There is a lot of controversy on the issue of turf fields (and its Crumb Rubber) and an increased risk of cancer. Proving causation is tough and would take years to prove, if there is an association or causation, as there are so many risk factors to consider in a patient who develops cancer.
Still, there is overwhelming evidence that crumb rubber or recycled rubber that is used in thousands of sports fields, including now our beloved Heights School’s new turf field, is full of chemical that may puts kids and their parents at an increased risk of cancer– in my opinion: this is not a hard fact but a statement of logic from the evidence coming out from many publications.
The first time I was on a turf field was 2 summers ago. The smell in the heat was overwhelmingly horrid. “How could this be healthy for kids?” I thought. Thus began a study looking into this. I even tried to convince our school to not go Turf.
So what are the risks:
The key issues are the polycyclic aromatic hydrocarbons (PAHs) and the many other carcinogenic compounds in these recycled rubbers. People smell these noxious compounds most especially in the summer.
Here are good reviews below.
For now, I recommend for my kids: 1. Never touch the turf with bare skin. 2. Always wear shoes when on turf and socks. 3. Avoid playing in the hot sun on turf fields 4. Do not lay on these fields even on a blanket. 5. Always choose natural grass over turf until studies prove without a doubt there is no increased cancer risk. 6. Never swim in “the pit” at the Heights as the run off of the turf field is likely bad news as well.
Gradient, 600 Stewart Street, Suite 1900, Seattle, WA 98101, USA
Gradient, 20 University Road, Cambridge, MA 02138, USA
Received 1 March 2017, Revised 27 July 2017, Accepted 17 September 2017, Available online 12 October 2017.
A human health risk assessment of recycled rubber in synthetic turf fields.
Youth athletes, as well as child and adult spectators, were considered.
For risk communication, a side-by-side comparison to natural soil was included.
Cancer risk and non-cancer hazard were below US EPA guidelines for soil and rubber.
For most scenarios, cancer risks were higher for natural soil fields.
Thousands of synthetic turf fields in the US are regularly used by millions of individuals (particularly children and adolescents). Although many safety assessments have concluded that there are low or negligible risks related to exposure to chemicals found in the recycled rubber used to make these fields, concerns remain about the safety of this product. Existing studies of recycled rubber’s potential health risks have limitations such as small sample sizes and limited evaluation of relevant exposure pathways and scenarios.
Conduct a comprehensive multipathway human health risk assessment (HHRA) of exposure to chemicals found in recycled rubber.
All available North American data on the chemical composition of recycled rubber, as well as air sampling data collected on or near synthetic turf fields, were identified via a literature search. Ingestion, dermal contact, and inhalation pathways were evaluated according to US Environmental Protection Agency (US EPA) guidance, and exposure scenarios for adults, adolescents, and children were considered.
Estimated non-cancer hazards and cancer risks for all the evaluated scenarios were within US EPA guidelines. In addition, cancer risk levels for users of synthetic turf field were comparable to or lower than those associated with natural soil fields.
This HHRA’s results add to the growing body of literature that suggests recycled rubber infill in synthetic turf poses negligible risks to human health. This comprehensive assessment provides data that allow stakeholders to make informed decisions about installing and using these fields.
Synthetic turf fields containing recycled rubber (also called “crumb rubber”) infill have been in use for decades. These fields typically consist of bottom backing layers composed of polypropylene, polyurethane, or latex, with polyethylene, nylon, or polypropylene blades woven into the material (Synthetic Turf Council, 2011). After the field is laid down, infill is added to soften the field and allow the individual turf blades to stand up (Fig. 1). One of the most common types of infill is recycled rubber, often mixed with sand (Synthetic Turf Council, 2011). Recycled rubber infill is typically made from recycled automobile and light truck tires, which are ground, shredded, and sorted into uniformly sized pieces (Synthetic Turf Council, 2011).
Chemosphere. 2018 Mar;195:201-211. doi: 10.1016/j.chemosphere.2017.12.063. Epub 2017 Dec 11.
Determination of priority and other hazardous substances in football fields of synthetic turf by gas chromatography-mass spectrometry: A health and environmental concern.
Laboratory of Research and Development of Analytical Solutions (LIDSA), Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Chemistry, E-15782, Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
Agronomic and Agrarian Research Centre (INGACAL-CIAM), Unit of Organic Contaminants, Apartado 10, 15080, A Coruña, Spain.
Laboratory of Research and Development of Analytical Solutions (LIDSA), Department of Analytical Chemistry, Nutrition and Food Science, Faculty of Chemistry, E-15782, Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: firstname.lastname@example.org.
