Electromagnetic radiation in the radiofrequency range emitted by cell phones, tablets and other wireless communication devices is absorbed by the human body and may affect heart health, according to a new EWG analysis.
Human and animal research studies show that the cardiovascular system is sensitive to radiofrequency radiation. The developing organism, from the fetal stage through early life, is especially vulnerable to these exposures and their potential harms.
In animal studies, exposure to radiofrequency radiation has been associated with structural and biochemical changes of the heart. These changes include irregularity and degeneration of heart muscle fibers, congestion of blood vessels in cardiac muscle, increases in cardiac weight, and changes in the levels of key metabolic substances important for heart function. Examples of these adverse impacts identified in laboratory animals are listed in Table 1.
In two long-term animal studies, one conducted by the National Toxicology Program and another conducted by the Ramazzini Institute, in Italy, heart tumors were observed among laboratory animals exposed to radiofrequency radiation. In the NTP study, ventricular cardiomyopathy, a type of degenerative disease of the heart, was observed in laboratory rats following a relatively short period of 19 weeks of exposure to radiofrequency radiation.
Studies in people suggest that radiofrequency radiation can raise the risk for cardiovascular diseases by increasing blood pressure, total cholesterol and low-density lipoprotein cholesterol. Changes in heart rate and altered response of the sympathetic and parasympathetic nervous system have also been reported following exposure to radiofrequency radiation. Examples of such findings from human epidemiological research, some from occupational settings, are listed in Table 2.
The mechanism of radiofrequency radiation effects on the cardiovascular system is not yet clear. Published studies suggest that radiofrequency radiation increases the production of reactive oxygen species, which in turn may enhance lipid peroxidation and lead to oxidative damage. Radiofrequency radiation exposures can also cause changes to the permeability and function of the cell membrane, as well as changes in intracellular enzymes and DNA damage.
Table 1. Harm to the cardiovascular system documented in research on laboratory animals exposed to radiofrequency radiation.
|Cardiovascular effects||Evidence from animal studies|
|Increased risk of heart tumors||In rats, exposure to radiofrequency radiation was associated with an increased risk of malignant heart tumors.1, 2|
|Increased risk of cardiomyopathy||Exposure to radiofrequency radiation among rats was associated with an increased risk of cardiomyopathy.2|
|Changes in heart rate||Changes in heart rate associated with radiofrequency radiation exposure in rabbits3 and rats.4|
|Structural changes of the heart||Changes to the heart structure and increased risk of mortality was associated with radiofrequency radiation exposure in chicken embryos.5
Prenatal exposure of rats to radiofrequency radiation was associated with structural changes and cell death in the heart tissue.6
Structural damage and death of myocardial cells was observed following radiofrequency radiation exposure in rats.7, 8
|Changes in lipids in heart tissue||Higher levels of lipids observed in the myocardial tissues of chicken embryos exposed to radiofrequency radiation during incubation.5|
|Increased risk of oxidative stress in heart tissue||Radiofrequency radiation exposure in rats was associated with increased levels of malondialdehyde and nitric oxide, markers of lipid peroxidation and oxidative stress, as well as decreased levels of superoxide dismutase, catalase, and glutathione peroxidase.9
Prenatal exposure of rats to radiofrequency radiation was associated with higher levels of malondialdehyde, superoxide dismutase, and catalase and a lower level of glutathione.6
Radiofrequency radiation exposure in rats was associated with decreased levels of malondialdehyde levels, a marker of oxidative stress, and decreased xanthine oxidase and adenosine deaminase enzyme activities in the heart tissues.10
|Changes in blood pressure and heart rate variability||Radiofrequency radiation exposure in rats was associated with increased systolic, diastolic, and mean arterial blood pressure; decreased heart rate variability, increased total cholesterol and higher heart nitric oxide levels.4|
|Changes in cardiac energy metabolism||Decreased adenosine triphosphate activity in myocardial tissues, decreased levels of antioxidative stress enzymes and increased levels of malondialdehyde observed in rats exposed to radiofrequency radiation. 7|
|Changes in heart function||Exposure to radiofrequency radiation in laboratory mice was associated with increased creatine phosphokinase, a marker of cardiac function, and decreased high-density lipoprotein cholesterol.11|
|Changes in cardiac weight||In rats, exposure to radiofrequency radiation was associated with increased weight of the whole heart as well as increases in systolic blood pressure.12|
Table 2. Findings from epidemiological studies on people exposed to radiofrequency radiation in occupational or research settings.
|Cardiovascular effects||Evidence from human studies|
|Increased cardiovascular risk factors||Exposure to radiofrequency radiation among operators in broadcasting and television stations was associated with increased systolic and diastolic blood pressure, total cholesterol, and low-density lipoprotein cholesterols. Radiofrequency radiation exposure was associated with greater chance of becoming hypertensive and dyslipidemic among these workers.13|
|Changes in heart rate||
Occupational exposure to radiofrequency electromagnetic fields was associated with lower heart rates among operators of radiofrequency plastic sealers compared to controls.14
Changes in heart rate variability reported among healthy volunteers exposed to radiofrequency radiation from cell phones.16,17,18