You know that if you go hang out at a used tire shop (I've worked in the business) you'll find the most of the danger is from mashing your fingers, getting a tire blown up in your kisser and the like. You probably won't find a lot of super health conscious types working at those places, but will find a lot of alcoholics and druggies .. That's not saying much for the industry. I've worked with hazardous materials most of my life and at 58 I can't say I'm too much more worse for the wear.. I have nervous ticks and other ailments, but most of them could be traced back to solvent exposure and slips and falls and other not so fun incidences.. I doubt that I'm going to die directly from whatever chemicals used tires might have put out.John Pollard wrote:
John Schinnerer wrote:I love how these topics go around and around and after 20 years the same guesses and assumptions live on and nobody seems to know about resources equally old.
Some actual research (whoever posted there's no science is incorrect) from University of Wisconsin, a compilation of a bunch of stuff, all under the heading "Use of scrap tires in civil and environmental construction" is here:
http://chbenson.engr.wisc.edu/images/stories/pdfs/Reports/UW-Madison%20Scrap%20Tire%20Reprints.pdf
There was one major report - probably included in this compilation, and I have a hard copy somewhere still I think - that was pointed to by the Earthship folks back in the day. It basically said that used tire material buried in the ground doesn't seem to leach much of anything and since it's buried there's no offgassing and no UV-destabilization. The use case was chunked up tires as part of a subsurface earthen fill and/or embankment material for civil engineering. Any buried tire application is essentially similar, unless there are also solvents in the ground that degrade tire material, in which case the tire is probably the least of the problems.
What might be of major concern is the use of tires on actual cars, where they are a major non-point pollution source spread all over the country and emitting whenever they are driven on, spewing out tiny particulates that move with the air and water.
So for anyone concerned about reducing pollution from tires, the place to start is cars. Forget that old tractor tire planter in Grandma's yard. Minor issue. Do something about all those cars!
We have a winner. The guy behind earthips, Michael Reynoulds, looked into this a long time ago. Tires have a half life of something like 30,000 years when buried in a landfill situation.(one half life used=50% life remaining) There is no way to recycle them but you can re-purpose them. When they're shredded for playground mulch, they still get sun, freezing temps and high temps. That makes them break down pretty quick and then the nasties get in the soil/water. Burning them of course, is way worse unless. There is an industrial recycling process called tire pyrolisis https://en.wikipedia.org/wiki/Tire_recycling#Tire_pyrolysis
Currently, burying them is the safest option there is for tires. Burying them in landfills, they get mashed, mixed with other stuff, might stick out of the ground at times and will have rainwater flowing against them. Buried in an earthship, they're kept cool, dry and out of the sun. I don't know think a study of the half life of them in that case would result in. 100,000 years?
Meanwhile, you can make some cool looking outdoor furniture.
As far as out-gassing through the dry soil and whatever you coat your inside walls with, keep it fresh and crack free. I know some old tires guys that have been in the business their whole life and that's with dealing with stinky new tires and seemingly had no health problems at the age of 60 or so.
Drive less and don't park your tires in the sun.