The EU wants to step up its efforts in the fight against endocrine disruptors (hormone-active substances). This year saw the introduction of new criteria for identifying these substances in pesticides and biocides. Now just recently, on 7 November 2018, the European Commission announced its intention to subject the legal provisions on endocrine disruptors to a full range of tests to determine their appropriateness as the public debate on the effects of endocrine disruptors is rapidly gaining in intensity. Critics complain that the laws still contain too many loopholes. In the light of these developments, Akademie Fresenius sent out their invitation to the ninth international conference “Endocrine Disruptors” on 20 and 21 November in Cologne/Germany. This conference provided an up-to-date overview of the legislation and discussed the latest guidelines to be issued by the EU Agencies and the OECD on the identification of endocrine disruptors.
In June this year, the European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) published a joint Guidance Document on identifying substances with endocrine disrupting properties in pesticides and biocides. Domenica Auteri from EFSA and Niklas Andersson from ECHA presented this Guidance Document at the congress. Last year, these two EU Agencies developed this joint Guidance Document by taking into account comments from various stakeholders and the public. A public consultation was held in December 2017 and January 2018. The drafting group whilst finalising the document considered all comments made.
Andersson explained that the starting point for the assessment of endocrine disrupting properties is the core data set of the standard information requirements, and that the Guidance Document is designed to make efficient usage of the available data and that all available information should be considered before generating new information. Furthermore, toxicological information and ecotoxicological information should be considered together. The scope of the Guidance Document are the endocrine modalities related to estrogen, androgen, thyroids and steroidogenesis (EATS) due to the fact that the test methods are not sufficiently developed for other endocrine modalities. The assessment strategy in the Guidance Document is designed in such a way that it is adversity in EATS-mediated parameters that drive the assessment. This is because these parameters provide information on adversity and at the same time due to the nature of the effect. Existing knowledge also indicates that these effects are likely to be endocrine related. Others expressed the view that adversity in EATS-mediated parameters is not exclusively caused by endocrine mechanisms, it can also be caused by other mechanisms. Andersson replied that if such alternative non-endocrine mode of action is proposed it needs to be substantiated by data. Furthermore, he stressed that assessment of endocrine disrupting properties is not a tick-box exercise, it will always require weight of evidence assessment and expert judgement to establish the biological plausible link between the observed endocrine activity and adverse effect(s).
Revised OECD Guidance Document 150 contains numerous enhancements
The OECD (Organisation for Economic Co-operation and Development) has also revised its Guidance Document, originally published in 2012, in order to make allowance for the scientific progress made in the use of test methods and the evaluation of the endocrine activity of chemicals. Peter Matthiessen, Independent Consultant (Great Britain), presented the changes contained in Guidance Document 150. This document describes the OECD’s Conceptual Framework for assessing endocrine disruptors and provides background information on standardised test methods and guidelines for interpreting individual tests. “The revised version of the Guidance Document sticks with the Weight of Evidence philosophy”, Matthiessen observed. He also said, however, that it covered some new modalities and dealt more fully with cross-species linkages – recognising, for example, that substances may have several modes of endocrine action. Although the revision of the Guidance Document 150 is now online and has been published in an easy-to-read layout, Matthiessen said that it was not designed to be read from cover to cover. Instead, he recommended “using it selectively.”
“The sad reality”: Histopathology procedures are often prone to error
Histopathology is often used to identify endocrine-related effects – a process that refers to the microscopic examination of tissue in order to diagnose adverse morphological and cellular changes in different organs. Lisa Baumann from the University of Heidelberg is using histopathology for the assessment of endocrine-related effects in reproductive organs of fish since over 10 years. In her work she was often confronted with misdiagnoses and misinterpretations of histopathological findings, which seem to occur more and more frequently. Recent studies show that almost 50% of published studies in peer-reviewed scientific journals lack credibility for the use in risk assessment. Baumann described the „sad reality“ by presenting examples from literature in which microanatomic structures were misidentified, abnormal findings were given incorrect diagnoses and artefacts produced during sample preparation were misidentified as effects. Baumann appealed to the audience that there is a need for better training of pathologists in ecotoxicology, an improved review process in journals and that regular quality controls and Good Laboratory Practice (GLP) were indispensable.
Die Akademie Fresenius GmbH
Die Akademie Fresenius GmbH