Environmental Toxicity and Bioaccumulation of Microplastics Derived from Petroplastics: A Cross-Ecosystem Review

The widespread use of petroplastics such as polyethylene and polypropylene has led to pervasive microplastic (MP) pollution across environmental compartments, raising serious ecological and public health concerns. This review synthesizes current knowledge on the environmental toxicity and bioaccumulation of microplastics derived from petroplastics, with a focus on their fate and impacts across marine, freshwater, and terrestrial ecosystems. A systematic literature review spanning 2005 to 2025 was conducted using PubMed, Scopus, ScienceDirect, and Google Scholar, incorporating over 150 peer-reviewed studies selected based on ecological effects, exposure levels, and species-specific responses. The findings reveal that in marine environments, MPs disrupt food webs by accumulating in plankton, fish, and seabirds, often serving as vectors for persistent organic pollutants (POPs). Freshwater ecosystems exhibit MP sedimentation and bioaccumulation in fish, frequently exacerbated by interactions with heavy metals. In terrestrial ecosystems, MPs reduce soil fertility and are ingested by organisms such as earthworms, although data remain comparatively scarce. Cross-ecosystem comparisons highlight common concerns like trophic transfer and biomagnification, alongside ecosystem-specific differences influenced by environmental variables. Notably, significant research gaps persist, including the lack of standardized sampling methods and limited understanding of long-term trophic transfer and co-contaminant interactions, particularly in terrestrial systems. These findings underscore the urgent need for interdisciplinary research, harmonized methodologies, and informed policy interventions to address the multifaceted threat posed by microplastics across ecosystems.