June 28, 2006
Officials Conduct Biomonitoring for Metals in Humans
A biomonitoring study by state and local public health officials has found elevated levels of heavy metals in some Montana residents.
The goal of the study was to find out whether Montanans have higher levels of arsenic and other metals in their drinking water and bodies compared to people in other states. Biomonitoring is the measurement of people’s exposure to substances in the environment.
The study was conducted by the Montana Department of Public Health and Human Services (DPHHS) in collaboration with county health departments. It was part of a six-state project that also involved Arizona, Colorado, New Mexico, Utah, and Wyoming. The study focused on 13 metals: arsenic, antimony, barium, beryllium, cadmium, cesium, cobalt, lead, molybdenum, platinum, thallium, tungsten, and uranium.
Because of Montana’s unique geology, many parts of the state have naturally high levels of arsenic and other metals in the groundwater that is used for drinking, according to Dr. Kammy Johnson, epidemiologist for the Montana Biomonitoring Program of DPHHS.
People can also be exposed to heavy metals through food, air, or soil.
Some metals are monitored and regulated in public drinking water supplies, but less is known about the quality of water drawn from individual private wells, Dr. Johnson said.
“We welcomed this opportunity to measure metals in humans and drinking water,” she said.
Eighty-seven people from Park, Jefferson, Madison, and Lewis and Clark counties volunteered to take part in the study. They were selected because they live in areas known or suspected to have high levels of metals in the groundwater.
Participants were asked to provide a urine sample and a drinking-water sample from their homes; both were tested for metals. They also were asked about daily activities to determine whether other factors might influence metal levels.
Participants received the results of both tests, along with a comparison of their results to human levels found in the U.S. population as a whole and to levels found in regulated water supplies.
“People from the Rocky Mountain West aren’t usually included in national exposure surveys,” Dr. Johnson said. “So the results will help determine the normal range of metal exposures for residents of this region.”
The study found that 54 percent of the participants had levels of arsenic or other metals in their bodies that were higher than national averages, Dr. Johnson said. Forty-seven percent of the wells tested had higher levels than are recommended for drinking water by the Environmental Protection Agency.
“But these results didn’t surprise us since we only tested people and water from areas we knew had a history of high levels,” she added. “We also need to remember that the test we used for the urine samples are screening tests and don’t mean that people may get sick.”
Participants were referred to their medical providers if they had concerns about test results. They also were given tips for making their well water safer to drink.
Knowledge about the quality of drinking water from private wells is often an overlooked aspect of health.
“Improving water quality has been one of the 10 greatest achievements of public health in the past century,” according to Dr. Steven Helgerson, state medical officer with DPHHS. “It is important to continue this tradition. This collaborative study between the Montana Biomonitoring Program and local health departments allows us an opportunity to understand and educate the public about how Montana’s unique geology may affect drinking water quality and, ultimately, public health.”
For more information about the biomonitoring study, visit www.cdc.gov/biomonitoring or call the Montana Biomonitoring Program at 406-444-0273.
For questions about drinking water quality and steps to protect your drinking water, contact the Montana Department of Environmental Quality, Public Water Supply Section, at 444-4400.
To have private well water samples tested for drinking water quality (including heavy metals), contact the DPHHS Environmental Laboratory at 406-444-2642.
Page last updated: 07/14/2006
