Biomonitoring of persistent organic pollutants in Egypt using Taphozous perforatus (Chiroptera: Emballonuridae)

Abstract

Organochlorine pesticides (OCP) and polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants (POPs) that have chronic toxicity, tendency to contaminate the environment, and transfer into the food chain. This study was conducted to explore the use of bats as bioindicators to help understanding the time trend of POPs at the present time. Liver and kidney tissues from the Egyptian tomb bat (Taphozous perforatus) were subjected to the QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction prior to quantification by LC-MS/MS analyses. DDT (dichlorodiphenyl trichloroethane) metabolites (e.g., o,p’-DDT, p,p’-DDD, p,p’-DDE), PCB congeners (e.g., PCB 118, PCB 138, PCB 180), hexachlorobenzene (HCB), dicofol and sulphur were found in variable concentrations in the tissues of T. perforatus. Their concentration levels were affected with the bat sex and the season of sampling. Liver and kidneys were found to contain 0.39 µg/g wet weights of DDTs and 0.11 µg/g wet weights of PCBs. Concentration of the compound dichlorodiphenyl ethane (p,p’-DDE) predominated over the other DDT metabolites; giving rise to the DDE/∑DDT ratio of 0.82 as an indicative of pronounced decline in new DDT inputs to the environment. Also, concentration of the PCB 138 predominated that of the other congeners. There were correlations between liver and kidney concentrations of OCP and PCBs in both of them. It was concluded that these pollutants are still detectable in the environment; however in low concentration levels and far from lethal toxicity. Nevertheless, these findings may encourage the use of other bat species from urban and rural regions, as well as agricultural and industrial locations, as bioindicators.