ASSESSING TOXIC IMPACTS ON AQUATIC ECOSYSTEMS - AiiDA

232 Pages·2004·1.33 MB·English

ASSESSING TOXIC IMPACTS ON
AQUATIC ECOSYSTEMS IN
LIFE CYCLE ASSESSMENT (LCA)
THÈSE NO 3112 (2004)
PRÉSENTÉE À LA FACULTÉ ENVIRONNEMENT NATUREL, ARCHITECTURAL ET CONSTRUIT
Institut des sciences et technologies de l'environnement
SECTION DES SCIENCES ET INGÉNIERIE DE L'ENVIRONNEMENT
ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE
POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES
PAR
Jérôme PAYET
DEA, INSA, Lyon, France
et de nationalité française
acceptée sur proposition du jury:
Prof. O. Jolliet, directeur de thèse
Dr K. Becker Van Slooten, rapporteur
Prof. L. Deschenes, rapporteur
Prof. N. van Straalen, rapporteur
Lausanne, EPFL
2004
II
A Milà et Sven

III
IV
Table of content

Abstract___________________________________________________________VII
Résumé___________________________________________________________XII
CHAPTER 1: General introduction__________________________________________1
Foreword____________________________________________________________2
Problem Setting _____________________________________________________3
Life Cycle Impact Assessment of Toxic Substances on Ecosystems _____7
Aim of the Thesis___________________________________________________10
References_________________________________________________________14
CHAPTER 2: Life Cycle Impact Assessment on Aquatic Ecosystems: The AMI method
[Assessment of the Mean impact]___________________________________________17
Abstract____________________________________________________________18
Introduction________________________________________________________19
Ecotoxicological measures__________________________________________22
Statistical estimator and uncertainty__________________________________24
Extrapolation from acute to chronic __________________________________28
Data availability and selection________________________________________30
Description of the AMI method_______________________________________33
Conclusions________________________________________________________44
References_________________________________________________________47
Appendix__________________________________________________________52
CHAPTER 3: Comparison of existing methods for LCIA on aquatic ecosystems_____59
Abstract____________________________________________________________60
Introduction________________________________________________________61
Description of Current Methods______________________________________62
Results ____________________________________________________________67
Discussion_________________________________________________________71
Conclusions________________________________________________________77
References_________________________________________________________80
Appendix___________________________________________________________85
CHAPTER 4: Statistical estimator for assessing impact on aquatic ecosystems in LCA91
Abstract____________________________________________________________92
Introduction________________________________________________________93
Presentation of the parametric and non-parametric methods ___________95
V
Aquatic toxicity data for the comparison of statistical estimators ______101
Analysis of the Aquatic toxicity data_________________________________101
Discussion________________________________________________________109
Conclusion________________________________________________________112
References________________________________________________________114
Appendix __________________________________________________________117
CHAPTER 5 : Application of the AMI method for comparative assessment of metals127
Abstract___________________________________________________________128
Introduction and presentation of AMI________________________________129
Application to metals_______________________________________________130
Conclusions_______________________________________________________133
References________________________________________________________136
CHAPTER 6: Analysis of data availability and reliability for calculation of LCIA Effect
Factors for Ecosystems__________________________________________________137
Abstract___________________________________________________________138
Introduction_______________________________________________________139
Presentation of the databases_______________________________________140
Analysis of the databases __________________________________________143
Description of the Dataset for the calculation of Effect Factors ________147
Estimation of the maximum number of possible Effect Factor _________155
Conclusion________________________________________________________157
References________________________________________________________159
CHAPTER 7: General conclusion_________________________________________161
Main findings______________________________________________________162
Key features of the AMI method: ____________________________________169
Perspectives ______________________________________________________170
Output of the thesis________________________________________________171
References________________________________________________________173
AMI Database_________________________________________________________175
List of Figures ________________________________________________________181
List of Tables _________________________________________________________183
Acknowledgements_____________________________________________________185
Curriculum Vitae______________________________________________________186
List of publications_____________________________________________________187

