Using "Cause and effect" as a text structure for your essay on recycling can be a strong choice. This approach allows you to explain how pollution results from waste and lack of recycling, as well as how recycling can mitigate these harmful effects.
However, "Problem and solution" might also be a fitting choice, as it can lead you to clearly define the problem of pollution and offer recycling as a solution. This structure emphasizes both the urgency of the issue and the practical steps people can take to help alleviate it.
In summary, both "Cause and effect" and "Problem and solution" are effective choices for your essay on recycling. You might even consider combining elements of both structures for a more comprehensive approach.