Crumb rubber toxicity in coastal marine systems

Crumb rubber granulate (CRG) produced from end of life tires (ELTs) is commonly applied on indoor and outdoor synthetic turf pitches (STPs), playgrounds, safety surfaces and walkways. In addition to fillers, stabilizers, cross-linking agents and secondary components (e.g. pigments, oils, resins, fibers), ELTs contain high levels of organic additive compounds and heavy metals. While previous environmental studies have focused on terrestrial soil and freshwater ecosystems, in Norway many sites applying CRG are coastal. In the current study, the organic chemical and metal content of 'fresh' and 'weathered' CRG and their seawater leachates was investigated, and the uptake of crumb rubber by the brown crab (Cancer pagurus) was studied as an example of an exposure route for CRG to coastal marine organisms. A combination of pyrolysis gas chromatography mass spectrometry (py-GC-MS) and chemical extraction followed by GC-MS analysis revealed similar organic chemical profiles for pristine and weathered CRG, including additives such as benzothiazole, N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine and a range of polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds (e.g. bisphenols). ICP-MS analysis indicated g/kg quantities of Zn and mg/kg quantities of Fe, Mn, Cu, Co, Cr, Pb and Ni in the CRG. A mixture of organic additives, metals and other inorganic compounds readily leached from the CRG into seawater. Benzothiazole was the organic compound with highest concentration (average of 136 mg/L), while PAHs (ranging from