VI
Abstract

In the last decade, several Life Cycle Assessment (LCA) methods for
assessing impact of products on living resources have been developed.
Beyond the quantified assessments of impacts on living systems, it also
checked the feasibility of the impact assessment on human health and
ecosystems quality and helps to identify the limits of such methods. Among
the different impact categories, that of toxic substances on ecosystems
occupies an important place. The extent of these impacts has been stressed
on many occasions and the necessity of preserving ecological areas and
biodiversity has become a major issue on an international level.
By focusing on aquatic ecosystems, this thesis aims at identifying constraints
connected with assessment of the impact of chemical substances on
ecosystems in LCA and setting up a method for assessing impacts of toxic
substances on aquatic ecosystems which meets the requirements of a
comparative approach like Life Cycle Assessment. The overall purpose of
the thesis is to propose a comparative method for the Life Cycle Impact
Assessment of toxics on aquatic ecosystems. With that aim, the dissertation
is going throughout 6 major issues:
1- The feasibility of the comparative impact assessment on ecosystems
and the identification of associated constraints.
2- The development of a statistical method for comparing impact on
ecosystems;
3- The review of the data availability for calculation of Effect Factors.
4- The choice of the most relevant ecotoxicity measure (ECxs1, NOECs2
and LOEC3s) for a comparative purpose.
5- The development of best-estimate extrapolation factors for assessing
chronic effects based on acute data.
6- The analysis of the ecological realism of the comparative assessment
method.
These points are analysed throughout the 7 chapters of the thesis.

Chapter 1 aims at introducing the thesis. A general presentation of Life
Cycle Assessment is proposed, following by a detailed description of the
Life Cycle Impact Assessment on ecosystems. This description covers the

1 ECx: concentration of susbtance that affects 50% of the individuals tested for a given effect.
2 NOEC: No Observable Effect Concentration
3 LOEC: Lowest Observable Effect Concentration
VII
state of the art of researches and identifies the development needed.
Therefore the scope of the thesis and the main points that must be addressed
by this research are presented.

Chapter 2 starts with a review of existing methods for Life Cycle Impact
Assessment on ecosystems (LCIA), the chapter presents the parametric
version of the AMI method (Assessment of the Mean Impact), which has
been developed during the PhD for the assessment of impact on aquatic
ecosystems. For this purpose, a framework and the main requirements for
the development of this method are presented. For a comparative
assessment, the Hazardous Concentration of a toxic affecting 50% of the
species over their chronic EC50 (Effect Concentration affecting 50% of
tested individuals), also called HC50 , is selected for the calculation of
EC50
Effect Factors to be implemented in current LCIA methods. The Confidence
Interval on the HC50 is provided, enabling comparison between the
EC50
impact values obtained as results of a Life Cycle Assessment study. The
choice of EC50s is based on review of the main ecotoxicological databases,
and analysis of the availability and reliability of test results. Moreover,
bearing in mind that mostly acute data are available, while LCA deals
mainly with chronic exposure, best-estimate extrapolation factors for the
HC50 and the associated uncertainty are provided for inorganics, non-
EC50
pesticide organics, and pesticide organics. Concerning the method itself, in
order to find the best methods for calculation of a toxicity indicator, several
statistical estimators, parametric and non-parametric approaches are
compared, identifying their properties and respective strengths for a
comparative method. The analysis relates to both the reliability of the
estimator and its Confidence Interval, especially in terms of statistical
robustness and Effect Factor stability. Based on these findings, the AMI
method is described in detail, and an example of application comparing two
wheat crop scenarios differing by the pesticides used is presented.

