Radon decay product particle radioactivity and oxidative stress biomarkers in patients with COPD.

Radon decay products include α-radiation emitting radionuclides that attach to airborne particles that have potential to promote oxidative tissue damage after inhalation. To assess associations between α-particle radioactivity (α-PR) with urinary biomarkers of oxidative tissue damage, 140 patients with chronic obstructive pulmonary disease (COPD) had up to four 1-week seasonal assessments (N = 413) of indoor (home) and ambient (central site) PM2.5 and black carbon (BC). Following environmental sampling, urine samples were analyzed for total and free malondialdehyde (MDA), biomarkers of lipid oxidation, and 8-hydroxyl-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage. Particle radioactivity was measured as α-activity on PM2.5 filter samples. Linear mixed-effects regression models adjusted for urinary creatinine and other personal characteristics were used to assess associations. Indoor α-PR was associated with an increase in 8-OhdG (8.53%; 95% CI: 3.12, 14.23); total MDA (5.59%; 95% CI: 0.20, 11.71); and free MDA (2.17%; 95% CI: 2.75, 7.35) per interquartile range (IQR) of α-PR [median 1.25 mBq/m3; IQR 0.64], similar adjusting for PM2.5 or BC. The ratio of indoor/ambient α-PR was positively associated with each biomarker and associations with ambient α-PR were positive but weaker than with indoor concentrations. These findings are consistent with a contribution of radon decay products as measured by α-PR to oxidative stress in patients with COPD, with a greater contribution of indoor radon decay products.

Association between gestational exposure to solar activity and pregnancy loss using live births from a Massachusetts-based medical center.

BACKGROUND: Solar activity has been linked to biological mechanisms important to pregnancy, including folate and melatonin levels and inflammatory markers. Thus, we aimed to investigate the association between gestational solar activity and pregnancy loss. METHODS: Our study included 71,963 singleton births conceived in 2002-2016 and delivered at an academic medical center in Eastern Massachusetts. We studied several solar activity metrics, including sunspot number, Kp index, and ultraviolet radiation, with data from the NASA Goddard Space Flight Center and European Centre for Medium-Range Weather Forecasts. We used a novel time series analytic approach to investigate associations between each metric from conception through 24 weeks of gestation and the number of live birth-identified conceptions (LBICs) -the total number of conceptions in each week that result in a live birth. This approach fits distributed lag models to data on LBICs, adjusted for time trends, and allows us to infer associations between pregnancy exposure and pregnancy loss. RESULTS: Overall, the association between solar activity during pregnancy and pregnancy loss varied by exposure metric. For sunspot number, we found that an interquartile range increase in sunspot number (78·7 sunspots) in all of the first 24 weeks of pregnancy was associated with 14·0 (95% CI: 6·5, 21·3) more pregnancy losses out of the average 92 LBICs in a week, and exposure in weeks ten through thirteen was identified as a critical window. Although not statistically significant, higher exposure to Kp index and to UV radiation across all 24 weeks of pregnancy was associated with more and less pregnancy losses, respectively. CONCLUSION: While exposure to certain metrics of solar activity (i.e., sunspot number) throughout the first 24 weeks of pregnancy may be associated with pregnancy losses, exposure to other metrics were not. Solar activity is a complex phenomenon, and more studies are needed to clarify underlying pathways.

Intense solar activity reduces urinary 6-sulfatoxymelatonin in patients with COPD.

BACKGROUND: Little is known about the link between solar activity and variations in melatonin. In this study, we investigated if melatonin's major urinary metabolite, urinary 6-sulfatoxymelatonin (aMT6s), is lowest under periods of intense solar activity. METHODS: We investigated associations between high-energy solar particle events [Coronal Mass Ejection (CME) mass, speed and energy] on creatinine-adjusted aMT6s (aMT6sr) concentrations in 140 patients with chronic obstructive pulmonary disease (COPD) using up to four seasonal urine samples (n = 440). Mixed effect models with a random intercept for each subject were used to estimate associations, including effect modification attributable to diabetes, obesity, and reduced pulmonary function. RESULTS: Higher values of CME were associated with reduced aMT6sr concentrations, with stronger associations in patients with diabetes. An interquartile range (IQR) increase in natural log CMEspeed averaged through two days before urine collection was associated with a reduction of 9.3% aMT6sr (95%CI: - 17.1%, - 0.8%) in aMT6sr. There was a greater reduction in aMT6sr in patients with diabetes (- 24.5%; 95%CI: - 35.9%, - 11.6%). In patients without diabetes there was no meaningful association (- 2.2%; 95%CI: - 12%, 8.4%). There were similar associations with CMEenergy and CMEmass. There was no effect modification attributable to reduced pulmonary function or obesity. CONCLUSIONS: This is the first study in patients with COPD to demonstrate strong detrimental impact of high-energy solar particle events on aMT6sr, with greater associations in patients with diabetes. Since melatonin is an anti-oxidant, it is possible that adverse effects of intense solar activity may be attributable to a reduction in circulating melatonin and that patients with both COPD and diabetes may be more susceptible.

