are often applied, and the backing may then be perforated for drainage. After the carpet has been <br />seamed and secured with tape or adhesives, the last stage is to add infill: The carpet then is filled with <br />particulate material, the type and depth of which will vary from system to system In-fill materials most <br />often are granulated rubber or rubber and sand, either layered or mixed. The rubber may be styrene- <br />butadiene rubber (SBR) granules, black in color and produced from re-cycled tires, or ethylene propylene <br />terpolymer (EPDM) granules, specifically produced to be granulated and available in black or in colors. <br /> <br />As this description makes clear, construction of artificial turf fields would be a change in land use that is in <br />it is almost impossible to return that area <br />to land that sustains life -- even to return it to a grass field since the soil, plants and microbes will all be <br />gone. Constructing artificial-turf recreation fields thus implies constructing a dead zone within the <br />riverfront area. <br />fenced off from animals and from people other than those engaged in their designated use. The current <br />grass Riverside Field, while not the ideal use of this land, is at least compatible with use by people to cross <br />to the river, or to adjacent natural areas, or for informal gatherings. <br /> <br />But that is not all. Artificial turf fields raise environmental and health concerns. Health issues have focused <br />on the adverse, and possibly carcinogenic, effects of contact with the widely used crumb rubber infill. <br />Crumb rubber is usually made from granulating used tires. C <br />2 <br /> Environmental concerns include leaching of <br />chemicals from the fields into the surrounding area. More specifically, both crumb rubber and synthetic <br />fiber fragments, arising from wear and tear, can be washed into nearby surrounding areas. That this is a <br />3 <br />significant concern was established in a recent report by the Swedish Environmental Research Institute. <br /> <br />In addition, crumb contains a range of organic contaminants and heavy <br />metals that can volatilize into the air and/or leach into the percolating rainwater, thereby posing a <br />potential risk to the While the quantitative importance of these risks is <br />organic contaminants and heavy metals into the air, water, and <br />soil in the surrounding environment occurs continuously, and their cumulative masses can be significant <br />4 <br /> functional lifetimes. Watterson (2017), after reviewing the available evidence, concludes <br />Public health professionals in the meantime may draw on established principles to support greater <br />5 <br />caution in setting crumb rubber exposure limits and controls. <br /> <br />Because of these concerns the industry is beginning to introduce new materials. We can anticipate we will <br />be told that while there may or may not have been legitimate environmental or health concerns about <br /> <br />2 <br /> in 5źƭƷźƌƌğƷźƚƓƭ, Fall 2015, Science History Institute. <br />3 <br /> <br />Report, C 183, March 2016, revised March 2017. <br />4 <br /> Hefa Cheng, Yuanan Hu, and Martin ReinhardEnvironmental and Health Impacts of Artificial Turf: A Review <br />9ƓǝźƩƚƓƒĻƓƷğƌ {ĭźĻƓĭĻ ğƓķ ĻĭŷƓƚƌƚŭǤ, 2014, Vol. 48, pp. 21142129. <br />5 <br /> Artificial Turf: Contested Terrains for Precautionary Public Health with Particular Reference to <br />Europe?LƓƷ W 9ƓǝźƩƚƓ wĻƭ tǒĬƌźĭ IĻğƌƷŷ, September 2017, Vol. 14(9): 1050. <br />4 <br /> <br /> <br />