Recent incidents with air traffic controllers have pointed up the hazards of shift work and the supremacy of the circadian rhythm. In one recent case, an air ambulance was forced to land at 2 a.m. without local air traffic controller guidance at Reno-Tahoe International Airport.
These recent incidents have pointed up the existence and causes of what medical science calls Shift Work Sleep Disorder, or SWSD. It’s not clear how many people are affected by SWSD, but it’s probably a fairly significant chunk of the 15% of Americans who perform night-shift work.
Lead (battery) balloon
When I was 19, I dropped out of school for a time and took a job working in a plant that melted down lead plates from car batteries and turned them into lead ingots. The lead ingots were then sold back to AC Delco and other manufacturers of lead-acid batteries.
My job was to maintain the efficiency of the blast furnace by climbing two stories to its top, where there was a small hole about twice the diameter of a pencil. I’d stick a hollow metal rod inside. On the cooler end of the rod was a hand pump and a toy balloon for collecting the gases. Then I’d bring the balloon back to the lab, rushing so that the entire thing didn’t leak, and run the gases through a chromatograph, an instrument that separated the gases by size. I’d report this to the engineers in the morning. These data would tell the engineers, who wore white hardhats, whether the furnace needed more air, or more fuel, to burn efficiently.