Reduction Of Ultraviolet Radiation Research Articles

Impacts of anthropogenic activities & climate change resulting from increasing concentration of Carbon dioxide on environment in 21st Century; A Critical Review

The human population explosion and rapidly increasing urbanization are two major problems of the current century. According to an estimate world human population is about 8 billion, while in the previous century, it was about 2.0 billion. These figures and facts shows that the future impacts of anthropogenic activities will be more harsh and comprise a more complex nature. Carbon emission induced in environment by anthropogenic activities is major cause for global warming. Climate change, different types of environmental pollution, wastage of raw materials, and ecosystem degradation are major important ecological challenges which are being faced by humanity. These problems are increasing every year due to increasing human population. Forests represent one of most frequent types of green area in cities. Their environmental settlement include perfection in air, water and soil quality, conservation of energy, carbon sequestration, low air temperatures, reduction in ultraviolet radiation and reduction in environmental pollution especially air pollution. The political ecology approach is based on interactions between humans and nature, talking about climate change mitigation and adaptation and technologies that are used for these purposes. Many environmental experts have initiated concept of green revolution to achieve mitigation and adaptation strategies. If human population explosion and establishment of new industrial structures go on increasing without considering the importance of trees then certainly there would be more critical changes for living organisms on surface of the earth in near future. So, “green revolution is the best solution to arrest the environmental pollution” in this changing climate of the world.

Brownification of freshwater promotes nitrogen-cycling microorganism growth following terrestrial material increase and ultraviolet radiation reduction

Brownification is an increasingly concerning phenomenon faced by aquatic ecosystems in the changing environments, and the microbiome plays an irreplaceable role in material circulation and food web construction. Insight into the influence of brownification on microbial communities is crucial from an ecological standpoint. In this study, we simulated brownification using a the mesocosm system and explored the relationship between the characteristics of microbial communities and brownification using excitation-emission matrix (EEM) fluorescence spectroscopy and ultraviolet (UV) spectroscopy combined with high-throughput amplicon sequencing techniques. The results showed that brownification reduced the richness of the microbial community and selectively promoted the growth of nitrogen-cycling microorganisms, including hgcI_clade, Microbacteriaceae, and Limnohabitans. Brownification affected microbial communities by altering the carbon source composition and underwater spectrum intensity; UV, blue, violet, and cyan light were significantly (p < 0.05) correlated with microbial community richness, and random forest analysis revealed that UV, C1 (microbial humic-like), and C3 (terrestrial humic-like) were the major factors significantly influencing microbiome variation. We found that brownification affected microorganisms in shallow lakes, especially nitrogen cycling microorganisms, and propose that controlling terrestrial material export is an effective strategy for managing freshwater brownification.

Economic evaluation of interventions to reduce solar ultraviolet radiation (UVR) exposure among construction workers

Solar ultraviolet radiation is one of the most common occupational carcinogens in Canada and is responsible for approximately 5,556 non-melanoma skin cancers per year. A large part of these cases are preventable by reducing solar ultraviolet radiation exposure. In this study, investigators estimated the potential economic impacts of different solar ultraviolet radiation reduction interventions among construction workers, as they are one of the largest at-risk occupational groups. Investigators performed an economic evaluation from a societal perspective, by comparing incremental costs in relation to incremental benefits achieved by two interventions—use of personal protective equipment by all exposed individuals and use of shade structure wherever and whenever feasible. Interventions costs were estimated for 2020–2050, and benefits with a 10-year delay, i.e., for the period 2030–2060. Economic evaluation estimates were reported by intervention costs, total costs of non-melanoma skin cancers cases averted, incremental cost per avert case, return on investment, and the break-even point. Various sensitivity analyses were undertaken with key parameters. Our findings indicate that if the rising trend of incidence continues, cases will be double in 2060, whereas by using personal protective equipment or shade structure, with the best-case scenario of full ultraviolet radiation removal, would result in 6,034 and 2,945 cases averted over 30 years, respectively. This translates into a total of $38.0 and $20.5 million of averted costs (all monetary values represented in 2017 Canadian dollars). Under this scenario investigators expect that by 2060, for every dollar invested in personal protective equipment and shade structures, $0.49 and $0.35 will be returned, respectively. Findings also suggested that under a conservative scenario, prevention of non-melanoma skin cancer cases by personal protective equipment and shade structures resulted in $5,812 and $7,355 incremental costs, respectively, over the 30-year period. This study provides important insights for decision makers about the potential impacts of solar ultraviolet radiation reduction interventions in the construction sector and other sectors with substantial outdoor work. Our estimates also can raise awareness of the importance of solar ultraviolet radiation reduction interventions.

Growth and development of Stevia rebaudiana Bert., in high and low levels of radiation

Stevia rebaudiana Bert., is a plant native to Paraguay that contains natural sweetener molecules, which, like growth, can be affected by environmental conditions. The solar radiation incident in the Colombian Caribbean is a stress factor for stevia crops because it can reach very high levels. This work aimed to evaluate the effect of low and high levels of radiation on the main growth rates of stevia. Biospace technology (BIOESP) was evaluated, which is based on the reduction of ultraviolet radiation. To achieve this, Stevia rebaudiana Bert. cv Morita II plants, were planted under BIOESP technology and compared to plants grown in direct solar radiation (DR). The main results indicated that photosynthesis can reach a point of light saturation close to 1200 μmol photosynthetically active radiation (PAR) m−2 s-1. The absolute and relative growth rates (AGR and RGR respectively) did not register differences in both environments. However, the net assimilation rate (NAR) and the harvest index (HI) showed greater efficiency in plants grown under BIOESP compared to those grown in the DR (NAR: 1.4 vs. 2.1 g m−2 d-1; HI: 0.54 vs. 0.62 % respectively). We conclude that BIOESP technology could be used as an efficient strategy of high radiation and temperature resilience caused by climate change in the Colombian Caribbean.

