Solar corpuscular radiation and mortality from various forms of ischemic heart disease in Bulgaria for the interval 2005 - 2015

20% of Bulgarians die of ischemic heart disease. A study was conducted in order to get more information on whether and to what extent mortality from ischemic disease in Bulgaria is related to external causes – the planetary magnetic field, the corpuscular solar radiation and the galactic cosmic rays. Data for mortality of ischemic heart disease in the interval 2005 – 2015 from the Bulgarian National Statistical Institute, were used. Data on solar corpuscular radiation was obtained from the Geostationary Operational Environmental Satellite series (GOES) via an NOAA site. Data on the geomagnetic field for Bulgaria (Panagyurishte magnetic observatory) was obtained from a website of INTERMAGNET. Data on galactic cosmic rays were obtained from the NMDB database for 5 European neutron monitors. Correlation and regression analysis were used to process the data. Between the annual number of protons with energy above 1 MeV and alpha particles with an energy of 4 to 10 MeV on the one hand and the male and female mortality for Bulgaria of ischemic disease, forms I20 to I25 according to the International Classification of Diseases 10^th revision, there is a high statistically significant correlation. The mortality from ischemic disease in Bulgaria is negatively correlated with the horizontal component of the geomagnetic field in Bulgaria. There are no statistically significant correlations between mortality from ischemic heart disease in Bulgaria and the average annual number of sunspots or x-ray radiation of the geostationary orbit. There are no statistically significant correlations between galactic cosmic radiation and mortality from ischemic heart disease in Bulgaria. The results indicate a possible causal relationship between mortality from ischemic heart disease in Bulgaria and the fluxes of solar corpuscular radiation, as well as with the horizontal component of the geomagnetic field. The contribution of these effects to the risk of mortality from ischemic heart disease in Bulgaria is about 6 – 10%. Geomagnetic field (horizontal component) deviates the flow of positively charged particles from the Earth’s surface and reduces the ischemic mortality for Bulgaria. It can be assumed that the peak fluxes of positively charged particles – mainly protons, penetrate deep into the atmosphere and reach the Earth’s ground in the region of the middle latitudes also (not only around the magnetic poles), affecting the biosphere and invoking processes leading to increased mortality from ischemic disease, statistically noticed in Bulgaria.