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Mexico’s Poisonous Cave



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Natural Exhaust Vent
Photograph by Stephen Alvarez

Just inside the cave’s main entrance a natural skylight illuminates a pool. About two dozen skylights perforate the roof of the cave, allowing toxic gases such as hydrogen sulfide and carbon monoxide to exit and be diluted by fresh air coming in. More than 20 subterranean sulfur springs throughout the cave react with oxygen to form sulfuric acid, which eats away at limestone and is rapidly enlarging the cave.



Camera: EOS-1N
Film Type: Fujichrome 100
Lens: 17-35mm
Speed and F-Stop: 30 seconds @ f/4
Weather Conditions: Unrecorded
Time of Day: 4 p.m.
Lighting Techniques: Long exposure with natural light

Special Equipment or Comments:
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