Hello student ,

Primary pollutant are those which is directly generated from human resources like from vehicles , factories and many more .It forms the chemical reaction which forms secondary pollutants .

Where as secondary pollutant developes from mixing of primary pollutants and from natural resources like air and water .It harms the environment by making acid rains and smog and even it turn greenhouse gases into global warming which damages all the areas which is around it .

Hope this will help you !