Tuesday April 7, 2009
Grey skies
Airborne pollutants are clouding the world.
THE sky over much of the world has grown dimmer since the 1970s due to a rise in airborne pollutants. Aerosols, tiny particles or liquid droplets belched into the air by the burning of fossil fuels and other sources, are responsible for the the grey pall over south and east Asia, South America, Australia and Africa. Visibility remain relatively stable over North America and improved over Europe.
“Aerosols are going up over a lot of the world, especially Asia,” said Robert Dickinson of the University of Texas, one of the researchers.
Dickinson and two University of Maryland researchers tracked measurements of visibility – the distance someone can see on clear days – taken from 1973 to 2007 at 3,250 meteorological stations worldwide.
Aerosols like soot, dust and sulphur dioxide particles all harmed visibility, they said in the journal Science. The aerosols from burning coal, industrial processes and the burning of tropical forests can influence the climate and be a detriment to health.
Other pollutants such as carbon dioxide and other so-called greenhouse gases are transparent and do not affect visibility.
The scientists blamed increased industrial activity in places like China and India for some of the decreased visibility, while they said air quality regulations in Europe helped improve visibility there since the mid-1980s.
The aerosols can have variable cooling and heating effects on surface temperatures, reflecting light back into space and reducing solar radiation at the Earth’s surface or absorbing solar radiation and heating the atmosphere, they added. – Reuters
Non-toxic textiles
MORE and more people are opting for organic cotton, with global sales of apparel and home textile products made from the material climbing 63% in 2008 to US$3.2bil (RM11bil).
The Organic Cotton Market Report said some of the leading organic cotton retailers are Wal-Mart, Anvil Knitwear, Nike, Pottery Barn and Greensource in the United States, and Zara of Spain, Inditex of Belgium, Coop Switzerland and Hess Natur of Germany.
The amount of organic cotton farmers grew worldwide in 2007/2008 increased 152%. It was grown on 161,000ha in 22 countries. Organic production is based on a system of farming that maintains and replenishes soil fertility without using pesticides, fertilisers or genetically modified seeds. – Reuters
Drugs in the water
FISH caught near wastewater treatment plants serving five major US cities had residues of pharmaceuticals in them, including medicines used to treat high cholesterol, allergies, high blood pressure, bipolar disorder and depression.
However, a person would have to eat hundreds of thousands of fish dinners to get even a single therapeutic dose, said study co-author Bryan Brooks, a Baylor University researcher and professor.
But researchers including Brooks have found that even extremely diluted concentrations of pharmaceutical residues can harm fish, frogs and other aquatic species because of their constant exposure to contaminated water.
Earlier research has confirmed that fish absorb medicines because the rivers they live in are contaminated with traces of drugs that are not removed in sewage treatment plants. Much of the contamination comes from the unmetabolised residues of pharmaceuticals that people have taken and excreted; unused medications dumped down the drain also contribute to the problem.
The US Environmental Protection Agency has called for additional studies about the impact on humans of long-term consumption of minute amounts of medicines in their drinking water, especially in unknown combinations. Limited laboratory studies have shown that human cells failed to grow or took unusual shapes when exposed to combinations of some pharmaceuticals found in drinking water. – AP
Newly found species
A Litoria frog, which uses a loud ringing song to call for a mate, was discovered in a rainforest in Papua New Guinea’s highlands wilderness in 2008 . A BRILLIANT green tree frog with huge black eyes, jumping spiders and a striped gecko are among more than 50 new animal species scientists have discovered in a remote, mountainous region of Papua New Guinea.
Conservation International found 50 spider species, three frogs and a gecko which have never been described in scientific literature before. The new frogs include a tiny brown animal with a sharp chirp, a bug-eyed bright green tree frog and another frog with a loud ringing call. One of the jumping spiders is shiny and pale green, while another is furry and brown.
“If you’re finding things that are that big and that spectacular that are new, that’s really an indication that there’s a lot out there that we don’t know about,” said expedition leader Steve Richards. “It never ceases to amaze me the spectacular things that are turning up from that island.”
The area the researchers explored provides a critical source of clean drinking water to tens of thousands of people living in surrounding communities and local clans rely on the region for hunting. – AP
Source:
RSS
