Mean Time(days at atmospheric T=25°C) SD Sample 1 1325 1047 Sample 2 4423 3990 Sample 3 811 185 Sample 4 1734 967 Sample 5 846 150 Sample 6 655 396 Sample 7 346 136 Sample 8 410 229 Sample 9 568 234

Table 7: Estimated mean time (days) and standard deviation (SD) for total release of B[a]A, Chry, B[a]P and B[ghi]Per (sum of the four PAHs) from rubber crumb samples. The triple horizontal line divides new crumb (samples 1-5) from crumb sampled from sporting installations (samples 6-9).