all water stories

Forty percent of world lacks clean water, solutions sought

50443248 — Tue, 02 Oct 2007 11:49:16 -0400

The pictures — of children with sunken eyes and shriveled skin; oxen being herded across a river where women clean their clothes and fill their pitchers; an African villager sipping water from a shallow puddle — made the point like no words could at the May 11 Center for International Development symposium “The Impact of the Global Water Crisis on Health and Human Development” at the Harvard School of Public Health (HSPH). Still, the statistics were almost equally startling: More than a billion people worldwide lack safe water sources, and 2.6 billion — 40 percent of the world’s population — have no basic sanitation. Nearly 2 million people a year, 90 percent of them children under 5, die from dehydration and associated malnutrition and microbial diseases.

Too much water can be life-threatening for marathoners

Tue, 10 Jul 2007 12:43:55 -0400

Runners who consume too much water or sports drinks during a marathon can develop a life-threatening condition called exercise-associated hyponatremia (EAH). Beyond drinking, however, researchers at Harvard-affiliated McLean Hospital report in the May 2007 issue of the American Journal of Medicine that this complication during endurance exercise is also the result of a hormonal stress response, which decreases urine formation and prevents the excretion of excess water.

Rainwater cleans vehicles, river

50443248 — Tue, 24 Jul 2007 15:57:27 -0400

In a demonstration project designed to conserve water, control pollutants washing into the Charles River, and recharge groundwater supplies for the dry summer months, Harvard has begun using rainwater to wash as many as 250 University-owned vehicles a week.
"We're directly on the Charles. This [project] reduces pollutant loading into the river and makes the river more usable," said Director of Environmental Health and Safety Joseph Griffin.

Harvard officials unveiled the project last week (April 13) in a tour offered to representatives of the Environmental Protection Agency and the Charles River Watershed Association (CWRA), who, along with NSTAR, had roles in the project.

Tiniest droplets produced from triangular nozzles

70652986 — Mon, 26 Mar 2007 05:33:35 -0400

Ultra-tiny taps - which could, in theory, create drops just 8 billionths of a millimeter in size - might prove a boon for technologies that employ sprays of costly materials. For instance, triangular taps could boost the resolution of ink-jet printers, which work by squirting fine droplets of ink onto surfaces. They could also cut the size of traditional silicon chips and biochips, both of which feature patterns that are sometimes produced by a tightly controlled spray of droplets. "Round nozzles are perfectly good for most applications," says Henry Chen, a graduate student in physics who presented the work at a meeting of the American Physical Society's Division of Fluid Dynamics. "Most nozzles don't need to perform with exacting volume or pressure, so it may not even have occurred to anyone to try anything other than a circular opening." The minuscule triangular nozzle envisioned by Chen and his adviser, Michael P. Brenner, allows just one tiny drop to squeeze through. The tap's three corners reduce a drop's curvature and in turn the pressure needed to eject it from the nozzle. Compared to droplets from a tiny round tap, the scientists found, drops from an equally small triangular nozzle require less pressure to spray them out, easing the toll on pipes.

Scientists show how fish save energy by swimming in schools

70652986 — Mon, 26 Mar 2007 05:32:59 -0400

Researchers at Harvard University and the Massachusetts Institute of Technology have provided new insights into the hydrodynamic benefits fish reap by swimming in schools. "The annual upstream voyage of fish to spawn has long been viewed as one of the classic struggles of the natural world, but our work suggests that this journey may not be nearly as exhausting and heroic as it appears," says author James C. Liao, a graduate student in Harvard's Department of Organismic and Evolutionary Biology. "Rather than swimming blindly upstream through turbulence, swimming fish use specific body motions to yield to natural eddy formations, using energy in the environment to direct their bodies upstream without much muscular investment." The results are reported in the Nov. 28, 2003 issue of the journal Science. Liao was joined in this research by George V. Lauder, professor of biology and Alexander Agassiz Professor of Zoology in the Museum of Comparative Zoology at Harvard, and by David N. Beal and Michael S. Triantafyllou at M.I.T. The work was supported by grants from Sigma Xi, the American Museum of Natural History, the Robert A. Chapman Memorial Scholarship at Harvard, and the National Science Foundation, as well as an M.I.T. Sea Grant.

Designing solutions to fresh water shortage

70652986 — Mon, 26 Mar 2007 05:33:05 -0400

Robert France, associate professor of landscape ecology at the Harvard Graduate School of Design, is a scientist who has studied the effect of environmental degradation of various plants and animals. Urban runoff is one of France's areas of expertise. His knowledge gives him a very different view of the rainwater that flows down our sewers and into our waterways than that of the general public. "The irony is that people are more scared of wastewater than they are of stormwater. In point of fact, the stuff that comes off the streets is worse than what comes from toilets. It's a cocktail of all sorts of nasties." Among the most dangerous pollutants, France mentions the toxic particles shed by car tires and brake drums, along with the bacteria contained in dog waste. Instead of the conventional methods of dealing with stormwater - directing it into sewers and drywells - France would like to see it channeled into specially designed rain gardens where the water is purified while it nurtures vegetation. Another beneficial innovation is the use of porous pavements for driveways and parking lots instead of concrete or asphalt, allowing rainwater to infiltrate the surface layer and filter down to the water table.

State of U.S. public health drinking water reliable

70652986 — Mon, 26 Mar 2007 05:19:18 -0400

"Over the last century, the U.S. has set the world standard for ensuring a reliable, relatively safe drinking water supply to the general public,” said Ronnie B. Levin, a research scientist in the Environmental Epidemiology Program at the Harvard School of Public Health. “But population demands, continuing scientific research and past public policy have created serious challenges for our public water supplies in the next century. The longer we delay, the higher the price tag will be. There are no surprises here." Levin and colleagues wrote an article, “U.S. Drinking Water Challenges in the Twenty-First Century,” offering a “state of the state” review of the nation's public drinking water systems. The researchers describe how reliable and safe water is available to nearly all 270 million U.S. residents. But, they also find that maintenance and repair of the public water infrastructure has been severely neglected. The article appears in the February 2002 supplement issue of Environmental Health Perspectives, Reviews in Environmental Health.

Powerful mutagen found in Massachusetts water

70652986 — Mon, 26 Mar 2007 05:19:16 -0400

Mutagen X, a by-product of chemicals used to disinfect public water supplies, is not monitored or regulated in the U.S. water supply. A new report from researchers at Harvard's School of Public Health provides the first broad evidence that Mutagen X, first discovered in Finland's drinking water more than ten years ago, also lurks in chlorinated U.S. drinking water. Researchers discovered small amounts of Mutagen X, which is a powerful genetic mutation-causing agent, in 36 Massachusetts towns served by 23 different public water systems. The findings may increase support for pending national regulations to tighten drinking water standards and refuel local efforts to identify safer ways to disinfect tap water.

Understanding how fish swim

70652986 — Mon, 26 Mar 2007 05:08:28 -0400

The pattern is hard to see at first because the movement seems to happen in the blink of an eye. The only thing that makes it visible at all is the fact that the bluegill sunfish in George Lauder's experiment is swimming through water that is awash with tiny silvery glass beads that catch the light and reveal the fluid's movement. "That's the fish's pectoral fin," Lauder says, pointing to the grainy, black-and-white-picture. "It's slowed down because the camera was taking 250 images per second. But do you see the way the water is moving in a sort of loop behind it?" Lauder is in the midst of conducting what may be the most thorough and technologically sophisticated study to date of how fish swim.