March 16, 2010
A study published 16 March 2010 ahead of print in the peer-reviewed journal Environmental Health Perspectives (EHP) finds that many
developing countries have high long-term levels of aerosol air pollution. The study is the first to use satellite data to estimate long-term fine particulate matter (PM2.5) concentrations across the entire globe.
PM2.5 consists of particles with a diameter of 2.5 micrometers (the size of many bacteria) or smaller and comes from such sources as forest fires, power plants, cars, industry, and in many countries, home heating and cooking. These particles pose a health concern because of their ability to penetrate deep into the lungs once they are breathed in.
The study found that 80 percent of the global population lives in places where concentrations of PM2.5 exceed the ultimate air quality guideline set by the World Health Organization (WHO) of 10 micrograms per cubic meter (µg/m3). The WHO has set several interim targets, the highest of which is 35 µg/m3, and even that is exceeded over central and eastern Asia for 38% and 50% of the population, respectively. Eastern China showed high levels of pollution; large regions showed an annual average of more than 80 µg/m3.
The study used satellite data gathered over a span of six years, providing some of the first long-term measurements of average PM air pollution concentrations for many regions with significant sources of air pollution but few if any ground-level sampling stations to substantiate the extent of human exposures—including many developing countries.
The methods described and validated by the study can be applied to further studies of health effects caused by exposure to PM air pollution around the world. These methods include combining data from different satellite instruments with a chemical-transport model to relate observations of the entire air column beneath the satellite to air quality near the surface. The authors validated this approach by comparing their estimates to those derived from ground-based sampling and found a significant level of agreement. However, they note additional research is needed to reduce uncertainty due to non-uniform satellite sampling, cloud cover, and other factors that may limit the accuracy of the satellite-based estimates.
The study is the first to combine data from two particular satellite instruments—MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR (Multi-angle Imaging SpectroRadiometer)—on a global scale.
Authors of the article are Aaron van Donkelaar, Randall V. Martin, Michael Brauer, Ralph Kahn, Robert Levy, Carolyn Verduzco, and Paul J. Villeneuve. This work was supported by Health Canada and by graduate fellowships from the Natural Science and Engineering Research Council of Canada (NSERC) and the Killam Trust.
Source: Environmental Health Perspectives
More information about aerosols: http://www.sflorg.com/space_weather/ato_multimedia/flvato_11
Posted by Scientific Frontline under Environmental Alerts, Global Warming / Climate Change | Comments (0)
March 12, 2010
The University of Sydney will lead a new project to improve existing methods of detecting a fish disease which is causing substantial
setbacks to the barramundi industry.
Thanks to a quantum leap in DNA-detection technology in 2009, a new test is available for the nervous necrosis virus—a serious disease affecting more than 35 species of fish worldwide. In Australia, the disease has primarily affected the production of barramundi, with losses of up to 100 per cent occurring in some hatcheries.
Principal Investigator Professor Richard Whittington, Chair of Farm Animal Health in the Faculty of Veterinary Science at the University of Sydney, says the disease has prevented the expansion of the industry and hampered productivity. It has also reduced options for restocking wild fisheries due to fears the disease may spread.
In the past, the gel-based polymerase chain reaction (PCR) method was the validated test used in laboratories to find signs of the nervous necrosis virus.
"The old test was not very sensitive, and in many cases, infection was present yet still turned up negative," Professor Whittington explains.
"For that reason, the result of the test did not really predict the likelihood of an outbreak occurring."
The new PCR method was first achieved at the University of Sydney through research and development funded by the Australian Research Council, and will allow researchers to concentrate the genome from the virus so that it can be detected in a very sensitive laboratory procedure.
The new study will also improve detection by developing and applying serological tests to complement the PCR method. This will provide the information as to whether the antibody status should be used as an indicator of infection in a fish population.
Launched after the largest consultative meeting in Australia in 2007, the project is a major national collaborative research program to control the disease. The meeting included State Departments of Primary Industries, CSIRO, representatives from the Australian Barramundi Farmers Association as well as the Department of Agriculture, Fisheries and Forestry.
Working with Professor Whittington, will be Dr Joy Becker and Alison Tweedie at the University of Sydney as well as team members listed below:
- Mark Crane, the fish health project leader, from the Australian Animal Health Laboratory at CSIRO;
- Jane Frances, Manager of Aquatic Biosecurity & Risk Management at the New South Wales Industry and Investment;
- Dr Peter Kirkland at Elizabeth Macarthur Agricultural Institute, New South Wales Industry and Investment;
- Dr Edla Arzey, at Elizabeth Macarthur Agricultural Institute, New South Wales Industry and Investment;
- Dr Kitman Dryting, from Aquatic Animal Health Northern Territory State Government;
- Dr Ian Anderson, the principal Veterinary Pathologist (Fish Disease) at the Queensland Department of Primary Industries.
Image Caption: Barramundi (Lates calcarifer)
Source: University of Sydney
Posted by Scientific Frontline under Endangered Species, Oceans Environment, Univ. Environmental News | Comments (0)
March 11, 2010
Under Embargo Till: 19:00 UTC March 11, 2010
Posted: 19:00 UTC 03/11/2010
An international convention will meet next week to decide whether to grant requests from Tanzania and Zambia to lower the protection
status of their elephants, allowing them to conduct one-time sales of stockpiled ivory.
An international team of 27 conservationists, writing in the March 12 edition of Science, says allowing the sale could lead to increased slaughter of elephants for their ivory throughout Africa. The team says there was a sharp increase in poaching even before 2007, when the Convention on International Trade in Endangered Species approved a lower protection status for elephants in Botswana, Namibia, South Africa and Zimbabwe.
