PROGRAM TITLE:	Health Effects of UV Radiation
SCIENCE ELEMENT:	Human Interactions


DESCRIPTION:  Four NIH institutes support research on the health effects of 
UV and near UV radiation:  the National Institute of Environmental Health 
Sciences (NIEHS), National Eye Institute (NEI), National Cancer Institute 
(NCI), and National Institute of Arthritis and Musculoskeletal and Skin 
Diseases (NIAMS).
The NIEHS program supports grants and intramural projects that investigate 
the effects of UV exposure on the immune system, aging process, sensitive 
tissues such as the retina and skin, and methods to reduce these harmful 
effects.  Other projects involve the comparison of mutagenic potential in 
bacteria of UV and near UV radiation at levels found in natural sunlight and 
at levels anticipated with a 15 percent depletion of stratospheric ozone.  
Several projects supported by NIEHS are investigating molecular changes in 
DNA that lead to aberrations and mutations.  These studies are conducted in 
many different models including human tissue, rodents, fruit flies, and 
bacteria.  In addition, these studies are investigating the variety of ways 
these organisms repair damage to DNA resulting from UV exposure.  NIEHS  also 
supports studies investigating cutaneous chemical phototoxicity the 
response of the skin to the combined effects of a chemical and sunlight.  
These studies are trying to determine the physiological and metabolic 
responses which may cause and result from toxicities.  Long-term goals of 
this project include improved treatments for this condition.
A major NEI initiative is underway to determine how and why eye cataract 
develops and to search for ways to prevent or slow the progression of cataract,
an age related eye disease that effects 17-20 million people globally.  
Studies under this initiative are investigating the role of UVB (ultraviolet 
wavelengths from 290 mm to 320 mm) radiation in cataract development, 
because it has been implicated as a risk factor.  Another important area of 
NEI research is the understanding of certain enzymatic and nonenzymatic 
detoxification systems in the eye and how they combat damage of UVB 
radiation.  The goal of this effort is to identify drugs that might have 
therapeutic or preventative applications.  UVB radiation has been implicated 
in the production of singlet oxygen or other active species of oxygen by 
photodynamic action of the photosensitizers present in the normal eye.  One 
of the long-term goals of NEI research is to define a molecular mechanism 
for the changes in the vitreous fluid and lens components (such as 
hyaluronic acid, collagen, and the crystalline proteins) and determine 
whether there is a link between photo-oxidation and certain eye diseases.
NCI - Chronic exposure of human skin to ultraviolet radiation has been 
shown to cause a variety of changes in the skin including photoaging, non-
melanoma skin cancers, and melanoma.  A wide range of studies are being 
conducted to characterize the etiology, biology, immunology, and pathology 
of these changes.  For example, the role of reactive oxygen molecules in 
development of melanoma is being studied as well as evaluation of the 
efficacy of antioxidants such as beta-carotene to prevent deleterious effects.
NCI research is also investigating UV-induced immunosuppression, which 
is critical to the development of UV-induced skin tumors.  Other research 
explores the cellular and molecular basis for the genetic predisposition to 
UVB-induced skin cancer of individuals with Basal Cell Nervous Syndrome.  
Researchers are also examining the way cells respond to solar UV-induced 
NIAMS supports basic and clinical research on the effect of UVA and UVB 
radiation on skin.  This includes:  direct toxic effects, drug-induced 
photosensitivity, photoaging, effects on the skin's immune functions, 
mutagenesis, and carcinogenesis.  In particular, the relative contributions of 
UVA and UVB to skin damage are important for public health policy 
consideration.  The effect of UV on the skin's pigment forming system and 
therapeutic uses of UV in the treatment of skin diseases are also topics of 
interest to NIAMS.  NIAMS also supports research on the effects of UV light 
on noncutaneous immunology and on a variety of systemic diseases.
The principal objectives of NIH research on UV and near UV radiation 
include an increased understanding of their effects on target organs 
(e.g., eyes, skin, immune system) and the molecular changes that lead to 
these effects, and the development of strategies to prevent the initiation 
of disease or to intervene before disease is clinically defined.  The tools
 of molecular biology developed within the last ten years offer considerable
 promise for rapid progress toward these objectives.
All NIH grants are subjected to four levels of review before funding:  an 
initial review by NIH staff to determine if the proposal is relevant to an NIH 
research objective; a rigorous and very competitive peer review by experts in 
the area resulting in a priority score; review by the institute's advisory 
council to determine priority among all areas of research funded by that 
institute; a final review and decision by the institute director.  Intramural 
research activities are also subjected to a rigorous, competitive review by
NIH program managers and by nonfederal peer review councils.
STAKEHOLDERS:  The international health community relies on NIH 
research for a major portion of the scientific results that affect prevention
and health care policies and strategies.  The primary beneficiary is Homo 
Sapiens, but as decisions are made to protect human health other vulnerable 
species (both flora and fauna) benefit.
POLICY RELEVANCE:  This program provides the health science base on 
which policymakers must rely in resolving the issues of ozone depletion and 
its impact on human health and activities.
PROGRAM CONTACT:  Mary Gant, NIEHS, Bldg. 31, Room B1-CO2, 
Bethesda, MD  20892, (301) 496-2919