Associations between solar and geomagnetic activity and peripheral white blood cells in the Normative Aging Study

Linkages Between Geomagnetic Activity and Blood Pressure

This review aims to critically examine and present evidence for and against potential linkages between geomagnetic activity and its effects on blood pressure (BP). Four databases were searched for peer-reviewed papers written in English: PubMed, Web of Science, EMBASE, and Biomedical Reference Collection. Retrieved titles were first screened for potential relevance followed by an abstract review for further clarifications if warranted. The preponderance of the reported evidence is consistent with the concept that space weather and related events that cause sufficiently large changes in the geomagnetic field (GMF) can impact BP. The associated BP change in most but not all cases is one in which both systolic blood pressure (SBP) and diastolic blood pressure increase, with SBP appearing to be more consistently involved. The magnitude of the reported BP increase ranges from about 3 to 8 mmHg depending on the intensity of the geomagnetic activity. The initiation of these BP changes has been variably reported to occur shortly before the GMF change or in synchrony with the abrupt change in the GMF. Such GMF-linked BP changes are not present in all persons and there appears to be increased sensitivity in women and in persons with co-existing hypertension. The utility of these findings in assessing or treating persons with known or suspected hypertension remains to be determined via future research. Further, research directed at determining the factors that determine responders from non-responders to GMF changes is warranted.

Associations of solar activity and related exposures with fetal growth

BACKGROUND

Solar and geomagnetic activity have been shown to suppress melatonin and to degrade folate levels, important hormones for fetal development. We examined whether solar and geomagnetic activity were associated with fetal growth.

METHODS

We included 9573 singleton births with 26,879 routine ultrasounds at an academic medical center in Eastern Massachusetts from 2011 through 2016. Sunspot number and Kp index were obtained from the NASA Goddard Space Flight Center. Three exposure windows were considered, including the first 16 weeks of pregnancy, one month prior to fetal growth measurement, and conception until fetal growth measurement (cumulative). Ultrasound scans from which we extracted biparietal diameter, head circumference, femur length, and abdominal circumference measurements were categorized as anatomic (<24 weeks' gestation) or growth scans (≥24 weeks' gestation) based on clinical practice. Ultrasound parameters and birth weight were standardized, and linear mixed models adjusted for long-term trends were fitted.

RESULTS

Prenatal exposures were positively associated with larger head parameters measured <24 weeks' gestation, negatively associated with smaller fetal parameters measured ≥24 weeks' gestation, and not associated with birth weight. The strongest associations were observed for cumulative exposure in growth scans, where an interquartile range increase in sunspot number (32.87 sunspots) was associated with a -0.17 (95 % CI: -0.26, -0.08), -0.25 (-0.36, -0.15), and -0.13 (95 % CI: -0.23, -0.03) difference in mean biparietal diameter, head circumference, and femur length z-score, respectively. An interquartile range increase in cumulative Kp index (0.49) was associated with a -0.11 (95 % CI: -0.22, -0.01) and -0.11 (95 % CI: -0.20, -0.02) difference in mean head circumference and abdominal circumference z-score, respectively, in growth scans.

CONCLUSIONS

Solar and geomagnetic activity were associated with fetal growth. Future studies are needed to better understand the impact of these natural phenomena on clinical endpoints.

Solar and geomagnetic activity reduces pulmonary function and enhances particulate pollution effects

BACKGROUND

Increased solar and geomagnetic activity (SGA) may alter sympathetic nervous system activity, reduce antioxidant activity, and modulate physiochemical processes that contribute to atmospheric aerosols, all which may reduce pulmonary function.

OBJECTIVES

Investigate associations between forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) with SGA, and assess whether SGA enhances adverse effects of particulate pollution, black carbon (BC) and particulate matter ≤2.5 μm in diameter (PM2.5).

METHODS

We conducted a repeated measures analysis in 726 Normative Aging Study participants (Boston, Massachusetts, USA) between 2000 and 2017, using interplanetary magnetic field (IMF), planetary K index (Kp), and sunspot number (SSN) as SGA measures. Linear mixed effects models were used to assess exposure moving averages up to 28 days for both SGA and pollution.

RESULTS

Increases in IMF, Kp Index and SSN from the day of the pulmonary function test averaged through day 28 of were associated with a significant decrement in FEV1 and FVC, after adjusting for potential confounders. There were greater effects for longer moving averages and enhanced effects of PM2.5 and BC on FEV1 and FVC with increased SGA. For example, for each inter-quartile increase (4.55 μg/m3) in average PM2.5 28 days before testing, low IMF (10th percentile: 3.2 nT) was associated with a -21.4 ml (95 % CI: -60.8, 18.1) and -7.1 ml (95 % CI: -37.7, 23·4) decrease in FVC and FEV1, respectively; high IMF (90th percentile: 9.0 nT) was associated with a -120.7 ml (95 % CI:-166.5, -74.9) and -78.6 ml (95 % CI: -114.3, -42·8) decrease in FVC and FEV1, respectively.

DISCUSSION

Increased periods of solar and geomagnetic activity may directly contribute to impaired pulmonary function and also enhance effects of PM2.5 and BC. Since exposure to solar activity is ubiquitous, stricter measures in reducing air pollution exposures are warranted, particularly in elderly populations.

The role of solar and geomagnetic activity in endothelial activation and inflammation in the NAS cohort

This study investigated the associations between solar and geomagnetic activity and circulating biomarkers of systemic inflammation and endothelial activation in the Normative Aging Study (NAS) cohort. Mixed effects models with moving day averages from day 0 to day 28 were used to study the associations between solar activity (sunspot number (SSN), interplanetary magnetic field (IMF)), geomagnetic activity (planetary K index (Kp index), and various inflammatory and endothelial markers. Biomarkers included intracellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), C-reactive protein (CRP), and fibrinogen. After adjusting for demographic and meteorological variables, we observed significant positive associations between sICAM-1 and sVCAM-1 concentrations and solar and geomagnetic activity parameters: IMF, SSN, and Kp. Additionally, a negative association was observed between fibrinogen and Kp index and a positive association was observed for CRP and SSN. These results demonstrate that solar and geomagnetic activity might be upregulating endothelial activation and inflammation.