Described herein are methods for reducing the risks of exposure to air pollutants, comprising nasally administering to a subject in need thereof a composition that counteracts the effects of one or more air pollutants, wherein the composition is adapted for nasal administration. In some embodiments the composition comprises an agent that binds to one or more air pollutants, wherein the agent comprises one or both of nonporous silicon dioxide and porous silicon dioxide and/or the composition provides a physical barrier between one or more air pollutants and internal nasal surfaces. Also described are nasal compositions comprising an agent comprising one or both of nonporous silicon dioxide and porous silicon dioxide, a lipophilic or partly lipophilic vehicle, and a surfactant, wherein the composition is adapted for nasal administration. The compositions also may comprise other agents, such as an immunosuppressant. Also described are methods of making and using the compositions.