Manganese Accumulation and its Effects on Hearing Loss by ICP-MS

Funding: National Institute of Occupational Safety and Health, NIOSH

Collaborators: Richard Salvi and Jerome Roth (University at Buffalo)

Our overall goal in this study is to evaluate the effect of manganese exposure focusing on the accumulation of manganese in ear and brain tissue and the effects accumulation has on other biologically relevant metals (copper, zinc, iron) as well as hearing loss. This project is in collaboration with the Center for Hearing and Deafness at the University at Buffalo. Our collaborators are working on determining the link between manganese accumulation in the inner ear and hearing loss. Hearing loss is a common symptom of miners where are exposed to high levels of manganese dust.

A rat model is being used for this study. Rats are exposed to manganese in their drinking water for 30 or 60 day periods. Rat tissue samples are then harvested for analysis by either solution mode or laser ablation ICP-MS.

The novel aspects of this study are the:

1. Development of a micro-scale acid digestion procedure to determine the concentrations of Mn, Cu, Zn, Fe in samples less than 20 mg.
2. Analysis of untreated ear and brain samples to determine the endogenous metal concentrations.
3. Long term (30 and 60 day) exposure studies to determine the uptake of Mn and the effect accumulation has on other biological relevant metals in tissues specific to the central nervous system and the auditory pathway.
4. Laser ablation ICP-MS imaging to determine areas of accumulation in brain slices.