Why is it desirable to use unleaded petrol in vehicles fitted with catalytic converters?

It is desirable to use unleaded petrol in vehicles fitted with catalytic converters because:

1. The catalytic converter present in the automobiles gets inactivated due to the lead present in petrol. Using unleaded petrol would not result in this issue and thus, control emission of pollutants.

2. Health issues like erythrocyte damage, anaemia, damage to Central Nervous System can be reduced.