Volcanic ash cloud – the latest news from SEPA - update
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The Scottish Environment Protection Agency
(SEPA) is monitoring the situation regarding the volcanic ash cloud
currently affecting the UK and its possible impact on Scotland’s
environment.
SEPA’s Director of Science and Strategy,
Professor James Curran, said:
“The greatest environmental concern from
volcanic ash, and the most significant risk to grazing livestock,
would be fluoride content in ash deposits. Information from SEPA’s
analysis of Scottish dust samples, and from similar analysis in
Norway, indicates low levels of fluoride in the current Icelandic
ash plume.
“We think, on the basis of the expected
deposition patterns and the nature of the ash, that there is a
minimal risk to the environment.”
Ongoing monitoring
Continuous environment monitoring will be ongoing over the
weekend and beyond, using information about from a wide network of
existing environmental monitoring sites across
Scotland.
SEPA and the Met Office will also attempt to
collect rainwater samples over the weekend of 17 to 18 April.
These will be analysed by SEPA for pH and soluble fluoride.
Radiation measurements taken across the UK and Europe indicate
there is no evidence that the volcanic ash contains radioactive
materials of any significance.
The Scottish Air Quality Database contains the
most up-to-date continuous ambient monitoring information across
Scotland. Members of the public can access this information at
www.scottishairquality.co.uk.
All concentrations have remained low at all monitoring sites across
Scotland.
Latest results from SEPA’s dust
analysis
SEPA analysed three dust samples collected in
Lerwick, Aberdeen and East Kilbride.
Lerwick sample which was collected from a
radiation monitor on the roof of the Met Office on to a paper
tissue.
Initially a small portion of the Lerwick
sample was placed on a microscope slide for examination. The
sample was dark grey, black in appearance. Under microscope
there were aggregrates of dark grey, black particles possibly
opaque material covered in a dark deposit. This was
interspersed with regular shaped angular particles of glassy
appearance. The particles ranged in size from 15 x 20 µm to
70 x 85 µm.
Lerwick sample. Photo at x100 mag.
The Aberdeen sample was also examined and was
found to contain angular particles of glassy appearance and were
approximately 60 x 70 µm in size.
Further analysis conducted by the Macaulay
Institute showed broadly uniformed sized (approximately 20 µm)
particles of angular shape some exhibiting striations and others
conchoidal (smooth curved surfaces) fractures (typical of quartz
and glass).
Most particles showed similar composition
consisting of silicon, oxygen, aluminium, sodium, calcium,
magnesium, potassium, iron and chloride. There was no
evidence of high concentrations of fluorine in this sample.
Based on the morphology of the particles
(angular with conchoidal fracture faces) and the fairly uniform
elemental composition of the particles it is likely that the sample
is of volcanic origin.
The sample collected at East Kilbride was
examined by microscopy in East Kilbride and also found to contain
glassy, angular particles which were identified as ‘new silica’ ie
sharp, bright and clear as opposed to smooth and opaque. This
is typical of volcanic material.
East Kilbride sample
Notes to editors
Environmental monitoring sites include 75 sites air quality
monitoring sites (results available live on www.scottishairquality.co.uk).
SEPA also uses data from other local air quality monitoring sites
across Scotland.
SEPA also runs 25 radioactivity monitoring sites across the
country. Some locations also have dust filters that are being
collected for analysis not only for their normal purpose but also
to provide additional samples for volcanic dust analysis.
SEPA’s field chemistry team is also collecting further
additional dust samples from across Scotland for analysis.
Some rainfall is predicted in north west
Scotland over the weekend. SEPA and the Met Office will attempt to
collect rainwater samples for analysis by SEPA for pH and soluble
fluoride.