Due to the high concern generated in the last years about the safety of recycled tire rubber used for recreational sports surfaces, this study aims at evaluating the presence of forty organic compounds including polycyclic aromatic hydrocarbons (PAHs), phthalates, adipates, vulcanisation additives and antioxidants in recycled tire crumb of synthetic turf football fields. Ultrasound Assisted Extraction (UAE) was successfully employed to extract the target compounds from the crumbrubber, and analysis was performed by gas chromatography-mass spectrometry (GC-MS). The transfer of the target chemicals from the crumbrubber to the runoff water and to the air above the rubber surface has also been evaluated employing solid-phase microextraction (SPME). Samples from fifteen football fields were analysed, and the results revealed the presence of 24 of the 40 target compounds, including 14 of the 16 EPA PAHs, with total concentrations up to 50 μg g-1. Heavy metals such as Cd, Cr and Pb were also found. A partial transfer of organic compounds to the air and runoff water was also demonstrated. The analysis of rain water collected directly from the football field, showed the presence of a high number of the target compounds at concentrations reaching above 100 μg L-1. The environmental risk arising from the burning of crumbrubber tires has been assessed, as well, analysing the crumbrubber, and the air and water in contact with this material, showing a substantial increase both of the number and concentration of the hazardous chemicals.
The chemical and morphological characteristics of materials released under chemical and physical stress by different rubber granulates used as infill materials in synthetic turf (recycled scrap tires, natural rubber, and a new-generation thermoplastic elastomer) were compared.The headspace solid-phase micro-extraction GC-MS analysis evidenced that at 70 °C natural rubber and thermoplastic elastomer release amounts of organic species much higher than recycled scrap tires. In particular, the desorption of mineral oils, with a prevalence of toxicologically relevant low-viscosity alkanes in the range C17-C22, and plasticizers (diisobutyl phthalate) was clearly evidenced. The new-generation thermoplastic elastomer material also releases butylated hydroxytoluene.In slightly acidic conditions, quite high amounts of bio-accessible Zn, Cu, and Co are released from recycled scrap tires, while natural rubber releases mainly Se and Tl. In contrast, the thermoplastic elastomer does not contain significant concentrations of leachable heavy metals.The formation of small particles, also in the inhalable fraction, was evidenced by electron microscopy after mechanical or thermal treatment of natural rubber.
Yes, I know these are just earthworms, but had to post this until we have animal data: which might take years..
Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumbrubberand using the material as infill for artificial turf. However, crumbrubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumbrubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumbrubber on the earthworms is unknown. Since many athletic fields contain aged crumbrubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumbrubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumbrubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumbrubber, like new crumbrubber, had high levels of zinc. However, while exposure to aged crumbrubber did not reduce earthworm body weight as did exposure to new crumbrubber, exposure to aged crumbrubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumbrubber and new crumbrubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.
Polycyclic Aromatic Hydrocarbons (PAHs) What Health Effects Are Associated With PAH Exposure?
Upon completion of this section, you will be able to
describe health effects associated with PAH exposure.
The most significant endpoint of PAH toxicity is cancer.
PAHs generally have a low degree of acute toxicity to humans. Some studies have shown noncarcinogenic effects that are based on PAH exposure dose [Gupta et al. 1991].
After chronic exposure, the non-carcinogenic effects of PAHs involve primarily the
renal, and dermatologic systems.
Many PAHs are only slightly mutagenic or even nonmutagenic in vitro; however, their metabolites or derivatives can be potent mutagens.
The carcinogenicity of certain PAHs is well established in laboratory animals. Researchers have reported increased incidences of skin, lung, bladder, liver, and stomach cancers, as well as injection-site sarcomas, in animals. Animal studies show that certain PAHs also can affect the hematopoietic and immune systems and can produce reproductive, neurologic, and developmental effects [Blanton 1986, 1988; Dasgupta and Lahiri 1992; Hahon and Booth 1986; Malmgren et al. 1952; Philips et al. 1973; Szczeklik et al. 1994; Yasuhira 1964; Zhao 1990].
It is difficult to ascribe observed health effects in epidemiological studies to specific PAHs because most exposures are to PAH mixtures.
Increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Epidemiologic reports of PAH-exposed workers have noted increased incidences of skin, lung, bladder, and gastrointestinal cancers. These reports, however, provide only qualitative evidence of the carcinogenic potential of PAHs in humans because of the presence of multiple PAH compounds and other suspected carcinogens. Some of these reports also indicate the lack of quantitative monitoring data [Hammond et al. 1976; Lloyd 1971; Mazumdar 1975; Redmond et al. 1972; Redmond and Strobino 1976].
The earliest human PAH-related epidemiologic study was reported in 1936 by investigators in Japan and England who studied lung cancer mortality among workers in coal carbonization and gasification processes. Subsequent U.S. studies among coke oven workers confirmed an excess of lung cancer mortality, with the suggestion of excessive genitourinary system cancer mortality. Later experimental studies showed that PAHs in soot were probably responsible for the increased incidence of scrotal cancer noted by Percival Pott among London chimney sweeps in his 1775 treatise [Zedeck 1980].
