platform for MNP detection and quantification within environmental scenarios. MNPs are materials produced by industrial processes that have at least one dimension less than 100 nm. Their small size increases their mobility and increases their reactivity meaning that it is difficult to predict where or if MNPs are found in the environment. Whilst much of the environmental exposure of MNPs is likely to be in the form of accidental release (point source) or release at end of life through erosion or damage (diffuse source), they have also been used to remove pollutants from biological environments. MNPs can be carbon based (e.g. carbon nanotubes), metallic (e.g. silver NPs), or metal oxide (e.g. TiO2) and their physicochemical properties may be as important as their inherent chemical toxicity. The movement of MNPs within the environment is also a matter for concern. MNPs may increase the damage that may occur when they enter into a larger environment (ecosystem) either through their disposal into waste water, combustion and resultant release into the atmosphere, or into soil through ground fill sites. These ecosystems, full of smaller organisms, may also suffer detrimental effects when MNPs are introduced and the accumulation of particles may occur (e.g. as shown with mercury and DDT) which would then effect organisms further up the food chain. The use of MNPs has increased with advances in technology and manufacturing capabilities. Such materials exhibit increased reactivity due to their small size and increased surface area, however the environmental exposure to such materials is difficult to quantify due to the mobility of the particles, limitations of existing detectors, and the number of biological nano-scale particles pre-existing in the environment. The lack of exposure data, as well as limited data on the environmental impacts of such materials, currently restricts the assessment of risk that MNPs pose. This in turn increases the uncertainty surrounding the use and generation of MNPs in industry. The proposed studentship will yield a capability to acquire real time information on MNP activity in the environment at discrete sites or across broad areas through distributed sensor networks; a capability that is currency unavailable. The project will involve: 1. The identification and characterisation of MNPs that are likely to be within a defined environment and determine the influences on their mobility and surface interactions within the environmental system (conceptual model, based upon prior art within the area); 2. The design of most appropriate detector platform (shape, structure, porosity etc) and likely design limitations of the developed sensor (e.g. sensitivity, full scale deflection, selectivity); 3. The synthesis of appropriate MNPs detection media and evaluation of interaction with MNPs; 4. The construction of a prototype sensor and refinement of sensor technology using industry standard test protocols; and 5. The demonstration of the operation of sensor and end use for real-time monitoring of MNPs in controlled and real environments. Currently, the regulation of nanomaterials is covered by REACH (EC 1907/2006) which does not automatically distinguish between the bulk material characteristics and the nano-form. However, with the present industrial production of MNPs expected to increase to 10^19 tonnes/annum by 2015, the specific risk assessment of MNPs is starting to be of concern. There is still a considerable data gap in the direct environmental monitoring of MNPs. A real-time MNP monitoring capability will be key for successful implementation of such schemes without adding unnecessary burden to industry.