Does an apple a day really keep the doctor away? The iconic fruit tops a new list of the most pesticide-laden produce in America, raising concerns that some health-conscious consumers are inadvertently hurting themselves with non-organic fruit. Apples moved up three spots for this year's edition of the "Dirty Dozen," an annual list of the 12 fruits and vegetables found to contain the most pesticide residues in federal tests. Released by the Environmental Working Group, and based on data gathered by the U.S. Department of Agriculture, the 2011 Dirty Dozen finds that 92 percent of apples contain at least two pesticides.
"We think what's happening to apples is more pesticides and fungicides are being applied after the harvest so the fruit can have a longer shelf life," EWG analyst Sonya Lunder tells USA Today. "Pesticides might be in small amounts, but we don't know what the subtle, long-term effects of many of these pesticides are yet." Apples overtook celery for this year's top spot on the list, pushing it down to No. 2, followed by strawberries, peaches and spinach in the top five. Many pesticides have been blamed for or at least associated with serious health problems in humans, including nervous-system damage, hormone disruption, infertility, birth defects and developmental problems in children. But the EWG isn't suggesting that anyone quit eating apples — they merely advise buying organic apples whenever possible. "Consumers don't want pesticides on their foods," says EWG president Ken Cook. "We eat plenty of apples in our house, but we buy organic when we can."
The EWG's Dirty Dozen is also balanced out every year by a much happier list: the "Clean 15." These 15 foods contained the lowest pesticide residues in USDA tests, making them ideal sources for the recommended five servings of fruits and vegetables a day, the EWG suggests. Onions top this year's clean list, followed by corn, pineapples, avocado and asparagus in the top five. It's usually safe to buy non-organic varieties of these cleaner foods, the EWG points out, allowing consumers to save their money for things like apples, celery and strawberries that are likely safer when grown organically. "With the increased emphasis on eating more fruits and vegetables," Lunder says, "we need to be vigilant about the food we're producing and serving."
The U.S. has been besieged by wild weather so far in 2011, and according to many predictions of global warming, it's just a taste of what we can expect for decades to come. This most recent bout of weirdness began as record snowfall blanketed the country in winter, followed by record rain, floods and tornadoes this spring — even as a historic drought dragged on at the same time, setting the stage for ferocious wildfires from Florida to Arizona. And now a heat wave is beating down on the East Coast, less than a week after a June snowfall in Hawaii. With hurricane season already gearing up, many weather-weary Americans are wondering if all this might be connected — a question LiveScience poses to a few experts on the subject.
Some of this year's chaos may be due to La Niña, says Martin Hoerling, a research meteorologist at the National Oceanic and Atmospheric Administration. "Some aspects of the recent U.S. climate anomalies, for example, the Texas, Arizona and New Mexico drought, are likely linked to a common factor: the cumulative effect of the prolonged La Niña event that has lasted from summer 2010 until this spring." La Niña could also be responsible for the heavy rain and snow of early 2011, which helped create the wild flooding along the Mississippi, Ohio and Missouri rivers. But, Hoerling adds, "the extreme nature of these rains is beyond what can be reconciled with La Niña alone." To more fully explain that "extreme nature," NOAA's David Easterling says it's reasonable to consider climate change. "The flooding and the heavy rainfall are consistent with what we expect with global warming," says Easterling, chief of NOAA's Global Climate Applications Division. "Looking at some of the modern trends, we've seen increases in the amount of water vapor in the atmosphere, drawing a direct link between what's happening in the Midwest and global warming."
All the extra heat from global warming essentially puts the atmosphere into overdrive, causing water to evaporate faster, fuel bigger storms and generally wreak havoc in ways no one can predict with precision. But the atmosphere is also too complicated to rule out seasonal variability, climate experts tell LiveScience, and we still have too few data points to definitively link a tornado, a wildfire or a flooded river to global warming. That may eventually be possible, but for now, Hoerling offers a sober yet unsatisfying conclusion: "In sum, there are many measures of extremes, and it's unclear if any aggregate change in extremes has indeed occurred."
