Which of the following is not a way of reducing air pollution?

The option that is not a way of reducing air pollution is "Recycling tins, cans, and bottles." Although recycling is an essential practice to reduce waste and conserve resources, it does not directly contribute to reducing air pollution. Recycling helps in reducing waste accumulation in landfills, which can lead to water and soil pollution, but it doesn't address air pollution. The other options mentioned are ways of reducing air pollution. Siting factories and power stations away from residential areas helps in minimizing the exposure of people to harmful air pollutants. Building tall factory chimneys allows pollutants to disperse over a larger area and not accumulate close to the ground level where people breathe. Passing waste gases through filters and absorbers removes harmful substances from industrial emissions before they are released into the air. Using lead-free petrol in cars helps in reducing emissions of harmful substances, such as carbon monoxide, nitrogen oxide, and particulate matter, which contribute to air pollution.