Palladium nanoparticles as emerging pollutants from motor vehicles: An in-depth review on distribution, uptake and toxicological effects in occupational and living environment

• Published in: The Science of the total environment 2022-06, Vol.823, p.153787-153787, Article 153787
• Main Authors: Aarzoo, Nidhi, Samim, M.
• Format: Article
• Language: English
• Subjects: aquatic organisms; catalysts; Catalytic converter; Chronic toxicity; environment; Environmental pollution; geographical distribution; nanoparticles; palladium; Palladium nanoparticles; pollution; research and development; risk assessment; species; Sustainable technology
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.153787

Palladium nanoparticles (PdNPs) play an integral role in motor vehicles as the primary vehicle exhaust catalyst (VEC) for tackling environmental pollution. Automobiles equipped with Pd-based catalytic converters were introduced in the mid-1970s and ever since the demand for Pd has steadily increased due to stringent emission standards imposed in many developed and developing countries. However, at the same time, the increasing usage of Pd in VECs has led to the release of nano-sized Pd particles in the environment, thus, emerging as a new source of environmental pollution. The present reports in the literature have shown gradual increasing levels of Pd particles in different urban environmental compartments and internalization of Pd particles in living organisms such as plants, aquatic species and animals. Occupational workers and the general population living in urban areas and near major highways are the most vulnerable as they may be chronically exposed to PdNPs. Risk assessment studies have shown acute and chronic toxicity exerted by PdNPs in both in-vitro and in-vivo models but the underlying mechanism of PdNPs toxicity is still not fully understood. The review intends to provide readers with an in-depth account on the demand and supply of Pd, global distribution of PdNPs in various environmental matrices, their migration and uptake by living species and lastly, their health risks, so as to serve as a useful reference to facilitate further research and development for safe and sustainable technology. [Display omitted] •Palladium nanoparticles (PdNPs) play a crucial role as vehicle exhaust catalysts to mitigate environmental pollution.•Stricter emission laws in various countries has led to increased demand and supply of Pd in the automobile sector.•Application of PdNPs in vehicular engines has led to increased exposure of PdNPs to the ecological environment.•PdNPs, biotransforms and bioaccumulates in living beings and enter the food chain.•PdNPs exert cytotoxic and pro-inflammatory effects animals plants and microorganisms.