Continued research regarding the mutagenic and carcinogenic effects from chronic exposure to PAHs and metabolites is needed. The following table indicates the carcinogenic classifications of selected PAHs by specific agencies.
U.S. Department of Health and Human Services (HHS)
Known animal carcinogens
International Agency for Research on Cancer (IARC)
Probably carcinogenic to humans
Possibly carcinogenic to humans
Not classifiable as to their carcinogenicity to humans
U.S. Environmental Protection Agency (EPA)
Probable human carcinogens
phenanthrene, and pyrene.
Not classifiable as to human carcinogenicity
PAHs generally have a low degree of acute toxicity to humans.
The most significant endpoint of PAH toxicity is cancer.
Increased incidences of lung, skin, and bladder cancers are associated with occupational exposure to PAHs. Data for other sites is much less persuasive.
It is difficult to ascribe observed health effects in epidemiological studies to specific PAHs because most exposures are to PAH mixtures.
Animal studies show that certain PAHs affect the hematopoietic, immune, reproductive, and neurologic systems and cause developmental effects.
Most synthetic turf fields have crumb rubber interspersed among the simulated grass fibers to reduce athletic injuries by allowing users to turn and slide more readily as they play sports or exercise on the fields. Recently, the crumbs have been implicated in causing cancer in adolescents and young adults who use the fields, particularly lymphoma and primarily in soccer goalkeepers. This concern has led to the initiation of large-scale studies by local and federal governments that are expected to take years to complete. Meanwhile, should the existing synthetic turf fields with crumb rubber be avoided? What should parents, players, coaches, school administrators, and playground developers do? What should sports medicine specialists and other health professionals recommend? Use grass fields when weather and field conditions permit? Exercise indoors? Three basic premises regarding the nature of the reported cancers, the latency of exposure to environmental causes of cancer to the development of clinically detectable cancer, and the rarity of environmental causation of cancer in children, adolescents, and young adults suggest otherwise.
In 2014, crumb rubber in synthetic turf fields was hypothesized to cause cancer in adolescents and young adults who used the fields, particularly lymphoma and primarily in soccer goalkeepers.
The concern has induced some school systems and park departments to abandon plans to install synthetic turf fields and governments to initiate major toxicology studies, the results of which are expected to take years to obtain.
Meanwhile, the state of the science of adolescent and young adult cancer causation does not support the hypothesis.
On the contrary, the potential for decreasing exercise by reducing access to playgrounds and sports fields may increase the rate of cancer occurrence in later life.
A hypothesis that synthetic turf fields can cause cancer was publicized after a soccer coach at the University of Washington collected a list of young adult soccer players, particularly goalkeepers, who had been diagnosed with lymphoma and other cancers . Because crumb rubber infill, the shock absorption layer within synthetic turf derived from recycled automotive tires, contains some potentially carcinogenic chemicals, the turf has been implicated. As goalkeepers are more likely than outfield players to ingest or inhale the crumb or absorb crumb constituents via their skin, the hypothesis gained credence. As a result, some school systems and park departments have abandoned plans to install synthetic turf fields, and some states have introduced bills to ban such installations . In 2015, the California Office of Environmental Health Hazard Assessment began an Environmental Health Study of Synthetic Turf, and in early 2016, three US federal agencies launched the Federal Research Action Plan on Recycled Tire Crumb Used on Playing Fields [3, 4, 5]. Millions of dollars have been earmarked for these studies  that are expected to take years to complete.
2 State of Science
Several studies of human cancer and/or non-cancer risk using data from direct measurements or data reported in the literature have been reported [7, 8, 9, 10, 11, 12, 13, 14]. Other studies have focused directly or indirectly on the toxicity of one or more constituents of crumb rubber [14, 15, 16, 17, 18, 19, 20, 21, 22, 23]. None of these studies have identified a significant human carcinogenic risk from exposure to crumb rubber at synthetic turf fields. Menichini and co-investigators  estimated that 0.4 ng/m3 of benzo(a)pyrene at an indoor facility had a potential for an excess lifetime cancer risk of 1 in a million athletes after an intense 30-year activity level. Marsili and coauthors  considered the hazard indices and cumulative excess risk values for cancer to be below levels of concern for measured chemicals; they reasoned that polycyclic aromatic amines in the crumb rubber could potentially increase cancer risk after long-term frequent exposures at fields under very hot conditions (60 °C). Polycyclic aromatic amines have been implicated in some studies as an occupational lymphomagen, but the most recent systematic review and meta-analysis of cohort studies refuted the association . Kim and colleagues  proposed a potential risk for children with pica behavior through ingestion of crumb rubber material at playgrounds. The most recent review published in a peer-reviewed journal concluded that users of artificial turf fields, even professional athletes, are not exposed to elevated risks . Since this review, the most detailed studies of potential carcinogenicity conducted to date, by the Washington State Department of Health in USA and the Dutch National Institute for Public Health and the Environment, did not find an association between the fields and an increased incidence of cancer in the susceptible age group [27, 28].
