What Happens To Rubber That Wears Off Auto Tires

Science Daily ^ | 11-28-2002

[blam]

Date: 11/28/2002

What Happens To Rubber That Wears Off Auto Tires?

Alison J. Draper, an assistant professor of chemistry at Bucknell University, Lewisburg, Pa., is doing research where the rubber meets the road -- literally. She's investigating the environmental and health impacts of automobile tire wear particles. As automobile tires move along a road, tiny particles are worn off, and can end up in the air and in nearby waterways. Draper previously did research on diesel exhaust, but says that tire rubber is "much more interesting chemically," containing heavy metals like zinc and cadmium, hydrocarbons, latex, and sulfur-containing compounds.

Draper's research is not yet complete. But so far her findings include preliminary but solid evidence that tire wear particles may have negative impacts on small organisms in water habitats. Airborne tire particles may also aggravate respiratory problems in human beings (such as asthma or allergies).

Draper's method has been to make up clean samples of water like those inhabited by several kinds of aquatic organisms -- algae, duckweed, daphnia (water fleas), fathead minnows, and snails -- and under controlled laboratory conditions, put finely ground tire particles into the samples. By letting the particles remain in the water for 10 days and then filtering them out, she created a "leachate" that included substances in the tire rubber. All the organisms exposed to the leachate died, and the algae died fairly quickly.

Draper is also working on determining the levels of tire rubber chemicals in water that cause sub-lethal effects, such as reproductive problems in the snails and pre-cancerous lesions in the minnows. Draper's work so far has been performed in a lab, under controlled conditions, but she says there's "good evidence" that tire rubber may have similar effects on similar organisms living in real waterways along real roadways.

An environmental chemist with a doctorate in toxicology (University of Kansas Medical Center, 1996), Draper is also the Clare Boothe Luce Professor of Environmental Chemistry at Bucknell. She says there's good evidence from the chemistry of tire rubber that it also has the potential to cause asthmatic and/or allergic-type reactions. "We're only at the very beginning of that investigation. But, given the chemicals in tire rubber and given how readily they leach out, we can expect a respiratory response [in human beings]," she says. "It depends on the levels of the chemicals and the level of exposure -- certain people will be more susceptible than others."

Draper's research started humbly, with an old tire that came from her father's 1981 Chevrolet Malibu and was already on the refuse heap. "My father was about to throw it out," Draper recalls, "and I said, 'Wait!' " Now she uses tire tread particles supplied by a company in Mississippi, already ground up, and consisting of mixed tire brands.

[RightWhale]

WHY IS THE MICHELIN MAN WHITE???

Raw rubber is sap from the rubber tree. It is white.

[INSENSITIVE GUY]

Well,here's someone else with too much time on their hands.Let's hurry up and get this out of the way so you won't have to worry anymore.The material wears off the tires,eventually settles on the ground due to gravity and it's own weight,then it rains several times where it returns to the earth from which it came.PROBLEM SOLVED,let's move on to the next thing.

[alloysteel]

The short answer is that the tires are ground into very fine dust, which settles as particulate matter relatively close to the road. This fine dust is attacked by bacteria in the environment, and reduced to its constituent elements, combined into organic compounds with a sulfur component. For those of you who have forgotten or never studied biochemistry, sulfur is an important component in several amino acids, building blocks of protein, and the supposed ill effects of sulfur are quickly mitigated.

Falling in water merely accelerates this biological activity, and the ecology simply absorbs the excess sulfur, much as excess carbon dioxide is taken up by plant life and various microorganisms. In the long view, the various populations of microorganisms shift, but none are driven to extinction, and no lasting harm ever results from extending the life cycle to include what is essentially debris from the industrial base.

[AZLiberty]

The reason that there is not a huge slag heap next to the oil refinery is that they take the un-refinable waste product and sell it for building roads and streets.

I thought it went somewhere else. I've always said that if it wasn't for Diet Coke, this country wouldn't know where to put all its toxic waste.

[Captainpaintball]

Johnnie Cochran, or Jackie Childs...where are you? This is your next big scheme, I mean, cause!!! Just imagine the press conference...

99.999% of today's tires are black. The current "Michelin Man" is an inaccurate representation of the racial makeup of tires everywhere, and therefore, is offensive.

We demand that Michelin change its "Michelin Man" to accurately reflect the racial make up of the vast majority of tires on and off the road...for tires that were, tires that are, and tires that will be in the future...for tires that are bald, and new tires that have those "extra, long thingies" on the tread...for racing tires, tractor tires, and even bicycle tires... we want recognition, representation, and most of all, reparations!!!

And, johnnie, or jackie... I want a cut of the "profits", since it was my idea!!!

[xm177e2]

There is "Sudden Oak Death," and there is the Oak Worm Moth. Neither of those has anything to do with rubber.

[-YYZ-]

Concrete roads are good for a number of reasons, but they suck in northern climates. Inevitably there are cracks that allow water to get at the rebar. In the winter this water includes road salt. The road salt greatly increases the rate of rusting of the rebar, until it expands enough to crack the concrete around it. Then you have a crumbling concrete road surface that needs patched, which just doesn't work well. And repaving a concrete road is a really major project.

