Niels Jonkers

Environmental fate of phenolic endocrine disruptors: field and laboratory studies

Alkylphenolic compounds derived from microbial degradation of non-ionic surfactants became a major focus of environmental research in the early 1980s. More toxic than the parent compounds and weakly oestrogenic, certain metabolites of nonylphenol polyethoxylate (NPnEO) surfactants, especially nonylphenol (NP), raised sustained concern over the risk they pose to the environment and triggered legal measures as well as partly voluntary actions by the manufacturing industry. Continuous progress in the development of analytical techniques is crucial to understand how these alkylphenolic compounds behave in wastewater treatment, the aquatic environment and in laboratory experiments. Measured concentrations and mass flows of phenolic endocrine disruptors, particularly nonylphenolic compounds, bisphenol A and parabens in municipal wastewater effluents and in the Glatt River, Switzerland, show that rain events leading to discharges of untreated wastewater into rivers have a great impact on the riverine mass flows of contaminants. Biotransformation experiments in our laboratory with nonylphenoxyacetic acid and individual NP isomers enabled the elucidation of degradation pathways of these compounds. The finding that nonylphenoxyacetic acid is metabolized via NP further underscores the role of NP as the most relevant metabolite in the degradation of NPnEO. Several Sphingomonadaceae bacterial strains were found to degrade α-quaternary 4-NP isomers by an ipso-substitution mechanism, and to use only the aromatic part of the molecule. These reactions turned out to be isomer specific, meaning that rate and extent of transformation depend on constitution, and possibly also on the absolute configuration of the alkyl side chain of a specific isomer. The observation that NP isomers with distinct oestrogenic activities are differentially degraded has significant implications for risk assessment.

Imposex levels and tributyltin pollution in Ria de Aveiro (NW Portugal) between 1997 and 2007: evaluation of legislation effectiveness

Nucella lapillus imposex levels and organotin (OT) concentrations in water and female tissues were measured in samples collected from the Ria de Aveiro (NW Portugal) between 1997 and 2007. Vas deferens sequence index (VDSI), relative penis size index (RPSI), mean female penis length (FPL) and percentage of imposex affected females (%I) were used to determine imposex levels at each site. A significant temporal decline in imposex intensity was observed during the assessed period. Imposex decrease was evident after 2003 although improvements were most notable from 2005 to 2007, probably due to the implementation of the EU Council Regulation no.782/2003 forbidding further application of tributyltin (TBT) antifouling on vessels carrying EU flags. Despite these improvements, OT analysis in N. lapillus female tissues and water indicate there are still recent TBT inputs into the study area.

Life cycle assessment of flame retardants in an electronics application

PurposeFlame retardants are added to plastics and textiles to save lives. However, certain brominated flame retardants (BFRs) form an environmental hazard and should be replaced by less harmful alternatives. In the recently completed European research project ENFIRO, we examined which alternatives are most suitable from a technical and environmental perspective. This study describes the LCA comparison of BFRs and halogen-free flame retardants (HFFRs) in an electronics product, in order to compare their environmental impacts over the whole life cycle and identify where in the life cycle the main impacts occur.MethodsThis cradle to grave LCA used the complete life cycle of a laptop computer as the functional unit. Specific attention was paid to often neglected aspects, including emissions of flame retardants in all life cycle phases, emissions during accidental fire and improper waste treatment. New characterization factors for toxicity of flame retardants were calculated using USES-LCA2 and included in the impact assessment.Results and discussionThe largest differences in impact were found to occur in the waste phase due to an increased dioxin emission formed out of BFRs during improper waste treatment. Minor human toxicity and ecotoxicity impacts of FRs are present due to volatilization in the use phase. FR emissions during accidental fire vary with the FR’s mode of action (active in the gaseous or solid phase). The BFR scenario has a higher impact than the HFFR scenario due to a higher rate of smoke formation and a higher terrestrial ecotoxicity score. In most phases of the life cycle of FRs, fossil energy use related impact categories dominate the LCA score, i.e. climate change, fossil depletion, and particulate matter formation. Over the full life cycle, the BFR scenario has a slightly higher environmental impact than the HFFR scenario, mainly through the contribution of human toxicity in the waste phase.ConclusionsThe study shows that for improvements of the life cycle environmental performance of FRs, the waste treatment phase is critical. Export and improper treatment of WEEE have the highest impact of all waste treatment options for both the BFR and HFFR scenarios, and efforts should be intensified to reduce the amount of WEEE ending up in this scenario. The study further shows that processes which are often ignored in LCA can give relevant insights into the environmental performance of a product. It is therefore recommended to broaden the scope and system boundaries of future LCA studies to include unofficial scenario options (specifically in the end-of-life phase) to provide a more complete description of the full environmental impact of a product’s life cycle and thereby contribute to relevant discussions in society and policy.