Relationship between variations in population health disorders in a subarctic region and heliogeophysical factors and oxygen status of surface air under different levels of solar activity

BACKGROUND: It is generally recognized that human health depends on the changes of space weather. However, the cyclic interactions of specific groups of diseases with the main components of solar radiation and its derivatives remain unresolved.

AIM: The work aimed to assess the stability of time series of health disorders in the northern population, as well as linear and phase synchronization with heliogeophysical factors and oxygen status depending on the level of solar activity.

METHODS: Data on sunspot numbers were obtained from the Royal Observatory of Belgium. To assess the level of solar radiation, as well as planetary and local indices of magnetic activity, materials from the All-Russian Research Institute of Hydrometeorological Information were used. Partial oxygen density was calculated from values of temperature, atmospheric pressure, and relative humidity. Data on ambulance calls were retrieved from the emergency service database. Indicators from 2001 and 2007 (years of high and low solar activity, respectively) were compared. Wavelet analysis was applied for mathematical processing.

RESULTS: In the overall ambulance call dataset, the degree of data dispersion in 2001 was 14.69%, compared with 15.83% in 2007; in men, the indicator was 25.78% and 24.40%, respectively, and in women 23.75% and 23.23%, independent of solar activity level. The temporal distribution of cases of infectious diseases, mental disorders, genitourinary pathology, pregnancy, and childbirth became heterogeneous with increasing solar activity, whereas for respiratory diseases a consolidation of the time series was observed. Linear synchronization was characterized by a moderate positive association (0.338) between ambulance calls and partial oxygen density, which decreased to a weak level (0.177) with rising solar activity; linear synchronization with sunspot numbers (0.139), solar radiation (0.278), and the local magnetic activity index (0.119) weakened to the level of statistical noise during high solar activity. In the active Sun year, the in-phase synchronization index of total ambulance calls increased with the number of sunspots (57.4% in 2001; 61.1% in 2007) and solar radiation (55.6% 2001; 60.4% in 2007), whereas synchronization between calls and partial oxygen density declined (77.2% 2001; 68.5% 2007). Assessment of phase desynchronization between heliophysical factors and specific nosological groups revealed three reaction types: absence of reaction, synchronization, and desynchronization.

CONCLUSION: With increasing solar activity, the temporal distribution of ambulance calls becomes heterogeneous for infectious diseases, mental disorders, genitourinary pathology, pregnancy, and childbirth. In the case of respiratory diseases, the opposite effect is observed in the form of time series consolidation. In a year of the quiet Sun, moderate linear synchronization exists between ambulance calls and partial oxygen density, which declines to weak synchronization with increasing solar activity, accompanied by pronounced sex-related differences. Associations of health disorders with sunspot numbers, solar radiation, and planetary and local magnetic activity indices weaken to statistical noise during active Sun periods. With increasing solar activity, phase desynchronization is observed between fluctuations in health disturbances and the variability of oxygen partial density. Desynchronization of health rhythms is observed only in relation to global planetary parameters. When comparing time series of ambulance calls stratified by nosological groups with the locally calculated magnetic activity index and partial oxygen density, phase desynchronization was found to decrease.