The effects of radioactive pollution on the dynamics of infectious diseases in wildlife

The interactions between infectious diseases and chemical pollution are well known and recognised as important factors in regulating the way wild animals respond to contaminant exposure. However, the impact of ionising radiation and radionuclides has often been overlooked when assessing host–pathogen interactions in polluted habitats, despite often occurring together with chemical contamination. Nevertheless, a comprehensive body of literature exists from laboratory and field studies on host–pathogen relationships under radiation exposure, and with a renewed interest in radioecology developing; an evaluation of infectious disease dynamics under these conditions would be timely. The present study assesses the impact of external ionising radiation and radionuclides on animal hosts and pathogens (viruses, bacteria, protozoans, helminths, arthropods) in laboratory studies and collates the data from field studies, including the large number of investigations undertaken after the Chernobyl accident. It is apparent that radiation exposure has substantial effects on host–pathogen relationships. Although damage to the host immune system is a major factor other variables, such as damage to host tissue barriers and inhibition of pathogen viability are also important in affecting the prevalence and intensity of parasitic diseases. Field studies indicate that the occurrence of host–pathogen associations in radioactively contaminated sites is complex with a variety of biotic and abiotic factors influencing both pathogen and host(s), resulting in changes to the dynamics of infectious diseases. ► Infectious diseases are important regulating factors in the way wildlife respond to contaminants. ► An assessment of the effects of radioactive exposure to host–pathogen relationships in animals is given. ► Radioactive exposure has a profound effect on host–pathogen interactions. ► Both hosts and pathogens may be either negatively or positively affected by radioactive contamination.