However, uncertainty about whether that action would further escalate poaching led the convention to impose a nine-year moratorium on ivory sales, but it was modified at the last minute so the moratorium only applied to those four countries.
The conservationists say Zambia and Tanzania are major sources and trafficking corridors for Africa’s illegal ivory, demonstrated by tons of contraband ivory seized in 2002, 2006 and 2009. DNA sampling on the 2002 and 2006 seizures traced the majority of that ivory back to those two nations.
"These two countries are at the center of the illegal ivory trade in Africa. It’s kind of unbelievable that their requests have gotten this far," said Samuel Wasser, a University of Washington conservation biologist and lead author of the paper published in the Policy Forum section of Science urging that the sale not be allowed.
In the last 30 years African elephants have declined to about 35 percent of their original numbers, and their population today stands at less than 500,000.
An international ban on ivory trade was enacted in 1989, and for four years the elephant poaching level dropped dramatically. But largely because of that success, money for enforcement dwindled. In the meantime, ivory demand from China, Japan and Thailand led to a sharp increase in poaching since 2000.
"More than 8 percent of the elephant population is being poached annually," Wasser said. "That rate of illegal take derails the laws of supply and demand, and makes it critical to maintain the moratorium until we have a better understanding of the impact of illegal trade and how it is affected by legal ivory sales."
The international convention begins meeting Saturday (March 13) in Doha, Qatar, to consider, among other things, the petitions from Zambia and Tanzania for one-time sales from their national ivory stockpiles.
The convention imposes two levels of protection for elephants. The strictest level, which currently applies to both Zambia and Tanzania, does not allow any sales of ivory. To be allowed limited trade, the countries are supposed to demonstrate that their elephant populations are secure, that law enforcement is effective in combating poaching and that the ivory sales will not be detrimental to elephants.
However, neither nation has met any of the criteria, Wasser said. In addition, China and Japan, the only nations approved to import ivory, are among the largest consumers of illegal ivory and have done little to ensure the ivory they sell was obtained legally. That means they also have not met the convention’s standards for taking part in legal ivory trade.
"We’re making decisions that have a huge impact on the world’s ecosystems and we’re not relying on the best available science," Wasser said. "This is a problem with the convention’s decisions in general, even the potential long-term impacts of those decisions is immense."
Source: University of Washington
Posted by Scientific Frontline under Endangered Species, Environmental Alerts, Univ. Environmental News | Comments (0)
March 10, 2010
In a discovery of consequence for efforts to save Tasmanian devils in the wild, scientists have found some devils from north-west
Tasmania are genetically different and potentially resistant to the deadly cancer threatening the species.
The discovery by University of Sydney and University of Tasmania researchers will have implications for efforts to contain the spread of Devil Facial Tumors Disease (DFTD) which has decimated 70 per cent of the devil population since the first diagnosis in east Tasmania in 1996.
Results from the collaboration, published in the latest edition of the journal Proceedings of the Royal Society B, describe levels of diversity in key immune genes in Tasmanian devils.
Lead author, University of Sydney Associate Professor Kathy Belov, from the Faculty of Veterinary Science, said the identification of a small number of genetically different devils in the north-west population opened exciting new research opportunities.
"The majority of devils in Tasmania are immunological clones and therefore susceptible to DFTD. This study has identified a group of devils that are genetically different. We think these devils may be able to see the cancer cells as foreign and mount an immune response against them," Associate Professor Belov said.
"We think more animals might survive in the wild than we initially thought."
DFTD is a transmissible cancer that affects only Tasmanian devils and is spread by biting. It is characterized by large facial tumors which often spread to internal organs. The disease has decimated populations on the east coast where the disease was first detected, because of a lack of genetic diversity at key immune genes.
A decade ago the Tasmanian devil was regarded as common but now it is listed as endangered at both a state and national level and extinction in the wild is considered to be a real possibility within 25-35 years.
Associate Professor Belov said the identification of the genetically different devils, may have implications for captive breeding if these devils are resistant to DFTD.
She said the long term aim of the breeding program however, should still be to maintain as much genetic diversity as possible for future generations and that the insurance breeding program should continue unchanged.
"Once we have a handle on the disease, we want to put the healthiest animals back into the wild. For this reason, we need to continue to breed both eastern and north-western devils in captivity. The possibility of breeding and releasing resistant devils into the wild would be an added bonus".
Save The Tasmanian Devil Program manager Andrew Sharman said it has been known for a while that there are populations of devils that appear to be responding differently to the disease, whether there are resistant individuals or not is still unclear at this stage.
"However, this work supports the idea that there may be some inherent resistance associated with these "genetically different devils". Every new piece of research that sheds light on the relationship between the devil genetics, the environment and the disease helps us develop strategies and tools to ensure the long term survival of the species."
This project has been funded by the Australian Research Council; the Save the Tasmanian Devil Program; an Eric Guiler grant; the Tasmanian Department of Primary Industry, Water, Parks and the Environment; Veterinary Science Foundation and the Elizabeth Gabler Charitable Trust.
The work of the Save the Tasmanian Devil Program is also supported by donations through its fundraising arm, the Save the Tasmanian Devil Appeal.
Visit: Save the Tasmanian Devil Appeal
More Information: Breakthrough Could Save The Tassie Devil
Image Caption: Diseased Tasmanian Devil
Image Credit: Sydney University
Source: Sydney University
Posted by Scientific Frontline under Endangered Species, Univ. Environmental News | Comments (0)
developing countries have high long-term levels of aerosol air pollution. The study is the first to use satellite data to estimate long-term fine particulate matter (PM2.5) concentrations across the entire globe. 
