Sacramento, Calif.— An independent scientific study confirms that fracking and other methods of oil development in California are harmful to human health, air quality, and the state’s water supply.

The study released today by the California Council on Science and Technology outlines serious risks associated with the oil development processes and says that California regulatory officials lack data to adequately protect the public or even to propose effective mitigation strategies to avoid health risks associated with fracking and other forms of oil development.

The scientists who authored the study conclude that operations close to human populations present substantial public health concerns including disproportionate risks on sensitive populations, including children, pregnant women, the elderly, and those with pre-existing conditions. More than 1.67 million Californians live within a mile of an active oil well in the Los Angeles Basin alone. The study says that fracking and other extreme methods are often performed at shallow depths in California, which “presents a higher risk of groundwater contamination, which groundwater monitoring may not detect.” The study also raises concerns about waste disposal, including unlined pits that allow chemicals to evaporate into the atmosphere as air pollutants, leak into aquifers, and contaminate soil.

“For the first time a government-sponsored study in California confirms that extreme extraction techniques and other harmful drilling techniques compromise the wellbeing of millions of Californians,” said Adam Scow, California director of Food and Water & Watch. “This new study combined with state’s own environmental impact report released last week leave no question that fracking poses a serious threat to our communities and the environment, and should be outlawed in California.”

CCST released the second and third volumes of its study titled “An Independent Scientific Assessment of Well Stimulation in California.” The first volume, released in January, included no information about health impacts associated with a third of chemicals used in fracking.  At the time, CCST estimated 100-150 hydraulic fracturing operations were happening monthly in California—mostly in the San Joaquin Valley—consuming between 130,000 to 210,000 gallons per well per frack at a time of severe drought.

The CCST study comes on the heels of a state-commissioned environmental impact report released last week by California’s Division of Oil, Gas, and Geothermal Resources (DOGGR). The EIR found that impacts to air quality, public safety and climate from extreme oil production methods are “significant and unavoidable.”  It says fracking will increase the release of greenhouse gases, in conflict with statewide emissions reductions goals.

“Our current understanding of human health risks associated with the new forms of gas and oil extraction, especially within vulnerable communities, should oblige Governor Brown to place a moratorium on such practices in California,” said Jessica Hendricks, program director with Global Community Monitor.

Both the environmental impact report and the independent scientific study were required by SB 4, legislation signed into law by Gov. Jerry Brown in 2013, in order to craft rules to regulate fracking and other extreme extraction methods. However, the state’s regulations were finalized in January and went into effect on July 1, before the CCST study and EIR were made public.

“Fracking is growing at a scale and pace that puts everyone in the U.S. at increased risk for many life-threatening diseases and disorders, including breast cancer,” said Breast Cancer Action Executive Director Karuna Jaggar. “The toxic and radioactive legacy of fracking threatens the health of future generations for years to come. We urge California to follow the science, step onto the right side of history, and ban fracking.”

New Scientific Study Shows Fracking, Oil Development Hurts Natural Resources and Exposes Millions of Californians to Health Risks