Effects of Platinum Group Metal Exposure on Chick Embryo Skeletal Development

The automobile industry depends heavily on the use of platinum group metals (PGMs), which include platinum (Pt), palladium (Pd), and rhodium (Rh). In this study, the toxicological effects of PGMs on skeletal development were investigated. Chick embryos were exposed to a low concentration (1ppm) solution of either Pt, Rh, Pd, or a PGM mixture. On the 7^th and 14^th day of incubation, embryos were injected with either a 0.5 mL or 1.0 mL dose treatment. After 20 days of incubation, the chick's white leghorn tibiotarsi were harvested. The tissues were embedded in paraffin, and 4 µm thick cross sections were stained with hematoxylin and eosin. Prepared slides were examined using a light microscope at 400X magnification. The number of chondrocytes in different developmental stages was recorded. The SPSS statistical package was used to analyze the differences between the Pt, Pd, Rh, and PGM mixture treatments. There was a statistically significant difference between the three developmental stages of chondrocyte cells. Based on calculations by percentage, the control revealed a significantly higher number of mature chondrocytes, immature transitional chondrocytes, and isogenous groups than the Pt and Rh exposures. However, all developmental stages numbered significantly higher in Pd than in all other exposures. Erythrocyte infiltration and multinucleated osteoclasts were present in the PGM mix exposure. Increased ossification was observed in Pt treated tissue. The results show that there is an effect of PGMs on embryo skeletal development, suggesting concerns regarding the possible effects of PGMs on the environment and human health.