… Nowhere in the country is turf use growing faster than in California — on school athletic fields, in city parks and on residential lawns. Exact numbers are not known, but it’s estimated that 1,100 acres of the material, or the equivalent of some 870 football fields, are being installed across the state each year. … “The fields do not require water, pesticides or fertilizers” … said Laura Chalkley, director of communications for San Mateo Union High School District. But a growing number of health experts, environmentalists and parents say the fields are harming children’s health and heating up the environment — and they’re pushing their cities, counties and school districts to ban them.