DENVER – A years-long scientific study commissioned by the Colorado Department of Public Health and Environment that was released Thursday found that people living in the vicinity of oil and gas operations could see short-term negative health effects caused by exposure to chemicals used in oil and gas operations under “worst-case” scenarios.

The study, “Human Health Risk Assessment for Oil & Gas Operations in Colorado,” was conducted by an environmental and health consulting company, ICF International, and a peer-reviewed summary of the study was published Thursday in the Journal of the Air and Waste Management Association.

The modeling study found that people living within 2,000 feet of oil and gas sites have a higher possibility of developing headaches, nosebleeds, dizziness and other irritations during “worst-case” conditions – specifically during the pre-production stages of getting a well constructed and operating. Current state laws require 500-foot setbacks.

Health officials said that the worst-case scenarios would be the result of certain weather conditions and certain points in pre-production when chemical emissions are highest.

The study built on evaluations of oil and gas impacts released by CDPHE in 2017, which also called for more research into possible health effects for people living near oil and gas sites. Another study using 2016 emissions data compiled by Colorado State University looked at emissions at facilities in northern Colorado and Garfield County.

Colorado health officials and Colorado Oil and Gas Conservation Commission (COGCC) officials said at a news conference Thursday that the findings will lead to changes in permitting and further studies of emissions near oil and gas operations.

The modeling study released Thursday did not measure concentrations of chemicals near well pads or health concerns people living nearby had reported over the past couple of years.

“It is an important addition to the increasing body of knowledge about the potential health risks associated with oil and gas operations,” said CDPHE’s Environmental Programs Director John Putnam. “As we learn more, we have a better roadmap for where we need additional research. … This study just reinforces what we already know: we need to minimize emissions from oil and gas sources.”

COGCC Director Jeff Robbins said as a result of the study, and after the passage of SB19-181 earlier this year, that new review measures would be going into place.

“Our response is threefold and includes a new plan for permit review, a new plan for testing, and then a plan to use the information from the testing for future regulation and rulemakings,” he said in a release.

The COGCC will be reviewing existing and new permit applications for sites that would sit within 2,000 feet of a building throughout the rulemaking process. The agency said that 39 applications from the 1,500-2,000 foot range would be reviewed.

The CDPHE and COGCC has also been ordered by the Polis administration to develop new testing methods that can be implemented to compile better data specific to monitoring – and not just modeling – that can be used to better understand the types of compounds being emitted at sites and when emissions are at their worst.

The COGCC hopes to get data from oil and gas sites to compare to the study released Thursday and said if that data corroborates the health risks, more regulatory steps could come next.

Either way, Robbins said, the new testing would go into the rulemaking process under SB19-181 as the COGCC and other stakeholders determine the framing of how the local control law will affect permitting and production statewide in the future.

“The COGCC is committed to implementing SB-181, regulating in a protective manner, and will work to ensure that the best data, from CDPHE’s study to the future data-driven studies, can be used to inform these critical decisions that impact all of Colorado,” he said in a statement.

Senate Majority Leader Steve Fenberg, D-Boulder, who sponsored SB19-181, said he plans to introduce legislation in 2020 that would implement a statewide epidemiological study on the impacts of oil and gas development on public health. He is also considering legislation that would increase regional air quality monitoring.

But with the legislative session still more than two months out, he said that the COGCC and CDPHE should deploy air quality monitoring near existing well sites near people, delay final decisions on pending permits until rulemaking is complete and again review emissions standards.

“This new CDPHE study is valuable, but what we really need is a comprehensive epidemiological study that looks at real health impacts on real people who live near oil and gas wells,” Fenberg said in a statement.

Colorado Petroleum Council Executive Director Lynn Granger said that there were limitations to using only models and said the council hoped to work with regulators and health officials to monitor air quality.

“Using modeled exposures instead of measured air quality data introduces uncertainties and limitations that may result in erroneous estimates of risk for a population,” Granger said in a statement. “As an industry we rely on data, facts and science and look forward to working with CDPHE and the COGCC on actual air monitoring in the future, which is what should be used when developing policy and regulations.”

Robbins said that while the pre-production phase was the most likely to produce “worst-case” scenarios, he would be reaching out to operators to see if there was interest in further reviewing existing wells.

“I am encouraged by the steps announced today to advance additional public health protections as the COGCC continues working to implement SB19-181, and call on them to continue taking urgent action to address air quality and health impacts of oil and gas operations,” said House Speaker KC Becker, another sponsor of SB19-181.

Colorado Oil and Gas Association officials were holding a news conference to address the study at 3 p.m.

This is a developing news story and will be updated.