America"s natural gas system is leaking methane and in need of a fix

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The first thorough comparison of evidence for natural gas system leaks confirms that organizations including the Environmental Protection Agency (EPA) have underestimated U.S. methane emissions generally, as well as those from the natural gas industry specifically.Natural gas consists predominantly of methane. Even small leaks from the natural gas system are important because methane is a potent greenhouse gas — about 30 times more potent than carbon dioxide. A study, “Methane Leakage from North American Natural Gas Systems,” published in the Feb. 14 issue of the journal Science, synthesizes diverse findings from more than 200 studies ranging in scope from local gas processing plants to total emissions from the United States and Canada.”People who go out and actually measure methane pretty consistently find more emissions than we expect,” said the lead author of the new analysis, Adam Brandt, an assistant professor of energy resources engineering at Stanford University. “Atmospheric tests covering the entire country indicate emissions around 50 percent more than EPA estimates,” said Brandt. “And that’s a moderate estimate.”The standard approach to estimating total methane emissions is to multiply the amount of methane thought to be emitted by a particular kind of source, such as leaks at natural gas processing plants or belching cattle, by the number of that source type in a region or country. The products are then totaled to estimate all emissions. The EPA does not include natural methane sources, like wetlands and geologic seeps.The national natural gas infrastructure has a combination of intentional leaks, often for safety purposes, and unintentional emissions, like faulty valves and cracks in pipelines. In the United States, the emission rates of particular gas industry components — from wells to burner tips — were established by the EPA in the 1990s.Since then, many studies have tested gas industry components to determine whether the EPA’s emission rates are accurate, and a majority of these have found the EPA’s rates too low. …


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Air pollution increases risk for hypertension in pregnant women

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Breathing the air outside their homes may be just as toxic to pregnant women — if not more so — as breathing in cigarette smoke, increasing a mom-to-be’s risk of developing deadly complications such as preeclampsia, according to findings from a new University of Florida study.UF researchers compared birth data with Environmental Protection Agency estimates of air pollution, finding that heavy exposure to four air pollutants led to a significantly increased risk for developing a high blood pressure disorder during pregnancy. The research was published in the January issue of the Journal of Epidemiology & Community Health.The pollutants include two specific types of fine and coarse particulate matter, carbon monoxide and sulfur dioxide. According to the EPA, particulate matter includes acids, dust, metals and soil particles. These inhalable particles are released from industries and forest fires and can form when gases react with each other in the air. Sulfur dioxide is emitted from power plants and industries. Most carbon monoxide is produced by car exhaust.”Fetal development is very sensitive to environmental factors,” said Xiaohui Xu, M.D., Ph.D., an assistant professor of epidemiology in the colleges of Public Health and Health Professions and Medicine. “That is why we wanted to do this research. Hypertension (high blood pressure), in particular, is associated with increased morbidity and mortality, causing a lot of problems for the mother and fetus, including preterm delivery.”Hypertensive disorders such as gestational hypertension, preeclampsia and the deadly condition it leads to, eclampsia, affect about 10 percent of pregnancies. Despite the serious risks to mother and baby, little is known about what specifically causes these conditions to develop in pregnant women, the researchers say.To gain a better understanding of how environmental factors may play a role in increasing the risk of developing hypertension during pregnancy, the researchers examined data from women who gave birth in Jacksonville, Fla., between 2004 and 2005 and environmental data from their communities. The sample included more than 22,000 pregnant women.The researchers did not include mothers with chronic hypertension, those who had previously given birth prematurely or those whose babies were born with other complications in the sample. …


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