10/01/2008: "Crumb Rubber The right surface for the new Friday Harbor Elementary School Playground?"
By Janice Peterson
The new playground has been anticipated for a long time and from what I have seen and heard, nearly everyone is very happy with it. The crumb rubber surface makes it much harder to get hurt and has the advantage of using recycled materials (tires). Some parents and concerned others, however, have raised questions about the material that should be satisfactorily answered - Is it safe in terms of toxicity levels? Is it flammable? Does run-off from the material cause any problems? Are there things we should know about it that might be negative? And so forth.
The information below comes solely from my online research. Additional information would be helpful. Conversation with others has brought up hazards to children with asthma (my grandson is one of them) but I haven’t been able to find documentation on this. I am also thinking of data I have heard is always supplied by manufacturers for the benefit of buyers which details the properties, advantages, disadvantages, and so on of construction materials. I haven’t had a chance to talk to anyone at the school to inquire about this. In fact, I should acknowledge that I haven’t talked to anyone at the school about crumb rubber at all.
What IS crumb rubber?
From Wikipedia, the free encyclopedia
Crumb rubber is a term usually applied to recycled rubber from automotive and truck scrap tires. During the recycling process steel and fluff is removed leaving tire rubber with a granular consistency. Continued processing with a granulator and/or cracker mill, possibly with the aid of cryogenics, reduces the size of the particles further. The particles are sized and classified based on various criteria including color (black only or black and white). The granulate is sized by passing through a screen, the size based on a dimension (1/4") or mesh (holes per inch : 10, 20, etc.).
There are over 3,000,000 registered importers and exporters of crumb rubber.
What the manufacturers have to say:
According to Northwest Rubber Crumb Rubber is ideal for:
Synthetic Playing Fields
Horse Arena Footing
Asphalt Crack Sealants
Paint Non-slip Additive
CRM is the largest manufacturer of crumb rubber -supplying over 70% of the country’s needs for the substance as “rubberized asphalt.” Their ads feature playgrounds but their major focus is the asphalt- quiet, smooth, long-lasting, and environmentally friendly since millions of tires are recycled through CRM.
The Crumb Rubber Universal Marketing Bureau (C.R.U.M.B.) was established to promote and facilitate trade in the Crumb Rubber Industry. Crumb Rubber is a product derived from the process of granulating rubber tires. This organization is doing big business in buying tires, processing them, and selling the crumb rubber.
The information below asserts that “Playfill” crumb rubber is clean, safe, non-toxic and more. It advertises an inherent deterrent to pets, rodents, and insects, which, of course, does prompt the question, “How does it do that, if not through some seriously aversive (stinky, poisonous, noxious) characteristic?”
Crumb Rubber Provides a Safe, Resilient, Non-abrasive Surface
• meets ASTM standards (1292-93) for 10' fall height
• clean, non-toxic
• non-staining, free draining
• effective in all climates
• can be installed over many existing surfaces
• deters pets, rodents and insects
• easily maintained
From an online ad: “PlaySafest™ Crumb Rubber PlayGround Surface is the authentic “Worlds Safest” PlayGround Surface that was featured and raved about on The CBS Morning Show, MSNBC, CNN, NJ News 12 and in the Wall Street Journal! it’s simply the finest surface material available for playgrounds, volleyball courts, around trampolines, pools, pool diving boards or slides. It protects children and adults from the impact of slips and falls. This rubber material was designed, engineered and produced with a method that cannot be duplicated. Only the durability and safety features rival its beautiful appearance. PlaySafest is available in black, as well as 4 vibrant colors: Terracotta Red/Brown, Forest Green, Ocean Blue, and Purple Passion. These colors will excite your child’s mind and enhance the appearance of any landscape. This product comes with a warranty in writing to assure you it will last a lifetime or we will replace product and provide labor free of charge.”
In sum, crumb rubber is a safe, non-toxic, recycled material with many advantageous qualities if you ask the people who produce it. However, some manufacturers (the tobacco companies come to mind) are not noted for preaching gospel truth. Crumb rubber is a massive and massively profitable industry. So what other news is out there?
Concerns raised and studies conducted:
Is there reason to worry about Friday Harbor children being exposed frequently and for long periods of time to crumb rubber?
Questions have been raised about crumb rubber despite its favorable assessments. A representative from a group concerned about crumb rubber as an additive to artificial turf explained, "Tires typically contain toxic substances which prohibit their disposal in landfills and oceans, so it is reasonable to question whether this material is safe for use on fields where children play." Unless I am looking in the wrong places there does not seem to have been a great deal of extensive study devoted to this issue.
Many of the concerns seem to focus on crumb rubber as an additive to materials used in artificial turf for playing fields, not playgrounds per se.
