Question

Which one of the following is measured in Dobson units (DU)?

Options

• Thermal pollution of water

• Thickness of ozone in a column of air

• Biochemical Oxygen Demand

• Biomagnification of DDT and Mercury

Answer 1

Thickness of ozone in a column of air

Explanation:

1 DU = 0.01 mm thickness of ozone if compressed at STP. It measures the thickness of ozone layer.