ERASSTRI - European Risk Assessment Study on Synthetic Turf Rubber Infill – Part 2: Migration and monitoring studies

Abstract

End-of-life tyre (ELT)-derived rubber granules are used as synthetic turf infill on sports fields. They contain various chemical substances and there are concerns that exposure to these substances might be harmful for human health. In this second part of a Europe-wide study to address these concerns migration of substances from rubber granules to artificial body fluids (sweat, saliva, gastric juice) was tested and exposure measurements at sports fields were performed to improve the database for exposure assessment. Some PAHs, aluminium, cobalt, benzothiazole, tert-butylamine, MIBK, 4-tert-octylphenol, bisphenol A, and the phthalates DINP and DEHP were found in at least some samples of sweat simulant. The migration rates calculated with these data were used to inform the dermal exposure assessment. In artificial saliva and gastric juice, only aluminium, cobalt, 4-tert-octylphenol and MIBK were detected and migrated fractions were calculated. Bioaccessibility from rubber granules in the gastrointestinal tract was estimated conservatively, assuming complete availability for most substances. In addition, air samples from 17 sports fields in six European countries were analysed. There were no increased concentrations of metals (aluminium, cobalt), PAHs, or other semivolatile substances in air samples, but some volatiles (MIBK: 95th percentile: 18 μg/m3, benzothiazole: 95th perc.: 7 μg/m3, tert-butylamine: 95th perc.: 31 μg/m3, 2-heptanone: 95th perc.: 0.4 μg/m3, cyclohexanone: 95th perc.: 1.5 μg/m3, and saturated aliphatic hydrocarbons >C9: 95th perc.: 26 μg/m3) were slightly increased in a few samples. In addition, skin wipe samples were obtained from 43 sportspeople after playing on synthetic turfs. Only aluminium was detected above the limit of quantification in these samples (95th perc.: 0.84 mg/sample). These data are important input for risk characterisation as performed in the final study phase. Bioaccessibility data are used for estimating oral and dermal exposure of sportspeople, and air measurements are essential for inhalation exposure assessment.