| 1. |
- Anand, Kritika, et al.
(författare)
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Solar and geomagnetic activity reduces pulmonary function and enhances particulate pollution effects
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 838
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Li, Longxiang, et al.
(författare)
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A spatiotemporal ensemble model to predict gross beta particulate radioactivity across the contiguous United States
- 2021
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120. ; 156
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Tidskriftsartikel (refereegranskat)abstract
- Particulate radioactivity, a characteristic of particulate matter, is primarily determined by the abundance of radionuclides that are bound to airborne particulates. Exposure to high levels of particulate radioactivity has been associated with negative health outcomes. However, there are currently no spatially and temporally resolved particulate radioactivity data for exposure assessment purposes. We estimated the monthly distributions of gross beta particulate radioactivity across the contiguous United States from 2001 to 2017 with a spatial resolution of 32 km, via a multi-stage ensemble-based model. Particulate radioactivity was measured at 129 RadNet monitors across the contiguous U.S. In stage one, we built 264 base learning models using six methods, then selected nine base models that provide different predictions. In stage two, we used a non-negative geographically and temporally weighted regression method to aggregate the selected base learner predictions based on their local performance. The results of block cross-validation analysis suggested that the non-negative geographically and temporally weighted regression ensemble learning model outperformed all base learning model with the smallest rooted mean square error (0.094 mBq/m3). Our model provided an accurate estimation of particulate radioactivity, thus can be used in future health studies.
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| 3. |
- Li, Longxiang, et al.
(författare)
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Exposure to unconventional oil and gas development and all-cause mortality in Medicare beneficiaries
- 2022
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Ingår i: Nature Energy. - : Springer Science and Business Media LLC. - 2058-7546. ; 7:2, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about whether exposure to unconventional oil and gas development is associated with higher mortality risks in the elderly and whether related air pollutants are exposure pathways. We studied a cohort of 15,198,496 Medicare beneficiaries (136,215,059 person-years) in all major US unconventional exploration regions from 2001 to 2015. We gathered data from records of more than 2.5 million oil and gas wells. For each beneficiary’s ZIP code of residence and year in the cohort, we calculated a proximity-based and a downwind-based pollutant exposure. We analysed the data using two methods: a Cox proportional hazards model and a difference-in-differences design. We found evidence of a statistically significant higher mortality risk associated with living in proximity to and downwind of unconventional oil and gas wells. Our results suggest that primary air pollutants sourced from unconventional oil and gas exploration can be a major exposure pathway with adverse health effects in the elderly.
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| 4. |
- Li, Longxiang, et al.
(författare)
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Ratios between Radon Concentrations in Upstairs and Basements : A Study in the Northeastern and Midwestern United States
- 2022
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Ingår i: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 9:2, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- Temporally resolved assessment of residential exposure to radon is essential for investigating radon's acute health effects. Recent studies have used large numbers of short-term radon measurements to model the spatiotemporal variations in radon concentrations. However, most short-term radon measurements in the northeastern and midwestern United States were conducted in the basements, which were less frequently occupied and had higher average radon concentrations than the upstairs spaces. Disproportionate usage of basement radon measurements in exposure assessment potentially introduces misclassifications. In an effort to mitigate the issue, we investigated the spatiotemporal gradients in ratios between the radon concentrations in the upstairs and basements (hereafter upstairs/basement ratio). Building-specific ratios were calculated on the basis of 10774 pairs of simultaneous short-term measurements and then aggregated by state and season. We found that upstairs/basement ratios of northeastern states are generally lower than those of Midwestern states, a pattern also found in 3508 pairs of simultaneous long-term radon measurements. Ratios in winter are higher than those in other seasons. Our results, in conjunction with behavior data, can improve the assessment of short-term residential exposure to radon and therefore facilitate future studies regarding the acute health effects of radon.
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| 5. |
- Zhong, Jia, et al.
(författare)
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B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:13, s. 3503-3508
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Tidskriftsartikel (refereegranskat)abstract
- Acute exposure to fine particle (PM2.5) induces DNA methylation changes implicated in inflammation and oxidative stress. We conducted a crossover trial to determine whether B-vitamin supplementation averts such changes. Ten healthy adults blindly received a 2-h, controlled-exposure experiment to sham under placebo, PM2.5 (250 μg/m(3)) under placebo, and PM2.5 (250 μg/m(3)) under B-vitamin supplementation (2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12), respectively. We profiled epigenome-wide methylation before and after each experiment using the Infinium HumanMethylation450 BeadChip in peripheral CD4(+) T-helper cells. PM2.5 induced methylation changes in genes involved in mitochondrial oxidative energy metabolism. B-vitamin supplementation prevented these changes. Likewise, PM2.5 depleted 11.1% [95% confidence interval (CI), 0.4%, 21.7%; P = 0.04] of mitochondrial DNA content compared with sham, and B-vitamin supplementation attenuated the PM2.5 effect by 102% (Pinteraction = 0.01). Our study indicates that individual-level prevention may be used to complement regulations and control potential mechanistic pathways underlying the adverse PM2.5 effects, with possible significant public health benefit in areas with frequent PM2.5 peaks.
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