The Global Fool

our planet is our village

Climate Change, Parasite Infections, and Immune Responses
Mar06

Climate Change, Parasite Infections, and Immune Responses

By Roberta Attanasio Global climate change noticeably impacts human health—safe drinking water, sufficient food, and secure shelter are threatened by rising sea levels and severe weather events. Heat waves dramatically increase death rates not only from heat strokes, but also from complications arising from cardiovascular, respiratory, and cerebrovascular diseases. Although global warming may bring some localized benefits, such as fewer winter deaths in temperate climates and increased food production in certain areas, the overall health effects of a changing climate are likely to be overwhelmingly negative. For example, climate warming is predicted to increase the transmission of parasite infections. Now, results from a recent study show that host immunity can influence the impact of warming on host–parasite interactions and mitigate its long-term effects. For the study (Host immunity shapes the impact of climate changes on the dynamics of parasite infections), researchers focused on soil-transmitted gastrointestinal helminths, also known as parasitic worms. In humans, these worms cause some of the most common parasitic infections worldwide. According to the World Health Organization (WHO), approximately 2 billion people are infected with soil-transmitted helminths globally, mostly in the poorest and most deprived communities. They are transmitted by eggs present in human feces, which in turn contaminate soil in areas where sanitation is poor. However, the researchers focused on two parasitic worms of rabbits, Trichostrongylus retortaeformis and Graphidum strigosum. In previous studies, the researchers found that, in rabbits, infections from one of the parasites are controlled by the immune response, whereas infections from the other parasite species are not controlled, even though the rabbits do mount an immune response to the parasite. Therefore, the researchers designed the new study to understand the contribution of climate change and immunity on the long-term and seasonal dynamics of infections caused by the two rabbit parasitic worms. They examined samples collected monthly between 1977 and 2002 in Scotland. The study results show that climate warming—rising temperature and humidity—increases the availability in pastures of the infective stages of both intestinal worms. The intensity of infection increases for the worm not regulated by immunity. In contrast, there is no significant long-term positive trend in the intensity for the immune-controlled worm. Specifically, G. strigosum infection is not controlled by the rabbit immune response. Therefore, the intensity of the parasite infection increases with warming, leading to significant accumulation of G. strigosum in rabbits, mostly in adult rabbits. Why? The rabbits aren’t able to clear the infection caused by G. strigosum with their immune response; therefore, the rabbits accumulate more and more parasites as they age—the result is that older individuals carry most of the infection in the population. However, because T. retortaeformis infection is...

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Soils Are Threatened: Can We Halt The Problem?
Dec04

Soils Are Threatened: Can We Halt The Problem?

By Roberta Attanasio Today, December 4, 2015, is World Soil Day — a day to connect people with soils, and raise awareness of their critical importance in our lives. Soils — the reservoir for at least a quarter of global biodiversity — have been neglected for too long. We fail to connect soil with our food, water, climate, and life. The maintenance or enhancement of global soil resources is essential to meet the world’s need for food, water, and energy security. Soil loss is an unfolding global disaster that will have catastrophic effects on world food production, according to scientists from the University of Sheffield’s Grantham Centre for Sustainable Futures.  “At the moment, intensive agriculture is unsustainable — under the intensive farming system current crop yields are maintained through the heavy use of fertilizers, which require high energy inputs to supply inorganic nitrogen via the industrial Haber-Bosch process. This consumes five per cent of the world’s natural gas production and two per cent of the world’s annual energy supply.” The scientists’ research is published in a report (A sustainable model for intensive agriculture) presented at the recent climate talks in Paris. But soil is important not only for agricultural practices. “Soil is a vital part of the natural environment. It is just as important as plants, animals, rocks, landforms, lakes, and rivers. It influences the distribution of plant species, and provides a habitat for a wide range of organisms. It controls the flow of water and chemical substances between the atmosphere and the earth, and acts as both a source and store for gasses in the atmosphere. Soil, together with the plant and animal life it supports, the rock on which it develops, its position in the landscape and the climate it experiences, form an amazingly intricate natural system. Soil may look still and lifeless, but this impression couldn’t be further from the truth. It is constantly changing and developing through time. Soil is always responding to changes in environmental factors, along with the influences of man and land use. Some changes in the soil will be of short duration and reversible, others will be a permanent feature of soil development.” So, what is the current status of soils, considering the influences of man and land use? We know that soil loss is an unfolding global disaster. There is another report that adds more information: The Status of the World’s Soil Resources, which has been produced by FAO’s Intergovernmental Technical Panel on Soils, and it has been released today, on Soil World Day. The report, which brings together the work of 200 soil scientists from 60 countries, concludes that...

