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Effects of ultraviolet radiation on man and environment

  

Effects of UV radiation in human eye

 

The effects of UV radiation to the eye may be acute or long term after an acute exposure. The commonest acute effect, photokeratitis (snow blindness) leaves few or no permanent effects  whereas cataract due to chronic exposure is irreversible or ultimately leads to blindness (Aucamp 10).

  

Effects of solar UV exposure on human skin

 

Acute exposure of the skin to solar UV radiation causes sunburn and in the long term skin cancer. The amount of UV radiation required  to produce sunburn depends on the absorption in the superficial layers (varying with the amount of pigment) of the skin and on other genetic factors. The efficacy with w3hicsh sunlight produces sunburn base on the amount of UV-B radiation is present at high altitudes and more is present at noontime sun than at earlier of later hours. Chronic exposure of the skin to UV radiation causes photo ageing (incflhuding wrinkling, thinning, and loss of elasticity); however UV-A may be more important than UV-B in causes these latter changes.

Basal and squamous cell carcinomas occur most often and with high frequency in fair skinned individual living in sunny  climates. Fortunately, most of these skin cancer are readily treated and rarely fatal. Cutaneous melanoma is considerably more dangerous, but occur with much lower frequency than the othjer types of skin cancer. (Aucamp 11).

   

Effects of UV radiation to the immune system

 

The immune system  can  be altered by UV  irradiation, leading to diminished immune responses to  infectious agents and skin cancer. Some cell of the immune system, called antigen presenting-cell, reside in the skin. Their function is to  survey the skin of foreign  challenges, such as invading microorganisms or  tumours proteins. Exposing then skin to UV-B causes several changes- one leads to a change in the antigen-presenting cells so that the immune response may induse suppression. Another is to stimulate the production of a particular range of immune mediators in the skin that also favour suppressing immune responses (Aucamp 12).

     

Affects of increase UV-B radiation on crops and forest

 

The UV-B radiation present in the sunlight causes a wide range of responses in crops and forests but most plants have natural mechanisms that provide some UV shielding, but do not always have sufficient amounts of complete protection. Some types of crops and wild plants may  suffer detrimental effects from increase UV-B radiation (Aucamp 13).

   

UV exposure affects the aquatic life

 

UV-B radiation can penetrate to ecologically significant depths in the clearest natural waters. UV radiation may damage those organisms that live at the surface of the water during the early life stages. UV-B radiation reaches different depths in ocean water depending on water chemistry, the density of phytoplankton, and the presence of dissolved and particulate matter.

 

Effects of pollution of lower atmosphere on UV- irradiation

 

Pollutants emitted by human activities can absorb UV-B radiation near the surface, while particles may lead to enhancement by scattering. While most of the atmospheric ozone is formed in the stratosphere by the chemical reactions between pollutants such as nitrogen oxide and hydrocarbons. This ozone is a component of the photochemical smog found in many polluted areas. Airborne particles (smog, dust, and sulphate aerosol) block UV radiation, but at the same time can increase the amount of the scattered light (haze) and therefore increase the UV exposure of side facing surfaces (e.g.  face, eyes) (Aucamp 7).

   Aucamp, Pieter J. “ Effects of Ultraviolet radiation on Man and the Environment”. Questions and answers about the effects of the depletion of the ozone layer on humans and the environment. South Africa: Faerie Glen, 2000: 10-14.     

Prevention of the destruction of the ozone layer.   

 

Saving the ozone layer

 

Since its foundation, the United Nation Development Programme (UNEP)

 

 3. Saving the Ozone Layer

 

Since its foundation, the United Nations Environment Programme (UNEP) has been concerned with the protection of the ozone layer. The UN Conference on the Human

Environment in Stockholm in 1972, which gave birth to UNEP, addressed the topic of ozone depletion, though damage from supersonic aircraft exhausts was then thought to be the main threat. The first major statement of scientific concern over ozone depletion from CFCs came in 1974, prompted by James Lovelock’s discovery of the presence of CFCs in the atmosphere all around the world. Sherwood Rowland and Mario Molina’s research (for which they were later to be awarded the Nobel Prize in chemistry) paved the way to the now thorough understanding of the processes by which CFCs diffuse up into the

stratosphere, are broken apart and destroy ozone molecules. Although the hypothesis was minitially disputed, the extent and growth of CFC use worldwide was enough to trigger calls for urgent action. In March 1977, experts from 32 countries met in Washington DC

to adopt the ‘World Plan of Action on the Ozone Layer’. The Plan included research into the processes that control ozone concentrations in the stratosphere; the monitoring of ozone and solar radiation; the effect of ozone depletion on human health, ecosystems and the climate; and the development of ways to assess the costs and benefits of control measures. UNEP was the coordinating agency, assisted by the Coordinating Committee on the Ozone Layer, made up of experts from intergovernmental agencies, governments and industry. In the US, the Washington meeting reinforced existing concerns over the impact of emissions from supersonic aircraft. An effective public campaign led to regulations prohibiting the use of CFCs as aerosol propellants in non-essential applications by 1978; Canada, Sweden and Norway soon followed. US production of CFC-11 and -12 fell from 46% of the world total in 1974 to 28% by 1985 as a result (Brack et al 8).

