Messenger While the news coming out of forests is often dominated by deforestation and habitat loss, research published today in Nature Climate Change shows that the world has actually got greener over the past decade. Despite ongoing deforestation in South America and Southeast Asia, we found that the decline in these regions has been offset by recovering forests outside the tropics, and new growth in the drier savannas and shrublands of Africa and Australia.
Rai and Amit Pal For the first time in his entire cultural history, man is facing one of the most horrible ecological crisis- the problem of pollution of environment especially with toxic metals, which sometime in the past was pure, virgin, undisturbed, uncontaminated and basically quite hospitable for him.
Today, the cry of "Pollution" is heard from all the nooks and corners of the globe and it has become a major threat to the very existence of mankind on the planet earth. Heavy metal pollution affects flora, fauna and other abiotic components of the ecosystem.
Metal leads to various metabolic alterations and undesirable changes, which in many cases may cause severe injury and health hazards. There are several factors like human population explosion, unplanned urbanization, deforestation, profit oriented society and technological advancement etc.
The ecological crisis of environmental pollution has been blamed on different things and one of the major things is the pollution due to metals in the environment.
Toxic metal pollution can be a much more serious and insidious problem, as these are intrinsic components of the environment.
At high concentrations, all the metals are toxic to animals and plants both. Metals are omnipresent in the environment occurring in varying concentrations in parent rock, soil, water, air and all biological matter.
Moreover, metals are also released into environment from a wide spectrum of anthropogenic sources such as smelting of metallic ores, industrial fabrication and commercial application of metals, agro-chemicals pesticides as well as burning of fossil fuels. These metals are redistributed in the biosphere and Health hazards of deforestation in the air, soil, water and consequently in human beings through food chain bio-magnification causing chronic ailments.
Metals are significant to human because some of them are most important trace elements as a co-factor in various metabolic enzymes and constituents of cells.
Human can tolerate times its total body content of Cr without harmful effects. However, increased concentration of these metals can affect mineral and enzyme status of human beings. The metals irreversibly bind to active sites of enzymes, thereby destroying normal metabolism producing high-level toxicity.
Human can be affected directly by air, water and soil metal pollutants as well as indirectly through contaminated food supplies. In recent past, a large number of silent epidemics have been reported due to metal contamination, which is escalating day by day.
In an unusual and painful disease of rheumatic nature was recorded in the case of 44 patients from a village on the banks of jintsu River, Toyama prefecture, Japan. During subsequent years it became known as 'itai-itai' disease meaning 'ouch-ouch' in accordance with the patients shrieks resulting from painful skeletal deformities.
The incubation period for chronic cadmium intoxication varies considerably usually between years but in some cases upto 30 years. During the first phase of poisoning, a yellow discolouration of teeth, "cadmium ring" is formed, the sense of smell is lost, and mouth becomes dry, subsequently the number of red blood cells is diminished which results in impairment of bone marrow.
The most characteristic feature of diseases is lumbar pains and leg myalgia. These conditions continuing for several years until the patient becomes bed ridden and clinical conditions progress rapidly.
Urinary excretion of albuminous substances result from the severe kidney damage. Cadmium induced disturbances in calcium metabolism accompanied by softening of bones; fractures and skeletal deformations take place with a marked decrease in body height up to 30 cm. The importance of arsenic as a health hazard, which is also known as 'slow killer' is now well recognised.
The most obvious signs are the blisters on the palms of the hands and soles of the feet, which can eventually turn gangrenous and cancerous.
Meanwhile, the poison also attacks internal organs, notably the lungs and kidneys, which can result in a battery of illnesses including cancers. Arsenic As poisoning has been reported from several places. A major outbreak of arsenic poisoning occurred in young children in the summer of in Japan.
The intoxication stemmed from the consumption of dry milk powder to which arsenic contaminated sodium phosphate had been added as a stabilizer.
The sodium phosphate was a waste product generated during production of aluminum from bauxite. Altogether cases were reported and of them more fatal.
The poisoning has been due to persistent changes in central nervous system including mental disturbances and changes in electroencephalograms. Epidemiological studies on children, living in the vicinity of a coal power plant in Czechoslovakia where coal that was used contained about g arsenic per tonne, showed respiratory symptoms and hearing loss.
Long term ingestion of arsenic contaminated drinking water produced gastrointestinal, skin, liver and nerve tissue injuries.
In Taiwan, wide spread occurrence of black foot disease resulted from high levels of As in ground water. The maximum arsenic value amounted to 2.
Chronic As poisoning appears to be regional but certainly not limited to Taiwan. Similar cases of As poisoning have been reported from West Bengal India and Bangladesh in recent years.
In the s, international agencies headed by the UNICEF began pumping millions of dollars of aid money into Bangladesh for tube-wells to provide "clean" drinking water.
According to the World Health Organization, the direct result has been the biggest outbreak of mass poisoning in the history. Upto half the country's tube-wells, now estimated to number 10 million, are poisoned. Tens, perhaps hundreds of thousands will die.
Indeed the WHO released a report in September estimating that between 35 and 77 million Bangladeshis may be drinking water containing more than the safety limit of 10 parts per billion of arsenic.Oct 21, · Deforestation, one of these physical demands, has been a growing problem for over the last several decades, especially in the Amazon rainforest.
In the Amazon, trees are being cleared for numerous reasons: some get turned into toilet paper, timber for houses, as a fuel supply, the list of what we use wood for goes on and on. Essays on Hazards Of Deforestation.
Hazards Of Deforestation Search. Search Results. Deforestation land ready for agriculture is predominant. It is the central reality of the deforestation crisis.
Modern Health Hazards or dangers arising from man-made circumstances threaten the wellbeing of humans’ environment.
Traffic, if not managed. The drivers of tropical deforestation have shifted in the early 21st century to hinge on growth of cities and the globalized agricultural trade, a new large-scale study concludes.
The observations starkly reverse assumptions by some scientists that fast-growing urbanization and the efficiencies of.
Deforestation increases the amount of carbon dioxide in the atmosphere leading to global warming due to green house effect. Silting of Rivers and Dams – Deforestation causes large scale deposition of sediments in the rivers. Deforestation Lead authors: Now forests are threatened by factors such as climatic hazards, diseases prompted by insects or pathogens, threats of a purely anthropogenic nature, fires, atmospheric pollution, deforestation and the increase in social pressure.
erosion of biodiversity, damage to the health of forest ecosystems, loss of. The health effects of these disruptions include increased respiratory and cardiovascular disease, injuries and premature deaths related to extreme weather events, changes in the prevalence and geographical distribution of food- and water-borne illnesses and other infectious diseases, and threats to mental health.