Air Particulates and XRF Laboratory
Our research into the composition and sources of air particulate matter in New Zealand helps us to understand human health effects and better manage air quality
We track changes in the sources contributing to air pollution over time and this information is used by government, regulatory authorities and industry to develop policies, measure the effectiveness of regulation and determine the impact of technology
Our Expertise
GNS Science has been researching the composition and sources of air particulate matter in New Zealand and overseas for over 20 years. Our research contributes to a global partnership programme run by the International Atomic Energy Agency (IAEA), which uses nuclear analytical techniques for environmental research.
The composition of Air Particulate Matter (APM) is crucial to identifying the contributions from both anthropogenic (human-created) and natural sources. The determination of particle composition is determined at GNS Science by Ion Beam Analysis and other analytical methods, including X-Ray Fluorescence (XRF) spectroscopy.
Trends in PM concentration and composition provides us with information that can be related to:
- Health impacts
- Source emissions and changes over time
- The effects of technological improvements
- Meteorological and climatic variability
- The effectiveness of policy interventions
- The impact of macro-economic factors
Our research helps to:
- understand human health effects (particle size and composition)
- manage air quality (sources and source contributions to total PM)
- measure changes over time (trends and step changes)
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Did you know ?
Air particulate matter is a recognised health and environmental hazard, with two-thirds of New Zealanders living in urban areas that experience episodes of degraded air quality. Air pollution kills an estimated seven million people worldwide every year. WHO data shows that 9 out of 10 people breathe air containing high levels of pollutants.
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What is X-Ray fluorescence spectroscopy (XRF)?
X-Ray fluorescence spectroscopy (XRF) is used to measure elemental concentrations in PM2.5 and PM10-2.5 samples collected on filters. XRF measurements are carried out at the GNS Science XRF facility using a PANalytical Epsilon 5 XRF spectrometer (PANalytical, the Netherlands). The Epsilon 5 is shown in Figure A1.1. XRF is a non-destructive and relatively rapid method for the elemental analysis of particulate matter samples.
XRF is based on the measurement of characteristic X-rays produced by the ejection of an inner shell electron from an atom in the sample, creating a vacancy in the inner atomic shell. A higher energy electron then drops into the lower energy orbital and releases a fluorescent X-ray to remove excess energy (Watson et al., 1999). The energy of the released X-ray is characteristic of the emitting element and the area of the fluorescent X‑ray peak (intensity of the peak) is proportional to the number of emitting atoms in the sample. From the intensity it is possible to calculate a specific element’s concentration by direct comparison with standards.
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Better knowledge, better policy, better air
GNS Science has been working closely with regional councils and unitary authorities for many years to determine airborne particle composition using state-of-the-art air filter and data analysis techniques to identify and quantify sources of APM within their polluted airsheds. We also work with overseas government agencies to provide both analytical services and planning advice.
Air particulate sources and activity inside school classrooms
Pilot study was undertaken to investigate the air quality in two primary school classrooms (ages 5 –9) over a three-week period, during August 2013. PM10 was monitored and sampled (hourly, 24/7) in two classrooms and outside of the Palmerston North School, New Zealand.
Arsenic concentration in air
Air monitoring work by GNS Science has found that atmospheric concentrations of arsenic, a known carcinogen, are above national and international guidelines in a number of New Zealand urban centres.
Our Equipment and techniques
The composition of Air Particulate Matter (APM) is determined at GNS Science by Ion Beam Analysis and (IBA) and X-ray fluorescence analysis (XRF), while light reflectance has been used to determine black carbon (BC) concentrations in all samples.
These are well established and internationally accepted methods for determining APM elemental composition.
IBA and XRF are both non-destructive analytical techniques and provide complimentary elemental results. XRF is more sensitive (lower limits of analytical detection) for heavier elements, particularly heavy metals, and IBA is more sensitive for lighter elements (Na to K) with the ability to determine hydrogen concentrations, a useful marker for hydrocarbon and secondary aerosol species.
We have a particular focus on tracking carbonaceous aerosol emitted by combustion processes as this source of pollution has both local air quality impacts while also contributing to global warming.
The resulting data is then analysed by multivariate techniques to provide information on the sources contributing to air pollution.
Our Clients
We are a trusted provider of research, knowledge and monitoring to New Zealand government agencies, and the work we do informs the development of government, national and regional policies, regulations and strategies.
Our fine particle air quality research underpins the National Environmental Standards for Air Quality as applied to local government authorities, who are required to manage air quality in their regions (local air sheds) to meet regulatory standards.
Our science also informs Ministry for the Environment, Ministry of Transport and Ministry of Health about sources of air pollution from the various sectors (domestic, transport, industry) for exposed populations.
We also have deep partnerships with a range of New Zealand research organisations, including universities, other CRI’s, and industry groups and our expertise is used internationally, by a range of government agencies and public and private organisations.
GNS Science is also the New Zealand representative on the International Atomic Energy Agencies (IAEA) Regional Cooperation Agreement air monitoring programme for Australasia and Southeast Asia.
Our Location
The Air Particulates and XRF Laboratory is located within our National Isotope Centre (NIC) in Gracefield, Wellington.
Meet the team
The Air Particulates and XRF Laboratory is led by Perry Davy, lead scientist, with support from Val Stucker.
NZ's clean air? – NZ's clean air? transcript
How we measure air quality at GNS Science.
NZ's clean air?
How we measure air quality at GNS Science