4th meeting of the
UK Natural Dust & Health Network
2nd Final Workshop!
16 December 2008
St Mary’s Medical School, London
Attended by:
Claire Horwell (Durham); Peter Baxter (Cambridge); Ross Anderson (St George’s, London);
Ed Derbyshire (Royal Holloway, London); Frank Kelly (Kings, London); Anna Hansell
(Imperial, London).
Aim
Follow up meeting to short meeting in July 2008 to address outstanding questions and way
forward for research and paper.
Discussion

Do we include biomass burning in our description of NMPs?
o Indoor exposure is dominant in many developing areas but it is an
anthropogenic activity. Decide that it should be left out. What about fires?
Forest fires can be ignited by lightning etc. – we did not come to a definite
conclusion but it looks likely that we will not include any biomass burning in
our review/research.

Are we considering all types of exposure or just respiratory?
o We decided that we are also considering other exposures e.g. skin exposure podoconiosis – mechanisms could be similar.

What research should be done to answer the question of whether NMPs cause health
problems?
o A study which involves epidemiology, exposure and air quality monitoring,
satellite data, emissions modelling … lots of problems though:
 Location – need an area with a large population (> million) and high
daily mortality to carry out time series or episode analyses (daily or
weekly). Also need to have good hospital record system and access to
records. Possible locations – China, Canaries (N. African source).
o Heterogeneity of exposure means it is hard to pick up a signal, particularly for
the fine particles. Roy Harrison has data on weather and coarse fraction –
urban pollutants are blown away leaving mineral fractions.
o Satellite data of dust storm geography
o Gravimetric and air quality monitoring – need lots of points rather than single
location collection to avoid bias of results.
o ‘Emissions’ modelling (meteorology etc.) for exposure prediction compared
with measured concentrations – e.g. Etna model – couldn’t work for desert
exposure which has multiple point sources. If
there are signature
minerals/chemicals you can measure them daily e.g. ratios of natural to
anthropogenic particles.
o We didn’t reach a conclusion on the design of a study.

Are existing models for anthropogenic air pollution relevant to NMPs?
o In vivo inflammation models need to be tested to ensure that they are viable for
natural dusts as well as anthropogenic sources.
o We don’t know for sure if our understanding of mechanisms and pathways of
toxicity apply to NMPs.

Review paper
o The literature review of Asian health and air pollution studies is available from
Ross Anderson as a draft report -.doesn’t include natural sources. Ross will
check to see if there is anything relevant.
o Bonn meeting (WHO) – null hypothesis: health effects not related to source,
size or chemistry of air pollution particles? Yes, there is evidence of
differences, according to size, source and chemistry but couldn’t quantify how
much. Did not exclude an effect of source …
o Künzli paper on Barcelona Saharan dust influence.
o EHP (?) special issue on dust storms.
o Taiwanese paper on desert dusts.
o We didn’t manage to delegate responsibilities for the authorship of the paper –
to be done by PJB and CJH soon.
o Regulators are now trying to exclude some particles from policy for PM10 sea salt, celebrations (fireworks). Source apportionment. It is important and
timely, therefore, for us to review available NMP literature and assess NMP
toxicity.
Other information and discussion points


Burden of disease from outdoor air pollution - study that Ross is chairing – working
just with PM2.5
MRC & HPA Environment & Health centre just launched which (partly) focuses on air
pollution and health. Director: Paul Elliott. Frank Kelly is deputy director. Kings &
Imperial. Ross Anderson on Executive Committee. Peter Burney leading on Air
Pollution (Imperial, heart and lung institute). Keen on external collaborations e.g. they
have talked to Roy Harrison and John Ayres. 10-11 March Meeting. NERC-MRC call
in Autumn 2009.