Ecotoxicological Assessment of Various Sizes and Shapes of Copper Nanoparticles on Soil Biological Indices

Abstrak

The increasing production and environmental release of copper (Cu) nanoparticles raise concerns about their ecotoxicological impact on terrestrial ecosystems. However, the effects of particle morphology and subtle size variations on soil biological properties remain unexplored. This study aimed to determine how shape (spherical vs. “torn” porous) and minor size differences (70 vs. 100 nm) influence Cu nanoparticle toxicity in Haplic Chernozem. A model experiment used 3 Cu forms: spherical nanopowders (70 and 100 nm), spherical nanopowders with a porous “torn” surface (70 and 100 nm), and macrodisperse particles (7,000 nm). Each form was applied at 5 concentrations: 1.5, 2, 3, 5, and 10 times the background level (30 mg kg-1). Soil biological activity was assessed via integral indicators of biological state (IIBS). All Cu forms significantly suppressed key biological parameters. Nanoparticles exhibited higher toxicity than the macrodisperse form, and this was governed by concentration and particle shape. The highest dose (300 mg kg-1) caused the most pronounced inhibition. “Torn” nanoparticles demonstrated greater ecotoxicity than spherical ones: spherical 70 nm particles reduced IIBS by 14 to 59%, whereas “torn” 70 nm particles reduced it by 27 to 63% relative to the control. Size-dependent effects were observed exclusively for the “torn” morphology: 70 nm particles decreased IIBS by 19 to 47%, while 100 nm particles caused a reduction of only 14 to 34%. These findings confirm that both size and shape are critical determinants of Cu nanoparticle toxicity in soil. This study provides a basis for refining environmental risk assessment and regulatory frameworks for metal nanoparticle contamination in agricultural soils.

Kata kunci

• soil science
• environment
• biodiagnostics
• enzymatic activity
• heavy metal pollution
• microbiological indicators
• phytotoxicity