Ultraviolet O3 Research Articles

Assessing the effects of ultraviolet radiation, residential greenness and air pollution on vitamin D levels: A longitudinal cohort study in China

Vitamin D metabolism is essential in aging and can be affected by multiple environmental factors. However, most studies conducted single exposure analyses. We aim to assess the individual and combined effects of ultraviolet (UV) radiation, residential greenness, fine particulate matter (PM2.5), and ozone (O3) on vitamin D levels in a national cohort study of older adults in China. We used the 2012 and 2014 Chinese Longitudinal Healthy Longevity Survey data, and measured the environmental exposure in the same year. We interpolated the UV radiation from monitoring stations, measured residential greenness through satellite-derived Normalized Difference Vegetation Index (NDVI), modeled PM2.5 with satellite data, and estimated O3 using machine learning. We dichotomized serum 25-hydroxy vitamin D (25(OH)D), the primary circulating form of vitamin D, into non-deficiency (≥50 nmol/L) and deficiency (<50 nmol/L) categories. We used the generalized estimating equation for analysis, adjusted for sociodemographic information, lifestyle, physical condition, and season of blood draw, and calculated joint odds ratios based on the Cumulative Risk Index. We also explored the interaction between interested exposures, modification of participants’ characteristics, and potential mediation. We included 1,336 participants, with a mean age of 83 at baseline. In single exposure models, the odds ratios of vitamin D deficiency (VDD) for per interquartile range increase in UV radiation, NDVI, PM2.5, and O3 and decrease were 0.39 (95 % CI:0.33,0.46), 0.90 (0.81,1.00), 1.65 (1.53,1.78), 1.67 (1.46,1.92), respectively. UV radiation mediated nearly 48 % and 78 % of the relationship between VDD and PM2.5 and O3, respectively. The association between UV radiation and VDD was stronger in females than men (OR: 2.25 vs 1.22). UV radiation, residential greenness can protect against VDD, while, PM2.5 and O3 increase the risk of VDD. UV radiation partly mediated the association between air pollution and VDD.

Effect of ultraviolet light and ozone on electrification performance of polymers

Triboelectric nanogenerator (TENG) has become a promising energy harvesting system in recent years, while the electron transferring at the contact interface is a key element to decide its performance. Herein, we employed TENG to study the effect of ultraviolet (UV) light and ozone(O3), which exists everywhere in near space, on the contact electrification(CE) of polymers. Testing results showed that the electron transfer at solid-solid, liquid-solid, and gas-solid interface can be weakened by UV light (light wavelength at 200 nm), and the inhibition can be further strengthen by O3. Additionally, we studied the photo-excitation electrification performance of polymers under UV light and O3. It is found that polymers can be positively charged under UV light, and the photo-excitation electrification can be further enhanced by O3. Meanwhile, the photoelectron excitation depends on the electron-withdrawing(EW) ability of polymers. Further, the photoelectron excitation model involving the photo-excitation and the change of the highest occupied energy levels of electrons is proposed to explain the effect of UV light and O3 on the electrification performance of polymers. The finding provides a strong evidence about the electron transfer process in the CE at solid-solid, liquid-solid, and gas-solid interface.

Effects of O2 plasma and UV-O3 assisted surface activation on high sensitivity metal oxide functionalized multiwalled carbon nanotube CH4 sensors

The authors present a comparative analysis of ultraviolet-O3 (UVO) and O2 plasma-based surface activation processes of multiwalled carbon nanotubes (MWCNTs), enabling highly effective functionalization with metal oxide nanocrystals (MONCs). Experimental results from transmission electron microscopy, scanning electron microscopy, x-ray photoelectron spectroscopy, and Raman spectroscopy show that by forming COOH (carboxyl), C-OH (hydroxyl), and C=O (carbonyl) groups on the MWCNT surface that act as active nucleation sites, O2 plasma and UVO-based dry pretreatment techniques greatly enhance the affinity between the MWCNT surface and the functionalizing MONCs. MONCs, such as ZnO and SnO2, deposited by the atomic layer deposition technique, were implemented as the functionalizing material following UVO and O2 plasma activation of MWCNTs. A comparative study on the relative resistance changes of O2 plasma and UVO activated MWCNT functionalized with MONC in the presence of 10 ppm methane (CH4) in air is presente...

Comparison of ultraviolet absorbance and NO-chemiluminescence for ozone measurement in wildfire plumes at the Mount Bachelor Observatory

The goal of this paper is to evaluate the accuracy of the commonly used ozone (O3) instrument (the ultraviolet (UV) photometer) against a Federal Reference Method (Nitric Oxide –chemiluminescence) for ozone measurement in wildfire smoke plumes. We carried out simultaneous ozone measurement with two UV O3 photometers and one nitric oxide–chemiluminescence (NO-CL) ozone detectors during wildfire season (Aug. 1–Sept. 30) in 2015 at the Mount Bachelor Observatory (MBO, 2763 m above mean sea level, Oregon, USA). The UV O3 shows good agreement and excellent correlation to NO-CL O3, with linear regression slopes close to unity and R2 of 0.92 for 1-h average data and R2 of 0.93 for O3 daily maximum 8-h average (MDA8). During this two-month period we identified 35 wildfire events. Ozone enhancements in those wildfire plumes measured by NO-CL O3 and UV O3 monitors also show good agreement and excellent linear correlation, with a slope and R2 of 1.03 and 0.86 for O3 enhancements (ΔO3) and 1.00 and 0.98 for carbon monoxide (CO)-normalized ozone enhancement ratios (ΔO3/ΔCO), respectively. Overall, the UV O3 was found to have a positive bias of 4.7 ± 2.8 ppbv compared to the NO-CL O3. The O3 bias between NO-CL O3 and UV O3 is independent of wildfire plume tracers such as CO, particulate matter (PM1), aerosol scattering, and ultrafine particles. The results demonstrate that the UV O3 absorbance method is reliable, even in highly concentrated wildfire plumes.

球载临边紫外辐射与臭氧斜柱浓度测量研究

With a novel light-weight and absolutely calibrated ultraviolet (UV) spectrometer, UV skylight radiances and O3 slant column densities are measured by balloon-borne limb measurements in Xinjiang area, China. UV skylight radiances measured at the height of 31 km are compared with the results from Modtran in the wavelength range from 290 to 420 nm. O3 slant column densities are derived from radiance spectra in the Huggins bands (320-335 nm) using differential optical absorption spectroscopy method. And the parameter exhibits a good correlation with the same value simulated by radiative transfer model (Tracy). The O3 profile simultaneously measured by an O3 sonde is used as input in Tracy calculations. The O3 sonde is launched on the same balloon.

Catalytic Effects of Ultraviolet Light and/or Ultrasound On The Ozone Oxidation of Humic Acid and Trihalomethane Precursors

This paper describes the singular and composite effects of two catalysts; ultraviolet (UV) light and ultrasound (US) on the ozone (O3) oxidation of a purified solution of a commercially available humic acid with the objective of minimizing trihalomethane formation potential (THMFP). The principal findings are that (1) the most effective reactor conditions for both thedestruction of nonvolatile total organic carbon (NVTOC) and THMFP utilized both US and UV in combination with ozon, and (2) bicarbonate alkalinity reduces the oxidation efficiency of the US–UV–O3 system apparently asa consequence ofradical scavenging.