Consequences of Developmental Exposure to Pollution: Importance of Stress-Coping Mechanisms

Abstract

Environmental pollution is a global phenomenon that affects all continents and dozens of types of pollutants with highly different properties can be found on Earth. These pollutants may result in detrimental environmental conditions with clear negative effects on fitness, but they can also induce more pernicious and subtle effects by triggering maladaptive responses to environmental conditions. Importantly, the impact of pollutants on organismal systems is often also exacerbated during the developmental stage. Indeed, developmental conditions are known to affect the ontogeny of multiple integrative organismal systems, and notably the ontogeny of stress-coping mechanisms. These mechanisms involve cognition, the fight or flight response and the HPA axis; they are crucial to consider in the context of pollution because they govern the ability of the individual to adjust to the environmental perturbations that may arise from physical pollutants. In addition, they may also be disrupted by chemical pollutants, resulting in a maladaptive response to environmental conditions and in pathologies. In this chapter, we first provide an example of how developmental exposure to a chemical pollutant (lead, Pb) may disrupt stress-coping mechanisms with detrimental consequences later in life. Then, we illustrate the impact of physical pollutants on performance by focusing on the example of noise pollution. We especially aim to highlight the importance of stress-coping mechanisms and their flexibility in determining the ability of individuals to cope with noise pollution. Finally, we propose several avenues of research to better understand how wild species may adapt to this polluted world. We emphasize (1) the importance of considering the cumulative and interactive effects of physical and chemical pollutants on stress-coping mechanisms and performance; (2) the potential importance of priming hormesis in adjusting the functioning and the flexibility of stress-coping mechanisms to a polluted environment; (3) the need to consider microevolution to assess whether selection acts on stress-coping mechanisms and favors specific stress-coping traits that are beneficial in a polluted world.