Exposure of Peregrine Falcons to Halogenated Flame Retardants: A 30 Year Retrospective Biomonitoring Study across North America.

Compared to aquatic ecosystem, terrestrial systems have been subjected to fewer investigations on the exposure to halogenated flame retardants (HFRs). Our study utilized peregrine falcon eggs collected from multiple habitats across North America to retrospectively explore both spatial distribution and temporal changes in legacy (e.g., polybrominated diphenyl ethers) and alternative HFRs over a 30 year period (1984-2016). The results reveal intensive HFR exposure in terrestrial ecosystems and chemical-specific spatiotemporal distribution patterns. The correlations between egg levels of the selected HFRs and human population density clearly illustrated a significant urban influence on the exposure of this wildlife species to these HFRs and subsequent maternal transfer to their eggs. Temporal analyses suggest that, unlike aquatic systems, terrestrial ecosystems may undergo continual exposure to consistently high levels of legacy HFRs for a long period of time. Our findings collectively highlight the effectiveness of using peregrine eggs to monitor terrestrial exposure to HFRs and other bioaccumulative chemicals and the need for continuous monitoring of HFRs in terrestrial ecosystems.

Organochlorine pesticides, PCBs, dioxins, and metals in postterm peregrine falcon (Falco peregrinus) eggs from the Mid-Atlantic states, 1993-1999.

Peregrine falcons were extirpated from the eastern United States by 1964 due to the effects of dichloro-diphenyl-trichlorethane (DDT) (Peakall and Kiff 1988). As a result of restoration efforts, peregrines have largely recovered in the region but remain a barometer of environmental contamination. In the course of monitoring nests, biologists in the mid-Atlantic states collected peregrine falcon eggs that failed to hatch. In the period 1993-1999, 93 eggs were collected from 66 nests in 31 locations in New Jersey, Pennsylvania, Delaware, Maryland, and Virginia. We analyzed eggs for organochlorine pesticides, PCBs, and metals, and calculated toxic equivalencies (TEQs) for dioxins and furans. Organochlorine contaminants were detected in eggs from all parts of the region. Although nest success in all parts of the region was good, the PCB TEQ in the Atlantic-New Jersey region was significantly related to nest success, and the regionwide PCB TEQ was nearly significant for nest success across the five-state area. dichloro-diphenyl-dichloroethylene (DDE), DDT, and total PCBs were negatively correlated with eggshell thickness, although eggshell thinning (10.4%) was not at a level associated with deleterious population effects. The five states represented in this study are productive for peregrine falcons and have contributed to the recovery of this species. However, the results suggest that Atlantic coastal peregrines might be subject to contaminant burdens that have the potential to decrease nest success and productivity.