So far, there has been little if any connection established between discarded scrap tires and the spread of the West Nile virus.
But that doesn't mean tires will forever have a clean bill of health regarding the virus, which so far this year has accounted for 46 deaths out of 1,201 reported U.S. cases, experts said. Scrap tires already are known to breed disease-causing mosquitoes if left alone and unprocessed.
The West Nile virus is spread by infected mosquitoes to birds, horses and other animals. The Centers for Disease Control and Prevention estimate that more than 110 species of birds in the U.S. have been infected with the virus. The CDC reports only six of the 48 continental states have escaped the virus entirely, and people have been infected in 29 states.
``The information that I have suggests that the mosquitoes that nest in tire piles aren't necessarily those that carry the West Nile virus,'' said Michael Blumenthal, senior technical director for the Rubber Manufacturers Association.
Mosquitoes of the species Culex-also known as ``wood'' mosquitoes-are by far the most likely to carry West Nile, according to Blumenthal. Culex mosquitoes tend to breed in water collected in or near trees, whereas the Aedes mosquito-including Aedes albopictus, or the Asian tiger mosquito, which first entered this country via infested tires-is the type most likely to lay eggs in stagnant water collected in scrap tires.
However, Culex mosquitoes sometimes breed in tires, and Aedes mosquitoes occasionally can carry the West Nile virus, particularly if they bite birds that have the virus. Aedes albopictus has a further nasty reputation as a carrier of encephalitis and dengue fever.
Scrap tire processing facilities aren't likely breeding grounds for West Nile-carrying mosquitoes, according to Blumenthal. A properly processed tire-chipped, ground or fumigated, or else moved off the property within two weeks-isn't a prospect for the laying or hatching of mosquito eggs.
``It takes 14 to 17 days between the laying and the hatching of a mosquito egg, so if you move the tires out within 14 days, you will disrupt the mosquito's life cycle,'' he said.
Furthermore, the vast majority of mosquitoes never travel farther than 500 to 1,000 yards from where they were hatched, Blumenthal said. Since most scrap tire processing facilities aren't in residential areas, they provide a dearth of human fodder for mosquitoes.
However, this does mean that single tires or small groups of tires on residential property-``abandoned in an old barn, or even used as a tire swing where someone forgot to punch a hole in the tire,'' he said-are potential danger zones.