The fact is, yes children have been playing on tire swings for a century. Has there not been any problems? Far from certain. Latex allergies have only been recognized for a very short time. Exposure issues quite likely have been around since we first started using latex, people just did not know what to ascribe the problems to. I would suggest that it is entirely too late to ask anyone who ever had a rash after playing on a tire swing to get tested for sensitivity to the latex protein.
It is also generally agreed that the vuclanized version of latex in a tire is more stable than the latex used in gloves or swim caps. However, there is significant documentation that as tires wear, and after tires are de-vulcanized (frozen to extreme temperatures so that they can easily be crushed to remove the steel lining) that the latex protein is released.
The following data sources provide significant information that essentially supports a more cautious approach than the scraptires site or the author of the comment:
A Case Study of Tire Crumb Use on Playgrounds: Risk Analysis and
Communication When Major Clinical Knowledge Gaps Exist
A couple key passages:
Regarding our central question of potential harm to children, the published literature
contained some information about the product, including an in vitro toxicity
model, but traditional published resources and a network of environmental health
experts could not establish the product’s safety in use with children. (Gapin Children Research page 1)
Risks may exist in working with the product, but the question regarding hazards posed tochildren playing on the amended playgrounds is left unanswered. (Gapin Children Research page 3)
Impacts of Tire Debris
The interaction between inhaled particles and lung cells is described in literature [66,67], as well as the correlation between tire particles and the release of latex allergy proteins [23,68].
In this study the latex protein extracted from car tires is nearly as high as the latex protein found in latex gloves, the study notes that it had expected the vulcanization process to destroy natural latex proteins, the authors found it notable that the presence of latex allergens in tire tread was confirmed across several different tests.
The commentor also noted:
There are hundreds of millions of tires in use on motor vehicles today. These tires wear off particles of rubber into our environment during their normal use with no known long term health hazard. Once removed from service, their composition does not change. If they are made up of materials that are hazardous to any portion of the population then we need to stop their production, unless there is no significant hazard here.
The following comments will illustrate that, in fact, there is a known problem.
Latex Allergens in Tire Dust and Airborne Particles
In conclusion, the latex allergens or latex cross-reactive material present in sedimented and airborne particulate material, derived from tire debris, and generated by heavy urban vehicle traffic could be important factors in producing latex allergy and asthma symptoms associated with air pollution particles.
As tires wear out, rubber is presumably deposited on the road
surface. Where is all that rubber?
All over the place, bud--including maybe in your lungs. For a long time conventional wisdom had it that tire particles were too coarse to do much harm and simply wound up as one more component of urban grit. Now we know better. Asthma and latex allergies have been on the rise in recent years, and some think tire dust is why.
Fine rubber particles, whether latex or synthetic, can lodge in your lungs and even enter your bloodstream. The Environmental Protection Agency has a whole category designated for such problematic particles: PM2.5, or particulate matter less than 2.5 microns in size. Excessive exposure can lead to reduced lung capacity, bronchitis, asthma, accelerated heart disease, and death. One study claims that nearly 60 percent of airborne tire particles are small enough to be easily inhaled.
Paving, Asphalt, Tires and Latex Allergies:
What is the Relationship?
If you are a latex allergy victim and you experience any type of reaction around streets that are being paved, or asphalt that is being added to roof structures, there is a very good reason. Asphalt, when combined with ground up tires in the paving process, contains natural rubber.
A study of blood samples from asthmatics and healthy persons from the Los Angeles area showed a high correlation in the increased incidence of latex allergen antibodies in asthmatics. Victims of latex protein hypersensitivity should avoid areas that are being paved or roofed when asphalt is being used. The airborne particles of natural latex proteins emitted in these processes are known to cause reactions in latex allergic individuals.
This particular study explores the impact of heat on latex. It is commonly thought that the vulcanization process will reduce the latex protein in tires. However, as the Groce article in the Latex from Tires notes, the heating process of rubber tires when included in asphalt releases the latex protein into the air. Why is this important in the framework of the poured rubber surface and rubber tiles surfaces at the playgrounds? From what we have found is that these surfaces use devulcanized rubber, devulcanization is a process to breakdown the binding aspects of vulcanized rubber to extract the natural latex rubber from the hardened tire. The devulcanized rubber appears to free the latex protein that may have been bound up in the hardening of the vulcanization process.
Latex Allergy in 2004
What’s Known, What’s Now, What’s Next
There is not yet good research about many aspects of preventing or managing latex allergy. For example, the use of recycled tires for surfacing playgrounds and athletic tracks is controversial. Given the current knowledge about latex allergy, we recommend that:
• In the general healthcare environment, non-latex or low-allergen unpowdered gloves should be the standard. This will reduce future sensitization.
• All individuals with spina bifida and related conditions should have a latex-safe environment from birth. This means in hospital, at clinics, in school and camp and in the community at large, including restaurants and shopping malls.
While this is a report provided for patients with Spina Bifida, the recommendations hold true for any latex allergic person.
So, back to the rubber industry quote “after all children have been swinging on tires for a century…” as a means of supporting the use of tires in playgrounds. Personally we recognized a problem on the Wing School Playground over two years ago when our son experienced hives when playing on the equipment. The contact hives were determined to generate from the black rubber bridge that was on the playground. This bridge was one element removed on the playground to make the area safer for latex allergic children. Of course, the starting point is recognizing the existence of a latex allergy in a child. Without that, connections are not made. A child could go into shock due to a latex allergy, and if that child is not known to be one of the between 2% and 8% of the general population considered to be allergic to latex the connection will not be made (Looking out for Latex).
So, anyway, yes tires can be landfilled in some states. Many, if not most landfills discourage such disposal of tires as they do not decompose (even though a properly sealed landfill will never decompose any of the buried material). I am far more familiar with the tire piles that have led to major pollution problems - especially when they have caught on fire:
Problems associated with landfilling of scrap tires Landfilling of scrap tires causes serious environmental pollution and health problems. Of the 283 million scrap tires generated in the United States in 2003, nearly one-fourth wound up in landfills. This is in addition to more than 300 million tires already stockpiled across the country. The estimated cost of cleaning up the existing tire stockpiles in the United States is in the range of $800 million to $1 billion. The most obvious hazard with the stockpiling of scrap tires is the potential for large uncontrolled fires. Scrap tires are petroleum-rich products, and as tires burn, they release particulate pollutants to the atmosphere and hazardous chemicals into groundwater. Several uncontrolled fires have recently occurred in tire stockpiles (e.g. California, 1999), which have posed tremendous hazards to the environment. Tire piles are also prime breeding grounds for mosquitoes and other vermin, which are vectors for human diseases such as Dengue fever, Malaria, and West Nile virus. The World Health Organization estimates that over two billion people live in areas at risk for epidemic transmission of these diseases.
Finally, in closing (while I have a tremendous number of other sources including ones looking at the dust on artificial football fields using rubber dust for the base) I found this post while writing this reply:
How Safe is Your Child’s Playground? Recycled Tire Cushioning Poses Health Concerns
"The next time my kids want to play on a recycled tire playground, I think we will walk on by to a playground made with safer materials."
