China
Africa
Explore chapters and articles related to this topic
Environmental Degradation as a Multifaceted Consequence of Human Development
Published in Rouf Ahmad Bhat, Moonisa Aslam Dervash, Khalid Rehman Hakeem, Khalid Zaffar Masoodi, Environmental Biotechnology, 2022
Zulaykha Khurshid Dijoo, Rizwana Khurshid
Ozone layer protects the planet from dangerous ultraviolet radiations coming from the sun. The presence of chlorofluorocarbons, hydrochlo-rofluorocarbons in the atmosphere is triggering the ozone layer depletion, due to which more destructive rays comeback to the earth (Buhaug et al., 2010; Raven et al., 1998). There are accounts of ozone depletion above Antarctica letting hazardous ultraviolet radiations to Earth. Overexposure to these radiations causes skin cancer and cataracts.
The Atmosphere and the Chemistry of Air
Published in Armen S. Casparian, Gergely Sirokman, Ann O. Omollo, Rapid Review of Chemistry for the Life Sciences and Engineering, 2021
Armen S. Casparian, Gergely Sirokman, Ann O. Omollo
Ozone is a toxic gas essential for life on the Earth. There is a layer of the atmosphere, referred to as the ozone layer, in which ozone is formed by the absorption of high-energy UV rays and thus serves to protect organisms living on the Earth from their potentially harmful effects. Ozone can sometimes also be formed closer to ground level, in which case it can be a potential hazard, as discussed in the next section.
International Environmental Regulations
Published in Mary K. Theodore, Louis Theodore, Introduction to Environmental Management, 2021
Mary K. Theodore, Louis Theodore
Depletion of the ozone layer, a major global problem, is linked to a group of chemicals called chlorofluorocarbons (CFCs). These chemicals were used widely by industries as refrigerants and by consumers in polystyrene products earlier. Once released into the air, they rise into the stratosphere and eat away at the Earth’s protective ozone layer. The ozone layer shields all life on the planet from the sun’s hazardous ultraviolet radiation, a leading cause of skin cancer.
Numerical investigation of flashing of propane (R-290) in a helical capillary tube
Published in Numerical Heat Transfer, Part A: Applications, 2023
Soumik Bose, Sofen Kumar Jena, Sewan Das Patle
With the development in the world’s economic condition, home appliances like refrigerators and air conditioners are more prevalent. The uses of these appliances touch sky root after the economic development of South Asian countries like India and Bangladesh. Extreme hot climate in the subcontinent region makes AC and refrigerators an essential household requirement. These HVAC devices provide cooling comfort in a closed space, while it disturbs the surrounding by contributing to global warming and emitting harmful gasses to the atmosphere. CFC (Chloro-Fluoro-Carbon) emission to the atmosphere results in stratospheric ozone layer depletion. At the same time, leakage of HFC (hydrofluorocarbons) is thousands of times more potent than carbon dioxide for the greenhouse effect. One kg R410a refrigerant has the same greenhouse impact as two tonnes of carbon dioxide, equivalent of driving a car continuously for six months. Humanity is caught in a feedback loop where warmer temperatures require essential cooling, and excessive use of cooling devices results in a warm environment. The action gradually contributes more to the original problems. This lethal deadlock provokes the scientific community the search for a quick, efficient, and sustainable solution. After the 2016 Paris agreement, international energy agency (IEA) is deliberately looking for an efficient cooling technique to tackle the reduction in new power sector infrastructure to meet rising HVACs demand. In hotter countries like India, AC in peak electricity load could reach 45 percent by 2050, from 10% today without discovering effective cooling mechanisms.
Improving ultraviolet protection properties of cotton textiles using Zinc oxide (ZnO) nanomaterials: an approach for controlling occupational and environmental exposures
Published in International Journal of Environmental Health Research, 2023
Nafiseh Nasirzadeh, Mohammadreza Monazam Esmaeelpour, Neda Naseri, Soqrat Omari Shekaftik
UV radiation is divided into three bands; 320–400 nm (UV-A), 280–320 nm (UV-B), and 200–290 nm (UV-C) (Jo et al. 2019). Sunlight is a main source of UV radiation (Driscoll 1997). The solar radiation that reaches the Earth’s surface ranges from 280 nm to 3000 nm (Koozekonan et al. 2021). So, the Earth’s surface commonly receive UVA and about 10% of UV-B radiation (Farouk Asmaa et al. 2010). UV lights are artificial sources of UV which are used in fluorescent, arc-lamps, or incandescent lighting (Zayat et al. 2007). Nonetheless, UV is a threat to health; it can cause erythema and sun tanning (Menter and Hatch 2003). Researches have shown that UV radiation produces free radicals (Gorjanc et al. 2014). So, long-term cutaneous exposure can stimulate aging, DNA damage, skin reddening, acne, and skin cancer (Nasouri 2019; Wang et al. 2021). Previously, the ozone layer acted as a shield against UV radiation, but now, the destruction of this layer in some parts of the planet, poses a greater threat to humans (Ghamsari et al. 2017). So, UV protection is mainly important for people who are exposed to UV in the workplaces or spend a lot of time outdoors (Rocholl et al. 2020).
Electron ionisation cross sections of CF3Cl and CF2Cl2 molecules
Published in Molecular Physics, 2022
Pawan Kumar Sharma, Rajeev Kumar
Worldwide industrial use of freons (Chlorofluorocarbons) like CF3Cl, CF2Cl2 etc. as refrigerants, solvents, agents used for foam blowing and aerosol propellants has drawn serious attention due to catalytic decomposition of atmospheric ozone resulting in depletion of the ozone layer in the stratosphere. The ozone layer acts as a shield for the earth’s environment from UV solar radiation known for disastrous effects [1–3] causing various skin hazards. Dissociation of chlorine from freons due to UV solar radiation sets off a chain reaction that changes ozone into oxygen more readily than fluorine radicals which causes a chain ending reaction for ozone depletion and hence can be considered less destructive [3]. The study of electron ionisation cross-section becomes a significant tool to understand the direct and dissociative ionisation behaviours of freons and also has remarkable use in industry and study of low-temperature plasma similar to as produced by solar winds in the stratosphere due to low energy electron release.