A light pollution can be heavy.Logical formLearned from3 sentences. (Air pollution) can be worst.Logical formLearned from3 sentences. Pollution may be associated with development.Logical formLearned from3 sentences. (Pollution problems) may be identified.Logical formLearned from3 sentences. Pollution may be caused by heavy metals.Logical formLearned from3 sentences. New technologies may generate pollution.Logical formLearned from3 sentences. Pollution may be caused by (soil erosion).Logical formLearned from3 sentences. Costs can be constituted-of-or-filled-with (pollution abatement).Logical formLearned from3 sentences. Pollution may pose challenges.Logical formLearned from3 sentences. A main source may pertain-to an (air pollution).Logical formLearned from3 sentences. (Air pollution levels) can be in a world-city.Logical formLearned from3 sentences. Cars may produce (air pollution).Logical formLearned from3 sentences. Pollution can be by water.Logical formLearned from3 sentences. A problem of pollution can be severe.Logical formLearned from3 sentences. Estuaries may undergo pollution.Logical formLearned from3 sentences.