Comment on “Why there is no evidence that pyridine killed the English crabs” by A. T. Ford, M. F. Fitzsimons and C. Halsall, Environ. Sci.: Adv., 2024, 3, 1385, DOI: https://doi.org/10.1039/D4VA00006D

Abstract

The risks to ecosystems that are posed by chemicals present in the environment need to be properly understood in order to ensure that they are both properly managed during their life cycle, and to understand the potential causes of serious ecological impacts. A mass mortality event which occurred off the North East coast of England in late 2021 affecting crabs and lobsters was an occasion when chemical risk assessment was used to help understand the possible causes. The environmental risk assessment of chemicals typically considers both the exposure to the chemical in question and the hazard posed by it to quantitatively evaluate the level of potential harm posed. There are established procedures for evaluating the relevance and reliability of both hazard and exposure data for chemicals, and their use within risk assessment provides traceability and clearly documents any limitations associated with the data which helps to ensure that they are not used inappropriately. The additional transparency surrounding the limitations and uncertainties associated with the data used can enhance the scientific credibility of assessments which are complex or politicized. This comment considers the quality of the evidence available for understanding whether pyridine may have been the cause of the mass crustacean mortality event which occurred off the North East coast of England in late 2021.