Predicting Monthly Community-Level Radon Concentrations with Spatial Random Forest in the Northeastern and Midwestern United States.

In 1987, the United States Environmental Protection Agency recommended installing a mitigation system when the indoor concentration of radon, a well-known carcinogenic radioactive gas, is at or above 148 Bq/m3. In response, tens of millions of short-term radon measurements have been conducted in residential buildings over the past three decades either for disclosure or to initially evaluate the need for mitigation. These measurements, however, are currently underutilized to assess population radon exposure in epidemiological studies. Based on two relatively small radon surveys, Lawrence Berkeley National Laboratory developed a state-of-the-art national radon model. However, this model only provides coarse and invariant radon estimations, which limits the ability of epidemiological studies to accurately investigate the health effects of radon, particularly the effects of acute exposure. This study involved obtaining over 2.8 million historical short-term radon measurements from independent laboratories. With the use of these measurements, an innovative spatial random forest (SRF) model was developed based on geological, architectural, socioeconomical, and meteorological predictors. The model was used to estimate monthly community-level radon concentrations for ZIP Code Tabulation Areas (ZCTAs) in the northeastern and midwestern regions of the United States from 2001 to 2020. Via cross-validation, we found that our ZCTA-level predictions were highly correlated with observations. The prediction errors declined quickly as the number of radon measurements in a ZCTA increased. When ≥15 measurements existed, the mean absolute error was 24.6 Bq/m3, or 26.5% of the observed concentrations (R2 = 0.70). Our study demonstrates the potential of the large amount of historical short-term radon measurements that have been obtained to accurately estimate longitudinal ZCTA-level radon exposures at unprecedented levels of resolutions and accuracy.

Solar and geomagnetic activity enhance the effects of air pollutants on atrial fibrillation.

AIMS: Cardiac arrhythmias have been associated with intense solar and geomagnetic activity (SGA) and exposures to air pollution. METHODS AND RESULTS: We examined whether oscillations of SGA can modify the effect of hourly exposures to air pollutants on atrial fibrillation ≥30 s (AF) risk in patients with dual-chamber implantable cardioverter-defibrillators. The effects of SGA on ambient particulate matter <2.5 µm (PM2.5), black carbon (BC), ultrafine particles (PN), and associations with AF were assessed. Measures of SGA included solar wind proton density (SW), total interplanetary magnetic field strength (IMF), and Kp index, a measure of global geomagnetic activity. Overall time lags between 0 and 24 h, periods of increased SGA (>50th percentile in IMF, SW, and Kp index) enhanced the effects of all three air pollutants on AF, while during periods of reduced SGA the associations were considerably weaker or absent. During periods of intense SW 6 h prior to an AF event, the odds ratio (OR) for PM2.5 exposure per interquartile range (IQR) of 5.6 µg/m3 was 1.7 [95% confident interval (CI) 1.3-2.3, P = 0.0001]. For periods of reduced SW, the OR for PM2.5 exposure per IQR was 1.2 (95% CI 0.9-1.5; P = 0.27). There were similar effects for PN and BC exposures. In patients with multiple AF events per hour, the associations with air pollutants during intense SGA were even greater. CONCLUSION: The effects of air pollutants up to 24 h before AF events were enhanced during periods of increased SGA. Our results suggest that these effects may account for variation in AF risk.

The impact of solar activity on ambient ultrafine particle concentrations: An analysis based on 19-year measurements in Boston, USA.

