Around 15 percent of scrap tires are taken back by, or returned to customers. Many disease carrying pests flourish in tire piles. Chief culprit are many kinds of mosquitoes that prefer to breed in the quiet, stagnant water that collects inside tires. In addition to being the normal pests that all mosquitoes are, several of these varieties can carry deadly diseases, including encephalitis and dengue fever. Control and eradication programs, short of removing the pile, are difficult.
Fire presents a second threat.
Scrap tire fires are difficult to extinguish, and can burn for considerable periods, releasing heavy black smoke and possibly contaminating the soil with an oily residue. This can cause considerable discomfort and damage to the environment. States however have been very active, with 48 states having some law or regulations specifically dealing with scrap tires. Experience from across the U.S. provide several examples of programs that can reduce illegal dumping and help clean up existing dumps. On a widely publicized day, any local citizen can bring a limited number of tires to a drop-off site free of charge.