Levels of Polycyclic Aromatic Hydrocarbons, Polychlorinated Biphenyls, and Organochlorine Pesticides in Various Tissues of White-Backed Vulture in India

Abstract

This study provides information on the current status of contamination by polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) in the tissues of endangered White-backed Vulture Gyps bengalensis in India. Chemical analyses revealed detectable amounts of PAHs, PCBs, and OCPs. Concentration ranges of ∑PAHs, ∑PCBs, and ∑OCPs in tissues were 60–2037 ng/g, 30–5790 ng/g, and 3.2–5836 ng/g wet weight, respectively. 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE) concentrations ranged from below detectable level to 599 ng/g wet weight, representing more than 90% of the total dichlorodiphenyltrichloroethane (DDT). Among the various OCPs analyzed, p,p′-DDE was detected most frequently. All the contaminants recorded show higher accumulation in liver than other tissues. Levels of contaminants measured in the tissues of vulture are comparable with the levels documented in a number of avian species and are lower than those reported to have caused deleterious effects. Although no threat is expected from the current level of contamination, the presence of varying levels of contaminants and their additive or synergistic toxicity is a cause of concern to vultures. Values reported in this study can serve as guideline for future research.

Polyaromatic hydrocarbons in pollution: a heart‐breaking matter

“…). This was notably shown in studies where tissue concentrations approximating to 3 µM were reported (Jacob & Seidel, ; Dhananjayan & Muralidharan, ), with levels being exacerbated by smoking (363 ng Phe per cigarette; Severson et al . ; Howard et al .…”

“…It is important to note that Phe, like most tricyclic PAHs, is highly lipophilic with a logP (octanol/water) coefficient of ß4.4, indicating tissue accumulation of Phe at levels higher than those observed in plasma (Carls et al 1999;Heintz et al 1999). This was notably shown in studies where tissue concentrations approximating to 3 µM were reported (Jacob & Seidel, 2002;Dhananjayan & Muralidharan, 2013), with levels being exacerbated by smoking (363 ng Phe per cigarette; Severson et al 1976;Howard et al 1998).…”

Protective role of the vulture facial and gut microbiomes aid adaptation to scavenging

“…Among the bacteria identified in higher abundance in the facial microbiome is Arthrobacter phenanthrenivorans , which is able to degrade phenanthrene, a skin-irritating polycyclic aromatic hydrocarbon (PAH). PAH are xenobiotic pollutants with negative health-effects found to be emitted from animal carcass [77], and previously reported in high concentrations in other vulture species [78]. Interestingly, the largest intra-samples variation on the metabolism of xenobiotics biodegradation was in the facial dataset (Additional File 5), with PAHs degradation metabolism being the most abundant subclass from the xenobiotics degradation pathway in both face and gut.…”

Protective role of the vulture facial skin and gut microbiomes aid adaptation to scavenging

“…Among the bacteria identified in higher abundance in the facial microbiome was Arthrobacter phenanthrenivorans , which is able to degrade phenanthrene, a skin-irritating polycyclic aromatic hydrocarbon (PAH). PAH are xenobiotic pollutants with negative health-effects found to be emitted from animal carcass [ 82 ], and previously reported in high concentrations in other vulture species [ 83 ]. Interestingly, the largest variation on the metabolism of xenobiotics biodegradation was in the facial skin dataset (Additional file 6 ), with PAHs degradation metabolism being the most abundant subclass from the xenobiotics degradation pathway in both facial skin and gut.…”