Pick out the wrong statement

• Low ozone layer thickness in polar regions is due to cold climatic conditions
• Amount of unburnt hydrocarbons emitted by two stroke petrol engine is more as compared to that emitted by a four stroke engine.
• Carbon monoxide present in the two stroke petrol engine exhaust is much less as compared to that emitted from a four stroke engine.
• Mercury as a pollutant can enter the blood stream & the digestive system/ lungs and is responsible for causing minamate disease.