Skip to content
CityLab
Environment

More Lights, More Diseases?

An ongoing study suggests light pollution’s effects on animals can help spread some viruses, like West Nile.
Chicago lights up at night.
Chicago lights up at night.Jim Young/Reuters

Light pollution is known to cause all kinds of problems. Studies show how it can throw sleep cycles out of whack and disrupt the natural ecosystem. Now biology researchers at the University of South Florida suggest yet another unintended consequence of artificial lights: They may help the spread of vector-borne diseases like the West Nile virus.

The West Nile virus is carried primarily by birds, and, in the right circumstances, can be passed on to humans via mosquitoes. Typically that infectious period in birds only lasts a few days as the immune system fights to lower the viral load. House sparrows, in particular, stay infectious for about two days.