The title says it all the dangers are endless! Yes, plane tree trichomes (tiny hair-like structures) have tiny hooks that allow them to get caught in airways, causing irritation. This physical irritation is responsible for the well-known "Chelsea Cough" or "plane tree dust" symptoms, which are distinct from an allergic reaction to pollen! 
The fibrous bristles on the trichomes have these microscopic hooks, which, once detached and airborne (especially during spring and summer when leaves and seed balls break down), can be inhaled. This can cause respiratory discomfort, eye irritation, and exacerbate conditions like asthma or bronchitis in sensitive individuals! Constant exposure can cause some individuals to develop asthma which can be a terrifying experience particularly for young children.