Chapter 3 presents in detail the four methods currently used for the
development of Effect Factors for the Life Cycle Impact Assessment (LCIA)
on Ecosystems: the parametric version of AMI (Assessment of the Mean
Impact) based on HC50 s; the Eco-Indicator based on HC50 s; USES-
EC50 NOEC
LCA based on both HC5 s and the Most sensitive species, and the PNEC
NOEC
(Predicted No- Effect Concentration) based on the Most sensitive species.
After presentation of the LCIA framework and its main divergences from
VIII
Environmental Risk Assessment for chemical regulation, the four methods
are detailed and applied for the calculation of Effect Factors for 83
substances, covering inorganics, non-pesticide organics, and pesticide
organics. Each method is therefore analysed concerning three key points:
applicability in the LCA framework, environmental relevance, and statistical
reliability.
Particular attention is paid to possible bias and the uncertainty, highlighting
the following findings: (1) HC5 s are on average 50 times higher than the
NOEC
most sensitive species, and this difference in conservatism introduces a bias
in the analyses for the method mixing HC5 s and most sensitive species.
NOEC
(2) Effect Factors based on the most sensitive species increase the relative
weight of the most toxic chemicals by two orders of magnitude, depending
on whether the study is based on US or European ecotoxicity databases. (3)
the methods based on HC50 s and HC5 s are the only ones able to
EC50 NOEC
provide a Confidence Interval on the Effect Factor, but the Confidence
Interval on the HC5 s can be more than 10 orders of magnitude greater
NOEC
than that of the HC50 s. (4) compared with the Confidence Interval on the
EC50
HC50 s, the most sensitive species cannot be distinguished from
EC50
HC50 s for chemicals characterised by fewer than 5 species, and the
EC50
HC5 s cannot be distinguished from the HC50 s for chemicals
NOEC EC50
characterised by fewer than 8 species.

Chapter 4 compares two statistical estimators, aiming at calculate the
average toxicity of substances on biological species. The two methods
provide an estimation of the HC50 and the associated Confidence
EC50
Interval. On the one hand, parametric method using the geometric mean and
a calculation of the confidence interval with Student is considered. On the
other hand, a distribution-free method calculates the HC50 based on the
EC50
median response of species and the confidence interval based on bootstrap.
In order to facilitate the use of the non-parametric method, a table linking
the number of species tested and the size of the confidence interval is
provided for samples from 5 to 500 species. The comparison is based on
actual data concerning 191 substances covering inorganics, non-Pesticide
organics, and Pesticide organics. The mean and width of the chronic EC50s
samples for all the substances are presented. The Shapiro-Wilk test is
performed for the 191 EC50s samples and the assumption of log-normality
of the distribution failed in more than 20% of the cases. Two causes of this
non Log-normality are identified; (1) the skewness, which is shown to be an
IX
important issue for the assessment of the average toxicity of chemicals while
(2) the multi-modal distributions, which are not likely to influence
considerably the final result. A detailed application of the two methods is
done with the comparison of two herbicides, the Sulfosulfuron and the
Prosulfuron, where the distribution-free method appears to be more powerful
than the parametric for a substance-to-substance comparison. Nevertheless,
the distribution-free method requires a minimum of 5 chronic EC50s, that
cannot be satisfied in most cases.

Chapter 5 aims at illustrating the previous chapter in using the non-
parametric version of the AMI method for the comparative assessment of the
impacts of metals on aquatic ecosystems. This chapter briefly describes the
method, then it focuses on the comparative analysis of 9 metals sometimes
tested with different salts and speciations. Two interesting results can be
highlighted: (1) the toxicity of metals covers the whole range of toxicity of
chemicals; (2) the confidence interval of the HC50 for metals is on
EC50
average twice as great for metals compared with other chemicals. This
increase in the variability of ecotoxicological responses from species is
likely to be due to the change in bioavailability of metals associated with a
change of test conditions (e.g. pH, or Organic Matter).

Chapter 6 reviews and analyses the reliability of existing aquatic toxicity
databases which can be used for the calculation of Effect Factors for Life
Cycle Impact Assessment (LCIA). For that purpose, the main LCIA methods
are presented focusing on their data requirement. It concerns: EDIP4 (based
on the PNEC); AMI5 (based on parametric HC50 ); Eco-Indicator (based
EC50
on the HC50 ); USES-LCA (based on the HC5 ). Moreover 6
NOEC NOEC
ecotoxicity databases available in an electronic format are analysed: Aquire;
Pesticide Ecotoxicity Database (PED); IUCLID; Acute Toxicity Database
(ATD); Fathead Minnow database (FMD); and ECETOC Aquatic Toxicity
Database (EAT). The analysis especially focuses on the identification of the
substances and organisms, the definition of the tests conditions, and the
control procedure of the database. A selection of tests is done, retaining a
dataset of 128,864 tests results, acute, sub-chronic and chronic.

4 EDIP: Environmental Design for Industrial Product
5 AMI : Assessment of the Mean Impact
X