Early Careers Group Meetup, London, June 2018

1. Griffin House
Market Street
Charlbury
Oxford OX7 3PJ
United Kingdom
Tel: (44) 1608 810110Dust and Air Quality Innovation and Expertise
Tel: +44 (0) 01608 810110 Web: www.dustscan.co.uk
What is in my dust?
Andrew Green
Senior Consultant – Air Quality and Exposure
07 June 2018

2. About Me
• Studied Environmental Science at University of
Portsmouth (2011-2014)
• Graduated with BSc First Class
• Joined DustScan later in 2014 as a Technical Assistant
• DustScan specialise in air quality and dust consultancy as
well as providing bespoke dust monitoring equipment
• Progressed over last 3.5 years to level of Senior
Consultant
• Previously attended IAQM meet-ups and wanted to get
involved

3. My role and technical responsibilities
• Air Quality Assessments for projects including industrial,
commercial and residential
• Workplace Monitoring and Assessments for exposure to
substances, including dust
• Project Proposals and Management
• Supervising analytical work and reviewing reports

4. What is Dust?
• It is widely accepted that dust is particles less than 75 µm
• Naturally occurring, caused by a number of processes
including abrasion, erosion and combustion
• Courser dust is responsible for loss of amenity
(Nuisance/disamenity)
• Particulate matter regarded as fine particles, categorised
by size fraction.
• PM10 - aerodynamic diameter less than 10 µm
• PM2.5 - aerodynamic diameter less than 2.5 µm

5. Objectives and Standards
• No Standards for nuisance dust but various guidance
(IAQM, EA) on recommended monitoring
• There is a case for further investigation into dust nuisance
and loss of amenity
• Environmental Standards included air quality objectives for
PM10 and target values for PM2.5
• Target values for some metals, including Pb, Cu and Ni
• Workplace (indoor) standards include all inhalable and all
respirable dust which are measured against workplace
exposure limits (WELs) set out by HSL in EH40/2005
• Other standards and objectives in different countries

6. Investigating Dust Sources
• What’s the reason for investigating? E.g. Occupational
concern, nuisance concern
• Understand background sources, local geology and soils
• Identify onsite activities that could produce dust
• Who/what are the receptors? E.g. Workers, businesses,
general public
• Consider control measures implemented and effectiveness
of mitigation
• Assess suitable method for monitoring and investigation

7. Methods of Dust Analysis
• Optical Light Microscopy: Visual interpretation using
different lighting conditions and high magnification
• Scanning Electron Microscopy: Higher magnification,
some chemical data available when coupled with energy
dispersive spectrometry
• X-Ray Diffraction: analysis on particle structure, used on
respirable samples for indentifying RCS
• Inductively Coupled Plasma – Mass Spectrometry:
Quantifies proportions of elemental composition

8. Case Study 1: Provenance of Warehouse
Dusts
• Forklift truck tyres: rubber dust
• Forklift truck brakes: metal
• Concrete floor: mineral dust including calcite (CaCO3) and
possible quartz (SiO2)
• Packaging, pallets and contents: cellulose fibres
• Large doors: dust from yard and external sources
• History of site: previous uses
• Diesel forklift trucks or HGVs: Diesel Engine Exhaust
Emissions (DEEE)

9. Case Study 1: Microscopy
Figure 1: Example of warehouse dust under reflected
light
Rubber
(tyre)
crumb
Blue pallet
fibre
Cementitio
us material
Cellulose
fibre
Metal
fragment

10. Case Study 1: SEM-EDS
Figure 2: SEM high resolution
image of warehouse dust
Figure 3: False-colour element maps showing
carbon (C), iron and aluminium (Fe, Al),
calcium and oxygen (Ca, O) and silicon and
oxygen (Si, O)

11. Case Study 2: Source of metals in PM10
• Previous study found elevated levels of certain elements
in PM10 samples, some metals above target values
• Metal foundry identified as potential source
• Installed directional and depositional dust monitors along
with gravimetric PM10 samplers
• SEM-EDS and ICP-MS used to investigate elemental
concentrations in alloys

12. Case Study 2: SEM-EDS
Figure 4: SEM image of PM10 filter

13. Case Study 2: SEM-EDS
2 4 6 8 10 12 14
keV
0.0
0.2
0.4
0.6
0.8
1.0
cps/eV
C
O
Si K
K
Fe
Fe
Mg
Na
N
Cl
Cl
Ca
Ca
Al
S
S
Ti
Ti
Ni
Ni
Zn
Zn
Cr
Cr
Cu
Cu
Figure 5: Energy Dispersive Spectrograph of PM10 filter

14. So...What’s in my house dust?
• Appling knowledge of dust sources, analysis through analytical
techniques including microscopy and SEM
• Mostly dead human skin cells: organic material
• Clothing fibres: fabric, cotton, wool
• Carpet fibres, flakes of paint, plasterboard (gypsum)
• Cellulose fibres from paper/cardboard/wood
• Other organic material from food, plants, invertebrate
• Material from outside: usually consists of minerals from local soils
and rocks
• Urban areas: can contain tyre rubber, exhaust condensate and
other road dusts
• Rural areas: can contain agricultural dust such as higher
proportions of organic fibres and pollen at certain times of the
year
• Extreme events e.g. Sahara dust, volcanic dust

15. Thank you for listening
• LinkedIn: www.linkedin.com/in/andrew-
green-1b422876/
• Website: www.dustscan.co.uk
• Email: andrewg@dustscan.co.uk