It's too bad, too, as concrete doesn't flex like asphalt, so roads paved with it tend to be flat and even and smooth, expcept for the expansion joints. Heavy trucks actually have less rolling resistance on concrete, as the asphalt road surfaces will actually flex under the wheels, so that the truck is essentially constantly pulling itself out of a dip in the road.

[Toidylop]

This so-called scientist apparently never heard of road kill...

[blam]

"The material wears off the tires,eventually settles on the ground due to gravity and it's own weight,then it rains several times where it returns to the earth from which it came.PROBLEM SOLVED,let's move on to the next thing."

Okay, next problem!

Warning Over Fish Mercury Levels (Heart Attacks)

[DallasMike]

They were subsequently cited by a county inspector for environmental violations involving hazardous waste, i.e. the old pavement. Apparently when it's in a parking lot it's innocuous, but when it's on a junk pile it's hazardous.

I was in the environmental business for 15 years (glad I'm out) and your last sentence sums things up quite nicely. One of my longest running projects was proving to the state that asphalt from Dallas city roads that were used as fill on private property did not adversely affect the environment. Stupid, stupid, stupid.

[Fintan]

"We're only at the very beginning of that investigation. But, given the chemicals in tire rubber and given how readily they leach out, we can expect a respiratory response [in human beings]," she says. "It depends on the levels of the chemicals and the level of exposure -- certain people will be more susceptible than others."

"And by that time, I'll make a fortune on the lecture circuit, deposit a huge book advance in my bank account, make numerous appearances on the 'Today' show, all without having ever worked a day in my life or done anything remotely beneficial for manking or society-at-large".

[ASOC]

How about "what happens to the oil that drips off my car?" as a related issue?
Non-point source oil spills - put more oil in the environment each year than the Exxon Valdez (albeit over a much larger area)
Or how about "Space dust from metorites" or"....well, you get the picture.
Some enviro stuff is important and affects us all (remeber Love Canal?) - some is junk science at best.

[VMI70]

I'm getting so old that I can barely remember my name.

Hope you had a Merry Christmas!

[Dick Bachert]

It becomes one with the road.

It's a ZEN thing.

[Dick Bachert]

BTW, suggest you dust off that STEEL WHEELED buckboard.

[mountaineer]

I hope the professor won't be plagiarizing any of this high school boy's research:

A Linsly junior recently won first place in the Regional Junior Sciences and Humanities Symposium held February 15 and 16 at West Virginia Wesleyan College in Buckhannon, West Virginia for his project, "The Hidden Consequences of Tire Wear." ....

The project, entitled "The Hidden Consequences of Tire Wear," examined where the rubber goes when tires wear out. Research for the project began in the fall of 2000. The idea for the project came to the student approximately two years ago when he was reading a question and answer column in a newspaper and he saw a question asking where the rubber goes after a tire wears out. As a result, the student decided to study the question himself. Joseph actually designed and built his own testing device for this project using a belt sander and a mounted tire.

The project indicated that rubber particles from tires can in fact be found in soil adjacent to highways and can become airborne. He has linked his findings to current research that has documented an increase in latex allergies and asthma over the past thirty years.

Recently, the research has led him to consider different methods of reducing the amount of tire dust which is thrown off vehicles. He has investigated whether the coarseness of the road surface affects the size of the rubber particles by using the tire wear tester he constructed with belts of differing grits. However, no measurable difference was found in the sizes of the rubber particles collected in this test, indicating that the condition of our highways has little relevance with the size of the particles coming off the tires. His next area of study involved designing and constructing several different devices that would collect the rubber particles as they are thrown off the tire. These have been tested in actual use conditions as well as with the tire wear tester.

The project on the topic of tire wear was the grand prize winner at last year’s West Liberty State College Regional Science and Engineering Fair and took 1st place in the Environmental Division at the West Virginia State Science Fair at Marshall University. Last may, the student presented his project at the International Science and Engineering Fair, held in San Jose, California, winning 3rd place in the Environmental Science division. The second year of this research will be presented March 22 and 23 at the West Liberty Science and Engineering Fair as well as the West Virginia State Science Fair at Marshall University on April 6, 2002. source; see also this

Or, this one from 11/2000:

I am planning on doing a tire bioremediation science fair experiment this year. I am 16 years old and am currently a junior. This will be my second year study; I completed a science fair experiment last year. The following is my abstract: Where did the Tires Go? A short-term study of bioremediation of vulcanized rubber by the bacteria Sulfolobus acidocaladarius ...

[Oberon]

One of my longest running projects was proving to the state that asphalt from Dallas city roads that were used as fill on private property did not adversely affect the environment.

Did nobody realize that, had they been able to prove the pavement hazardous, the city and county could both have been tasked with cleaning up the enormous "hazardous substance" deposits lining the surface of every municipal right-of-way?

Not to mention resurfacing all the roads with concrete?

[Lessismore]

Concrete roads are good for a number of reasons, but they suck in northern climates.

True. But consider that one of the consequences of switching to an alternative fuel system, like hydrogen fuel cells using hydrogen produced from water by fusion nuclear plants, will be that there will be no more asphalt for paving. So using fuels made by other than refining crude oil implies using another paving system, be it concrete or something else.

[SauronOfMordor]

WHY IS THE MICHELIN MAN WHITE???

Can you imagine the hassle they would get for having the Michelin man in blackface?

[chilepepper]

Easy, it goes into your brain and makes you want to watch MTV.