Autism spectrum disorders show a troubling correlation with pollution exposure, researchers from the University of Utah tell the Salt Lake Tribune, arguing the link deserves more study after they found that children with the disorders are more likely to have been born near facilities that emit toxic chemicals or heavy metals. "If you take this combined with the other studies [showing links between pollution and autism], it’s pointing to something that we need to seriously look at," says Judith Pinborough-Zimmerman, a psychiatry professor and researcher at the university.
To establish the connection, the researchers looked at the maternal addresses listed on birth certificates of children born in three Utah counties who were later diagnosed with autism spectrum disorder. Children born to mothers who lived within a mile of "Toxic Release Inventory" sites — which emit or dispose of toxic chemicals and heavy metals that are regulated by the EPA — were more likely to have an autism-related condition, the study revealed. The risk of having an autism spectrum disorder was 3.5 times higher for children born within a mile of a TRI site that releases 5,000 to 10,000 pounds of halogenated chemicals (including dioxins, polychlorinated biphenyls and trichloroethylene), the Tribune reports, while the risk was twice as high within a mile of a TRI site that emits up to 5,000 pounds of the heavy metals arsenic, cadmium, lead, nickel and mercury. Living within a mile of these sites also boosted the risk for developing an intellectual disability, but for some reason it seems to lower the odds of developing a speech-language impairment, too.
This isn't quite a smoking gun linking environmental pollution to autism, the researchers acknowledge, since there are a few bases the study didn't cover. It didn't include length of exposure to chemicals or to heavy metals, for example, or other exposure sources in the home or workplace. It also didn't investigate whether the mothers were exposed to chemicals during the first trimester of pregnancy, which is a critical time for fetal development. "We need to take this study to the next step and have it peer-reviewed and published," says study co-author Amanda Bakian.
(Source: Salt Lake Tribune)
Scientists have been warning for years that global warming is triggering a jellyfish boom, proliferating the opportunistic animals that are sometimes called "cockroaches of the sea." But according to a new study in the journal Proceedings of the National Academy of Sciences, jellyfish may in turn be making the problem even worse, producing more carbon than the world's oceans can handle.
Certain bacteria normally act as garbagemen of the seas, recycling extra nutrients that are released when other plants and animals die and decay. But while these bacteria can absorb the carbon, nitrogen, phosphorus and other nutrients from most fish and other sea life, they apparently can't do the same with jellyfish. The gelatinous blobs decay into biomass with an especially high carbon content, the researchers report, which the bacteria struggle to absorb and break down. Instead of using this carbon as a nutrient to fuel their growth, the bacteria instead exhale it as carbon dioxide, releasing more of the greenhouse gas into the atmosphere that helped cause the jellyfish boom in the first place. It also worsens ocean acidification, the "evil twin" of global warming, marine scientist Carol Turley tells the Guardian. "Oceans have been taking up 25 percent of the carbon dioxide that man has produced over the last 200 years, so it's been acting as a buffer for climate change," Turley says. "When you add more carbon dioxide to sea water it becomes more acidic. And already that is happening at a rate that hasn't occurred in 600 million years."
On top of worsening climate change and helping to acidify oceans, jellyfish are also upending the marine food web, the researchers add. By gobbling up large amounts of plankton, which forms the food web's base, they're denying fish a crucial food source — making it much harder for top-level predators like tuna, sharks or whales to make a living. "This restricts the transfer of energy up the food chain," says lead author Rob Condon, from the Virginia Institute of Marine Science, "because jellyfish are not readily consumed by other predators."
Exxon Valdez captain gets in more trouble, U.S. and U.K. mend fences after BP spill, and more.
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Photo (apples): David Wasserman/Jupiter Images
Photo (storm clouds in Colorado): Tal Atlas/Flickr
Photo (TRI site in Delaware): EPA
Photo (jellyfish): National Science Foundation