A Meta-Analysis of Poly- and Per-Fluorinated Compounds in Birds around the World
Per- and poly-fluoroalkyl substances (PFAS) are anthropogenic chemicals used for waterproofing and as surfactants. They are an important group of chemicals for many industries due to their thermal and chemical stability, contributing to their persistence in the environment. As Persistent Organic Pollutants (POPs), PFAS bioaccumulate and are biomagnifed through food webs, and pose a threat to wildlife and ecosystems. Birds are often used as bioindicators for monitoring environmental conditions (e.g., the effects of DDT on raptor species). Many studies have focused their attention on eggs as indicators of contaminants ranging from heavy metals to PCBs. Limited knowledge exists regarding the relationship between environmental, maternal, and egg PFAS transfer rates. This meta-analysis will examine a few key dynamics regarding PFAS concentration in birds: (a) the transfer of PFAS from the environment to the egg in order to assess how PFAS in eggs are indicative of environmental conditions; (b) the relationship between PFAS in eggs and maternal plasma; (c) inter- and intra-specific variation; (d) geographic and temporal variation. By learning more about the distribution and transfer rates of these contaminants it will be easier to set up more consistent and focused studies that address the fate and consequences of PFAS in wild populations of birds. This study will also identify which groups of birds are most at risk as well as which areas of the world have the highest levels of PFAS.