The Global Fool

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Global Threats: Children’s Exposure to Toxic Pesticides
May17

Global Threats: Children’s Exposure to Toxic Pesticides

By Roberta Attanasio In 2012, the American Academy of Pediatrics (AAP) released a policy statement to outline the harmful effects of pesticides in children, and to make recommendations on how to reduce exposure. According to the statement, prenatal and early childhood exposure to pesticides is associated with pediatric cancers, decreased cognitive function, and behavioral problems. In addition, the statement pointed out that recognizing and reducing children’s exposure to pesticides requires improved medical training, public health tracking, and regulatory approaches, and made recommendations on specific actions that should be taken to decrease such exposure. Despite the recognition of the dangers associated with pesticide use, and the AAP recommendations on limiting children’s exposure, not much has been done since 2012 — indeed, it’s likely going to get worse before it gets better. The AAP recommended that pediatricians should ask parents about pesticide use around the home and yard, offer guidance about safe storage, and recommend parents choose lowest-harm approaches when considering pest control. Are pediatricians following these recommendations? At this time, let’s say this is an open-ended question — although we may guess what the correct answer is. Let’s now move from the local (the American Academy of Pediatrics – AAP) to the global (the Food and Agricultural Organization of the United Nations – FAO). According to the International Labour Organization (ILO), nearly 100 million boys and girls between 5 and 17 years old are engaged in child labor in agriculture. Many are directly exposed to toxic chemicals while working on the farm — however, children are also exposed when they help with family chores or play, and through the food they eat and the water they drink. Exposure can result in acute poisoning and sickness immediately after contact. But often, it also has longer-term, chronic impacts on their health and development. Children are particularly vulnerable to pesticide exposure for various biological and behavioral reasons. They breathe in more air than adults and so take in more dust, toxic vapors, and droplets of spray. Relative to their body weight, children need to eat and drink more than adults, and if food is contaminated, they absorb more toxins. The surface area of a child’s skin per unit of body mass is greater than that of an adult, and their skin is more delicate. All these factors can lead to greater absorption of chemicals, and children’s organs are less able to detoxify pesticides because they are not yet fully developed. Now, recognizing that education is crucial to limit exposure to pesticides (as stated by the AAP in 2012), FAO and ILO extension workers in Africa and elsewhere are engaging with rural communities to reduce...

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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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Global Threats: Contamination of Surface Waters by Agricultural Insecticides
Apr26

Global Threats: Contamination of Surface Waters by Agricultural Insecticides

By Roberta Attanasio The use of agricultural insecticides — toxic substances developed to target and kill insects that damage crops — has sparked controversy since the dawn of the “chemical age”, which started in the 1950s. The benefits of agricultural insecticides — for example, increased food production — are undeniable. Unfortunately, along with benefits, there are considerable unwanted effects. Ideally, insecticides must be lethal to the target insects, but not to non-target species. However, these toxic substances do not target only insects — they target many more organisms, including man. Thus, the toxic brew of agricultural insecticides threatens the ecological integrity of aquatic and terrestrial ecosystems. Indeed, agricultural systems play a significant role in global environmental degradation — among other harmful effects, they drive the loss of aquatic biodiversity. In 2013, a team of researchers from German and Australian institutions showed that the loss of aquatic biodiversity in regions of Germany, France, and Australia, is primarily due to the disappearance of several groups of species — stoneflies, mayflies, caddisflies, and dragonflies — which are especially susceptible to insecticides. These insects are important members of the food chain right up to fish and birds. Despite these worrisome results, the degree of insecticide contamination worldwide was unknown until two weeks ago, when results from a new study (Agricultural insecticides threaten surface waters at the global scale) showed that surface water pollution resulting from the current use of agricultural insecticides constitutes an excessive threat to aquatic biodiversity. For the new study, researchers at the Institute for Environmental Science of the University of Koblenz-Landau evaluated, for the first time, comprehensive global insecticide contamination data for agricultural surface waters. They examined 838 studies conducted between 1962 and 2012 and covering 2,500 aquatic sites in 73 countries, using the legally-accepted regulatory threshold levels (RTLs) as defined during the official pesticide authorization procedures. The researchers found that insecticide contamination occurs rarely in the aquatic environment — only an estimated 2.6% of the samples contained measurable levels of insecticides. However, for the sites containing insecticides, the results were alarming — more than 40% of the water-phase samples, and more than 80% of sediment samples in which insecticides were detected, yielded concentrations that exceeded the respective RTLs. They concluded that insecticides pose substantial threats to the biodiversity of global agricultural surface waters and that the current regulatory risk assessment schemes and pesticide authorization procedures fail to protect the aquatic environment. Ralf Schulz, one of the researchers, said in a press release: “Potential reasons for these findings are failures of current risk assessment procedures, or the non-adherence of farmers to pesticide application prescriptions.” It is likely that the global picture emerging from the...

