Why does two stroke engine pollute air more than a four stroke engine?

Two-stroke engines generally pollute the air more than four-stroke engines due to their design and operation. In a two-stroke engine, the combustion cycle is completed in just two strokes of the piston, which often leads to incomplete combustion and unburned fuel escaping during the exhaust phase. Additionally, two-stroke engines typically mix oil with fuel for lubrication, resulting in higher emissions of hydrocarbons and particulate matter. In contrast, four-stroke engines have a more efficient combustion process and separate lubrication systems, leading to lower emissions.