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Global Threats: Climate Change is a Medical Emergency
Jun23

Global Threats: Climate Change is a Medical Emergency

By Roberta Attanasio For many years, we’ve been aware of the impacts of global climate change on human health and well-being. For example, safe drinking water, sufficient food, and secure shelter are threatened by rising sea levels and severe weather events. Heat waves dramatically increase death rates not only from heat strokes, but also from complications arising from cardiovascular, respiratory, and cerebrovascular diseases. However, the impacts of global climate change on human health are even greater than previously thought — according to a report published today (June 23, 2015) in The Lancet, the threat from climate change is so great that it could undermine the last fifty years of gains in development and global health. The report (Health and climate change: policy responses to protect public health) which frames climate change as a health issue, is by a multidisciplinary and international Commission — the Lancet Commission on Health and Climate Change — formed to map out the impacts of climate change, and the necessary policy responses, in order to ensure the highest attainable standards of health for populations worldwide. More precisely, the Commission includes European and Chinese climate scientists and geographers, social and environmental scientists, biodiversity experts, engineers and energy policy experts, economists, political scientists and public policy experts, and health professionals. By making the case for climate change as a health issue, the Commission hopes for greater public resonance. Public concern about the health effects of climate change has the potential to accelerate political action. The report shows that the direct health impacts of climate change come from the increasing frequency and intensity of extreme weather events, especially heat waves, floods, droughts and storms, whereas the indirect impacts come from changes in infectious disease patterns, air pollution, food insecurity and malnutrition, involuntary migration, displacement and conflicts. Because appropriate responses to mitigate and adapt to climate change have direct and indirect health benefits — from reducing air pollution to improving diet — concerted global efforts to tackle climate change represent one of the greatest opportunities to improve global health this century. Commission co-Chair Professor Peng Gong, from Tsinghua University, Beijing, China, said in a press release: “The health community has responded too many grave threats to health in the past. It took on entrenched interests such as the tobacco industry, and led the fight against HIV/AIDS. Now is the time for us to lead the way in responding to another great threat to human and environmental health of our generation.” The commission points out that a strong international consensus is essential to move the world to a global low-carbon economy, harnessing a crucial opportunity to protect human health —...

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Clean Air: The Effects of U.S. Power Plant Carbon Standards on Human Health
May04

