Persistent Organic Pollutants (POPs): Environmental Risks, Toxicological Effects, and Bioremediation for Environmental Safety and Challenges for Future Research

Abstract

The persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were detected in different media of environment such as air, water, and soil due to its persistence in nature. POPs have the efficacy to contaminate, accumulate, and bioaccumulate in any living organisms through the food chain. Since these are lipophilic and semi-volatile in nature, can move or transport through air mass in the far distance such as Arctic region and mountainous region where the pollutants were never used before. Thus, POPs have the tendency to retain in cold climate for a longer time. Stockholm Convention is a focus to control or eliminate the production and implement the policy against the toxic POPs because these can lead to serious health effects including cancers, birth defects, and dysfunctional immune, nervous, and reproductive systems. The Cucurbita family of plant species including pumpkins, squash, and zucchini has been used widely to uptake the PCBs, DDT, and PAH from contaminated sites. Some of the bacterial group such as Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Pseudomonas aeruginosa, Pseudomonas putida, and Bacillus were also reported for the degradation of DDT compounds. The gram-negative (Pseudomonas, Alcaligenes, Achromobacter, Burkholderia sp.) and gram-positive (Rhodococcus, Corynebacterium, and Bacillus sp.) bacteria have been reported for the degradation of PCB compounds, respectively. Many of the native microorganisms develop complex and significantly effective metabolic pathways that allow the biodegradation of toxic compounds released into the environment.