Ultraviolet treatment for water suggested
TEL AVIV, Israel, April 22 (UPI) -- Most water treatment plants use chlorine to keep water free of bacteria but Israeli scientists say ultraviolet light might be a better method.
Tel Aviv University postdoctoral researcher Hadas Mamane, doctoral student Anat Lakretz, Professor Eliora Ron and their team said although chlorine keeps water free of micro-organisms, it also produces carcinogenic byproducts.
The scientists say they recently determined the optimal UV wavelength water treatment plants and large-scale desalination facilities could use to destroy health-threatening micro-organisms, as well as make the facilities more efficient.
"UV light irradiation is being increasingly applied as a primary process for water disinfection," Lakretz said. "In our recent study, we've shown how this treatment can be optimized to kill free-swimming bacteria in the water -- the kinds that also stick inside water distribution pipes and clog filters in desalination plants by producing bacterial biofilms."
The researchers said they used lamps that emit a multi-wavelength UV spectrum and are more advanced than the single-wavelength UV lamps found in home water systems.
"The best way to control and kill these micro-organisms was to damage their DNA," Lakretz said. "The damage that the UV light causes has no known negative effect on the water."
The scientists noted their approach is even more helpful against parasites that aren't adversely affected by chlorine treatment but place children, the elderly and those in developing nations at particular risk.
Small amounts of chlorine or other oxidants will still be necessary to make sure residual bacteria don't enter the water further along the distribution pipeline, the researchers said.
The study appears in the journal Biofouling.
Mercury is higher in some tuna species
NEW YORK, April 22 (UPI) -- Mercury levels are higher in some species of tuna than others, U.S. researchers found.
Researchers combined DNA barcoding used at the American Museum of Natural History with analysis of mercury content at Rutgers University and found tuna sushi purchased in supermarkets -- yellowfin tuna -- might be healthier than that from restaurants.
Sushi samples were taken from 54 restaurants and 15 supermarkets in New York, New Jersey and Colorado, and all of were identified with DNA barcoding as either bigeye tuna, yellowfin tuna or bluefin tuna species.
The samples were all tested for relative mercury content.
"We found that mercury levels are linked to specific species," Jacob Lowenstein, a graduate student affiliated with the museum, said in a statement. "So far, the (United States) does not require restaurants and merchants to clarify what species they are selling or trading, but species names and clearer labeling would allow consumers to exercise greater control over the level of mercury they imbibe."
The findings are published online in Biology Letters.
Astronauts enjoy very slow shuttle ride
CAPE CANAVERAL, Fla., April 22 (UPI) -- NASA astronauts who will soon roar into space aboard space shuttle Atlantis said they enjoyed taking a slow shuttle trip to the launch pad.
The astronauts rode part of the way with their spacecraft early Thursday during its 6 1/2-hour journey from the Kennedy Space Center's Vehicle Assembly Building to Launch Pad 39A on NASA's giant crawler-transporter.
"Riding the crawler last night was absolutely fantastic," said Cmdr. Ken Ham. He said the crawler, powered by destroyer ship engines, reminded him of a Navy ship, even though it moves across gravel instead of rolling waves.
Because of time constraints, few crews arrive at Kennedy in time to watch the shuttle rollout, NASA officials said, but in this case the rollout had been postponed a few nights because of poor weather at Kennedy.
The STS-132 astronauts are at the space center for the Terminal Countdown Demonstration Test -- a multi-day training exercise that offers the crew and launch teams a full simulation of pre-launch activities.
Atlantis is scheduled to lift off May 14 at 2:19 p.m. EDT.
Climate change and human health studied
BETHESDA, Md., April 22 (UPI) -- The U.S. National Institutes of Health says it has identified specific medical consequences of climate change that require further research.
The NIH report highlights key disease categories and other health consequences researchers say are occurring or will occur due to climate change. The scientists said their study provides a starting point for coordination of federal research to better understand climate's impact on human health and identify who will be most vulnerable and what efforts will be most beneficial.
"This white paper articulates, in a concrete way, that human beings are vulnerable in many ways to the health effects of climate change," said Linda Birnbaum, director of the National Institute of Environmental Health Sciences and the National Toxicology Program. "It lays out both what we know and what we need to know about these effects in a way that will allow the health research community to bring its collective knowledge to bear on solving these problems."
The white paper highlights the state-of-the-science on the human health consequences of climate change on such maladies as asthma, respiratory allergies and airway diseases, mental health and stress-related disorders, cancer, neurological disorders, cardiovascular disease and stroke, waterborne and food-borne disease, nutrition, weather-related morbidity and mortality, vector-borne and zoonotic diseases and human developmental effects.
The report is available at www.niehs.nih.gov/climatereport and in a special supplemental issue of the journal Environmental Health Perspectives.
