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Feature Respiratory implications of a changing climate
Published Online April 16, 2013 http://dx.doi.org/10.1016/ S2213-2600(13)70069-9 See News page 187 For more on the World Bank’s Turn Down the Heat report see http://climatechange.worldbank. org/sites/default/files/Turn_ Down_the_heat_Why_a_4_ degree_centrigrade_warmer_ world_must_be_avoided.pdf For the WHO factsheet on climate change and health see http://www.who.int/media centre/factsheets/fs266/en/ For more on asthma and ozone see http://www.lung.org/ associations/charters/northeast/ programs/msb/news/Climate_ Change_and_Respir_Hlth_ Webinar.html For more on exposure to pollution in children see http:// www.ncbi.nlm.nih.gov/pmc/ articles/PMC1241973/pdf/ ehp0112-000760.pdf For the American Thoracic Society report on climate change see http://www.thoracic. org/statements/resources/eoh/ climate-change-and-humanhealth.pdf For the European Respiratory Society report on climate change see http://dev.ersnet.org/ uploads/Document/cc/WEB_ CHEMIN_5568_1260432234.pdf For the study on how public attitudes toward climate change fluctuate with weather see Climatic Change 2013; published online Feb 5. DOI:10.1007/ s10584-012-0690-3
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Discussion about climate change heated up in Australia after a brutal 2012–13 summer, in which a 4-month heat wave culminated in severe episodes of drought, brush fires, and flooding. Globally, the increased frequency of extreme weather is a worrying sign of a shifting climate. Global atmospheric CO2 levels reached an unprecedented high of 396·8 parts per million in early 2013. Limiting the global rise in temperature to 2°C above preindustrial levels— an internationally agreed upon point at which ecosystems and human systems face dangerous consequences—now seems unachievable. Without substantial cuts in global greenhouse emissions, temperatures could rise by 4°C or more. In 2012, World Bank President Jim Kim warned that “the poor and most vulnerable would be hit hardest. A 4°C [warmer] world can, and must, be avoided”. Even with the present extent of global warming (0·8°C higher than the preindustrial average), the dire effects of extreme weather on health are evident. A heat wave in Europe in 2003 led to more than 70 000 excess deaths from cardiovascular and respiratory problems, many of which were in older people. A WHO study concluded that warmer average temperatures caused 140 000 deaths annually by 2004, and that total direct health costs of climate change will reach US$2–4 billion per year by 2030. In addition to increasing the risk of heat-related mortality, climate change is associated with other problems related to respiratory health. Warmer temperatures promote formation of ground-level ozone, which is an irritant to airway and lung tissue. Direct links between ozone exposure and asthma have been reported in epidemiological studies in the USA, with controlled exposure studies also showing that increased exposure to ozone increases airway inflammation and airway responsiveness to allergens in people with asthma compared with healthy controls. Increased ozone smog, and increased air pollution overall, poses a specific threat to paediatric health. Children are more susceptible than adults to pollutants that injure airways, and chronic exposure to irritants decreases lung growth and function from birth to young adulthood. Exposure to particulate matter, nitric oxide, atmospheric acidity, elemental carbon, and traffic pollution are associated with decreased lung function. The American Thoracic Society (ATS) and European Respiratory Society (ERS) have published position papers outlining the effects of climate change on respiratory health, and have called for more research collaboration on topics relevant to both climate change and clinical sciences. For example, warmer average temperatures translate to longer pollen seasons, leading to increased
allergic reactions in sensitised individuals and to changing plant habitats that can expose more people to new allergens. Climate change will also affect the geographical range of vector-borne and zoonotic diseases, possibly increasing the prevalence of infections that can have respiratory complications, such as malaria and hantavirus. Additionally, human migration necessitated by climate change could increase the spread of tuberculosis. A concern echoed by the ATS, ERS, and other health and medical organisations is the health burden of climate change on susceptible populations, particularly children, older people, and communities without adequate health care. High temperatures exacerbate the heat-island effect, whereby heat and air pollution are highest in urban areas without parks or green spaces—often low-income areas. Thus, during a heat wave, many of the adverse effects on respiratory health are felt most by people with poor access to medical care. Globally, increased respiratory complications will disproportionately overburden low-resource countries that already struggle with respiratory-health challenges, such as poor air and water quality, high rates of childhood pneumonia, and inadequate health-care infrastructure. In the politically charged dialogue about climate change, the clinical community has an important role in providing a rational perspective on public health challenges and solutions. Involvement of the medical community could help with progress towards a reduction in greenhouse gas emissions. In the face of opposition from industry, strong clinical evidence of harm and a united voice from doctors could help to ensure that the health consequences of greenhouse gas emissions are reflected in political action. Mitigating the health costs of climate change also depends on public appreciation of the problem, but views on the reality of global warming and its causes remain inconsistent. Polls in the USA and UK in 2012 reported that about two-thirds of respondents believed climate change is occurring, but only about 42% agreed that human activity is a contributor. Views on climate change strongly align with political party affiliation, but can also be affected by the weather, as recently reported by researchers at the University of British Columbia (Vancouver, BC, Canada). Analysis of US media coverage and opinion polls since 1990 revealed that scepticism increased during cold spells, and public concern about climate change rose in line with national average temperature. Hopefully, as the northern hemisphere heads into summer, hot air will translate into real action on mitigating the respiratory and overall health effects of climate change.
