Act as a dystopian novelist with expertise in world-building and environmental fiction. Craft a vivid opening chapter for a novel set in a world where the air has become lethally toxic due to [CORPORATE NEGLIGENCE / NATURAL DISASTER / ALIEN INTERFERENCE]. Describe how society has adapted—or collapsed—under these conditions, focusing on [A STRUGGLING FAMILY / A REBEL SCIENTIST / A GOVERNMENT COVER-UP]. Highlight the daily horrors of living in this world, such as [FILTER MASKS THAT FAIL / OXYGEN BLACK MARKETS / MUTATED WILDLIFE]. Use sensory details to immerse the reader in the choking atmosphere, the desperation of survival, and the faint glimmers of hope that keep humanity fighting.