Thursday, March 25, 2010

Chemistry and Biology Of Artificial Turf Fields

More and more matches and training sessions are being held on the new artificial turf fields. These fields are virtually maintenance free and research shows that injury-risks may be reduced compared to grass field. However, some are concerned that exposure to the infill material may have health risks. Recycled rubber from tires is the most common type of material used. This material does indeed contain some highly toxic substances. Despite low levels of expose, health concerns remain. A new study carried out by IndusTox Consultants of Nijmegen, The Netherlands focuses on exposure polycyclic aromatic hydrocarbons (PAH) during a soccer match played on artificial turf. They find that PAH uptake is minimal and no greater than that from the environment or normal diet.

Recycled tire rubber contains some very toxic compounds. These are primarily heavy metals (zinc), volatile organic compounds (benzothiazole, toluene), secondary amines and PAHs although most are found in very low concentrations. PAHs are highly carcinogenic and are one of the key carcinogens found in cigarette smoke. Because of this and since recycled tire crumb dust attaches to the skin inside of the mouth and nasal cavity, the investigators focused on levels of PAH found in the body.

A group of players participated in a match on a newly installed artificial turf field. The field used recycled tire crumbs as the infill similar to field installed by companies such as FieldTurf, ProGrass and Mondo. Before the start of the match, players engaged in 30 minutes of ground exercises to maximize skin contact with the infill material. They crawled over, slid on and sat on the turf. Immediately after, they warmed up for 15 minutes then played in a 90 minute match. In all, they were exposed to the turf for 2.5 hours.

Urine levels of PAH were measured over the course of 7 days: 3 days prior to a simulated soccer match and 4 days afterwards.

PAHs are also found in the environment and in many foods. Thus, the researchers asked to players to avoid areas of tobacco smoke and fire places and to not use products that contained substances like glues and tar. They were also asked to also avoid eating smoked or fried meats and fish and cured meats such as barbecue and bacon.

After the match, it was clear that the players’ knees, hands and elbows were covered with a black residue of crumb dust.

As for urine concentrations of PAH, only one player showed elevated levels during the days after the match. When asked, this player admitted to eating a fried hamburger directly after the match. This could easily explain why his PAH levels spiked 24 hours post-match. It also emphasizes the influence diet can have on in the intake of PAHs.

The remaining players had urine PAH levels that were slightly lower than their pre-match levels. Also, both pre- and post-match levels were similar to what is expected of young, non-smokers living in The Netherlands. They were also below reference values of the German Federal Environmental Agency committee on Human Biomonitoring. Thus, there was very little absorption PAHs from playing on artificial turf.

Based on their results, the authors conclude that any uptake of PAH during play on rubber infill turf fields is minimal. Any exposure is very limited and within the range of what is taken up from the environment or diet. The bottom line - playing on artificial turf fields containing recycled tires does not put players at risk of PAH exposure. These results support a number of governmental agencies and independent researchers who suggest that chemical exposure new artificial turf fields do not pose significant health risks.

Reference:

van Rooij JGM, Jongeneelen FJ (2010) Hydroxypyrene in urine of football players after playing on artificial sports field with tire crumb infill. International Archives of Occupational and Environmental Health. 83:105-110.