Disease carrying pests, such as rodents, may live in tire piles. Mosquitoes can also breed in the stagnant water that collects inside tires. Several varieties of mosquitoes can carry deadly diseases, including encephalitis and dengue fever.
Fires
Fire presents a second concern. Scrap tire fires are difficult to extinguish, and can burn for long periods. Tire fires release thick black smoke and can contaminate the soil with an oily residue. Tire fires generally start either as a result of arson or an accident.