Homing pigeons as a biomonitor for atmospheric PAHs and PCBs in Guangzhou, a megacity in South China

Highlights: • Higher levels of PAHs and PCBs were detected in lung compared with liver and fat. • Tricyclic PAHs dominated PAH composition in pigeon, similar as that in local air. • Intense flying may explain higher level of POPs in lung and liver of young pigeons. • Biotransformation affected the levels of PAHs and PCBs in fat of homing pigeons. - Abstract: The occurrence of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyl (PCBs) in urban atmosphere in Guangzhou, China were assessed using homing pigeons as a biomonitor. Contaminant concentrations in lung were significantly higher than those in liver and fat, indicating chemical uptake was mainly through respiratory route. Tricyclic PAHs and low chlorinated PCBs dominated composition of PAHs and PCBs in homing pigeons, similar as their composition in local atmosphere. Different age-dependent bioaccumulation patterns were noted for PAHs and PCBs. For 1-year old homing pigeons, higher levels of PAHs and PCBs in lung and liver tissues were probably ascribed to more intense flying than 5- and 10-year groups. Fat concentrations of PCBs were greater in aged pigeons than 1-year old pigeons, but PAH concentrations in fat slightly decreased in aged pigeons because of relatively fast biotransformation. Overall, homing pigeons could serve as a suitable biomonitor for urban atmospheric contaminants in coastal cities.