Solar radiation plays a major role in atmospheric photochemistry, contributing to the formation and growth of ultrafine particles (PN). PN affect global Earth's radiation balance, climate system, and human health. However, the impact of solar activity on ambient PN remains unclear. In this study, we investigated the associations between daily ambient PN concentrations [particle number (PN)/cm3] and solar radio flux [solar activity index (F10.7 in sfu)] as a solar activity parameter, shortwave solar radiation (SWR), daylight time (DL), cosmic ray-induced ionization (CRII), and air pollution [PM2.5, black carbon (BC) and SO2] over a 19-year period in Boston, MA. We used generalized additive models adjusted for local environmental conditions. We found that F10.7 was the strongest predictor for daily PN concentrations over all time lags (0-28 days of lags) and seasons. The effects were higher in winter and fall. In winter, an interquartile (IQR) of 60 sfu F10.7 corresponded to an increase of 5770 PN/cm3 in the day of PN collection. In fall, an IQR of 75.5 sfu F10.7 was associated with an increase of 5429 PN/cm3. The effects of F10.7 on PN concentrations were slightly greater when the models were adjusted for air pollution. In summer, ambient PN concentrations were statistically significantly associated with F10.7, SWR, and BC, with the strongest association found for PN and BC in the day of PN collection. Unlike the effects of F10.7, SWR and local pollutants on PN concentrations, DL and CRII were negatively associated with ambient PN in the analyses. These findings suggest that solar activity may have a significant impact on daily ambient PN concentrations that affect the Earth's climate system and human health.

The urban lead (Pb) burden in humans, animals and the natural environment.

Centuries of human activities, particularly housing and transportation practices from the late 19th century through the 1980's, dispersed hundreds of millions of tons of lead into our urban areas. The urban lead burden is evident among humans, wild and domesticated animals, and plants. Animal lead exposures closely mirror and often exceed the lead exposure patterns of their human partners. Some examples: Pigeons in New York City neighborhoods mimicked the lead exposures of neighborhood children, with more contaminated areas associated with higher exposures in both species. Also, immediately following the lead in drinking water crisis in Flint MI in 2015, blood lead levels in pet dogs in Flint were 4 times higher than in surrounding towns. And combining lead's neurotoxicity with urban stress results in well-characterized aggressive behaviors across multiple species. Lead pollution is not distributed evenly across urban areas. Although average US pediatric lead exposures have declined by 90% since the 1970s, there remain well defined neighborhoods where children continue to have toxic lead exposures; animals are poisoned there, too. Those neighborhoods tend to have disproportionate commercial and industrial lead activity; a history of dense traffic; older and deteriorating housing; past and operating landfills, dumps and hazardous waste sites; and often lead contaminated drinking water. The population there tends to be low income and minority. Urban wild and domesticated animals bear that same lead burden. Soil, buildings, dust and even trees constitute huge lead repositories throughout urban areas. Until and unless we begin to address the lead repositories in our cities, the urban lead burden will continue to impose enormous costs distributed disproportionately across the domains of the natural environment. Evidence-based research has shown the efficacy and cost-effectiveness of some US public policies to prevent or reduce these exposures. We end with a series of recommendations to manage lead-safe urban environments.

Lead seasonality in humans, animals, and the natural environment.

Lead adversely impacts the health of humans, animals, and the natural environment. Higher lead burdens in warm weather occur in humans, domesticated and wild animals; land and water species; urban and rural, developed and pristine environments. The array of evidence suggests that lead seasonality is multifactorial within the natural world, including humans. Seasonally higher temperatures, solar radiation, humidity and anthropogenic pollution result in lower pH (acidification) in air, water and soil. Environmental acidification increases lead's bioavailability and mobility thus intensifying human, animal and plant exposures. In addition, lead seasonality in the biosphere is influenced by higher growth rates, slightly increased exposures, and more Vitamin D metabolism. Methodologically, we applied a One Health perspective to EPA's Integrated Science Assessments of Lead to review the published literature, supplemented with subsequent and related publications to assess data on the seasonality of lead exposure across species and through the earth's systems. Our integrated assessment suggests that: 1) 'Seasonality' is a multifactorial, terrestrial phenomenon affecting the natural world; human activities have exacerbated natural cyclicities that impact lead exposures across species. 2) To be sustainable, human lead remediation strategies must consider the total environment. 3) Global warming and climate change events may increase lead exposures and toxicity to all species throughout the natural environment.

Domestic radon exposure and childhood cancer risk by site and sex in 727 counties in the United States, 2001-2018.

