National Geographic News
Mines at Risk of Spilling Toxic Waste
A spill at a mine that turned a Colorado river orange and sent toxic waste barreling downstream 100 miles has many people wondering if the mining site in their town could be next. The answer from experts: Yes. Last week’s spill of three million gallons of acidic mining waste from the historic Gold King mine into the Animas River north of Durango “was an accident waiting to happen,” says Jennifer Krill, executive director of Earthworks, a Washington advocacy group that works on environmental issues associated with the mining industry. “There are a lot of similar disasters waiting to happen, at thousands of abandoned mine sites around the U.S.,” says Krill.
For instance, a year ago at Mount Polley in British Columbia, five million cubic metres of tailings pond wastewater from a copper and gold mine spilled into Hazeltine Creek, rendering a community’s water supply unusable. Toxic mine waste also spilled into the Animas River at least two other times, in the 1970s, says Ronald R. Hewitt Cohen, an environmental engineer who studies mine waste treatment at the Colorado School of Mines. In Colorado, an estimated 4,650 abandoned mine sites are currently leaking toxic waste, says Cohen. Much of that waste is contained in ponds that weren’t designed to last a long time, meaning “the longer we wait to clean them up the better they have to fail and cause big spills,”
Source:-http://news.nationalgeographic.com/2015/08/150814-hardrock-mines-toxic-waste-pollution-colorado-mine-environment-gold-king-spill/
River Algae Known as Rock Snot Boosted by Climate Change?
Thick algal mats that cover river bottoms are flourishing in our warmer world. Scientists call it Didymosphenia geminata. But it's more widely known as "rock snot"—mats of algae carpeting the bottoms of some rivers and lakes—and it's quickly spreading around the globe, possibly because of climate change, a new study says. So far, scientists say its effects on the environment are unknown, though they are concerned specifically about the impact on salmon. The mats can cover up to 75 percent of a river bottom in some places. As the algae spread worldwide in recent decades, including to New Zealand, South America, and the United States, scientists theorized that it was an invasive organism whose cells were hitchhiking with people as they enjoyed the outdoors. Not so, found Joshua Kurek, a biologist at Queen's University in Ontario, Canada, and his colleagues. Their investigations of lake sediments and historical research papers revealed that didymo has been in rivers—at least in eastern Canada—for nearly 200 years. Instead, Kurek's research suggested that the algae's spread is intensifying because "climate warming is pushing these river systems into conditions that didymo prefers," including less ice cover and fewer nutrients.
Scientists first recorded a bloom of didymo in 2006 in Quebec's Matapédia River, whose bottom was covered in sections by thick clumps that resemble a "filthy shag carpet," according to Kurek, a co-author of the new study, published February 26 in the Canadian Journal of Fisheries and Aquatic Sciences. "Prior to 2006, no one had officially reported a bloom to a management authority or government agency in eastern Canada," he said, although the species has been described since the early 20th century. "What we're seeing now is exceptional." For the study, Kurek and colleagues analyzed sediments dating to 1970 that were taken from two lakes near where rock snot was first discovered. The results "were really telling—out of the 20 samples that we analyzed, 19 of them had evidence of didymo," said Kurek. The team also found evidence that didymo had exploded in one lake by 5,000 percent between 1970 and modern times. Local air temperatures rose and ice cover on lakes and rivers shrank over the same time period.
Source:http://news.nationalgeographic.com/news/2014/03/140311-rock-snot-rivers-freshwater-science-environment
Entrepreneur Changes Life in Uganda by Turning Waste In to Fuel
Sanga Moses grew up barefoot in a small Ugandan village of thatched roof dwellings that lacked electricity. Yet he became his clan's first college graduate and took a bank job in Kampala. Returning home for a visit from the Ugandan capital in 2009, he met his 12-year-old sister on the road. "She stood there crying, with a heavy bundle of wood on her head," Moses remembers. "She was upset because, like most rural girls, she missed days of school each week searching for fuel wood.
"My sister … was losing the only opportunity she had to make her life better—education." It wasn't the only change Moses noticed in his hometown. "When I was young, our home was surrounded by national forests," he says. "Now all those trees are gone, and children must walk longer and longer distances to gather wood." Searching for a solution to problems born of burning wood, Moses quit his job and began learning everything he could about renewable resources. Eventually he came across the increasingly popular practice of turning organic waste into fuel. "I looked out my window and saw a huge pile of sugar cane debris," he says. "Uganda is primarily agricultural, but farm waste is just abandoned." So Moses began working with engineering students to design kilns and briquetting machines. Four years later, 2,500 farmers use his kilns to turn farm waste—coffee husks and waste from sugar cane and rice—into charcoal. A company that Moses founded, called Eco-Fuel Africa, buys the char and turns it into briquettes for cooking that burn cleaner and cost less than wood. The company takes those briquettes to market, providing fuel for more than 19,000 Ugandan families. "Burning fuel wood not only destroys Uganda's trees," Moses says, but it also affects "the health and educational opportunities of our poorest people. "We're giving them an alternative."
Source:http://news.nationalgeographic.com/news/2014/12/141215-sanga-moses-uganda-energy-wood-burning-fuel/
Can Houseplants Really Clean the World's Smoggiest City?
NEW DELHI—On the roof of an office building in India's capital, the world's smoggiest city, Kamal Meattle has a unique tactic for cleaning the air: a greenhouse with 400 common plants, including mother-in-law's tongue.
Kamal Meattle, CEO of Paharpur Business Centre in New Delhi, India, grows 400 plants in his office building's greenhouse to help clean its indoor air.
Meattle, the CEO of Paharpur Business Centre, has 800 other plants spread throughout the building's lower six floors, greening each room and hallway. Their job: remove soot and other chemicals from the often charcoal-colored outdoor air.
In India, where almost no one wears filter masks on the streets as many do in China, Meattle is seen as a radical. He says he's even been dubbed the Mad Hatter of Nehru Place, a high-tech hub that's home to his leafy building and an adjacent lot he converted from a slum into an oasis of 2,000 trees.
He uses rainwater collected in cisterns to spray the trees so they can grow faster and absorb more pollutants. He's urging India's new government to require rainwater harvesting and to paint roofs, and buses, white. And he's pushing to build one of the world's largest energy-efficient office parks, complete with greenhouses.
Meattle hardly seems a firebrand. A soft-spoken grandfather, he's a scion of India's elite who attended school with Rajiv Gandhi and later earned a chemical engineering degree from the Massachusetts Institute of Technology. He sees his efforts, touted in a 2009 TED talk that's attracted more than two million views, as common sense.
"Sustainability is good business, and energy efficiency is low-hanging fruit," says Meattle, whose 25-year-old building was India's first to earn the top rating (in 2010) for a retrofit from the U.S. Green Building Council. He says it uses one-fifth as much energy per square meter as the average office building in India. At least 10 percent of its energy savings is due to plants, which obviate the need to pump in ambient air.
His horticulture is also a practical nod to ancient tradition. "Why did Buddha sit under the peepul [or bodhi] tree?" he asks, adding that the sacred fig with heart-shaped leaves releases oxygen even at night, allowing those beneath a light sleep. Read more.
Source:- http://news.nationalgeographic.com