Bad air. Malaria. We fear what lurks in the dark, in the creeping tendrils of fog, hiding in plain sight...
We humans used to flee the cities in summer, to get away from the bad air. Sicknesses ran rampant in the warmest times. In the times when the fog lifted off the river and ports and rolled inland, bringing an eerie feeling with it...
For good reason, it turns out. Not that fog deserves the level of fear pulp novels and B movies have imbued it with. Interestingly, there's actual science behind our fears of night, of fog, of swamps: mosquitoes and pathogens alike lurk in them. This opens the possibility that yes, an open sewer system could give rise to an outbreak of sickness when the fog droplets aerosolize the microbial load of what lies stewing in them. In a modern landscape, sewage is hidden away and cannot bring this threat to light, but not all of the world looks out on an up-to-date vista. And where there is money, there are pesticides and screens and mosquito nets. We wrap ourselves up in gauze against the miasma of the night, and sleep soundly.
Halloween season brings with it a renewed sense of bumps in the night being something to worry over. But for me, it's what you can't see coming that is worrisome. I can arm myself against intruders, zombies, and monsters. Germs? Not a whole lot you can do if they are in the air you breathe. True horror is not making any convenient bumping sounds, much less moaning and shambling.