-Watchdog Earth blog: Many of the excerpts below are informative from the standpoint of at least three issues:
* Does high heat release toxic fumes? (And is this relevant to Friday Harbor where high temperatures are rare and isolated to the summer months when the playground is not in regular use?)
* Is the stuff toxic if ingested? (Are kids likely to find tire rubber a taste treat?)
* Does the profit motive exert an inordinate amount of influence? (The article notes that millions of dollars in grants are available in one state -money that would mean a significant return on investment for CRM et. al. Nothing better for the corporate nest egg than a fat government contract).
Bruggers: “Sometimes I look into something and decide it's not ready for prime time. That happened recently with the issue of crumb rubber, which the state of Kentucky is encouraging in a big way -subsidizing it, even…
A number of people in the Northeast are concerned about some new studies that suggest ground up bits and pieces of tires that are used on children's playgrounds may be releasing toxic vapors. A state laboratory in Connecticut, for example, has found that, in laboratory settings, the toxic vapors are released when heated to temperatures that would be common a sports field in the summer.
What's needed, says Mary Jane Incorvia Mattina, with the Connecticut Agricultural Experiment Station, are tests on these fields.
Also weighing in Environment and Human Health Inc., a nonprofit research and education outfit. It has released this report on the subject recently.
The state of California recently published a report, found here, that identified toxic chemicals coming from crumb rubber. But it didn't find any serious health threats. That said, it only examined risk from ingestion of rubber pieces, ingestion from hand to mouth contact, and skin contact. That study didn't look at risk from breathing any vapors that come from the rubber.
Back East, news organizations are starting to cover the story as controversy heats up at local school boards.
Meanwhile, Kentucky this year awarded nearly $2 million in grants to local communities that promise to use crumb rubber for sports fields or playgrounds. It's part of a state program that the Fletcher administration has hailed as a major success that helps "recycle" mountains of used tires... The program is supported by a waste tire trust fund that requires tire retailers to collect a $1 fee on all new replacement motor vehicle tires sold.
When I talked to Nancy Alderman, president of Environment and Human Health, Inc., she gasped. "I thought oh my God, government in Kentucky playing a role in this stuff. They are recycling these tires with children."
So why not make a splash with this story in the newspaper now? I've got a lot of the elements of a page one story: scary chemicals, children, something as common-place as tires, the popular issue of recycling, and backing by the state of Kentucky.
First of all, the who-haw back East seems to focus on all-synthetic fields, and the state's Division of Waste Management tells me its sports fields grants have involved using rubber "as a soil amendment" with living grass. The rubber sinks into the soil, and, it seems, would not likely get as hot -- thus, fewer vapors. Also, less rubber is used.
Setting aside the question of whether rubber, which does not biodegrade, is a good soil amendment (there are also studies that it can leach metals that make some plants hard to grow), I was also told by the state that any rubber used in Kentucky playgrounds has been painted. And the paint complicates things. I know of no studies that would help me understand how paint on rubber pieces might affect vapors.
Further, I know of no parents who are objecting to crumb rubber here in Kentucky, as they are in the East. I hate to say it, but controversy does generate news.
So in the triage that occurs every day in a newsroom that's bombarded by potential news stories, this issue was relegated to the blog -- at least for now.
But ... that could change. Maybe there are all-synthetic sports fields around here also made with crumb rubber that I don't know about. Maybe local school or health authorities will decide that they need to take a look at how crumb rubber is being used, just like authorities back East.”
Another report on health risks is summarized below:
“The New York City Health Department hired consultants to assess potential health risks associated with crumb-rubber turf fields. The report concludes that the risk of harm from exposure to hazardous chemicals such as lead in the rubber appears to be very low unless the chemicals are basically eaten.
According to the report, another possibility is that players may inhale chemicals that vaporize to form a gas. Health assessments suggest that the exposure levels are likely below a level of concern to human health. But these assessments use conservative estimates of exposure. The report says additional studies measuring chemical exposures of players on turf fields should be conducted "to give more representative data on exposures related to urban field use."
Since crumb-rubber turf absorbs and retains heat, the NYC Health Department report says heat is the primary health concern associated with playing on the fields. It says people can suffer dehydration, heatstroke and thermal burns at field temperatures above 115 degrees.”
Heat retention does not appear to be a problem for Friday Harbor.
There are more studies an interested reader might want to explore but the two excerpted below seemed fairly representative of what is available:
Environ Health Perspect. 2006 January; 114(1): 1-3.
Published online 2005 August 17. doi: 10.1289/ehp.7629.
Copyright This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.
