Where you live may increasingly become as important as how you live in determining your health as we continue to recognize how environmental factors affect our lives and may hasten our deaths.
“No longer can we just kind of sit back and say those are all just lifestyle (influences) … just stop eating frybread and throw some vegetables in there,” said Chris Shuey, director of the Uranium Impact Assessment Program for the Southwest Research and Information Center.
For more than three decades, Shuey has tracked the environmental influences on long-term health for the Navajo people linked to the region’s past uranium mining. He foresees growing acknowledgment of how human-caused environmental changes and naturally occurring threats may affect our health.
Shuey is very familiar with one environmental factor tied to uranium mining but that can affect people everywhere.
Radon is a colorless, odorless gas that develops when naturally occurring radioactive materials breakdown and is listed as the second-leading cause of lung cancer in the United States and Canada. It is the leading cause of such cancer in non-smokers and is linked to as many as 20,000 lung cancer deaths annually in the United States – where National Radon Action Month just past in January.
Studying how radon exposure affected miners actually brought to light the radioactive gas’ negative health impact. But even before radon was identified as an element and lung cancer as a disease, the elevated rate at which miners died indicated a link between their work environment and their health.
In 1556 a German scholar first noted the high mortality rate of miners in Eastern Europe, and 300 years later, autopsies revealed chest tumors were the likely cause of death in miners, according to a report by Drs. Howard Frumkin and Jonathan M. Samet. Radon, first called “niton” wasn’t identified as an element until 1900.
Some tribal lands – including those of the Navajo – are rich in uranium. Mining that radioactive mineral has left legacies of problems for generations. There are 521 abandoned uranium mines recognized on Navajo lands, but there are probably more than 1,000 and closer to 2,000 areas contaminated during the movement and temporary storage of mine tailings, Shuey estimated.
“We’re 70 years into the uranium legacy (on Navajo lands). It started in the ’50s, closed down in the ’60s, and yet the contamination is there.”
The health service studies started in the 1950s split miners into two groups: 3,238 “whites” and 757 “non-whites.” The latter category include 753 Native miners, mainly Navajo. The miners chosen worked at least one month in uranium mines between 1950 and 1960.
The studies have found considerably increased rates of death by lung cancer and other lung or related diseases in both groups. Based on the normal rate of death from lung cancer, for example, the study would have anticipated 10 deaths among the 757 non-white miners studied, but there were 34 deaths – three times higher than normal. From other lung diseases, 8 deaths would have been the normal rate, but 20 miners died from such illnesses
Similar increases were noted in “white” miners, among which 64 deaths from lung cancer were expected but 371 deaths occurred, six times the normal rate.
“From the start, radioactive radon gas and radon ‘daughters’ in the air were suspected as the cause of the lung cancer,” according to the study summary posted on the Centers for Disease Control site.
These studies were the catalyst for the 1990 Radiation Exposure Compensation Act allotting compensation money to eligible miners and attaching this apology: “The Congress apologizes on behalf of the Nation to the (affected individuals) and their families for the hardship they have endured.”
Such studies of miners – from centuries ago Europe to those on the Navajo-land mines – have contributed to knowledge that can help everyone create healthier home environments. These kinds of studies alerted researchers to the fact that radon gas, while released in higher quantities in mining operations, also naturally occurs and can accumulate in homes or workplaces.
“Radon can be anywhere – it doesn’t have to be associated with uranium mining or wastes,” Shuey said.
An important aspect of radon exposure was revealed through the Navajo miners in the studies because most of them did not smoke outside ceremonial use of specialized tobacco.
“Navajo is a non-smoking population. That’s why the Navajo underground miners were such an important sub-unit of the cohort,” Shuey said. “The Navajo cohort debunks the whole notion that the uranium miners’ lung cancer relates to smoking.”
While exposure to radon gas can exacerbate the likelihood of lung cancer, studies of these Navajo miners demonstrated that long-term exposure to radon itself can cause lung cancer.
Shuey is involved with a new study relating to the legacy of uranium mining around Navajo lands and again radon gas will be an element of this research.
The Navajo Birth Cohort Study is being conducted to determine whether exposure to uranium mining and milling waste affects the outcome of pregnancies or the development of children. The study, which so far has 400 participants, hopes to recruit 1,500 mother-infant pairs. The project involves a partnership of University of New Mexico Community Environmental Health Program, SRIC, Navajo Nation Department of Health, Navajo Area Indian Health Service, and the Centers for Disease Control and Prevention. It is funded through Congress as part of the federal government’s second five-year plan to address uranium contamination on the Navajo Nation.
Checking radon levels in their homes is just one aspect of the environmental monitoring, Shuey said. While the U.S. Environmental Protection Agency calls for action if a home tested for radon shows more than 4 picocuries per liter (pCi/L), the leaders of this study suggest changes for anything more than 2.7 pCi/L, which is the World Health Organization standard. Homes with 2.7 pCi/L or more are referred to the Navajo Nation EPA for follow up.
Long-term exposure to radon gas at 4 pCi/L equals a lung-cancer risk similar to smoking 2 packs a day, Shuey said. It’s important to know that radon level in places like the Navajo lands, where studies show people usually live more than 30 years in the same home.
Just as past studies of miners helped set direction toward better health for others, studies like this birth cohort study should help to determine how environment influences health.
“What contribution is our environmental factors playing into all of these diseases?” said Shuey. “The radon exposure is just one element, one facet of the uranium legacy.”