Date: Thu, 2 May 2002 19:29:07 +1000
From: Rod Seppelt <Rod.Seppelt@aad.gov.au>
In reply to Shalini Sharma,
If heavy metals are being precipitated from rain or from atmospheric fallout,
they would be taken up by the soil as much as they would by a plant. It is
possible that the plants may absorb additional elemental material from the soil.
I would ask the question: Why do you need to use a moss growing on soil?
If you are interested in recording heavy metals from rain, you could use
something inert as a catchment device - e.g., a tissue paper (or better still,
fibre glass wool); a rain gauge. In the case of the former, heavy metals can be
washed fom the substrate and analysed; in the case of the latter, direct
analysis of the water can be performed.
If you want to use an organic substrate, you could use a large moss such as, for
example, Hypnum cupressiforme, suspended in a bag. You could subsequently
perform analysis of the rinse water to ascertain how much of the metals, etc.,
remains on the surface and then, by digestion, analyse for heavy metals, etc.,
in the moss.
I would try and minimise potential variables. Soil is a bit of an unknown
quantity, not just because of the elements it contains but because of its
inherent characteristics - cation exchange capacity, microbial activity, etc.
You could do a literature search of bryophytes and heavy metal pollution and see
what you come up with. There is a lot published on the influence and analysis
of heavy metals and other pollutants in bryophytes and other plants.
Prof. Rod Seppelt
Australian Antarctic Division,
Channel Highway, Kingston,
Tasmania 7050, Australia
Ph: +61 (03) 62 253 445