Hydraulic fracturing uses a host of highly toxic chemicals that could be contaminating drinking water supplies, wildlife and crops, according to a report released Thursday by a California science panel. The long-awaited final assessment from the California Council on Science and Technology said that because of data gaps and inadequate state testing, overwhelmed regulatory agencies do not have a complete picture of what oil companies are doing. The risks and hazards associated with about two-thirds of the additives used in fracking are not clear, and the toxicity of more than half, the report concluded, remains "uninvestigated, unmeasured and unknown. Basic information about how these chemicals would move through the environment does not exist." Seth Shonkoff, lead author on the public health sections of the report, said he was surprised to learn during his research that recycled wastewater from oil fields was being used on crops. "We've got to know what to test for ... to know that what we are putting onto the crops is safe," he said. "Until we have that data, I don't know how we can assure farmers and consumers that their food is safe." Among the findings of the report: Oil operations in federal waters offshore are discharging wastewater directly into the ocean, against EPA regulations, more than half the produced water from fracked wells is disposed of in unlined pits, [and] about one-third of the oil field wastewater pits in the Central Valley are operating without proper permits.