Environment and health
Liam J. Donaldson, Paul D. Rutter in Donaldsons' Essential Public Health, 2017
The ozone layer constantly passes through natural cycles. At some periods, it thins only then to replenish itself. In the last 30 years, much scientific attention has focused on so-called ozone-depleting substances that destroy the ozone layer to the extent that natural processes cannot heal it. Chief among these are chlorofluorocarbons (CFCs), but there are many others. They had become firmly established in products that were highly successful adjuncts to modern living, such as refrigerator coolants, aerosols and some other solvents. Ultraviolet light interacts with these products and chlorine atoms are released. There is then no natural process to break them down as they drive up into the stratosphere. One chlorine atom destroys 100,000 molecules of ozone. Most concern has been concentrated on the Antarctic, where a so-called ‘hole’ in the ozone layer developed. The low temperatures in this region speed up the conversion of chlorofluorocarbons to chlorine atoms. The hole is not a true gap in the ozone layer, but rather a substantial reduction in its thickness. International agreements, such as the Montreal Protocol, have sought to phase out chlorofluorocarbon-based products. This has been a successful demonstration of collaborative international action – so much so that scientists monitoring the ozone layer report some recovery of the previous damage, but estimate a further 50 years for it to be made good, provided that there is no reversal.
New Nebulizer Technology
Hans Bisgaard, Chris O’Callaghan, Gerald C. Smaldone in Drug Delivery to the Lung, 2001
Nebulizers are principally used by children (<5 years) and adults (<55 years) who have difficulty coordinating the use of MDIs and DPIs, by patients with severe asthma or chronic obstructive pulmonary disease (COPD), and in the emergency room for acute episodes of bronchospasm. Today the bulk and cost of nebulizers relative to MDIs and DPIs makes them inappropriate for the majority of patients. However, pMDIs using chlorofluorocarbons (CFCs) contribute to ozone depletion (8), with subsequent environmental and public health impacts. The pending ban on CFCs for use in medical aerosols has resulted in research being directed toward providing efficient alternative methods for pulmonary delivery of drugs, particularly using alternative propellants such as hydrofluoroalkanes (HFAs) or alcohol, DPIs, and new nebulizer delivery systems. Presumed environmental problems with the HFAs may further promote development of new nebulizer technologies as well as further DPI development.
Non-Melanoma Skin Cancer
Pat Price, Karol Sikora in Treatment of Cancer, 2020
The most potent environmental agent capable of inducing skin cancer is ultraviolet (UV) light exposure. The incidence of NMSC increases with decline in latitude, being highest in Australia, with an annual incidence rate per million population of 1372 for men and 702 for women.4,5 Ozone depletion in the atmosphere, allowing more harmful radiation to reach human skin, is probably partly responsible for the alarming increase in incidence. This is compounded by the popularity of sunny holidays abroad, outdoor recreational activities, and the culture of the bronzed body beautiful. Soldiers during World War II who had high UV light exposure while serving in North Africa have a very high incidence of NMSC and are entitled to compensation from the Ministry of Defence (MOD), which many have successfully claimed.
Statistical regression analysis of functional and shape data
Published in Journal of Applied Statistics, 2020
Mengmeng Guo, Jingyong Su, Li Sun, Guofeng Cao
Ozone hole area is another important factor that can be used to analyze the ozone depletion over these years. We compute the correlation coefficient between the first principal component score 9. Figure 9 shows the first principal component score with registration has the higher correlation with the area. Such results also can be seen in Figure 5(a). The correlation coefficient increases from 0.82 to 0.95 after registration, which verifies our framework is more accurate with registration. The variation of adjacent difference of ozone hole areas may also be related with these influencing factors. To check this, we find shooting vectors between adjacent ozone hole contours, which is given by 10 demonstrates the first component score
A rutin nanocrystal gel as an effective dermal delivery system for enhanced anti-photoaging application
Published in Drug Development and Industrial Pharmacy, 2021
Jing Li, Weilong Ni, Mayinuer Aisha, Juanjuan Zhang, Minjie Sun
Skin photoaging is a kind of accelerated skin-aging damage resulting from continuous exposure to ultraviolet (UV) radiation, which is mainly characterized by dryness, erythema, deep wrinkles, and pigment formation [1]. UV radiation, actually referring to UVA (320–400 nm) and UVB (275–320 nm), often induces the overproduction of reactive oxygen species (ROS), leading to the destruction of oxidative stress dynamic balance and the accumulation of lipid peroxidation, which is the critical determinant in the formation of skin photoaging [2–4]. In recent years, the risk of photoaged skin has increased sharply due to the deterioration of ozone depletion, which has seriously threatened human health [5]. The application of dermal preparations containing antioxidants is a potent approach to inhibit photoaging caused by UV irradiation.
Inhalant misuse reported to America’s Poison Centers, 2001–2021
Published in Clinical Toxicology, 2023
Raymond L. Hogge, Henry A. Spiller, Sandhya Kistamgari, Marcel J. Casavant, Natalie Rine, Nichole L. Michaels, Motao Zhu, Gary A. Smith
The reversal in 2010 of the rate of “Freon and other propellants” misuse was abrupt and dramatic, and it coincided with the initiation of a 10-year plan by the US EPA to phase-out refrigerants that contain hydrochlorofluorocarbons through Section 608 of the Clean Air Act [27]. The Clean Air Act was amended in 1990 to establish long-term goals according to the Montreal Protocol, an international environmental agreement aimed at regulating the production and consumption of ozone-depleting substances contributing to climate change [28]. The Montreal Protocol established the goal of completely phasing out hydrochlorofluorocarbons by the year 2030 [28]. To meet this goal, the US EPA banned the production, import, and use of the refrigerants FreonTM (also known as hydrochlorofluorocarbon [HCFC]-22 or R-22) and HCFC-142b starting January 1, 2010, except for continuing servicing needs of existing equipment [27,29]. Although a complete ban on the production and import of these refrigerants (including for servicing of existing equipment) did not occur until January 1, 2020, the 2010 regulation resulted in a sharp decline in the use of FreonTM and HCFC-142b in home refrigerating units [28].
Related Knowledge Centers
- Atom
- Catalysis
- Chlorofluorocarbon
- Haloalkane
- Ozone
- Ozone Layer
- Propellant
- Ultraviolet
- Refrigerant
- Photodissociation