Smoke from the factory chimney. Environmental pollution. Air emissions polluting the city. Industrial waste is hazardous to health.

Azure Empyrean Firmament Heavens Lid Vault Welkin Air Pressure Envelope Sky Troposphere Atmosphere Breeze Wind Blast Draft Ozone Puff Stratosphere Ventilation Waft Whiff Zephyr Humidity Temperature Altitude Aridity Clime Conditions Latitude Dusk Nightfall Sundown Twilight Eve Evening Eventide Gloaming Crisis Emergency Exposure Insecurity Instability Jeopardy Menace Peril Pitfall Possibility Probability Risk Threat Uncertainty Vulnerability Clouds Dynamite Endangerment Exigency Precariousness Precipice Slipperiness Storm Venture Contaminated Crummy Disheveled Dusty Filthy Greasy Grimy Messy Muddy Murky Nasty Polluted Sloppy Stained Unkempt Bedraggled Begrimed Black Defiled Disarrayed Foul Fouled Smudged Spattered Spotted Sullied Automation Machinery Computers Mechanics Mechanization Robotics Telecommunications Belfry Castle Citadel Column Fort Fortification Fortress Keep Lookout Mast Minaret Monolith Obelisk Pillar Refuge Skyscraper Spire Steeple Stronghold Turret Coincidental Inconclusive Indirect Alarming Bad Critical Deadly Fatal Perilous Precarious Risky Serious Terrible Threatening Treacherous Ugly Unhealthy Unsafe Unstable No-go Industrialized Mechanical Modern Technical Business Commerce Corporation Management Production Trade Manufactory Mob Monopoly Outfit Traffic Duct Hose Line Pipeline Sewer Vent Vessel Aqueduct Canal Channel Conduit Conveyer Main Spout Trough Conservation Preservation Bionomics Smoke Vapor Effluvium Fumes Hot air Miasma Stream Harmful Lethal Noxious Pernicious Virulent Abuse Corruption Deterioration Infection Adulteration Blight Decomposition Defilement Desecration Dirtying Foulness Impairment Impurity Misuse Profanation Rottenness Soiling Spoliation Taint Uncleanness Vitiation Exhaust Fog Gas Mist Pollution Smog Soot Butt Branch Cooperative Firm Industry Laboratory Mill Shop Workshop Forge Foundry Mint Sweatshop Warehouse Workroom Works Construction Manufacture Manufacturing Assembly Bearing Blossoming Creation Direction Elongation Fabrication Formulation Fructification Generation Giving Lengthening Making Origination Preparation Presentation Prolongation Protraction Provision Rendering Reproduction Return Staging Yielding