Page 290 - Materials Chemistry, Second Edition

274 4 Life Cycle Impact Assessment

• Usually large dilutions occur for an exposure via environmental media, thus the
effect thresholds are usually not reached.
• Acutely toxic substances (not always, see polychlorinated dibenzo-p-dioxin and
polychlorinated dibenzofuran, PCDD/F) are often reactive and therefore, by
trend rapidly degradable (abiotically or biotically) 290) contrary to non-reactive
(persistent) substances; strong toxics as, for example, phosphine (PH ) are
3
therefore not relevant in the environment except in the case of accidents. Even
then long-term damaging consequences seldom occur because of dilution and
degradation. Short-term acute impacts are part of the impact category casualties,
which is hardly ever used.
Contrary to acute often short-lived poisons (in the narrow sense of the term)
persistent substances can be ranked as potentially environmentally toxic even for
minor toxicity and minor concentrations. This is especially true for ecotoxicity 291) ,
for an exposure by environmental media and by the nutrition chain, but also for
human toxicity.
All quantification procedures exceeding a simple weighting or the formation of
groups by means of limit values must introduce the investigation of uptake pathways
and exposure analysis 292) , a usual procedure in toxicology and in chemical risk
assessment. A general treatment of human toxicity according to SETAC 293) formally
corresponds to ecotoxicity (see Section 4.5.3.3) but the protection goals differ:
• Human toxicity: personal health of every individual (also the unborn).
• Ecotoxicity: the functionality of the system characteristics of entire ecosystems as
well as the biodiversity, not however, with few exceptions 294) , single individuals.

In anticipation of the section on ecotoxicity and as delimitation from human health
and its significance (human toxicity) it is already noted here that the expression
‘ecosystem health’ is not undisputed. 295) For ecosystems that are not organisms,
as they, for example cannot multiply and have no strict boundaries in space,
no illnesses can be defined, also the absence of illness, that is, health, practically
cannot be defined. The pleasant metaphor of an animated earth as a super organism
(Gaia 296) ) used by J. Lovlock’s also belongs to that issue. A descriptive definition of
the unique characteristics of organisms has been provided by Monod. 297)
It is true for the above distinction that for human toxicity the individual and with
ecotoxicity the ecosystem is the primary safeguard subject. The species (animals
and plants) is at the centre of these two extremes. Species protection is a declared
safeguard subject in an ecosystem that is not of absolute importance: another
species can (often) adopt the same function (occupy the same ecological niche)

290) Kl¨ opffer (1996b) and Kl¨ opffer and Wagner (2007a,b).
291) Kl¨ opffer (1989, 1994a, 2001) and Scheringer (1999).
292) Mackay (1991), Trapp and Matthies (1996, 1998) and TGD (1996, 2003).
293) Udo de Haes (1996) and Udo de Haes et al. (2002).
294) Exceptions are species threatened with extinction with only single specimen left and especially
beautiful old trees (‘natural monuments’).
295) Suter (1993).
296) Lovelock (1982, 1990).
297) Monod (1970).