The reader can infer that napalm had what effect?

Napalm bombs generate carbon monoxide while simultaneously removing oxygen from the air. The air in the bombing area can be 20 percent or more carbon monoxide [source: GlobalSecurity.org]. This effect occurs because napalm partially combusts the oxygen in the air, turning CO2 (carbon dioxide) into CO (carbon monoxide).

However if you want a more clear answer I need a image of the passage.

the light represents granny weatherall's life.