February 28, 2007
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Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 2, NUMBER 10, OCTOBER 1989
CLIMATE CHANGE AND HEALTH
This collection of papers sets the stage for the upcoming conference on this
topic in Washington, December 4-6, 1989, organized by the Center for
Environmental Information. Most of the concern in this area relates to effects
of increased ultraviolet radiation in the B range (UV-B) resulting from ozone
depletion; very little work has been published to date on human health effects
of global warming. Readers are encouraged to submit any recent
publications on this (or any other) topic for possible use in Global Climate
"Potential Carcinogenic Effects of Stratospheric Ozone
Depletion," M.L. Kripke (Dept. Immun., Anderson Cancer Ctr., Univ. Texas,
Houston TX 77030), H. Pitcher, J.D. Longstreth, Environ. Carcinogenesis Rev.,
in press, Oct. or Nov. 1989.
A review summarizing information prepared for the U.S. EPA that formed the
basis for the decision of the United States to sign the Montreal Protocol; more
recent information is also included. Increased UV-B from ozone depletion is
expected and has already been demonstrated in the Southern Hemisphere. It will
almost certainly lead to increased incidence of non-melanoma skin cancers (NMSC)
and cutaneous melanoma, both of which are already rising rapidly. Increased UV-B
may lead to a preferential increase in the more serious form of NMSC, squamous
cell carcinoma; more data are needed to assess the impact on cutaneous melanoma.
A different threat is the demonstrated ability of ultraviolet radiation to
impair immune responses to infectious agents in animal models, but the
implications of this result for humans is completely unknown.
"Wavelength Dependence of Pyrimidine Dimer Formation in DNA of
Human Skin Irradiated in situ with Ultraviolet Light," S.E. Freeman
et al., B.M. Sutherland (Biol. Dept., Brookhaven Nat. Lab., Upton NY 11973),
Proc. Natl. Acad. Sci. U.S.A., 86, 5605-5609, July 1989.
The authors determined an action spectrum for the frequency of pyrimidine
dimer formation induced in the DNA of human skin. Convolution of this dimer
action spectrum with the solar spectra corresponding to a solar angle of 40°
under current levels of stratospheric ozone (0.32-cm O3 layer), and with spectra
for 50% ozone depletion (0.16-cm O3 layer), indicates about a 2.5-fold increase
in dimer formation. These results, combined with epidemiological data, suggest
that a 50% decrease in stratospheric ozone would increase the incidence of
nonmelanoma skin cancers among white males in Seattle, Washington, by 7.5 to
8-fold, to a higher incidence than is presently seen in the corresponding
population of Albuquerque, New Mexico.
"Exposure to Sunlight and Other Risk Factors for Age-Related
Macular Degeneration," S.K. West (Wilmer Inst., Johns Hopkins Hosp., 600 N.
Wolfe St., Baltimore MD 21205), F.S. Rosenthal et al., Arch. Ophthalmol.
107, 875-879, June 1989.
To address a growing concern over a possible relationship between long-term
exposure to ultraviolet radiation and increased risk of age-related macular
degeneration, a survey was conducted of 838 Maryland watermen who had
well-characterized ocular UV-A and UV-B exposure. Found that, even with high
levels of sunlight exposure, there was no evidence of increased risk of
age-related macular degeneration associated with UV-B or UV-A exposure.
"Ultraviolet Light Exposure and Risk of Posterior Subcapsular
Cataracts," T.W. Bochow, S.K. West (address immed. above) et al., ibid.,
369-372, Mar. 1989.
A case-control study was undertaken to investigate the role of exposure to
ultraviolet light in the B range and other potential risk factors for the
development of posterior subcapsular (PSC) cataracts, which are visually
disabling and account for 40% of surgical cases. Surgical PSC cataract cases
from a large rural ophthalmic practice on the lower eastern shore of Maryland
were matched with phakic controls without PSC cataract changes from the same
geographic area by age, sex and referral pattern. Matched-pairs analyses
indicated that a history of relatively high exposure to UV-B was associated with
increased risk of PSC cataracts, and suggests that UV-B exposure may be an
important risk factor for PSC cataracts.
