Lung-deposited surface area deposition of airborne nanoparticles in different environments

Airborne nanoparticles (<100nm) are the smallest fraction of particulate matter, which can penetrate deep into the lungs, and have more severe health impacts than their larger counterparts. Nanoparticles are often measured in terms of their particle number concentration or size distribution, but their adverse effects on public health are better correlated with their lung deposited surface area (LDSA) dose. There can however be a large variation between measurements of LDSA performed by different instruments and further research is required including the evaluation of the uncertainty of measurements.

This research will focus on the measuring LDSA of airborne nanoparticles in a more robust manner. Through monitoring in real-world situations using commercially-available instruments and low-cost sensors, and modelling, this research will develop a framework to estimate the LSDA of nanoparticles under varied environmental conditions, and fully defining the uncertainty of these measurements.

The expected outputs include a LSDA framework in the form of a tool and 3-4 open-access research publications to build a better understanding of airborne nanoparticle doses in various outdoor and indoor environments. The results of the research are also expected to contribute to the European standardisation committee (CEN TC 264/WG 32) that is developing a Technical Specification for determining the LDSA in ambient air using a diffusion charger-based aerosol monitor.

The 4-year EPSRC i-CASE PhD project will commence on 1 October 2022 and will be supervised by Professor Prashant Kumar, who is a founding Director of the Global Centre for Clean Air Research (GCARE) and co-supervised by Dr Andrew Brown (NPL). The candidate will have the opportunity to closely work with the diverse and multidisciplinary GCARE team and collaborate with various ongoing projects and beyond. They will work with the NPL and relevant GCARE collaborators, and will be an active member of the Guildford Living Lab.

GCARE has a multidisciplinary team where researchers from all backgrounds are most welcome. This project will be suitable for a student with a degree in science (atmospheric, physics, chemistry, mathematics, geoscience or material science), engineering (environmental, civil, mechanical, chemical, computer), or a closely related environmental/physical science discipline. Some experience of physicochemical characterisation of particles and data analysis would be extremely useful.

English language requirements

If English is not the first language, IELTS 6.5 or above (or equivalent) is required, with no sub-test score less than 6.

GCARE is a multidisciplinary centre that was founded and directed by Professor Kumar. Its research is supported through a wide range of UKRI (e.g., NERC, EPSRC, ESRC, Innovate UK), H2020, industrial and international (e.g., FAPESP Brazil, QNRF Qatar) grants. With the mission to realise ‘clean air for all’, GCARE’s Air Quality Lab is well-equipped with a wide range of experimental facilities/equipment (e.g. ENVILUTION® chamber for sensor evaluation; portable PM and gaseous measurement equipment) and large body of research developed in the topic area to support the advertised project.

In addition, NPL has an advanced set of exposure chambers, besides field facilities, and leading expertise in the sensor area for evaluating the performance of the LCSs. These capabilities will be employed to support sensor validation measurements of CO₂, VOCs, relative, humidity, temperature and aerosols The facilities will be available to the student to characterise the performance of the sensor system being developed to enable limitations to be identified and addressed under controlled conditions. In addition, NPL’s technical contribution to expert committees such as Defra’s AQEG and the standardisation activities being carried out within CEN through the development of a Technical Specification for sensors, will enable the underpinning metrology to be applied to the system and methods being developed and to establish measurement uncertainty. Further information can be found on the GCARE website.