What is this article can trees keep air clean mainly about? Trees with large leaves have the greatest ability to capture pollutants that can cause irritation to people's lungs. The cost of a reforestation project in Texas, not including the cost of the land, would be about the same as using scrubbers to clean the air. A chemical company and a conservation group are working together on a plan to use reforestation to clean up air polluted by factories. A forest of pecan, ash, live oak, and hackberry trees along a stretch of the Texas Gulf Coast was cleared by settlers so they could build communities