There are four main types of air pollution sources: mobile sources â such as cars, buses, planes, trucks, and trains stationary sources â such as power plants, oil refineries, industrial facilities, and factories
Incubation Period: Average 9-10 days. Period of Communicability: Highly communicable in the early phase and at the beginning of the paroxysmal cough stage (first 2 weeks). The child is no longer contagious after 5 days of treatment.
The contagious period is the amount of time during which a sick child can give the disease to others. For major illnesses (such as hepatitis), a child will need to stay at home or in the hospital until all chance of spread has passed.