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The Global Travels of Chikungunya Virus: Is it Coming to You?
Mar30

The Global Travels of Chikungunya Virus: Is it Coming to You?

By Roberta Attanasio Chikungunya virus is spreading fast — worldwide. First described during an outbreak in southern Tanzania in 1952, it caused sporadic illness in Africa and large urban outbreaks in Thailand and India in the 1960s and 1970s. As of now, it has been identified in over 60 countries in Asia, Africa, Europe and Americas. The virus, which causes fever and severe joint pain, is transmitted to humans by the bites of infected female mosquitoes, most commonly by Aedes aegypti and Aedes albopictus — two species that can also transmit other mosquito-borne viruses, including dengue. There is no vaccine and no specific treatment for the infection. Gemma Handy aptly describes the onset of the disease in an Antiguan patient: “The acute ache started in her ankles before quickly spreading through her body, crippling her muscles, pounding her joints and leaving her hands and feet severely swollen.” The patient said: “”I was fine when I went to bed, but when I woke up in the morning and tried to get up my ankles hurt so much I couldn’t stand. It was very scary. After that I started getting different pains all over my body. Soon my hands were so swollen I couldn’t hold anything.” Indeed, “chikungunya” derives from a word in the Kimakonde language, which is spoken by the Makonde, an ethnic group in southeast Tanzania and northern Mozambique — it means “to become contorted”, and describes the stooped appearance of sufferers with joint pain. Most patients recover fully, but in some cases joint pain may persist for several months, or years — and even become a cause of chronic pain and disability. In 2007, disease transmission was reported for the first time in a localized outbreak in north-eastern Italy. Outbreaks have since been recorded in France and Croatia. According to the Centers for Disease Control and Prevention (CDC), the first local transmission of Chikungunya virus in the Americas was identified in Caribbean countries and territories in late 2013 — local transmission means that mosquitoes in the area have been infected with the virus and are spreading it to people. Beginning in 2014, Chikungunya virus disease cases were reported among U.S. travelers returning from affected areas in the Americas and local transmission was identified in Florida, Puerto Rico, and the U.S. Virgin Islands. The current numbers of people infected with the virus within the Americas are staggering: the Pan-American Health Organization reports that, as of the end of February 2015, the initial handful of cases had exploded to 1,247,400 suspected and confirmed cases, affecting almost every country in the hemisphere. After the first locally acquired case of Chikungunya was reported...

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Small Predator Diversity Plays a Significant Role in the Spread of Infectious Diseases
Mar23

Small Predator Diversity Plays a Significant Role in the Spread of Infectious Diseases

By Roberta Attanasio Biodiversity is a term coined to describe the diversity of all living things, from human beings to microorganisms. A New York Times editorial published almost two decades ago aptly describes the importance of the biodiversity concept: “Biodiversity is a hugely important concept that stresses the coherence and interdependence of all forms of life on earth and a new willingness to appraise the meaning of that interdependence, not just for humans but for every one of life’s component parts.” The editorial goes on to illustrate the alarming effects of biodiversity loss: “Biodiversity is a way of talking about what scientists have long understood and a way of reminding the rest of us of a cardinal fact: that we are standing in the midst of the earth’s sixth great extinction of diverse species, that this extinction is driven by us and that we are not now and will never be immune to its effects.” One of these effects is the worldwide spike in infectious diseases, as suggested by a study recently published in the journal Proceedings of the National Academy of Sciences. The study (Predator diversity, intraguild predation, and indirect effects drive parasite transmission) explores how the diversity of small predators shapes the transmission of parasites in wetlands. Lead author Jason Rohr said in a press release by Penn State: “In the last century, there has been an unprecedented global increase in infectious diseases and a concomitant decline in and homogenization of biodiversity. The controversial ‘dilution effect hypothesis’ suggests that the two phenomena might be linked, or that biodiversity often decreases disease risk.” The study, which included a series of laboratory experiments, field surveys and mathematical modeling, shows that — in presence of various species of dragonfly larvae — there is a reduction of frog infections caused by trematodes, which are parasitic flatworms also known as flukes. The dragonfly larvae are small predators that eat trematodes. Val Beasley, senior author of the study, said in the press release that various species of trematodes penetrate tadpoles. The trematodes sometimes kill the tadpoles. In other instances, the trematodes weaken them by causing tissue damage, kidney failure, or severe limb deformities while the tadpoles develop into frogs. He added that other vertebrate species commonly catch trematode infections from bodies of water. These vertebrate species include wildlife, domestic animals and humans — mostly children — who are commonly affected by schistosomiasis in tropical parts of the world. Schistosomiasis is a parasitic disease carried by freshwater snails infected with one of the five varieties of the parasite Schistosoma, a type of trematode. Although the worms that cause schistosomiasis are not found in the...

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