Commentaries & Reviews
A Case Study of Tire Crumb Use on Playgrounds: Risk Analysis and Communication When Major Clinical Knowledge Gaps Exist
Mark E. Anderson,1,2 Katherine H. Kirkland,3 Tee L. Guidotti,4 and Cecile Rose5
1Department of Community Health Services, Denver Health, Denver, Colorado, USA
2Department of Pediatrics, University of Colorado Health Science Center, Denver, Colorado, USA
3Association of Occupational and Environmental Clinics, Washington, DC, USA
4Department of Environmental and Occupational Health, Mid-Atlantic Center for Child Health and the Environment, School of Public Health and Health Sciences, George Washington University Medical Center, Washington, DC
5Departments of Medicine/Preventive Medicine and Biometrics, National Jewish Medical and Research Center, Denver, Colorado, USA
Address correspondence to M.E. Anderson, 777 Bannock St., Mail Code 1911, Denver, CO 80204 USA. Telephone: (303) 436-4098. Fax: (303) 436-3056. E-mail: firstname.lastname@example.org
The authors declare they have no competing financial interests.
Received September 30, 2004; Accepted August 17, 2005.
“Physicians and public health professionals working with the U.S. Environmental Protection Agency’s Region 8 Pediatric Environmental Health Specialty Unit (PEHSU) received several telephone calls requesting information regarding the safety of recycled tire crumb as a playground surface constituent placed below children’s play structures. There were no reported symptoms or adverse health effects in exposed children. The literature available on the safety and risk of exposure to crumb rubber constituents was limited and revealed no information quantifying exposures associated with product use. Callers were informed by the PEHSU that no evidence existed suggesting harm from intended use of the product, but gaps in knowledge about the product were identified and communicated. Here the case of crumb rubber on playgrounds is used as a model to present an approach to similar environmental medicine questions. From defining the question, to surveying traditional and nontraditional resources for information, synthesis of findings, and risk communication, the case provides a model to approach similar questions.”
A second study is from Environmental Health Perspectives and is abstracted below:
“A case study of tire crumb use on playgrounds: risk analysis and communication when major clinical knowledge gaps exist
Environmental Health Perspectives, Jan, 2006 by Mark E. Anderson, Katherine H. Kirkland, Tee L. Guidotti, Cecile Rose
To examine further the known risks to children from exposure to the playground product, we turned to traditional published scientific literature and the network of PEHSUs in the United States. One study, done by investigators working in Alberta (Birkholz et al. 2003), examined the human and ecosystem hazard presented by tire crumb using in vitro mutagenicity assays. The associated hazard analysis suggested that the risk associated with playground use was very low. Toxicity to all of the aquatic organisms tested was observed in the fresh aqueous extract, but activity disappeared with aging of the tire crumb for 3 months in place on the playground. The investigators concluded that the use of tire crumb in playgrounds results in minimal hazard to children and the receiving environment, assuming intended use of the product, such as exclusive outdoor use and the presence of no solvents other than water. 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.”
An enterprise of this sort is fraught with temptation. If questions have been raised, concerns expressed, and negative outcomes hypothesized, then there must be something to worry about. “Where there is smoke, there must be fire” is more than a cliché. Keeping an open mind is necessary but the attraction to startling revelations is undeniable.
Based on what I have read on the subject of crumb rubber, the startling revelations are not there. It is entirely possible that I have missed the bad news or that it will be revealed when the standard scholarly requirement, “Further research should be done,” is satisfied, but so far my browsing has shown little if any verifiable concern. In some areas, further research looks like a priority imperative. Do we know if crumb rubber has adverse effects on children with breathing disorders like asthma? (As noted earlier, a more thorough researcher should try to find data on this). What toxic fumes does it expel if it catches fire? (Obviously tires do catch fire; we have all seen and smelled them). Might it be hazardous to run-off water because of its own properties or because of the dirt, oil, and what-not that it retains during dry periods? How extensively has crumb rubber been tested for playground use? What effects, if any, do time and natural deterioration have on crumb rubber? Are manufacturers and users allowing the demonstrable advantages such as reduced injuries from falls and its recycling appeal to affect their zeal for answering important questions? These and other questions are still open.
After I finished reading about crumb rubber, I drove over to FHES to look at the new playground. The stuff is messy in that it escapes the confines of the play space and probably gets dragged into buildings. It does have a slight smell. It is spongy and nice to walk on. The surrounding athletic areas are surfaced with asphalt or gravel, both of which are mean ground covers for falling down.
I will summarize my tentative conclusions:
* Available information (that I’ve found) does not provide significant concern about health and safety for our children as it regards crumb rubber.
* Advantages of the product in letting kids bounce around without hurting themselves seem to outweigh disadvantages such as smell.
* Although questioning should continue, from what is known now, it doesn’t seem appropriate to remove the crumb rubber unless the messiness is a big problem or the kids decide to eat the stuff. Hard to imagine that, although the substance would come into contact with hands, faces, and mouths through the normal process of playing.
Doubtless there is much more to know and say but this concludes my preliminary work. If serious concerns remain, the primary sources of valid data should be consulted.