The increased usage of petroleum oils in cold regions has led to widespread oil pollutants in soils. The harsh environmental conditions in cold environments allow the persistence of these oil pollutants in soils for more than 20 years, raising adverse threats to the ecosystem. Microbial bioremediation was proposed and employed as a cost-effective tool to remediate petroleum hydrocarbons present in soils without significantly posing harmful side effects. However, the conventional hydrocarbon bioremediation requires a longer time to achieve the clean-up standard due to various environmental factors in cold regions. Recent biotechnological improvements using biostimulation and/or bioaugmentation strategies are reported and implemented to enhance the hydrocarbon removal efficiency under cold conditions. Thus, this review focuses on the enhanced bioremediation for hydrocarbon-polluted soils in cold regions, highlighting in situ and ex situ approaches and few potential enhancements via the exploitation of molecular and microbial technology in response to the cold condition. The bibliometric analysis of the hydrocarbon bioremediation research in cold regions is also presented.

The ubiquitous plastic contaminant is impossible to avoid in today's world and occurs in the marine environment as microplastic particles, which are particles larger than 5 millimeters. It has been discovered that there is pollution in the ocean caused by plastics in areas that were previously thought to be pristine. These areas include the oceans of the Arctic and Antarctic. Many marine ecosystems are negatively impacted by plastic pollution caused by a variety of human activities, which can occur via a variety of pathways. In light of this, the purpose of this review is to talk about marine microplastics while putting an emphasis on the possible occurrence routes taken into marine ecosystems with subsequent sedimentation events. Recent research has pointed to the possibility of using plastic bioremediation as a method for its removal; consequently, this mini review covers the potential exploitation of marine microorganisms and animals has been analyzed in light of the problem of marine plastic pollution.