10.12.2006 12:00 AM
Group Says NIH Study Confirms Adverse Effects From Denver Tower RF
A recent posting on the Canyon Area Residents for the Environment (CARE) Web site
quotes a study by Colorado State University's Department of Environmental and Radiological Health Sciences showing the number of T cells and lymphocytes increased with exposure to RF among people living near the Lookout Mountain. The mountain is home to three analog transmission facilities, which broadcasters propose to replace with one new DTV tower.
The study, Human Responses to Residential RF Exposure
examined the effect of residential RF exposure on melatonin and other human biomarkers in a population of 280 residents of Lookout Mountain in Golden, Colo. The study notes that "Several publicly accessible areas closest to these towers have exceeded the U.S. general public non-ionizing radiation standard on each occasion that they were measured." In addition to RF exposure, the study also considered exposure to extremely low frequency (ELF) fields from 60 Hz power lines.
The study found no association between RF exposure and melatonin production, but did find that "among those exposed to RF above the median, persons in the highest quartile of exposure to ELF had an increase in both their total overnight melatonin excretion and their melatonin concentration when either geometric mean or cumulative exposure to ELF was used as the exposure metric." Evaluation of 8-OHdG (8-hydroxydeoxyguanosine) concentration, an indicator of DNA damage, found no significant increase in 8-OHdG in persons in the highest quartile of average residential exposure to RF and those in the lowest exposure quartile. The study found that an increase in RF exposure "appeared to be associated with a decrease in ODC activity in both mitogen stimulated and unstimulated blood leucocytes" but found no association between RF exposure and polyamine concentration.
The study found an association between immune markers and RF. "For the group of individuals with low melatonin excretion, the concentrations of total white blood cells, total lymphocytes, total T cells, helper T cells, and cytotoxic T cells were all significantly increased among persons in the highest compared to the lowest quartile of household RF exposure."
Is this significant? According to CARE, it is. However, the article "Foes of TV tower grasping at straws"
in the October 5 issue of Rocky Mountain News disagrees. It quotes James Burch, one of the study's authors, explaining, "Just like all good scientific research, more questions have been raised than answered. I don't know that we have the data to make the determination of just exactly what it means, or exactly what is going on, or whether it is significant." The article said everyone knows the human body responds to certain kinds of electromagnetic radiation and compares RF to sunlight, which can have good or bad effects on health. Dr. Mark Johnson of the Jefferson County Department of Health and Environment said the changes measured by the study "are within the range of normal human variation."
The author of the article in Rocky Mountain News makes an interesting point in closing -- the new tower, on average, would reduce RF exposure!