Risk Analysis, Vol. 22, No. 5, 945-961

Assessing Human Health Response in Life Cycle Assessment using ED10s and DALYs Part 2: Non-Cancer Effects

David Pennington1, Pierre Crettaz 1,2, Annick Tauxe1, Lorenz Rhomberg 3, Kevin Brand 4 , Olivier Jolliet1

1 Life Cycle Systems, Swiss Federal Institute of Technology - Lausanne, GECOS - bat. DGR, ENAC, CH-1015 Lausanne EPFL, Switzerland
2 Present address: Swiss Federal Office of Public Health, Chemical Products Division, 3098 Köniz, Switzerland
3 Gradient Corporation and Harvard School of Public Health, 238 Main Street, Cambridge, MA 02142, USA.
4 Department of Epidemiology and Community Medicine, McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Canada

ABSTRACT
In Part 1 of this article we developed an approach for the calculation of cancer effect measures for life cycle assessment (LCA).  In this paper, we propose and evaluate the method for the screening of non-cancer toxicological health effects.  This approach draws on the non-cancer health risk assessment concept of benchmark dose, whilst noting important differences with regulatory applications in the objectives of an LCA study.  We adopt the central tendency estimate of the toxicological effect dose inducing a 10% response over background, ED10, to provide a consistent point of departure for default linear low-dose response estimates (ßED10).  This explicit estimation of low-dose risks, while necessary in LCA, is in marked contrast to many traditional procedures for non-cancer assessments.  For pragmatic reasons, mechanistic thresholds and non-linear low-dose response curves were not implemented in the presented framework.  In essence, for the comparative needs of LCA, we propose that one initially screens alternative activities or products on the degree to which the associated chemical emissions erode their margins of exposure; which may or may not be manifested as increases in disease incidence.  We illustrate the method here by deriving the ß ED10 slope factors from bioassay data for 12 chemicals and outline some of the possibilities for extrapolation from other more readily available measures, such as the No Observable Adverse Effect Levels (NOAEL); avoiding Uncertainty Factors that lead to inconsistent degrees of conservatism from chemical to chemical.  These extrapolations facilitated the initial calculation of slope factors for an additional 403 compounds; ranging from 10-6 to 103 [risk per mg/kg-day dose].  The potential consequences of the effects are taken into account in a preliminary approach by combining the ßED10 with the severity measure Disability Adjusted Life Years (DALY); providing a screening-level estimate of the potential consequences associated with exposures, integrated over time and space, to a given mass of chemical released into the environment for use in LCA.
 
 
 
 

 

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Last update: 02/Oct/2002