Introduction to Special Series: Science‐Based Guidance and Framework for the Evaluation and Identification of PBTs and POPs

Abstract

There is a growing sense of urgency among scientists and environmental policy-makers concerning the need for improving the scientific foundation supporting international regulations for identifying and evaluating persistent, bioaccumulative, and toxic (PBT) substances and persistent organic pollutants (POPs) in the environment. The current national and international regulations define PBTs and POPs in terms of fairly strict criteria that are based on the state of the science in the late 1970s and early 1980s. Since then, an evolution in the state of the science has produced new insights into PBT substances and an array of new methods to identify PBT chemicals. The development of regulatory criteria has not kept up with the rapid development in environmental chemistry and toxicology, and as a result, scientists often find themselves in the situation where guidance on PBT and POPs criteria is limited and, in some respects, out of date. With this background, a Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop brought together experts from academia, government, and industry to reach consensus on the significance of advancements in our understanding of the behavior and potential impact of POPs and PBTs in the environment, the current understanding of the state of the science, as well as recommendations for policy-makers to improve and coordinate national and international regulations on this issue. The workshop builds on the outcome of a previous Pellston workshop, held in 1998, which focused on the evaluation of persistence and long-range transport of organic chemicals in the environment, and is linked to other recent Pellston workshops, among them the Tissue Residue Approach for Toxicity Assessment workshop held in 2007. The results of this workshop are conveyed in a series of 9 articles, published in this issue of Integrated Environmental Assessment and Management, and describe the coordination of science, regulation, and management needed to more effectively achieve a common goal of managing chemicals on our planet.

Comparison of Bioconcentration and Biomagnification Factors for Poorly Water-Soluble Chemicals Using Common Carp (Cyprinus carpio L.)

“…Thomann (1989) and Qiao et al (2000) observed that at naturally occurring food-to-water concentration ratios, uptake of highly lipophilic chemicals (i.e., log K ow [ 6) from water into biota is generally low compared with uptake by way of consumption of contaminated foodstuffs, with the importance of dietary uptake increasing with increasing K ow values. A recent review resulting from an international Pellston workshop (Klecka et al 2009) proposed a flowchart for the assessment of bioaccumulation criteria. The flowchart indicates that a field trophic magnification factor (TMF) value is the best criterion by which to determine chemical bioaccumulation, followed by a BMF value, and then a BCF value, with an estimate based on physicochemical parameters generating the lowest degree of confidence ).…”

PBT assessment and prioritization by PBT Index and consensus modeling: Comparison of screening results from structural models

“…Currently, identifying substances as potential PBT or POP candidates relies mainly on determining if specific properties of a chemical exceed threshold values for each property related to PBT behavior (commonly, half-life in various compartments for P, BCF for B and a number of toxicity evidences for T) (Muir and Howard, 2006;Klecka et al, 2009;Moermond et al, 2011;Solomon et al, 2013). However, in the most recent papers (Moermond et al, 2011;Solomon et al, 2013) it was highlighted that there is no uniform PBT or vPvB assessment of chemicals, as various regulatory frameworks use different criteria for categorization.…”

“…In this scenario of not generally accepted and widely used rules, it is evident that the best approach for reliable PBT assessment is to be confident in the assignments obtained by agreement from different tools (a consensus approach). Klecka et al (2009) correctly highlighted that there is a fundamental difference in methods used to rank, as well as prioritize, chemicals for PBT or POP properties when compared with detailed PBT or POP assessment of chemicals that were already prioritized. "In this first, prioritysetting phase, rapid and efficient approaches should be used and, generally, will be developed to minimize the probability of potential false negative results.…”

Assessment of PBTs in the European Union: a critical assessment of the proposed evaluation scheme with reference to plant protection products

“…The focus of our search was on PPPs but, where relevant, data for other substances were used to inform our analysis. The report and papers resulting from the Society of Environmental Toxicology and Chemistry (SETAC) POPs workshop held in 2008 [11], et seq., were particularly useful in this regard.…”