Meanwhile, what should parents, players, coaches, school administrators, and playground developers do and physicians recommend? Avoid synthetic turf fields and use grass fields when weather and field conditions permit? Three basic premises suggest otherwise.
2.1 The Cancers Cited in Media Reports About Soccer Players are Precisely those Cancers that are Expected to Occur in the Age Group of Concern
Not only is lymphoma the most common cancer in high-school and college-age persons, the other cases in the reported cohort—leukemia, sarcoma, testis cancer, thyroid cancer, and brain tumors—are the next most common cancers in the age group. Together with lymphoma, these cancers account for 80–90% of the cancers in male individuals of middle-school, high-school, and college age and 50–80% of female individuals in the age group (Fig. 1) . In other words, the suspect cancers are precisely those expected without having to invoke exogenous factors.
The issue then is whether the absolute frequency is more than expected. An ecologic investigation applied to the state with the largest number of synthetic fields, California, and to 17 other regions of USA, did not indicate that the incidence is greater in counties and regions with synthetic fields or that the incidence is proportional to the prevalence of such fields when race/ethnicity and socioeconomic status of those who have access to synthetic fields are included in the analyses . The method used did not, however, directly measure the incidence in soccer players per se and could miss an increase of lymphoma in them, particularly if only a small percentage of cases have exposure to synthetic turf fields. In the State of Washington, about 25% of 15-year-old individuals have been estimated to play soccer at some point in their lives . The proportion is likely to be higher in California, given the more conducive weather and the greater Hispanic population. If so, the ecologically derived data are more meaningful in assessing the risk than the face value of the results. A more complete ecologic study of all 58 counties in California is in progress.
2.2 Exposure to Environmental Causes of Cancer During Childhood, Adolescence, and Early Adulthood Results in Cancer Later in Life
Figure 2 shows two established causes of cancer resulting from exposures during childhood and adolescent: melanoma after ultraviolet radiation and breast cancer after chest radiation. The type of melanoma caused by ultraviolet rays is rarely diagnosed before the age of 35 years (Fig. 2, brown curve) and breast cancer caused by chest radiation for cancer has a median latency of 14 years and rarely occurs before 30 years of age (Fig. 2, pink curve). When melanoma occurs in younger persons, it is nearly always not related to external exposure. If crumb rubber causes cancer in young athletes, it would be expected to become clinically detectable at an older age than during adolescence or early adult years.
2.3 Environmental Causation of Cancer in Children, Adolescents, and Young Adults is Rare
During the 1990s, the world’s largest pediatric cancer research organization, the Children’s Cancer Group, was awarded millions of dollars of research grants to determine what caused cancer in the young. None of those studies, nationally and in multistate surveys, within homes and with environmental sampling, of childhood and prenatal exposures, and a host other variables, uncovered evidence for an environmental factor that “might explain more than a small fraction of the observed cases” . The conclusion was that, with few exceptions, cancer during childhood, adolescence, and early adulthood is a mistake of nature—spontaneous mutation to malignancy—and not the result of exogenous causes .
All the prior studies and the perspectives expressed here cannot completely exculpate crumb rubber as a cause of cancer. Even the Washington State study of the very soccer players whose cancer raised the concern is not without significant limitations, as fully expressed by the investigators  and critiqued by others . The concern of parents, coaches, school administrators, sports medicine specialists, other healthcare professionals, and the players themselves is reasonable, especially when, if the hypothesis were true, the adverse outcome is potentially preventable. After all, cancer is one of the most feared diseases  and to have it happen in the young could not be worse.
It is also human nature to blame. Blaming autism on vaccines is a recurrent quintessential example. It also illustrates another human behavior: refusal to believe objective scientific irrefutable evidence  and this anti-science attitude appears to be increasing in our society [37, 38]. This human need and attendant denial causes unnecessary alarm, especially when cancer is the fear and especially in the United States. When American adults were asked which of five major diseases they were most afraid, 41% said cancer, 31% said Alzheimer’s disease and only 6-8% named heart disease, stroke or diabetes .
Regular physical activity during adolescence and early adulthood helps prevent cancer later in life . Restricting the use or availability of all-weather year-round synthetic fields and thereby potentially reducing exercise could, in the long run, actually increase cancer incidence, as well as cardiovascular disease and other chronic illnesses . That the Washington State study found a much lower incidence of cancer in their soccer players than expected from their general population  supports the concern that restricting access to such fields and playgrounds may lead to the opposite of what was intended.