Uncertain numbers and uncertainty in the selection of input distributions--consequences for a probabilistic risk assessment of contaminated land.

Risks from exposure to contaminated land are often assessed with the aid of mathematical models. The current probabilistic approach is a considerable improvement on previous deterministic risk assessment practices, in that it attempts to characterize uncertainty and variability. However, some inputs continue to be assigned as precise numbers, while others are characterized as precise probability distributions. Such precision is hard to justify, and we show in this article how rounding errors and distribution assumptions can affect an exposure assessment. The outcome of traditional deterministic point estimates and Monte Carlo simulations were compared to probability bounds analyses. Assigning all scalars as imprecise numbers (intervals prescribed by significant digits) added uncertainty to the deterministic point estimate of about one order of magnitude. Similarly, representing probability distributions as probability boxes added several orders of magnitude to the uncertainty of the probabilistic estimate. This indicates that the size of the uncertainty in such assessments is actually much greater than currently reported. The article suggests that full disclosure of the uncertainty may facilitate decision making in opening up a negotiation window. In the risk analysis process, it is also an ethical obligation to clarify the boundary between the scientific and social domains.

NATURVETENSKAP Geovetenskap och miljövetenskap Miljövetenskap hsv//swe
NATURAL SCIENCES Earth and Related Environmental Sciences Environmental Sciences hsv//eng
Distribution assumptions
Imprecise numbers
Interval analysis
Monte Carlo analysis
Probability bounds analysis
Environmental chemistry
Miljökemi
Environmental Chemistry
Miljökemi

Bergbäck, BoHögskolan i Kalmar,Naturvetenskapliga institutionen(Swepub:lnu)nbebo (författare)
Öberg, Tomas,1956-Högskolan i Kalmar,Naturvetenskapliga institutionen(Swepub:lnu)qobto (författare)
Högskolan i KalmarNaturvetenskapliga institutionen (creator_code:org_t)

Ingår i:Risk AnalysisNew York : Plenum Press26:5, s. 1363-13750272-43321539-6924

Om ämnet

NATURVETENSKAP: NATURVETENSKAP; och Geovetenskap och ...; och Miljövetenskap

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.