Question

measuring air pollution
lead is an air pollutant.
when was lead removed as an additive from gasoline?
the 1970s
the 2010s

Explanation:

The question is about when lead was removed as an additive from gasoline. Historical and environmental regulations show that lead was phased out from gasoline in the 1970s due to air pollution concerns and regulatory actions like the Clean Air Act amendments, so the correct option is "The 1970s".

Answer:

The 1970s