Climate change extreme and seasonal toxic metal occurrence in Romanian freshwaters in the last two decades\u2014case study and critical review

Andreea Maria Iordache,Constantin Nechita,Kevin A Schug,Tomáš Pluháček,Cezara Voica

doi:10.1038/s41545-021-00147-w

Abstract

The relationship between metal levels in the Olt River ecosystem in southern Romania (measured during 2018‒2019, with 1064 sediment and water samples) and daily climate data were explored to assess the need for targeted source identification and mitigation strategies. In 2018, there was a strong relationship between the sediment Pb, As, Cd, and Hg contents and temperature (r > 0.8, p < 0.001). Mercury in sediments had a positive correlation with precipitation, and Hg in the water correlated with minimum temperature in May 2018 (p < 0.01). In July 2019, heavy metals were positively correlated with precipitation and negatively correlated with temperature. According to nonsymmetrical correspondence analysis, the four climate parameters analyzed were linearly correlated with the frequency of metal detection (p < 0.001) in both years. The statistical analysis showed strong relationships between heavy metal levels and climatic factors and attributed the discrepancies in elemental concentrations between 2018 and 2019 to climate warming.

Highlights

The IPCC Working Group II Fourth Assessment Report found that many natural systems are already affected by regional climate warming[1]
Contrary to the pattern in 2018, the combined effect of summer days (SD) > 25 intervals and increased TX mean value shifted in 2019 (Fig. 1a), which increased the variability of temperature and the occurrence of extreme events
nonsymmetrical correspondence analysis (NSCA) revealed a linear dependence between trace elements sediment from Baiaga stream ( Transylvania) located near related to site and period data in 2018 (p < 0.001) compared to 2019 when the results were nonsignificant for the same statistical significance test

Summary

Introduction

The IPCC Working Group II Fourth Assessment Report found that many natural systems are already affected by regional climate warming[1]. This study evaluated the extreme climate indices that explicitly linked environmental conditions with metal levels in water and sediments in 2018 and 2019.

Results

Conclusion