Clean Air: The Effects of U.S. Power Plant Carbon Standards on Human Health

By Roberta Attanasio A little more than a year ago, the World Health Organization (WHO) reported that in 2012 around 7 million people died — accounting for one in eight of total global deaths — as a result of exposure to air pollution. These estimates more than doubled the previous ones, and confirmed that air pollution is now the world’s largest single environmental health risk. The WHO concluded that reducing air pollution globally could save millions of lives. But, what policy changes would be most effective at saving lives? The answer comes from a new study published in the journal Nature Climate Change (May 4, 2015.) The study, (US power plant carbon standards and clean air and health co-benefits), was based on data from the Census Bureau as well as detailed maps of the more than 2,400 fossil-fuel-fired power plants operating across the U.S. It outlines how changes in carbon dioxide emissions could lead to considerable health benefits for the U.S population. According to the WHO, the diseases caused by air pollution include ischemic heart disease (40%), stroke (40%), chronic obstructive pulmonary disease (11%), lung cancer (6%), and acute lower respiratory infections in children (3%). For the new study, the researchers analyzed three possible policy options for power plant carbon standards. The policy option leading to the biggest health benefits was the one that included changes proposed by the U.S. Environmental Protection Agency (EPA) on June 2, 2014, in the Clean Power Plan. Modeling analysis indicated that this option could prevent an expected 3,500 premature deaths in the U.S. every year, and avert more than a thousand heart attacks and hospitalizations annually from air pollution-related illness. Thus, according to the study, the formula presented in the draft Clean Power Plan is on the right track to provide large health benefits, and these health benefits depend entirely on critical policy choices that will be made by the EPA in the final Clean Power Plan expected in July. The Plan is the nation’s first attempt to establish standards for carbon dioxide emissions from power plants. It is also viewed as an important signal of U.S. leadership in the run-up to international climate negotiations in Paris in December. Jonathan Buonocore, one of the researchers involved in the study, said in a press release: “If EPA sets strong carbon standards, we can expect large public health benefits from cleaner air almost immediately after the standards are implemented.” Power plants are the nation’s largest source of carbon dioxide emissions that contribute to climate change. However, they release not only carbon dioxide, but also other pollutants such as sulfur dioxide, nitrogen oxides and particulate matter — precursors to smog and...

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Climate Change: A Key Driver of the Syrian Conflict?
Mar11

Climate Change: A Key Driver of the Syrian Conflict?

By Roberta Attanasio Climate change is happening here and now, with significant damage to natural systems and society. The shrinking of the Arctic sea ice, the melting of the Greenland and Antarctica ice sheets, the acidification of the oceans, the sea level rise, the shifting patterns of precipitation, and the amplified threat of wildfires, are some of its well-recognized effects. There are also significant concerns related to the consequences that climate change could have on freshwater availability and agricultural productivity worldwide — resulting in increasing poverty and further weakening of fragile governments. Indeed, climate change has been identified as a “threat multiplier” — it can exacerbate political instability in the world’s most dangerous regions. “Droughts, floods, food and water shortages and extreme weather can uproot communities, cause humanitarian crises and increase the chances of armed conflict.”   Now, results from a study carried out by researchers at Columbia University and the University of California Santa Barbara (published in the scientific journal Proceedings of the National Academy of Sciences on March 2, 2015) show that the Syrian conflict has been caused, at least in part, by a record drought. The drought occurred approximately from 2007 to 2010, and was worsened by global warming. The researchers wrote: “For Syria, a country marked by poor governance and unsustainable agricultural and environmental policies, the drought had a catalytic effect, contributing to political unrest.” The Syrian uprising began in the Spring of 2011 and then escalated into an ongoing civil war, leading to one of the largest refugee exoduses in recent history — neighboring countries such as Lebanon, Jordan and Turkey are struggling to accommodate the displaced populations. According to the BBC, “Almost 200,000 Syrians have lost their lives in the escalating conflict between forces loyal to President Bashar al-Assad and those opposed to his rule. Syria’s bloody internal conflict has destroyed entire neighborhoods and forced more than nine million people from their homes.” In addition, the war has now acquired sectarian overtones. In their published study, the researchers point out that the 2007−2010 record drought caused widespread crop failure and a mass migration of farming families to urban centers. In 8 years, the Syrian urban population rose by 50%. But what caused, precisely, the widespread crop failure? According to the researchers, unsustainable farming practices led to a massive depletion of groundwater while the region was experiencing a long-term decline in rainfall. At the same time, summer temperatures rose, drying out much of the remaining moisture in the soil. Colin Kelley, leading author of the study, wrote in The Conversation: “We found that there is very little evidence to suggest that long-term trends toward higher...

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