BACKGROUND: Childhood cancer has few established risk factors and environmental influences are underexplored. This ecologic study investigated the association between domestic radon exposure and childhood cancer risk in a large sample of United States (U.S.) counties. METHODS: Monthly ZIP code-level basement radon estimates from a geographic machine learning model were aggregated annually to counties, analyzed as continuous and dichotomized (cut point: 74 Bq/cubic meter (Bq/m3) or 2.0 picocuries/L (pCi/L)) versions, and lagged by one year. Annual county-level counts of sex- and site-specific (all, leukemia, brain and central nervous system [CNS], and other sites) incident cancer diagnoses among those 0-19 years from 2001 to 2018 were obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program database. Sex- and site-specific counts were modeled as zero-inflated Poisson distributions in a Bayesian spatiotemporal framework and sequentially adjusted for random and fixed confounder effects. RESULTS: In 727 counties across 14 states, the average population aged 0-19 years was 41,599 people at baseline. Results from fully adjusted spatiotemporal statistical models indicated 1.05 (95% credible interval, CrI: 1.00, 1.09) times higher relative risks (RRs) of leukemia among both sexes and a RR of 1.06 (95%CrI: 1.00, 1.12) in males from a 50 Bq/m3 (1.35 pCi/L) increase in radon concentration the year prior. For radon exposures ≥74 Bq/m3 (2.00 pCi/L) the year prior, RRs were 1.08 (95%CrI: 1.02, 1.15) for both sexes and 1.12 (95%CrI: 1.04, 1.22) for females. No associations were found with other cancer sites or sexes from prior year radon exposures. CONCLUSIONS: County-level childhood leukemia risk in both sexes were associated with average radon levels below U.S. Environmental Protection Agency guidelines recommending mitigation (148 Bq/m3 or 4.00 pCi/L). These findings warrant further investigation using population-based and individual-level study designs.

Detrimental impact of solar and geomagnetic activity on plasma B-complex vitamins in the VA normative aging study cohort.

It has been hypothesized that ultraviolet (UV) radiation can lead to depletion of plasma folate and B12 vitamin, but few studies have investigated effects of other parameters of solar and geomagnetic activity (SGA). We investigated the association between four SGA parameters-interplanetary magnetic field (IMF), sunspot number (SSN), Kp index, and ground shortwave solar radiation (SWR)-and three plasma B-complex vitamins-folate, B6, and B12-in 910 participants from the Normative Aging Study (NAS) between 1998 and 2017. Mixed-effects regression models were used for 1- to 28-moving day averages of SGA exposure, adjusted for covariates. We compared the impact of SGA in individuals under higher and lower B-complex supplementation (> or < 50th quartile). Our findings show that increases in solar activity variables IMF and SSN were found to be significantly associated with decreases in B12 vitamin. IMF and SSN were associated with decrease in folate levels, especially in individuals under higher levels of B-complex supplementation. No associations were found for SWR and Kp index. To our knowledge, this is the first study that demonstrated the detrimental impact of solar activity on plasma B12 and folate in a large cohort. These findings have clinical implications during periods of high solar activity.

Annual space weather fluctuations and telomere length dynamics in a longitudinal cohort of older men: the Normative Aging Study.

BACKGROUND: Space weather has been associated with increased risk of cardiovascular diseases in space and flight crew. However, limited research has focused on the ground population, particularly among the elderly who are vulnerable to aging-related diseases. OBJECTIVE: We evaluated the association between space weather alterations and biological aging using leukocyte telomere length as a biomarker in healthy elderly men. METHODS: We used data from the Normative Aging Study, a longitudinal cohort of healthy elderly men in Massachusetts, USA. Leukocyte telomere length and health information were measured at in-person examinations approximately every three years, contributing to a total of 1,850 visits from 791 participants. Regional space weather information was collected daily, including cosmic ray-induced ionization, neutrons, sunspot number, interplanetary magnetic field, and Kp-index as our exposure of interest. We used mixed-effects models with a random intercept per individual to evaluate the associations between annual averages of space weather indicators and relative telomere length while accounting for participant demographics, environmental parameters, and secular trends. RESULTS: The mean age at baseline was 72.36 years. A one-year increment in age is associated with a 1.21% reduction in leukocyte telomere length. In the fully adjusted model accounting for individual and environmental factors, an interquartile range (IQR) increase of annual cosmic ray induced ionization (110.0 ion pairs cm-3 sec-1) was associated with a 17.64% (95%CI: -27.73%, -7.55%) decrease in leukocyte telomere length, equivalent to 15-years age increment. Solar and geomagnetic activities were associated with increased leukocyte telomere length, but the association became absent after adjusting for cosmic ray indicators. IMPACT: Galactic cosmic rays may accelerate the aging process in populations on the Earth, despite the protection by the Earth's atmosphere and magnetic field. This research enhances our understanding of how changes in space weather can impact health, highlights potential risks from space to Earth's inhabitants, and helps inform health strategies for vulnerable populations.

