Short-term geomagnetic disturbances driven by solar activity have been linked to a broad range of adverse health effects.
In this blog, author Carolina Leticia Zilli Vieira discusses her recent article, published in Environmental Health, which looks at the effects of GMD on cardiovascular diseases, myocardial infarction, and stroke in 263 U.S. Cities.
Daily geomagnetic disturbances, or geomagnetic storms, are temporary distortions in the Earth’s magnetic field caused by solar wind shock waves that strike the magnetic field hours after a solar event. These geomagnetic storms are the cause of the aurora at the earth’s poles, and have been found to affect the physiology, standard metabolism and behavior pattern of humans and other species (e.g. birds, whales, reptile, insects, and bacteria).
High geomagnetic disturbances are usually associated with solar flares and solar coronal mass ejections, in which billion tons of high energy magnetic plasma from the sun is released into the solar wind. This release of high energy magnetic varies according to the 11-year solar cycles, and is more intense during solar maxima periods. These periods are also characterized by a high number of geomagnetic storms (GMD) that have been linked to numerous health outcomes, including cardiovascular diseases (CVD), neurological system diseases, behavioral diseases, and total deaths.
While previous research groups have found evidence of the connection between GMD and CVD, there is a need to determine the temporal and spatial impact of short term exposure to geomagnetic disturbances on deaths in a larger cohort. To address this, we conducted a large national epidemiological study to investigate the effects of geomagnetic disturbances on total and cause-specific mortality in 263 U.S. cities.
Overall, our study found that geomagnetic disturbances lead to an increase in city-specific and season-stratified total, cardiovascular diseases (CVD), and myocardial infarction deaths in the selected 263 U.S. cities. The effects of GMD on total deaths were found in all seasons, and on CVD and myocardial infarction deaths in spring and fall. When comparing this with the effect of particulate matter our study found that the effects of GMD on total, CVD, and myocardial infarction deaths were also higher spring and fall than there were for particulate matter alone. This may be explained by increased numbers of geomagnetic storms during spring and fall.
But how do increased geomagnetic disturbances lead to an increase in deaths related to cardiovascular diseases and myocardial infarction?
Our results may be explained through the direct impact of environmental electric and magnetic fields produced during GMD on the human autonomic nervous system. Interactions between GMD and the autonomic nervous system are likely to induce a cascade of reactions in the body’s electrophysiology that culminate in the collapse of organ functions and death.