Toxicology of Mixtures – Cd +PCBs Experimental Model.
Indeed, to study and assess the potential health risks of “cocktails of pollutants” properly, it is of paramount importance to understand the basic concepts of joint action and interactions of chemicals. Components of a mixture can act independently in the body leading to the addition of doses or responses, or their actions can combine thus leading to stronger – synergistic or weaker – antagonistic response. Furthermore, the investigations on the toxicity of chemical mixtures provide evidence that both chemicals with similar or dissimilar modes of action may produce combined effects at doses below their No Observed Effect Level/No Observed Effect Concentration (NOEL/NOEC), suggesting that a mixture can produce a toxic effect not observed for any component of the mixture.
The study demonstrated significant effects on body weight gain suggesting possible developmental toxicity, and also confirmed hematotoxic, hepatotoxic and nephrotoxic effects of these toxic agents. The obtained results also gave the evidence of thyroid disrupting effects: cadmium mainly caused decrease in T3 hormone levels suggesting predominant disruption of extrathyroid processes, while PCBs showed more profound effect on T4 hormone levels presumably as the result of PCBs direct effect on thyroid gland.
Our findings implicate that toxicity of mixture can be more profound than the toxicity of its components, and furthermore that mixture of chemicals can produce toxicity although the same dose regime of single components induces no toxic response. This study contributes to better understanding of mixture toxicity and gives one more piece of evidence that exposure assessment and safety evaluation should focus on chemical mixtures rather than on single chemicals.
Toxicol Forensic Med Open J. 2016; 1(1): e9-e11.doi: 10.17140/TFMOJ-1-e004