It is impossible to determine how much mercury exposure neighbors of an illegal gold mill near Mancos may have experienced while operating, according to a recent report by the state health department.
The level of mercury inhaled by neighbors of the Red Arrow Gold Mill on Grand Avenue was likely low because contamination was largely centralized inside the building and much lower levels of mercury contamination were found outside the building, the Colorado Department of Public Health and Environment report said.
But officials were unable to determine the potential health impacts from mercury in the air because no monitoring was done while the mill was operating.
"We have not drawn any conclusions regarding the past mercury exposures," said Tista Ghosh, director of the Disease Control and Environmental Epidemiology Division.
Researchers were not able to run any tests on any neighbors because too much time had passed for a urine analysis to reveal exposure to mercury, she said.
A high level of mercury from 13 power plants within 200 miles of the site also made it difficult to tell how much contamination was from the mill.
The heavy-metal contamination which included antimony, arsenic, chromium, copper, lead, in addition to mercury was completely contained by the Environmental Protection Agency on July 29. Illegal practices at the Red Arrow Gold Mill in Mancos left behind 240 pounds of liquid mercury waste in the building.
The mill was shut down last summer when the illegal activity was discovered, and the EPA announced in December that the health risk from the site had been contained.
Shortly after the mill was closed, officials removed contaminated mining tailings at the mill site, from a nearby farm and from Western Excelsior Corporation, a nearby manufacturer of erosion-control products.
The report found that exposure to these tailings likely did not increase neighbors' risk of cancer or other harmful effects because they were not actively disturbing the tailings that contained chromium, arsenic and mercury.
This soil contamination on site and surrounding properties was found to be shallow, and so officials opted not to test groundwater or surface water for contamination.
Public-health officials took nearly nine months to release the nearly 100-page report. However, it did not address health risks workers at the mill may have experienced because that is regulated by the Occupation Safety and Health Administration.
Those who know or suspect they were exposed to large amounts of mercury should seek medical attention to reduce its burden on the body, Ghosh said. Mercury vapors are easily absorbed and distributed throughout the body and impact the nervous and renal systems.
However, the state has not received any reports from Mancos of mercury appearing in blood urine tests.
A public meeting to review the health report will be held at 6 p.m. Sept. 23 at Mancos Town Hall. The report's authors will be there to answer questions.
mshinn@durangoherald.com
