Based on various earlier studies, RIVM concluded that it was unlikely that playing sports on synthetic turf fields with rubber granulate would have any health effects and that people playing sports could continue using rubber granulate fields. In 2006, RIVM conducted a thorough study of the information available worldwide at that time about the possible health effects of exposure to rubber granulate. In 2007, RIVM performed air measurements above synthetic turf fields and published a report on the matter. RIVM works in an international network of experts and never bases any of its recommendations on a single study.
In 2006, RIVM concluded that PAHs could indeed be released in small quantities from rubber granulate in synthetic turf fields. Based on the available data there did not seem to be any grounds for concluding that these small quantities could lead to a health risk. The granulate also contains so-called plasticisers. No health risk had been described in connection with plasticisers in the event that granulate was swallowed. As regards the other chemical substances which may be found in rubber granulate, no data were available which could be used to estimate the health risk. Given that no health risk was associated with PAHs, which are the most hazardous component in rubber granulate, it seemed likely that the same would apply to other substances.
The recommendations by RIVM in 2006 and 2007 to the then Ministry of Housing, Spatial Planning and the Environment (VROM) were based on, inter alia, research carried out by INTRON on behalf of sports organisations, the rubber industry, suppliers of sports fields and end users (KNVB/ NOC*NSF/ WG materialen/ VACO/ DSM/ RecyBEM /TenCate). At the time, RIVM representatives sat on the technical supervisory committee of this research. RIVM was asked to fulfil the role of independent assessor with regard to the research design and results.
INTRON published the final report of this research in 2007. An element of this was a study by Industox during which degradation products of Polycyclic Aromatic Hydrocarbons (PAHs) were measured in the bodies of seven players of a local soccer team after they had been in contact with rubber granulate. At the time this was the only study which assessed the degradation products of PAHs in the bodies of people after contact with rubber granulate.
At the request of, and in collaboration with, the Public Health Services Gelderland Midden (HGM), RIVM conducted air measurements above four synthetic turf fields in Arnhem and reported on the matter in 2007. Rubber granulate had been used as infill material on these synthetic turf fields. The aim of the measurements was to assess whether carcinogenic nitrosamines might be released from the rubber granulate which could present a health risk for those playing sports on the fields. RIVM performed air measurements at two heights above the various sports fields. None of these measurements detected nitrosamines in the air above the fields. Additional materials research in the laboratory revealed that only minor quantities of nitrosamines were released from rubber granulate. Based on these findings, RIVM concluded that nitrosamines did not constitute a health risk for users of sports fields.
In 2007, RIVM established that it was not possible, based on the information available worldwide at that time, to draw a definitive conclusion about the possible consequences for people's health and the environment of the use of rubber granulate on synthetic turf fields. Rubber granulate contains substances which may be detrimental to people's health and the environment. Those substances can be released from the rubber granulate. The research carried out by Intron and Industox confirmed the previous conclusion that PAHs from rubber granulate do not result in additional health risks.
This advice was drawn up in response to the comments by Martijn Berger, professor of statistics and methodology in Maastricht, on the IndusTox research in 2006. RIVM believes that the INTRON research contains valuable data for assessing the possible influence on people's health of PAHs in rubber granulate on synthetic turf fields. The research was carried out and documented properly. On the basis of this thorough analysis of the criticism by Mr Berger, RIVM stands by its previous assessment: Although PAHs can be released from rubber granulate, on the basis of the information available at the time, the amount released is not expected to lead to health effects for those playing sports on these fields. Because a lot of new research has been carried out into PAHs in rubber granulate since 2006, RIVM concluded by recommending another thorough assessment of the research that has been performed worldwide since 2006.