"Abrogation of Skin Lesions in Cutaneous Leishmaniasis by
Ultraviolet B Irradiation," S.H. Giannini (Ctr. Vaccine Devel., Univ.
Maryland Sch. Med., Baltimore MD 21201), E.C. De Fabo, in Leishmaniasis: The
Current Status and New Strategies for Control, D.T. Hart, Ed., NATO ASI Series
A: Life Sciences, 683-690, 1989 (Plenum Pub. Corp., New York).
Studies the effect of narrow-band UV-B at either end of the UV-B spectrum on
mice infected with leishmania, still a serious health problem in the tropics and
subtropics. UV-B radiation suppressed obvious skin ulcers, but left mice heavily
parasitized and non-immune. Implications for humans in the tropics are
"Cutaneous Malignant Melanoma and Ultraviolet Radiation: A
Review," J. Longstreth (ICF/Clement Assoc., 9300 Lee Highway, Fairfax VA
22031), Cancer Metas. Rev., 7, 321-333, 1988.
Summarizes a comprehensive report prepared for the U.S. EPA as part of a
risk assessment of stratospheric ozone depletion. Cutaneous malignant melanoma
(CMM) rates have been increasing in the United States at an average rate of
about 4% per year; the exact cause is unknown, but several lines of evidence
described in this paper suggest that increasing exposure to UV-B radiation may
be a factor. With increasing levels of UV-B possible from stratospheric ozone
depletion, it has become important to understand the relationship between UV-B
and CMM to estimate increased risks. Based on empirical relationships between
UV-B and CMM incidence and mortality rates, a 1% depletion of ozone was
predicted to result in increases of 1-2% in CMM incidence and 0.8-1.5% in CMM
"Impact of Ozone Depletion on Skin Cancers," M.L. Kripke
(M.D. Anderson Cancer Ctr., Univ. Texas, Houston TX 77030), J. Dermatol.
Surg. Oncol., 14(8), 853-857, Aug. 1988.
A review concluding that the most obvious effect on human health of
increased UV-B radiation resulting from a decrease in the protective ozone layer
will be an increase in the incidence of basal and squamous cell carcinomas.
Other possible effects include a contribution to the development of cutaneous
melanoma, ocular changes leading to the formation of cataracts, and immunologic
"Ozone Depletion and Skin Cancer," J.C. van der Leun (Inst.
Dermatol., Univ. Utrecht, Catharijnesingel 101, Utrecht, Neth.), J.
Photochem. & Photobiol., B: Biol., 1, 493-494, 1988.
One conclusion from 16 years of research on UV-B radiation and skin cancer
is that the number of patients with non-melanoma skin cancer will increase more
sharply than the rate at which the amount of ozone decreases. This is expressed
as an amplification factor made up of a radiation factor and a biological
factor, giving the percent increase in incidence caused by a 1% decrease in the
amount of ozone. For photocarcinogenesis, the radiation amplification factor has
a value of about 2. The biological amplification factor has a value of about 2
for basal cell carcinoma and about 3 for squamous cell carcinoma.
"Effect of Ultraviolet Radiation on Cataract Formation," H.R.
Taylor (address immed. above), S.K. West et al., 319, 1429-1433, Dec. 1,
To investigate the relation of ultraviolet radiation and cataract formation,
the authors undertook an epidemiologic survey of 838 watermen (mean age, 53
years) who worked on Chesapeake Bay. The annual ocular exposure was calculated
from the age of 16 for each by combining a detailed occupational history with
laboratory and field measurements of sun exposure. Cataracts were graded by
ophthalmologic examination for both type and severity. Results indicate that
there is an association between exposure to UV-B radiation and cataract
formation, which supports the need for ocular protection from UV-B.
Guide to Publishers
Index of Abbreviations