Lyme disease. West Nile virus. Malaria. Over the past several decades, scientists and public health officials have documented the outbreak of many troubling infectious diseases: illnesses once thought well under control are making a comeback or appearing in locations where they had never been seen before; brand new diseases are suddenly appearing on the scene.

Over the same time period that the frequency of emerging infectious diseases appears to be increasing, natural habitats and biological diversity (the abundance, composition and distribution of species) have been declining, primarily due to deforestation, development projects, and other human activities. Is there a link? While the current scientific literature suggests the answer is yes, there have been few integrative, interdisciplinary studies exploring the scientific connections between human health and biodiversity. A new research initiative at the U.S. Environmental Protection Agency aims to fill that void.

EPA recognizes the critical role healthy ecosystems play in protecting our health and well-being, and conserving biological diversity is a primary way to sustain healthy ecosystems and the critical benefits-including protection from disease-they provide.

EPA scientists are exploring the underlying mechanisms of disease emergence and their links to biodiversity through their contributions to GEOSS (the Global Earth Observation System of Systems), a large national and international cooperative research effort to better understand worldwide changing environmental conditions through the development, use, and sharing of earth observations. Using such comprehensive imaging allows EPA scientists to combine data across multiple spatial scales and academic disciplines, at once exploring the scientific factors linking human-caused environmental stressors (such as deforestation and climate change), changes in biological diversity, and the transmission of diseases from animals to people.

As one of the few truly interdisciplinary research efforts, the EPA/GEOSS emerging disease/biodiversity program is bringing experts together from many different fields to coordinate earth observations and integrate it with social, ecological, and health information. The approach is to focus new knowledge and tools in order to inform decision-makers, ultimately leading to improved integrated pest management programs, land use/development guidance, and social-behavioral changes that together better protect both human health and the environment. EPA is working with U.S. Federal partners and international organizations to advance this work.

منبع: سازمان محیط زیست آمریکا

به گزارش مهر، سازمان ناسا اعلام کرد که حفره لايه ازن در 12 سپتامبر 2008 تا 27.2 ميليون کيلومتر مربع گسترش يافته است. اين در حالي است که در سال گذشته اين مساحت 25.1 ميليون کيلومتر مربع تخمين زده شده بود.

به گفته محققان ناسا بزرگترين ميزان گستردگي اين حفره در سال 2006 بوده که در آن سال گستردگي حفره به 27.4 ميليون کيلومتر مربع رسيده بود.

گاز ازن که از ترکيب سه اتم اکسيژن به وجود مي آيد، قابل تنفس نيست اما به دليل جذب شعاع هاي ماورا بنفش نور خورشيد که براي سلامتي انسانها بسيار مضر شناخته شده است، نقش اساسي را در حفاظت از سياره زمين به عهده دارد.

به گفته ناسا، اين حفره در طي ماه هاي سپتامبر و اکتبر به بيشترين ميزان گستردگي خود رسيده و سپس به صورت حفره هايي پراکنده و کوچک قسمت هاي جنوبي زمين مانند نيوزيلند، استراليا و آمريکاي جنوبي را تحت تاثير خود قرار مي دهد.

بر اساس گزارش سي بي سي، سازمان ناسا فرايند گسترش اين حفره را از دهه 1970 مورد پي گيري قرار داده و افزايش مساحت اين حفره در دهه 1980 باعث برانگيختن فعاليتهايي مبني بر ممانعت استفاده از کلورو فلورو کربن ها شد.

با اين حال استفاده گسترده از ديگر مواد مخرب ازن، مانند هايدرو کلورو فلورو کربن ها که به ميزان زيادي در تجهيزات سرد کننده، تهويه هوا و سيستم هاي اتباع حريق مورد استفاده قرار مي گيرند، مي تواند به گسترش حفره ايجاد شده در اين لايه حياتي از اتمسفر کمک کرده و حيات گونه هاي بسياري از جانداران، گياهان و حتي انسانها را با خطر بزرگي روبرو کند.