sentence: Ozone is a gas that is helpful and takes in harmful rays from the sun.
sentences_before: Secondary pollutants are pollutants that are made from chemical reactions when pollutants mix with other primary pollutants or natural substances like water vapor. Many secondary pollutants are made when a primary pollutant reacts with sunlight. Ozone and smog are secondary pollutants.
sentences_after: When it is near the ground, though, ozone is a dangerous pollutant that influences the health of all organisms.
concept_name: ozone
headings: Air pollution Types of air pollution