GLOBAL WARMING AND POVERTY RELATED SKIN DISEASES
18th Congress of the European Academy of Dermatology and Venereology
Berlin, 7-11 October 2009
During the past century, global surface temperatures have increased 0.6°C per century (1.1°F per century); this trend is today 3 times higher than 1976. Human activity, particularly the burning of fossil fuels, has very likely (90% probability) driven this rise by greatly increasing atmospheric concentrations of carbon dioxide
(CO2) and other greenhouse gases (GHGs).
Climate warming may have significant impacts on human health.
Van der Leun and de Gruijl have estimated that the long-term temperature increases by 2° C, as a consequence of climate change, may raise the carcinogenic effectiveness of solar UV by 10%. The most definitive evidence exists for Non Melanoma Skin Cancer (NMSC) being linked to chronic, repeated exposure to mid-range UVR (UV-B: 290-320 nm) and therefore being likely to increase because of the ozone depletion. Individuals greatly differ in susceptibility, first of all for genetic reasons, but the major determinant of the occurrence of skin cancer is the quantity and the quality of sunlight exposure.
There is weaker evidence of the role of UVR exposure in the development of Melanoma (MM). There is considerable evidence that sunlight exposure plays a role, but the mechanism is certainly different from the one operating in NMSC. Although it is much more difficult to estimate numerical effects, epidemiological studies in the United States suggest that for a 1% reduction in ozone, MM might increase by 0.6%.
Climate warming may also have significant effects on the distribution and seasonality of vector-borne diseases (i.e. malaria, dengue, leishmaniasis, tick-borne diseases). Cardenas et al reported the impact of the El Nino Southern Oscillation climatic fluctuations during 1985-2002 with regard to the occurrence of
leishmaniasis in Colombia, showing that cases of leishmaniasis increased during El Nino and decreased during La Nina phases.
Global warming and climate change may alter the frequency, timing, intensity, and duration of extreme weather events.
These weather events, such as extreme precipitations and severe storms, cause hundreds of deaths and injuries in the USA every year.
In 2005, following the occurrence of Hurricane Katrina and subsequent flooding, the Centers for Disease Control and Prevention (CDC) reported wound infections with methicillin-resistant Staphylococcus aureus (MRSA), Vibrio vulnificus , and Vibrio parahaemolyticus in evacuees of Hurricane Katrina, and tinea
corporis, folliculitis, miliaria, and arthropod bites amongst rescued workers. These skin infections were provoked by the prolonged flooding and the exposure to contaminated water. Hiransuthikul et al related that 515 (66.3%) tsunami survivors with traumatic wounds were diagnosed to have skin and soft-tissue
infections. The most common isolated organisms were Aeromonas species. Multidrug resistant bacteria, polymicrobial infections, and infections with uncommon pathogens, such as Burkholderia pseudomallei, Cladophialophora bantiana, and Mycobacterium abscessus, were also reported, as the result of exposure to
contaminated freshwater due to flooding.
In recent decades, the emergence and the resurgence of various infectious diseases has been linked in part to regional climatic changes. New infectious agents have also been encountered because of increasingly disruptive patterns of land use.
Some populations and geographic regions will be particularly vulnerable to the impacts of global change. Climatic changes will tend to increase various health problems in countries affected by poverty, malnutrition, lack of water, consequences of extreme weather events, inequality, and social-economic differences among
There is a complex nexus between population pressure, poverty and environmental degradation, entailing various mutually reinforcing processes. If the present environmental trends persist, leading to changes in environmental climatic conditions and ecological relationships, adverse health consequences will become
more evident in vulnerable populations, especially those in low-income tropical countries.
Africa is one of the most helpless continents to climate change. Climate change and variability are likely to impose additional pressures on water availability, water
accessibility and water demand in Africa. About 25% of Africa’s population (about 200 million people) currently experience high water stress. The population at risk of increased water stress in Africa is estimated to be between 75-250 million and 350-600