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Assessing Children's Potential Exposures to Harmful Metals in Tire Crumb Rubber by Accelerated Photodegradation Weathering



Lee L. Yu, Li Piin Sung, YuYe Tong, Robyn Winz, Dejun Chen


Whether the use of tire crumb rubber (TCR) playground through the product's service life would expose children to potentially harmful chemicals contained within, such as vulcanization additives, (semi)volatile organic chemicals, and toxic metals, is still a largely open question that begs comprehensive scientific data for urgently needed answers. We studied the metals available for pick up by direct hand contact with the surface of TCR tiles for 2.2 years by accelerating the aging of the TCR in the NIST-SPHERE (National Institute of Standards and Technology - Simulated Photodegradation via High Energy Radiant Exposure). Throughout the aging study, we adopted a US EPA (Environmental Protection Agency) method of composite surface wiping to take samples from the tile surface and measure the release of ten selected metals (Be, Cr, Cu, As, Se, Cd, Sb, Ba, Tl, Pb) using inductively coupled plasma mass spectrometry. Six different release patterns of metal from the surface were observed. Although only Cr was found at a potentially harmful level on the surface of the as-received tiles, the cumulative release of Cu, As, Tl, and Sb on the surface reached potentially harmful levels at various times within 3 years. However, TCR playgrounds may still be safe for use taking into consideration the cleansing effect of precipitation or periodic rinsing with water.
Nature - Scientific Reports


rubber crumb, playground, toxic metal, accelerated aging, health and safety, environmental release


Yu, L. , Sung, L. , Tong, Y. , Winz, R. and Chen, D. (2023), Assessing Children's Potential Exposures to Harmful Metals in Tire Crumb Rubber by Accelerated Photodegradation Weathering, Nature - Scientific Reports, [online],, (Accessed June 15, 2024)


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Created August 24, 2023, Updated September 18, 2023