Springer Science and Business Media LLC

A total of 10 surface soil samples representing the entire area of Linfen City were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons. The total polycyclic aromatic hydrocarbon concentration ranged from 1.1 to 63.7 μg g−1. Analysis of the sources of contamination revealed that polycyclic aromatic hydrocarbons in the soil were derived from combustion sources. Specifically, the primary source of polycyclic aromatic hydrocarbons was coal combustion, but the samples were also effected to varying degrees by traffic emissions. Furthermore, increased levels of contamination were observed in northeast Linfen due to the distribution of industrial plants.

As important members of earth biosphere, higher plants are inevitably exposed to nanoparticles (NP) released into the environment. Therefore, determining NP-induced phytotoxicity is ecologically important. Currently, researches into genotoxic effects of NP on plants are limited. In this study, Arabidopsis thaliana lines transgenic for homologous recombination (HR) and transcriptional gene silencing (TGS) reporter genes were for the first time adopted to assess the genotoxicity of Zinc oxide NP (ZnO–NP). Results showed that the root exposure to ZnO–NP led to increased HR and alleviation of TGS in the aerial tissues, indicative of the genotoxicity of ZnO–NP in plants. The increased Zn content after root exposure to ZnO–NP and the similar induction of HR and TGS alleviation after root exposure to equivalent Zn ions suggested that the genotoxicity of ZnO–NP might be mainly induced by Zn ions in aerial tissues that were transported from decomposed ZnO–NP in either medium or plant roots.

A key step in deriving an Environmental Quality Standard (EQS) is assessing the reliability and relevance of the underpinning ecotoxicity data. While the assessment of data reliability is relatively well established, the detailed evaluation of data relevancy is a more recent development. We applied broadly accepted relevancy criteria to a series of non-standard ecotoxicity studies on diclofenac, focusing on some aspects that should be accounted for in studies used in EQS derivation. Specific relevancy issues include potential experimental bias, claimed ‘significant effects’ that are indistinguishable from controls, or within the range of normal, and lack of environmental applicability. We highlight that rigorous, comprehensive and, where necessary, specialist assessment of data relevancy for studies potentially applicable for EQS setting is critical if studies are to be appropriately used regulatory decision-making. We provide recommendations for researchers and environmental practitioners to ensure robust accounting of relevancy in non-standard studies is undertaken.

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