   ,Brack, Dunkan, Michael Graber, Ruth Batten, Gerald Mutisya, Saving the Ozone Layer”:  Action on  Ozone 2000 ed. UNON Printshop, 2000:8. Conclusion:  While the international community has devised policies and measures through theMontreal Protocol to address the serious environmental and human health impacts ofstratospheric ozone depletion, much remains to be done before full recovery of the ozone layercan be realized.The market for non-ozone depleting products is robust, competitive and growing,providing consumers with many alternatives to ozone depleting products well ahead of requiredphase-out dates.Government and industry have worked well to chart a path for ozone layer recovery.Additional steps, including the accelerated phase-out of ozone depleting products, increased public awareness for ozone protection and consumer incentives for non-ozone depleting alternatives are all timely for consideration.  Recommendation: 

What the Public Can Do? While the solutions to ozone depletion are largely being dealt with on the international

level and through cooperative efforts between governments and industries, the public has an

important role to play in affecting how quickly products and services that rely on the best

substitutes penetrate into the market. To continue to make progress and repair the ozone layer,

consumers must keep abreast of the latest developments on this issue and how they are being

incorporated into the products and services they use and access.

As product formulations change and become available in new products or for retrofit,

consumers can have a significant impact by purchasing non-ODS products and services that have

the least capacity to contribute to ozone depletion. While no universal label or indicator system

has been developed to inform consumers of their best choices in this regard, there is a substantial

amount of currently available information on the relative impacts of various substitutes and the

products and applications they are used in from the U.S. EPA, manufacturers and service

providers.

The public should also keep up to date about the latest developments regarding the ozone

hole through major publications and news outlets, particularly on how areas in the world that are

most exposed, like Punta Arenas, are having to adapt and cope with the impacts. Views and

concerns about these developments, the importance of this issue, and the need for the U.S. to

continue to lead in making technological advancements that help to protect and repair the ozone

layer should be regularly communicated to local, state and federal government leaders.

Furthermore, since ozone depletion is a problem that spans multiple generations, it is important

to educate children about the ozone layer, its importance to their health and well being, and what

is being done to help to remedy the situation.

Raising and Maintaining Public Awareness.Creating and maintaining a vitally aware public on any issue, including stratospheric

ozone, falls mainly on the shoulders of the government, non-profit communities, and the media.

While all of these entities develop and deliver information about stratospheric ozone, there are a

number of possibilities for expanding and deepening the current state of public awareness on this

issue, including:

The federal government should continue to maintain and expand public sources of

information in ways that make it easier for the public to recognize what they can and

should do to help mitigate ozone depletion.

More state governments could create exchange outlets that link to federal and

international resources to make information more readily available to their

communities.

Federal and state governments, many environmental groups, and the media have

exhibits and events to raise environmental awareness on Earth Day, whose timing

does not coincide with the annual appearance of the ozone hole. Holding exhibits and

events specifically related to the issue of stratospheric ozone during the fall season

when the effects of ozone depletion are evident and in the news, will help to reinforce

the public awareness of this serious issue.

Federal and state governments and environmental groups should create distinct and

separate messages on ozone depletion and the importance of the ozone layer, in

addition to the combined messages on stratospheric ozone and climate change that

have more recently been created and disseminated. This is necessary because the

recent emphasis on climate change and its impacts, combined with fewer

individualized messages about stratospheric ozone and the impacts of its depletion,

may cause the public to surmise that the latter problem is resolved. It is important

that the public understand that these are two different environmental problems that

affect our atmosphere and our planet in different but inter-related ways, and that

diligence and technological innovation are still necessary now and well into the future

to achieve our goals of repairing and maintaining a healthy ozone layer to protect

them.

The federal government and private sector should consider creating a visible and

universally recognizable labeling approach and advertising campaign (e.g., the U.S.

EPA’s Energy Star label for energy efficient products) that will help consumers and

businesses understand more easily recognize what they need to look for when

purchasing products or services, and that will keep the ozone depletion issue out in

front over a longer horizon than the annual ozone hole event time frame.

Motivating Beneficial Choices.

As the public continues to become more informed and aware, it is critical that policies

and programs are created or expanded to help motivate the choices and actions of consumers and

industry alike. Again, the federal and state governments play a critical role here, working with

industry and the public to formulate and implement such programs and policies. Certainly there

are additional and more aggressive policy actions that the federal government can initiate to

catalyze change and improve the condition of the ozone layer, including:

Tax incentives, at the federal or state level, to encourage the use of non-ozone

depleting products.

The U.S. EPA should re-institute or revitalize the Industry Cooperative for Ozone

Layer Protection, or another group like it, to continue to advance technology and

policy innovation.

The federal government could expand the scope of economic instruments, such as the

tradable consumption permit system for CFCs and halons, and the CFC tax, to help

achieve environmental goals with respect to other ODS with flexibility and at less

cost.

The federal government could create new programs modeled after the U.S. EPA’s

“Golden Carrot” approach on super-efficient refrigerators to tap into industry’s

innovative and competitive spirit to create new products and processes that will help

to meet future phase-out goals, and to focus on “win-win” solutions to the overlap

between ozone depletion and climate change.

State and local governments, while not directly delegated the responsibility for ozone

depletion mitigation, can also take additional actions to motivate change at the community level,

including:

State and local governments should leverage the examples of policy, regulatory and

economic incentive/initiative programs developed at the state and local level to facilitate

greater adherence to freeze and phase-out schedules and to promote faster changeover to

substitutes and alternatives.

Significant achievements in the market penetration of alternatives can be achieved

through the revamping of government procurement policies. This has been shown in the

U.S. Department of Defense’s progress in changing over from CFC-based refrigerants

and solvents, and replacement of halon systems for fire suppression. State and local

government purchasing power is significant, and could be targeted toward the best

products and services from an ozone depletion mitigation standpoint. Many state and

local governments are taking such action on the climate change front, promoting the

purchase of energy efficiency products and services that will reduce greenhouse gas

emissions. More specific and easily accessible information about choices affecting ozone

depletion would need to be developed to facilitate such action.

 

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