DOI: 10.5281/zenodo.15721640
title: Dataset from Exposure to a mixture of organic pollutants in a threatened freshwater turtle Emys orbicularis: effects of age, sex, and temporal variation

description: This repository contains the raw data and the revised R script used for the analyses presented in the revised preprint: "Exposure to a mixture of organic pollutants in a threatened freshwater turtle Emys orbicularis: effects of age, sex, and temporal variation"

The data file includes information on individuals as well as quantification of 46 organic compounds from 7 chemical families (PAHs, PAEs, PCBs, OCPs, pyrethroids, DEET, and PBDEs) in plasma samples collected from two populations of European pond turtles from the Camargue wetland (Southern France) in 2019 and 2020. 

The R script has been revised from version 1 and reproduces all the statistical analyses and figures of the manuscript.

The ReadMe file briefly summarizes the sampling and chemical analysis method and gives a precise description of the variables in the dataset. The revised version includes the new title.

Contact: merleau@tourduvalat.org

This version of the dataset was deposited before the manuscript was submitted to a preprint server. A newer version of this record, including the preprint DOI, will be made available shortly. Please consult the Zenodo record history for the latest version.

Current version: v2 — DOI: 10.5281/zenodo.15721641
description: Freshwater ecosystems constitute major sinks for organic contaminants, increasing anthropogenic pressures and threatening the unique biodiversity they harbour. In addition to persistent legacy compounds, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), various pollutants are less persistent but are chronically released, including polycyclic aromatic hydrocarbons (PAHs), phthalate diesters (PAEs), pyrethrinoid pesticides, and insect repellent. Heretofore, these pollutants have received insufficient attention in freshwater reptiles, considering their potential to trigger detrimental effects on organisms. During two years (2019 and 2020), we quantified plasma levels of 46 compounds from 7 chemical families in two monitored populations of the protected European pond turtle (Emys orbicularis) in the Camargue wetland, France. PAHs and PAEs were found predominantly and concomitantly, with similar occurrences and levels in the two populations. We observed similar inter-annual variations in PAHs and PAEs with differences between males and females, highlighting the need for a better assessment of the role of sex in the exposure pathway and the toxicokinetics of contaminants, especially in turtles. The negative relationship between PAH levels and age, as well as the high intra-individual variation in levels of both contaminant families, provides further evidence of limited bioaccumulation of these pollutants in the blood of E. orbicularis. This could be explained by the metabolic biotransformation of parent compounds, highlighting the need to quantify the levels of PAH metabolites and phthalate monoesters. Finally, our work underscores the importance of long-term monitoring to better determine the vulnerability of turtle populations already exposed to a wide range of contaminants.