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.

Geomagnetic disturbances reduce heart rate variability in the Normative Aging Study.

BACKGROUND: Solar and geomagnetic activity (GA) have been linked to increased cardiovascular (CVD) events. We hypothesize that heart rate variability (HRV) may be the biological mechanism between increased CVD risk and intense geomagnetic disturbances (GMD). METHODS: To evaluate the impact of GA and intense GMD on HRV in 809 elderly men [age mean 74.5 (SD = 6.8)] enrolled in the Normative Aging Study (Greater Boston Area), we performed repeated-measures using mixed-effects regression models. We evaluated two HRV outcomes: the square root of the mean squared differences of successive normal-to-normal intervals (r-MSSD) and the standard deviation of normal-to-normal heartbeat intervals (SDNN) in milliseconds (ms). We also compared the associations between Kp and HRV in patients with and without comorbidities such as diabetes and coronary heart diseases (CHD). We used data on global planetary K-Index (Kp) from middle latitudes as a GA and GMD (>75th Kp) parameters from the National Oceanic and Atmospheric Agency's Space Weather Prediction Center. RESULTS: We found a near immediate effect of continuous and higher Kp on reduced HRV for exposures up to 24 h prior to electrocardiogram recording. A 75th percentile increase in 15-hour Kp prior the examination was associated with a -14.7 ms change in r-MSSD (95 CI: -23.1, -6.3, p-value = 0.0007) and a -8.2 ms change in SDNN (95 CI: -13.9, -2.5, p-value = 0.006). The associations remained similar after adjusting the models for air pollutants over the exposure window prior to the event. In periods of intense GMD, the associations were stronger in patients with CHD and non-diabetes. CONCLUSIONS: This is the first study to demonstrate the potential adverse effects of geomagnetic activity on reduced heart rate variability in a large epidemiologic cohort over an extended period, which may have important clinical implications among different populations.

Solar Activity Is Associated With Diastolic and Systolic Blood Pressure in Elderly Adults.

Background Since solar activity and related geomagnetic disturbances modulate autonomic nervous system activity, we hypothesized that these events would be associated with blood pressure (BP). Methods and Results We studied 675 elderly men from the Normative Aging Study (Boston, MA) with 1949 BP measurements between 2000 and 2017. Mixed-effects regression models were used to investigate the association of average 1-day (ie, day of BP measurement) to 28-day interplanetary magnetic field intensity, sunspot number, and a dichotomized measure of global geomagnetic activity (Kp index) in 4-day increments with diastolic and systolic BP. We adjusted for meteorological conditions and other covariates associated with BP, and in additional models adjusted for ambient air pollutants (particulate matter with an aerodynamic diameter ≤2.5 µm, black carbon, and particle number) and ambient particle radioactivity. There were positive associations between interplanetary magnetic field, sunspot number, and Kp index and BP that were greatest with these exposures averaged over 16 through 28 days before BP measurement. An interquartile range increase of 16-day interplanetary magnetic field and sunspot number and higher Kp index were associated with a 2.5 (95% CI, 1.7‒3.2), 2.8 (95% CI, 2.1‒3.4), and 1.7 (95% CI, 0.8‒2.5) mm Hg increase, respectively, for diastolic BP as well as a 2.1 (95% CI, 0.7‒3.6), 2.7 (95% CI, 1.5‒4.0), and 0.4 (95% CI, -1.2 to 2.1) mm Hg increase, respectively, for systolic BP. Associations remained after adjustment for ambient air pollutants and ambient particle radioactivity. Conclusions Solar activity and solar-driven geomagnetic disturbances were positively associated with BP, suggesting that these natural phenomena influence BP in elderly men.