Evidence linking cadmium and/or lead exposure to immunomodulatory effects in mammals based upon an adverse outcome pathways approach, and research perspectives.

For decades, studies have shown how exposure to non-essential trace metals such as lead (Pb) and cadmium (Cd) largely impact global wildlife. Ecoimmunotoxicology has emerged in the past two decades and focuses on the effects of pollutants on the immune system of free-ranging organisms. Adverse outcome pathways (AOPs) represent a conceptual approach to explore the mechanistic linkage between a molecular initiating event and adverse outcomes, potentially at all biological levels of organisation.

Essential mineral elements in roe deer: Associations with parasites and immune phenotypes in two contrasting populations.

Low levels of essential mineral elements such as cobalt, copper, and iron, in organisms reduce immune function, increasing the chances of parasitic infection. This phenomenon has been demonstrated widely in domestic animals but rarely in wildlife. In this study, we used data from 7- to 9-month-old roe deer (), living in two different populations facing contrasting environmental conditions (Trois-Fontaines and Chizé), to investigate whether the parasitic and immunological statuses could be related to essential element status.

Environmental pollution and nutritional quality modulate immune response of the wood mouse (Apodemus sylvaticus) through hormonal disturbances.

Cadmium (Cd) and lead (Pb) are known to enhance immune cell damages and to decrease cellular immunity, promoting higher susceptibility to infectious diseases. Selenium (Se) is an essential element involved in immunity and reactive oxygen species scavenging. This study aimed at evaluating how Cd and Pb and low nutritional (Se) quality modulate immune response to a bacterial lipopolysaccharide (LPS) challenge in wood mice (Apodemus sylvaticus).

Effects of chronic exposure to toxic metals on haematological parameters in free-ranging small mammals.

Blood circulates through the vascular system to carry oxygen, nutrients and metabolites to and away from tissues, and as such is a key-component of animal physiology. The impacts of metal pollution on blood, however, are poorly documented in free-ranging vertebrates. While the counteracting effect of selenium on mercury toxicity is well known in marine mammals, its potential role against the toxicity of other metals is less studied, especially on terrestrial wildlife.

Pervasive exposure of wild small mammals to legacy and currently used pesticide mixtures in arable landscapes.

Knowledge gaps regarding the potential role of pesticides in the loss of agricultural biodiversity worldwide and mixture-related issues hamper proper risk assessment of unintentional impacts of pesticides, rendering essential the monitoring of wildlife exposure to these compounds. Free-ranging mammal exposure to legacy (Banned and Restricted: BRPs) and currently used (CUPs) pesticides was investigated, testing the hypotheses of: (1) a background bioaccumulation for BRPs whereas a "hot-spot" pattern for CUPs, (2) different contamination profiles between carnivores and granivores/omnivores, and (3) the role of non-treated areas as refuges towards exposure to CUPs. Apodemus mice (omnivore) and Crocidura shrews (insectivore) were sampled over two French agricultural landscapes (n = 93).