Xenobiotics

Xenobiotics are chemical substances that are foreign to animal life and are not naturally produced or expected to be present within the organism[1][3]. They can also cover substances that are present in much higher concentrations than are usual[1].

Natural compounds can also become xenobiotics if they are taken up by another organism[1]. The term xenobiotics is often used in the context of pollutants such as dioxins and polychlorinated biphenyls and their effect on the biota[1]. Xenobiotics are understood as substances foreign to an entire biological system, i.e. artificial substances, which did not exist in nature before their synthesis by humans[1]. They are synthetic and mostly recalcitrant in nature[4]. The US EPA defines xenobiotics as new, having environmental and health effects, and as being poorly understood in terms of damage[5]. Various directives and regulations aim to improve the quality of the environment by regularly monitoring a list of hazardous compounds[5].

Citations:
[1] https://en.wikipedia.org/wiki/Xenobiotic
[2] https://www.sciencedirect.com/topics/immunology-and-microbiology/xenobiotic
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872059/
[4] https://www.sciencedirect.com/topics/earth-and-planetary-sciences/xenobiotic
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8628977/
[6] https://www.ebi.ac.uk/chebi/searchId.do?chebiId=35703