factory and eventually entered the food chain of fish in a local bay.
Around the same time as the Minamata incident there was a similar outbreak
of Itai-itai disease, a form of chronic cadmium poisoning that developed in
farmers in Toyama, Japan. In this case cadmium-contaminated rice and drinking
water was the cause. The cadmium from a mining area and a lead/zinc ore
concentration plant reached the affected community via a river that they used to
irrigate their paddy.
Lead is the most abundant heavy metal and the natural (preindustrial) blood
lead concentration of humans is estimated to be much lower than the lowest
reported levels in contemporary humans living in remote regions. Although
several high-income countries have legislated for new lower standards on
environmental lead levels, exposure is still a particular problem in urban
environments of low-income countries. Childhood lead poisoning (a
particular hazard for the neuro-cognitive development of children) is an
increasing problem, and high blood lead levels have been widely observed in cities
such as Bangkok, Jakarta, Taipei, Santiago and Mexico City.
Stratospheric Ozone Layer
An intact stratospheric ozone layer (SOL) prevents excessive health-damaging
ultraviolet radiation reaching the Earth’s surface. Until the early 1970s this layer
was intact (although there was a natural variation in the thickness of the SOL,
depending on latitude, season and volcanic eruptions). The depletion of
stratospheric ozone, first observed in the 1970s over Antarctica, is primarily
caused by the build-up of human-made ozone-destroying gases in the stratosphere,
such as the chlorofluorocarbons (CFCs), and is causing an increase in ultraviolet
irradiation (UVR) at the Earth’s surface. Ambient terrestrial levels of UVR are
estimated to have increased by over 10% at mid-to-high latitudes since 1980.
In terms of the adverse effects on human health we can expect, for the first half
of the 21st century, an increase in the severity of sunburn and the incidence of skin
cancers in fair-skinned populations, and the incidence of various disorders of the
eye (especially cataracts). Since cataract accounts for a majority of the tens of
millions of cases of blindness in the world, even a marginal impact of increased
UVR exposure on their occurrence would be significant. Some UVR-induced
suppression of immune functioning may also result, thus increasing susceptibility
to infectious diseases and perhaps reducing vaccination efficacy.
A. J. McMichael, T. Kjellstrom and K. Smith, in International Public Health, ed. M. Merson, R.
Black, and A. Mills, Aspen Press, Gaithersburg, MD, 2000.
L. M. Schell, in Effects of Pollutants on Human Prenatal and Postnatal Growth: Noise, Lead,
Polychlorobiphenyl Compounds and Toxic Wastes, Yearbook of Physical Anthropology, Vol. 34,
1991, pp. 157—188.
S. Tong, Y. E. von Schirnding and T. Prapamontol, Bull. World Health Org., 2000, 78, 1068.
J. C. Farman, B. G. Gardiner and J. D. Shanklin, Nature, 1985, 315, 207.
R. McKenzie, B. Connor and G. Bodeker, Science, 1999, 285, 1709.
United Nations Environment Program, Environmental Effects of Ozone Depletion, UNEP,
Lausanne, Switzerland, 1998.
World Health Organisation, Ultraviolet Radiation, Environmental Health Criteria, No. 160,
WHO, Geneva, 1994.
Global Environmental Changes and Human Health
147
Around the same time as the Minamata incident there was a similar outbreak
of Itai-itai disease, a form of chronic cadmium poisoning that developed in
farmers in Toyama, Japan. In this case cadmium-contaminated rice and drinking
water was the cause. The cadmium from a mining area and a lead/zinc ore
concentration plant reached the affected community via a river that they used to
irrigate their paddy.
Lead is the most abundant heavy metal and the natural (preindustrial) blood
lead concentration of humans is estimated to be much lower than the lowest
reported levels in contemporary humans living in remote regions. Although
several high-income countries have legislated for new lower standards on
environmental lead levels, exposure is still a particular problem in urban
environments of low-income countries. Childhood lead poisoning (a
particular hazard for the neuro-cognitive development of children) is an
increasing problem, and high blood lead levels have been widely observed in cities
such as Bangkok, Jakarta, Taipei, Santiago and Mexico City.
Stratospheric Ozone Layer
An intact stratospheric ozone layer (SOL) prevents excessive health-damaging
ultraviolet radiation reaching the Earth’s surface. Until the early 1970s this layer
was intact (although there was a natural variation in the thickness of the SOL,
depending on latitude, season and volcanic eruptions). The depletion of
stratospheric ozone, first observed in the 1970s over Antarctica, is primarily
caused by the build-up of human-made ozone-destroying gases in the stratosphere,
such as the chlorofluorocarbons (CFCs), and is causing an increase in ultraviolet
irradiation (UVR) at the Earth’s surface. Ambient terrestrial levels of UVR are
estimated to have increased by over 10% at mid-to-high latitudes since 1980.
In terms of the adverse effects on human health we can expect, for the first half
of the 21st century, an increase in the severity of sunburn and the incidence of skin
cancers in fair-skinned populations, and the incidence of various disorders of the
eye (especially cataracts). Since cataract accounts for a majority of the tens of
millions of cases of blindness in the world, even a marginal impact of increased
UVR exposure on their occurrence would be significant. Some UVR-induced
suppression of immune functioning may also result, thus increasing susceptibility
to infectious diseases and perhaps reducing vaccination efficacy.
A. J. McMichael, T. Kjellstrom and K. Smith, in International Public Health, ed. M. Merson, R.
Black, and A. Mills, Aspen Press, Gaithersburg, MD, 2000.
L. M. Schell, in Effects of Pollutants on Human Prenatal and Postnatal Growth: Noise, Lead,
Polychlorobiphenyl Compounds and Toxic Wastes, Yearbook of Physical Anthropology, Vol. 34,
1991, pp. 157—188.
S. Tong, Y. E. von Schirnding and T. Prapamontol, Bull. World Health Org., 2000, 78, 1068.
J. C. Farman, B. G. Gardiner and J. D. Shanklin, Nature, 1985, 315, 207.
R. McKenzie, B. Connor and G. Bodeker, Science, 1999, 285, 1709.
United Nations Environment Program, Environmental Effects of Ozone Depletion, UNEP,
Lausanne, Switzerland, 1998.
World Health Organisation, Ultraviolet Radiation, Environmental Health Criteria, No. 160,
WHO, Geneva, 1994.
Global Environmental Changes and Human Health
147