The vast northern area from Brazil is covered by the Amazon basin, including the largest remaining tropical forest in the world. This immense tract of jungle covers a third of Brazil's total land mass, and is nourished and drained by the massive Amazon river. The Amazon is the single largest river in the world; it holds 34% of the entire earth's fresh water and is navigable for ocean steamers for 2.300 miles from its mouth at the Atlantic Ocean to Iquitos, Peru.

The Amazonian region occupies a total area of more than 7.5 million square kilometers, being part of the territory of nine countries: Brazil, Venezuela, Colômbia, Peru, Bolívia, Equador, Suriname, Guiana and French Guiana. However, about 85% of its area is located in Brazilian territory, where it occupies more than 5 million square kilometers, or about 61% of the country's area. Its population, however, represents less than 10% of the total inhabitants of the country. The Brazilian Amazonia is seven times bigger than France and corresponds to the joint area of 32 countries of Western Europe. These values mean 7% of the planet's surface.

The Forest
 

Amazonia has 3,54 million square kilometers of continuous forest-covered areas, the largest in the world. Paradoxically, however, it is a soil with low fertility: 78% of it is acid and difficult to use for agriculture. Biodiversity is also the largest in the world: while there are 4 to 25 tree species per hectare in North America, there are between 40 and 300 different tree species in the Amazon forest. There are more than 5,000 species of trees.

The volume of rain in the Amazon river basin is truly  amazing: more than 15 trillion cubic meters per year. Of the overall rainfall, 48% evaporates, 52% flows to the rivers, and ultimately to the sea. The rainforest ecosystem changes significantly this average: in its environment, only 25% is evaporated and 25% goes to the rivers: the major part is retained in the forest itself.

The Amazon forest may be considered a kind of "ecological filter" for carbon dioxide (CO²) in the atmosphere, because the plants in the forest absorb more CO² than they release. Unfortunately, the accelerated human occupation of the Amazonia is causing a series of environmental problems, due to the amount of destruction of its original ecosystem. It has been estimated that approximately 12,5% of the original forest cover, or 500,000 km2, has been deforestated or burnt. Logging companies, miners in search of gold and other valuable metals and agricultural occupation are the main culprits. Although the destruction rates have decreased lately, it still continues at a worrying pace.

The Fauna
 

The Amazon forest is extraordinarily rich in all forms of animal life, from insects to mammals. A cubic meter of soil has 100 times more insects and worms there than in the Northern hemisphere. The gigantic volume of water and the mild temperatures make a kind of fertile incubator, too: there are more than 3,000 fish species in Amazon, representing 85% of all species living in South America, and 15% of the species in the world. However, only 40% of these species have been studied by scientists, and about 36 fish species are economically exploited.

The region has many astounding records in terms of fauna. It has more than 100 species of New World monkeys (the smallest one is no larger than a fountain pen; the largest is comparable to a chimpanzee), thousands of bird species, like the colorful macaws (araras) and toucans(tucanos) and dozens of exotic and interesting animals such as the sweet-water pink dolphin (boto) and the manatee (peixe-boi), capibaras (the largest rodent in the world), tree sloths, alligators (jacaré), the feared spotted jaguar (onça),  turtles and gigantic anacondas (sucuri), which can reach up to 30 feet (9 meter long).

The People
 

The Brazilian Amazon region is inhabited by 17 million people only, despite its continental dimensions. Therefore human density is amongst the lowest in the world: overall, 3.4 inhabitants per km². There are regions the size of Belgium or Spain, with less than 1 inhabitant per km². Approximately 62% of the population lives in urban areas: Manaus and Belém are the two largest cities, accounting for more than 90% of the urban population, together. The rural population lives in function of the two seasons: rainy and high waters, and dry and low waters. During the rainy season the main rural activity is extractivism (such as rubber, fruits and Brazil nuts), fishing and hunting. During the dry season it is subsistence agriculture.

The Amazonian region was colonized and inhabited for tens of thousands of years by Indians, which lived undisturbed in isolated small tribal villages spread about the huge forest. More than 160 ethnic groups and different languages have been mapped, but the original number of indigenous habitants have dwindled more than 90% since the discovery of the region by Spaniards and Portuguese in the 16th century. There are currently about 85,000 Indians living in Amazonia, most of them in federal reservations. Their original culture is Stone-age, with no metal artifacts or permanent habitation, written language or urban civilization. The Brazilian Indian Agency (FUNAI) estimates that there are still 30 or so tribes which have never been contacted.

Transportation is done almost exclusively via the wide array of navigable rivers, and therefore is very slow. The second most important mode of transportation is by air. The Amazonian flotilla of boats and planes is therefore one of the largest in the world. Roads are scarce and impassable most of the year: its construction is rendered an almost impossible task by virtue of an astounding number of rivers that sometimes reach a width of more than 20 km!

The Health Situation
 

The Amazon forest is a breeding ground for all kinds of insect vectors and natural reservoirs of dozens of tropical diseases. Malaria has been the most serious endemical problem: there are more than 500,000 new cases of infections per year, and more than 30,000 deaths. In some cities, such as Porto Velho, 90% of the population has caught malaria at least once.

The incidence of dengue fever, yellow fever, tuberculosis, leprosy and leishmaniosis are among the highest in the world. Exotic infections, such as ouropoche (a kind of dengue) and hemorrhagic fever diseases brought about by arborviruses, are comparable in mortality to the Ebola virus in Africa. Fighting mosquitoes and other kinds of blood-sucking insects is an impossible task, due to the size of the forest and the low density of human populations. The environmental inbalance caused by deforestation and killing of natural predators of insects, such as birds, has aggravated the problem. Deforestated areas show a much higher incidence of malaria, for instance.

The rural population is very poor and despite living in an area teeming with life, undernutrition problems are endemic: 72,2% of the population suffers from it, and 70% of the children show nanism (short stature and stumped growth), 18% have muscle atrophia and 37.5% have anemic disorders.

Access to health care prevention and medical treatment for the rural and aboriginal populations is critical. Being very poor, they depend on the public health sector. A network of specialized health care facilities for Indians is being built by National Health Foundation, in collaboration with several NGO's, some of them operated by Indians themselves.

In contrast, researchers estimate that hundreds of useful drugs may be hidden within the tropical plants and animais in the rainforests. Their total market value may exceed $147 billion. Tropical rainforests provide between 25 to 40% of all pharmaceutical products. Of these, it is estimated that more than 2,000 plants may have anticancer properties. Many of them are already extinct. Only 1% of tropical plants have been examined for possible medicinal uses. But, those that have yield ¼ of all prescription drugs sold in the United States.

Source: INPA - Instituto Nacional de Pesquisas da Amazônia