Possible Clues:

• Pollutant in a Jersey ditch?
• Drops environmentally unfriendly car India produced
• Form of pollution -- a constant one associated with sewer
• Pollutant from a sewer enveloping capital of Caribbean island
• Corrosive precipitation
• Pollutant in a Channel Islands sewer?
• Precipitate from a Jersey evacuation?
• Using air-conditioning I draw off form of pollution
• Inca raid (anag) — it's a combination of industrial gas emissions with water in the atmosphere
• One lot of detectives having shower, possibly cause of bad atmosphere