Potential effects of ultraviolet radiation reduction on tundra nitrous oxide and methane fluxes in maritime Antarctica

Stratospheric ozone has begun to recover in Antarctica since the implementation of the Montreal Protocol. However, the effects of ultraviolet (UV) radiation on tundra greenhouse gas fluxes are rarely reported for Polar Regions. In the present study, tundra N2O and CH4 fluxes were measured under the simulated reduction of UV radiation in maritime Antarctica over the last three-year summers. Significantly enhanced N2O and CH4 emissions occurred at tundra sites under the simulated reduction of UV radiation. Compared with the ambient normal UV level, a 20% reduction in UV radiation increased tundra emissions by an average of 8 μg N2O m−2 h−1 and 93 μg CH4 m−2 h−1, whereas a 50% reduction in UV radiation increased their emissions by an average of 17 μg N2O m−2 h−1 and 128 μg CH4 m−2 h−1. No statistically significant correlation (P > 0.05) was found between N2O and CH4 fluxes and soil temperature, soil moisture, total carbon, total nitrogen, NO3−-N and NH4+-N contents. Our results confirmed that UV radiation intensity is an important factor affecting tundra N2O and CH4 fluxes in maritime Antarctica. Exclusion of the effects of reduced UV radiation might underestimate their budgets in Polar Regions with the recovery of stratospheric ozone.

Vertical redistribution of zooplankton in an oligotrophic lake associated with reduction in ultraviolet radiation by wildfire smoke

AbstractWe used a natural experiment to test whether wildfire smoke induced changes in the vertical distribution of zooplankton in Lake Tahoe by decreasing incident ultraviolet radiation (UV). Fires have a variety of effects on aquatic ecosystems, but these impacts are poorly understood and have rarely been observed directly. UV is an important driver of zooplankton vertical migration, and wildfires may alter it over large spatial scales. We measured UV irradiance and the distribution of zooplankton on two successive days. On one day, smoke haze from a nearby wildfire reduced incident UV radiation by up to 9%, but not irradiance in the visible spectrum. Zooplankton responded by positioning themselves, on average, 4.1 m shallower in the lake. While a limited data set such as this requires cautious interpretation, our results suggest that smoke from wildfires can change the UV environment and distribution of zooplankton. This process may be important in drought‐prone regions with increasingly frequent wildfires, and globally due to widespread biomass burning.

Applying spaceborne reflectivity measurements for calculation of the solar ultraviolet radiation at ground level

Abstract. Long-term analysis of cloud effects on ultraviolet (UV) radiation on the ground using spaceborne observations requires the use of instruments that have operated consecutively. The longest data record can be built from the reflectivity measurements produced by the instruments Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI) flown on EOS Aura since 2004. The reflectivity data produced by TOMS on Earth Probe is only included until 2002. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing the standard reflectivity are compared with measurements of UV irradiances at eight European low-elevation stations. The reflectivity data of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage, i.e. 2–3%. In contrast, the reflectivity product of OMI requires correction of 7–10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The average reduction of UV radiation due to clouds for all sites together indicates a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of the reflectivity data would have indicated the opposite. An optimal area was established for reflectivity data for the calculation of daily sums of UV radiation. It measures approximately 1.25° in latitudinal direction for square-shaped areas overhead the ground-based UV stations. Such an area can be traversed within 5 to 7 h at the average wind speeds found for the West European continent.

Ultraviolet radiation exposure in children: a review of measurement strategies.

Rates of skin cancer in the U.S. are high and have been increasing rapidly. Recommendations for primary prevention focus on the reduction of ultraviolet radiation (UVR) exposure, especially in childhood. Valid, reliable strategies are needed to measure UVR exposure in children, to document baseline levels, and to assess intervention impact. This article reviews strategies reported in observational and intervention studies and considers their potential usefulness for application with children. The strategies include verbal report (by self or parent), direct observation, visual inspection, ultraviolet (UV) sensitive film, the Erythema Meter, the spectrophotometer, and the colorimeter. Each strategy is described along several dimensions, including ease of use, cost, and whether it is suitable for measuring acute and cumulative exposure. The review describes the existing validity and reliability data and points out a need for further research assessing the reliability and validity of most of these measures. Additionally, suggestions for matching strategies with measurement and intervention objectives are presented.

Executive Summary of the Ozone Trends Panel Report

The report evidently focuses on global aspects of ozone, and the Antarctic ozone hole is just one part. But it is mainly in the Antarctic, where the extreme cold and unique atmospheric circulation of the southern spring occur, that the evidence for drastic decreases in ozone is unequivocal and where, because of direct measurements of the chemical composition of the statosphere during the Antarctic ozone expeditions, the primary responsibility for ozone depletion can be assigned to CFCs. Small decreases in ozone have been found over the rest of the globe, but they are not yet alarming since they are comparable to natural variations. In fact, most of the decrease in ozone in the Northern Hemisphere from 1979 to 1985 appears to have been associated with the 11-year sunspot cycle and with the reduction in ultraviolet radiation emitted from the sun during that period. As well, previously published reports of much larger decreases in ozone amounts were biased by drift in the calibration of the satellite instruments used, as the executive summary explains.