Over-exposure to carbon monoxide (C0) of low-level can cause damage to kids' ears leading to permanent hearing-loss.In a research conducted over rats, UCLA scientists have discovered how chronic exposure to low levels of carbon monoxide (CO) damages the inner ear of young rats, resulting in permanent hearing-loss. This study appeared in this month's issue of the Journal of Neuroscience Research.At the Ca/OSHA's exposure limit of 0.0025 per cent