According to the official website of the common wealth of Kentuck:
The Energy and Environment Cabinet (EEC) is redirecting future funds used in the crumb rubber grant program. Kentucky has an annual inventory of 4 million tires through the sale of new tires as well as imports from other states. The crumb rubber program is funded through a statutory tire fee levied on the purchase of each new tire in Kentucky.
The use of crumb rubber on athletic fields and school playgrounds has been shown to help reduce injuries and reduce maintenance cost. However, there are no large-scale, national studies on the possible health issues associated with inhalation, ingestion or contact to the skin for those who use these fields and playgrounds for recreational purposes. Out of an abundance of caution, the EEC has made the decision to redirect crumb rubber grant allocations to other uses rather than continue funding applicants wishing to use crumb rubber on playgrounds and athletic fields.
During FY 2015, the EEC will make available grants for crumb rubber for use in landscaping projects. Also, the cabinet will utilize funding from the program to assist local governments in retrieving tire piles, and for providing direct grant dollars to counties to manage waste tires.
Also, the EEC is currently building a framework for a program to use rubberized asphalt material for chip and seal road maintenance projects. The agency plans to offer grant opportunities to counties for chip and seal programs in FY 2016.
With regards to playgrounds and athletic fields that currently contain crumb rubber, there is no conclusive evidence that crumb rubber surfacing for playgrounds or athletic fields is unsafe for recreational users. Research to date has been inconclusive, contradictory or limited in scope. The cabinet supports a national study to measure any possible impacts of recreational use of crumb rubber surfacing.