A new review summarizes the effects of water pollution on cancer incidence in wild animals

The recent review, published in International Environment and led by the University of Tartu, summarizes the impact of water pollution on cancer incidence in wild animals with the help of more than 300 revised studies.

Authors shed light on areas that are not yet so important in cancer research in wild animals – summarizing the main effects and identifying future research avenues to overcome the puzzle of why which cancers develop in polluted environments.

The propensity to fish was immediately apparent in current research on aquatic wildlife cancer. However, with this bias it is particularly interesting that this cancer is associated with contamination in 10% of aquatic animals diagnosed with cancer; a figure we expect to be much higher in reality. “

Ciara Baines, Principal study author, University of Tartu

The new article combines the information available in the scientific literature about cancer events in aquatic and semi-aquatic species.

The authors suggest psychiatric approaches that link pollution and cancer, including the main pathways of metabolic detoxification, the effects of oxidative damage, diseases, and changes in the microbiome.

In addition, it is determined: what types of aquatic animals are more vulnerable to cancer caused by pollution, what types of pollutants are mainly cancer-related the aquatic ecosystems, and what types cause cancer pollution.

All aquatic ecosystems are vulnerable. Toxic substances such as persistent organic pollutants, toxins, and heavy metals, but also pharmaceuticals and microplastics, have been shown to adversely affect the health and survival of aquatic organisms.

Cancer is one of the pathologies caused by pollution that should be at the heart of attention in ecological and evolutionary research, as anthropogenic pollution has led to a rapid increase of oncogenic substances in natural habitats. .

Pollutants can suppress the host immune system and thus increase the vulnerability of organisms to pathogens that cause cancer and / or the accumulation of pollutants and thin damage in organs in the long run. This can then initiate oncogenic processes. Based on the current study, cancer has been linked to pollution in about 30 aquatic species.

Skin cancer is often the result of living in polluted waters in several species of fish. Accordingly, alongside skin cancers, liver cancers, which help process contaminants, have been described in many fish species.

Interestingly, malignant tumors in lipid-rich brain cigarettes, which may be a promising study guide in the future, are often underestimated and under-examined throughout the literature. One of the aims of a review was to identify gaps in research.

Tuul Sepp, PI of the research group on cancer evolution at the University of Tartu, highlights two aspects of the coin in wildlife cancer studies: “Conversely, if our actions cause cancer in animals water, we have a duty to know about it, to try to make it better. On the other hand, wild animals in polluted environments act as sentinels for environmental quality for humans. “

A better understanding of tumor development processes and linkage to environmental pollution by oncogenic chemicals plays an important role in preventing the adverse effects of pollution on wild populations as well as humans.

The authors highlight the need for future research to focus on understanding how knowledge of oncogenic pollution levels is moderately low, along with other ecological factors affecting the health of aquatic animals. Moreover, understanding the combined effects of environmental parameters and pollution cocktails on cancer incidence is an area that requires urgent study.