Jill Jouret www.thelancet.com/respiratory Vol 1 May 2013
Science Photo Library
Feature Respiratory implications of a changing climate
Published Online April 16, 2013 http://dx.doi.org/10.1016/ S2213-2600(13)70069-9 See News page 187 For more on the World Bank’s Turn Down the Heat report see http://climatechange.worldbank. org/sites/default/files/Turn_ Down_the_heat_Why_a_4_ degree_centrigrade_warmer_ world_must_be_avoided.pdf For the WHO factsheet on climate change and health see http://www.who.int/media centre/factsheets/fs266/en/ For more on asthma and ozone see http://www.lung.org/ associations/charters/northeast/ programs/msb/news/Climate_ Change_and_Respir_Hlth_ Webinar.html For more on exposure to pollution in children see http:// www.ncbi.nlm.nih.gov/pmc/ articles/PMC1241973/pdf/ ehp0112-000760.pdf For the American Thoracic Society report on climate change see http://www.thoracic. org/statements/resources/eoh/ climate-change-and-humanhealth.pdf For the European Respiratory Society report on climate change see http://dev.ersnet.org/ uploads/Document/cc/WEB_ CHEMIN_5568_1260432234.pdf For the study on how public attitudes toward climate change fluctuate with weather see Climatic Change 2013; published online Feb 5. DOI:10.1007/ s10584-012-0690-3
196
Discussion about climate change heated up in Australia after a brutal 2012–13 summer, in which a 4-month heat wave culminated in severe episodes of drought, brush fires, and flooding. Globally, the increased frequency of extreme weather is a worrying sign of a shifting climate. Global atmospheric CO2 levels reached an unprecedented high of 396·8 parts per million in early 2013. Limiting the global rise in temperature to 2°C above preindustrial levels— an internationally agreed upon point at which ecosystems and human systems face dangerous consequences—now seems unachievable. Without substantial cuts in global greenhouse emissions, temperatures could rise by 4°C or more. In 2012, World Bank President Jim Kim warned that “the poor and most vulnerable would be hit hardest. A 4°C [warmer] world can, and must, be avoided”. Even with the present extent of global warming (0·8°C higher than the preindustrial average), the dire effects of extreme weather on health are evident. A heat wave in Europe in 2003 led to more than 70 000 excess deaths from cardiovascular and respiratory problems, many of which were in older people. A WHO study concluded that warmer average temperatures caused 140 000 deaths annually by 2004, and that total direct health costs of climate change will reach US$2–4 billion per year by 2030. In addition to increasing the risk of heat-related mortality, climate change is associated with other problems related to respiratory health. Warmer temperatures promote formation of ground-level ozone, which is an irritant to airway and lung tissue. Direct links between ozone exposure and asthma have been reported in epidemiological studies in the USA, with controlled exposure studies also showing that increased exposure to ozone increases airway inflammation and airway responsiveness to allergens in people with asthma compared with healthy controls. Increased ozone smog, and increased air pollution overall, poses a specific threat to paediatric health. Children are more susceptible than adults to pollutants that injure airways, and chronic exposure to irritants decreases lung growth and function from birth to young adulthood. Exposure to particulate matter, nitric oxide, atmospheric acidity, elemental carbon, and traffic pollution are associated with decreased lung function. The American Thoracic Society (ATS) and European Respiratory Society (ERS) have published position papers outlining the effects of climate change on respiratory health, and have called for more research collaboration on topics relevant to both climate change and clinical sciences. For example, warmer average temperatures translate to longer pollen seasons, leading to increased
allergic reactions in sensitised individuals and to changing plant habitats that can expose more people to new allergens. Climate change will also affect the geographical range of vector-borne and zoonotic diseases, possibly increasing the prevalence of infections that can have respiratory complications, such as malaria and hantavirus. Additionally, human migration necessitated by climate change could increase the spread of tuberculosis. A concern echoed by the ATS, ERS, and other health and medical organisations is the health burden of climate change on susceptible populations, particularly children, older people, and communities without adequate health care. High temperatures exacerbate the heat-island effect, whereby heat and air pollution are highest in urban areas without parks or green spaces—often low-income areas. Thus, during a heat wave, many of the adverse effects on respiratory health are felt most by people with poor access to medical care. Globally, increased respiratory complications will disproportionately overburden low-resource countries that already struggle with respiratory-health challenges, such as poor air and water quality, high rates of childhood pneumonia, and inadequate health-care infrastructure. In the politically charged dialogue about climate change, the clinical community has an important role in providing a rational perspective on public health challenges and solutions. Involvement of the medical community could help with progress towards a reduction in greenhouse gas emissions. In the face of opposition from industry, strong clinical evidence of harm and a united voice from doctors could help to ensure that the health consequences of greenhouse gas emissions are reflected in political action. Mitigating the health costs of climate change also depends on public appreciation of the problem, but views on the reality of global warming and its causes remain inconsistent. Polls in the USA and UK in 2012 reported that about two-thirds of respondents believed climate change is occurring, but only about 42% agreed that human activity is a contributor. Views on climate change strongly align with political party affiliation, but can also be affected by the weather, as recently reported by researchers at the University of British Columbia (Vancouver, BC, Canada). Analysis of US media coverage and opinion polls since 1990 revealed that scepticism increased during cold spells, and public concern about climate change rose in line with national average temperature. Hopefully, as the northern hemisphere heads into summer, hot air will translate into real action on mitigating the respiratory and overall health effects of climate change.
Jill Jouret www.thelancet.com/respiratory Vol 1 May 2013
