Worker studies suggest unique liver carcinogenicity potential of polyvinyl chloride microplastics

Abstract

BackgroundPlastic debris pervades our environment. Some breaks down into microplastics (MPs) that can enter and distribute in living organisms causing effects in multiple target organs. MPs have been demonstrated to harm animals through environmental exposure. Laboratory animal studies are still insufficient to evaluate human impact. And while MPs have been found in human tissues, the health effects at environmental exposure levels are unclear.AimWe reviewed and summarized existing evidence on health effects from occupational exposure to MPs. Additionally, the diverse effects documented for workers were organized by MP type and associated co‐contaminants. Evidence of the unique effects of polyvinyl chloride (PVC) on liver was then highlighted.MethodsWe conducted two stepwise online literature reviews of publications focused on the health risks associated with occupational MP exposures. This information was supplemented with findings from animal studies.ResultsOur analysis focused on 34 published studies on occupational health effects from MP exposure with half involving exposure to PVC and the other half a variety of other MPs to compare. Liver effects following PVC exposure were reported for workers. While PVC exposure causes liver toxicity and increases the risk of liver cancers, including angiosarcomas and hepatocellular carcinomas, the carcinogenic effects of work‐related exposure to other MPs, such as polystyrene and polyethylene, are not well understood.ConclusionThe data supporting liver toxicity are strongest for PVC exposure. Overall, the evidence of liver toxicity from occupational exposure to MPs other than PVC is lacking. The PVC worker data summarized here can be useful in assisting clinicians evaluating exposure histories from PVC exposure and designing future cell, animal, and population exposure‐effect research studies.

Systematic review of microplastics and nanoplastics in indoor and outdoor air: identifying a framework and data needs for quantifying human inhalation exposures

“…This has implications on the quality and comparability of data. The specific polymers targeted in this review are not exhaustive of the different types of source material of MPs [ 4 , 83 ]. This leaves a gap for future research on other or specific polymer sources of airborne MPs.…”

Impact of microplastics and nanoplastics on liver health: Current understanding and future research directions

“…Lastly, the “long-term uncontrolled inflammation” by MPs/NPs can be a cause of tumor induction. Although one epidemiological study suggested polyvinyl chloride MPs exposure may increase the risk of liver cancers[ 67 ], it is uncertain whether the carcinogenic effect is caused by MPs or vinyl chloride monomer per se . Nevertheless, the more prominent existence of different MPs in cirrhotic patients than in healthy subjects implies that MPs/NPs may play a more important role in pre-cancerous lesions[ 49 ].…”

Hubs for Interactive Literature (HILs) as a Complimentary Visual Tool for Reviews

“…This HIL enables a focused screening of the data to identify only those studies associated with a particular microplastic substance, which reflects the related review. This feature is helpful in comparing health effects due to a single microplastic exposure, such as to polyvinyl chloride (PVC), to many other specific microplastic substances [6]. The HIL contains 3 interactive tabs reflecting the figure from the original publication.…”