Personally I have played sports my entire life. I’ve played basketball, baseball, lacrosse, soccer, and ran cross country throughout my athletic career. For a majority of these sports, many of them required the use of an outdoor grass field. A field like this requires constant maintenance. The field has to be watered properly, mowed every week, new lines have to be spray painted on for certain sports, and when it rains the field is usually rendered unable to use. To combat this synthetic turf was created.
Synthetic turf fields, as most of you may know, are fields that mimic grass fields without using real grass. The actual turf part is made out of synthetic fibers, usually containing nylon, polyethylene, and polypropylene. None of these materials are necessarily harmful to humans in the format they are being used in. To base the turf, a combination of sand and crumb rubber is used.
http://www.rubber-granules.com/tag/crumb-rubber/
Crumb rubber is where the problem lies.
Crumb rubber are the little black pellets that lie within the strands of artificial grass. The crumb rubber is usually made from recycled tires, and other recycled rubbers. Because it is made from recycling other objects, the exact ingredients within each granule of crumb rubber could be different. Some of these ingredients have also been proven to be harmful. A usual scrap tire contains 70% recoverable rubber, 15% steel, 3% fiber, and 12% of filler materials. In order to make the crumb rubber, the tire goes through an ambient process in which the recoverable rubber is separated out from the rest of the materials. Each company has its own ambient process and this is currently unregulated which can lead to harmful granules being produced.
So what exactly is harmful about the crumb rubber?
Other than the lack of regulation, many studies have bee done to examine what is really harmful in the crumb rubber. One study conducted by the University of Connecticut Health Center (UCHC) studied air concentrations on five different active fields, and looked for 200 different chemicals. The study was looking for any volatile organic compounds (VOC) or semi-volatile organic compounds (SVOC) found in the air surrounding the fields or within the crumbs themselves. The four most common VOCs found within the rubber crumbs were acetonitrile, methylene chloride, methyl alcohol, and methyl isobutyl ketone. As far as compounds in the air, the SVOC Benzothiazole was the most common. Not much is known about these compounds in regards to human consumption, although they all contain acute-toxicity. Benzothiazole (BZT) is known to cause respiratory issues and dermal sensitization. BZT has also been found in salmonella during metabolic activation, which means when the compound is broken down by the body, a carcinogen could be activated and mutations could occur, which is what causes cancer.
Another study conducted by The Connecticut Department of Public Health once again revealed toxic compounds on synthetic turf fields. Four fields were studied, an adult outdoor and indoor field, and a children’s outdoor and indoor field. Two VOCs that cause the greatest risk for cancer were found in the fields were benzene and methylene chloride. BZT was found in higher numbers in the indoor fields, as the compound is airborne, and the indoor facilities contain it more than the outside fields. Because of this, the indoor field cancer risks were two-fold that of the outfield. Although it was concluded that even though cancer risks were slightly above the minimum regulatory levels, the cancer risk was not to be published as a public safety concern.
Lead was found in a study by Connecticut Department of Environmental Protection where runoff from turf fields was tested for different leached metals. Along with this, high levels of zinc were found and were proved to be harmful to the surrounding groundwater and surface water.
As shown by these studies multiple toxins and possible carcinogens have been proven to be within and emitted by crumb rubber pellets. The main problem is a lack of testing. Many of these toxins have unknown effects on humans, and there potential as carcinogens is unknown. There are also an extreme amount of confounding variables as each granule can differ in what it contains, as well as the fact that each company could use different tires, materials, and methods to produce them. This makes creating a statistically significant result that is widespread very challenging There is also discrepancy on high the levels of these VOCs and SVOCs have to be to cause an effect on humans, but either way more testing has to be done in order to solve this potential issue.
Really interesting… I had to read this post because I played lacrosse on my high school turf field for 3 years so if there was any chance I was going to get cancer I wanted to know. Also, I never knew the word for those little black things on the field (what I now know is crumb rubber) but they are the most annoying things ever and would always end up all over my clothing so it’s not surprising that if there is a link it would be because of crumb rubber. While these studies have proved there are many toxins, I agree that we need to know more about these carcinogens to draw any conclusions. That although doesn’t mean that there is not correlation between cancer and turf, but if anything it leaves room for more chance. But your post highlights that while turf may save water, it may not be worth the it if there’s a possibility that it risks lives.
Your blog post was extensive and very informative. The idea that turf grass could be linked to cancer has never crossed my mind. As soon as I started reading this I wondered whether a grass field would actually be any better. Most well kept grass fields are treated with a vast number of chemicals including herbicides and pesticides. I also feel like anything could be linked to cancer. We truly don’t understand how cancer develops and what causes the disease. I have played on turf my entire life so hopefully it does not prove to be too harmful to my health. It’s also interesting that you brought up the fact that different companies can make different types of crumb rubber with varying amounts of purities to them. It actually really scares me because I know my school is cheap and probably purchased the worst quality crumb rubber on the market. Now that I’m surfing the web I’m looking at a plethora of articles on crumb rubber and cancer correlations. I suppose we will find out if they are truly correlated soon. Article on the issue- http://www.huffingtonpost.com/entry/cancer-artificial-turf-crumb-rubber_us_570960a3e4b0142232493441
My sister and I were both two sport athletes throughout our entire high school career and that crumb turf was everywhere. I could not go one day without finding it in our clothes, our cars and even in our hair. To hear that it may have dangerous affects on our health is mind blowing. I always figured that this advancement in sports technology was nothing but a benefit to athletes, but I think a lot of teams would be very interested to know about the possible health impacts of this turf on their athletes. I would be curious to see with testing moving forward how they could eliminate the influence of the third variables such as the type of turf and type of activity performed on it.
The title of your post caught my attention because I too played sports on high school. I conditioned on the field in the summer for volleyball, I ran on the field for track, and, since I was in the marching band, we practiced on the field almost every day.
I knew that the crumb rubber you speak of was from recycled tires, but I never thought there would be a correlation between it and cancer (..now I’m regretting all the times I collected all the crumb rubber into a little pile to throw at my friends…).
I could tell you did a very extensive job at researching for this post, and the amount of studies you mentioned support your arguments.
Perhaps, when more research is done, we would find out if crumb rubber is truly dangerous. Until then, I found an article that mentions other alternatives for crumb rubber ( http://www.sportsfieldmanagementmagazine.com/maintenance/artificial-turf/crumb-rubber-alternatives/ ). The article mentions we could use other plastic, or even recycled chopped-up tennis shoes.