Table 2.

Some studies/policy documents from the scientific literature indicating potential risk from crumb rubber on 3G pitches, commercial pavers and playgrounds.

Subject	Type of Study/Methods/Size/Strengths and Weaknesses	Reference	Results
Contents of metals and chemicals in artificial turf. Lab-based and exposure study	Recycled rubber granulate content from 13 Italian fields. Analysis of 25 metals, 9 PAHs. Air samples from 2 fields. Small sample size and lack of actual exposure scenarios issues.	[42]	BaP and zinc levels in granulate exceeded Italian “green” soil standards by 2 orders of magnitude. Worst case excess cancer risk assessment of BaP in air was 1 × 10−6. over 30 years at 0.4 ng/m3
Hazardous organic chemicals in rubber recycled tire playgrounds and pavers. Lab-based	21 rubber mulch samples collected from 9 different urban playgrounds and 7 commercial paver samples from a store. Analysis done for 31 PAHs, phthalates, anti-oxidants and of vapour phase above samples. Relatively small sample size, other sources of chemicals question raised.	[48]	High levels of several toxic chemicals found in the recycled materials especially BaP found in 5 samples. PAHs in commercial pavers was “extremely high”, up to 1%
PAHs, heavy metals release from rubber crumb in synthetic turf fields. Lab-based	Lab analysis of 9 football pitch samples of rubber crumb normally found in tires and their metals and PAHs. Risk assessment at 25 °C was done. Study preliminary and relatively small and acknowledges risk assessment over-estimates PAH contribution from fields.	[43]	Toxic equivalent of evaporates from crumb rubber “not negligible” and represented major part of total daily PAH intake by different routes. Noted “continuous release” of PAHs from evaporation and issue of chronic exposure
Threshold levels for carcinogens and policy implications of the NIOSH analysis	Review of chemical carcinogens policy. Looks at classification risk management limits and advocacy of a policy of elimination or substitution and implementation of engineering controls. Limitations include its purpose is to consider worker exposure although exposures to carcinogens do not differentiate between worker, consumer and citizen and the precautionary principle applies across the board.	[64]	“Underlying this policy is the recognition that there is no known safe level of exposure to a carcinogen and therefore that reduction of worker exposure to chemical carcinogens as much as possible through elimination or substitution and engineering controls is the primary way to prevent occupational cancer”