The best methods of air pollution control often depend on the individual or industry using them, but in most cases they focus both on reducing pollution at its source and minimizing the overall effects on the environment. Factories and other industrial complexes that emit a lot of toxins into the air sometimes find that using active carbon can be an effective way to filter air before it is released into the atmosphere, and biofiltration — a process that uses natural bacteria and fungi to reduce emissions — often works in a similar way. Building cleaner car engines can help reduce traffic-related emissions, as can different behavioral and monetary incentives for commuters to reduce the time they spend driving. Different countries and regions have different standards and best practices, but in most cases the core goals of air pollution schemes are similar.