Lower Hunter residents were concerned about the levels of
visible black dust in the lower Hunter region. The EPA commissioned a study to
examine the quantity, composition and likely sources of deposited dust. To
ensure that the views of the community were fully considered, the EPA
established a project reference group.
Key findings included
- dust deposition rates ranged from 0.5 to 1.1
grams per square metre per month (g/m2/month) and were below the
EPA’s annual criterion of 4 g/m2/month
- dust particle composition in the 12 dust
deposition samples comprised 17% black particles, contributing 0.09 to 0.19 g/m2/month
to annual average dust composition
- coal would contribute 0.05 to 0.11 g/m2/month
to annual average dust composition
Laboratory analysis revealed that the samples, visible to
the eye as black dust, were comprised of
- brown particles of soil or rock
- black particles of coal, soot and rubber
- lighter coloured particles of salt, ash, plant
and insect debris, alumina and paint
Dust particle composition in 72 samples averaged
- 69% soil, ranging from 40% to 90%
- 10% coal, ranging from 0% to 25 %
- 4% rubber, ranging from 0% to 20%
- 3% soot, ranging from 0% to 20%
- 14% other components, including salt, ash,
insect and plant debris, alumina and paint
The Lower Hunter Dust Deposition
Final Report (PDF 2MB) details sampling,
analysis and results from the Dust Deposition study.
Appendices A to E (PDF 6.3MB)
include a community flyer inviting residents to host sampling sites,
meteorological data, wind conditions during sampling periods, fieldwork records
and laboratory certificates for dust gauge analyses.
Appendices F and G (PDF 8.4MB):
contain laboratory microscopy reports and a summary of stereomicroscopy results
for dust gauge, Petri dish and brush samples.