Health effects today: climate change, ozone hole, and biomass

Reading Ian McEwen’s excellent Solar, I ran across some numbers and checked them with Intergovernmental Panel on Climate Change.

From Working Group 2, chapter 8 (pdf, go to document to see sources)

8.2.10 Ultraviolet radiation and health
Solar ultraviolet radiation (UVR) exposure causes a range of health impacts. Globally, excessive solar UVR exposure has caused the loss of approximately 1.5 million disability-adjusted life years (DALYs) (0.1% of the total global burden of disease) and 60,000 premature deaths in the year 2000. [Note: an unknown percentage comes from ozone layer depletion.] The greatest burdens result from UVR-induced cortical cataracts, cutaneous malignant melanoma, and sunburn (although the latter estimates are highly uncertain due to the paucity of data). UVR exposure may weaken the immune response to certain vaccinations, which would reduce their effectiveness. However, there are also important health benefits: exposure to radiation in the ultraviolet B frequency band is required for the production of vitamin D in the body. Lack of sun exposure may lead to osteomalacia (rickets) and other disorders caused by vitamin D deficiencies.

Climate change will alter human exposure to UVR exposure in several ways, although the balance vary depending on location and present exposure to UVR. Greenhouse-induced cooling of the stratosphere is expected to prolong the effect of ozone-depleting gases, which will increase levels of UVR reaching some parts of the Earth’s surface. Climate change will alter the distribution of clouds which will, in turn, affect UVR levels at the surface. Higher ambient temperatures will influence clothing choices and time spent outdoors, potentially increasing UVR exposure in some regions and decreasing it in others. If immune function is impaired and vaccine efficacy is reduced, the effects of climate-related shifts in infections may be greater than would occur in the absence of high UVR levels… Global burden of disease study
The World Health Organization conducted a regional and global comparative risk assessment to quantify the amount of premature morbidity and mortality due to a range of risk factors, including climate change, and to estimate the benefit of interventions to remove or reduce these risk factors. In the year 2000, climate change is estimated to have caused the loss of over 150,000 lives and 5,500,000 DALYs (0.3% of deaths and 0.4% of DALYs, respectively). The assessment also addressed how much of the future burden of climate change could be avoided by stabilising greenhouse gas emissions. The health outcomes included were chosen based on known sensitivity to climate variation, predicted future importance, and availability of quantitative global models (or the feasibility of constructing them).

8.7.1 Health and climate protection: clean energy
In many low-income countries, access to electricity is limited. Over half of the world’s population still relies on biomass fuels and coal to meet their energy needs. These biomass fuels have low combustion efficiency and a significant, but unknown, portion is harvested non-renewably, thus contributing to net carbon emissions. The products of incomplete combustion from small-scale biomass combustion contain a number of health-damaging pollutants, including small particles, carbon monoxide, polyaromatic hydrocarbons and a range of toxic volatile organic compounds. Human exposures to these pollutants within homes are large in comparison with outdoor air pollution exposures. Current best estimates, based on published epidemiological studies, are that biomass fuels in households are responsible annually for approximately 0.7 to 2.1 million premature deaths in low-income countries (from a combination of lower-respiratory infections, chronic obstructive pulmonary disease and lung cancer). About two-thirds occur in children under the age of five and most of the rest occur in women.

cooking stoves
Better cooking stoves use less fuel, reduce air pollution, reduce the burden on the environment and the women who collect wood, and reduce attacks on the women.

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