From: Mersiowsky, Ivo 
Sent: Wednesday, May 22, 2002 7:44 AM
To: lcm@lcacenter.org
Subject: AW: LCM - LCM of Solid Waste RESPOND TO THIS MESSAGE WITH
---REPLY TO ALL---

Dear Keith, dear Karsten,

First of all, kudos to Keith for such a comprehensive work. I guess this is
still a continuation of what Mrs. Thorneloe presented about the LCA-based
decision support for US municipalities at SARDINIA Landfill symposia
1997/1999?

With respect to modelling landfills in LCA and particularly the leaching of
heavy metals from electronic scrap (as Karsten asked about it), I would like
to offer the following comments:

* In the course of an international research project, I have investigated
the long-term behaviour of PVC products in landfills. These included
lead-stabilised cables as well as other products which may -- to a certain
extent -- serve as examples of plastics in general. We found that only minor
leaching takes place, as lead stabilisers may be washed off from the
surface, then leaching subsides. These emissions, however, will usually be
completely drowned by the "background noise" originating from other waste
components. To my knowledge, specifically dust and ashes as well as
putrescibles/biowaste and -- of course -- specific materials such as crushed
batteries constitute major sources of heavy metals. This means, yes, there
are heavy metal emissions from landfills, but they probably cannot be
significantly attributed to plastics. Mind that solders etc. might be an
entirely different matter altogether. If you are interested, the results of
this project on PVC can be accessed on my website:
http://home.t-online.de/home/ivo.mersiowsky/pvc.htm

* The work by Gregory, Revans et al. in the UK suggests that landfills may
well act as a sink of heavy metals (precipitating and
adsorbing/incorporating them on a permament basis). One may claim that
eventually everything will be released into biosphere (mineralisation of
plastics and humic matrix), but this will not be the leachate emissions
during the surveyable period. Finnveden from Sweden, Baccini et al. from
Switzerland have developed models to describe the fate of metals in
landfills during time and depending on the original material.

* During my PhD work, I have begun to look into possibilities to integrated
this knowledge into LCAs. The most wide-spread models allocate on a mass
basis (assigning overall landfill emissions to waste materials based upon
their mass share). To my view, these models are inadequate: biogas and
polluted leachate originate primarily from degradation of putrescibles;
heavy metals come from diffuse sources (dust, ashes) or specific materials
(as indicated above). Therefore we need product-specific emission models.
Among the few I have found, was LCA-Land by Nielsen and Hauschild (then at
DTU Technical Univeristy of Denmark). I continue to address this problem and
would be happy to share ideas.

* I currently deal with LCAs on plastics waste management, so this problem
keeps coming up (landfill as the business as usual or reference scenario).
In fact, I can understand the people lobbying against lead-free electronics
-- to a certain degree. In some materials, the lead (or other heavy metals)
are very firmly bound and they were usually originally put there for a very
good reason, namely their good performance (i.e. benefit). Now, in the
attempt to solve a rather diffuse toxicity and substance flow management
problem, authorities and NGOs take a substance-oriented point of view and
try to phase out lead from each and every application -- possibly including
the rather unproblematic ones. While I claim that most current LCA models
will overestimate the lead-in-landfill problem as far as plastics are
concerned, I will also say that we most likely did not ask the correct
question in the first place. To support a WEEE directive, we would need
something like a screening life cycle risk assessment, to identify the real
hot spots. This is along the lines I am currently thinking -- also in this
regard, contact/questions/comments are welcome anytime.

I hope you find these -- admittedly none too succinct -- comments helpful
for your work.

Kind regards

Ivo


__________________________________________________________
Dipl.-Ing. Ivo Mersiowsky
c/o Solvay Management Support GmbH
Tel. +49.511.857-2148 (Mon--Thu)

Company Contact:
TuTech Integrated Management
TUHH Technologie GmbH
Schellerdamm 4, D-21079 Hamburg / GERMANY
Tel. +49.40.766180-52 (mobile)

WWW: http://home.t-online.de/home/ivo.mersiowsky/homepage.htm