Biosphere consequences

The sad paradox is that, despite the primary importance of the latter problem convincingly substantiated in the scientific literature and the secondary role of the two former ones, UNCED documents have missed the primary importance of the following sequence of events socio-economic development (stimulated by growing population size) —> anthropogenic impact on the biosphere —> consequences of these impacts for the environment (climate, ozone, etc.). 

Prediction of the consequences of degradation release conventionally involves data and models for three steps of analysis geosphere transport, biosphere transport, and biosphere consequences. I will discuss these and add two others analysis, rather than assumption, of repository degradation, and consideration of the geosphere/biosphere interface and its effect on biosphere consequences. These refinements to safety assessment procedures, when developed and implemented, can be expected to aid validation of results. 

Prediction of biosphere consequences is coupled with modeling of biosphere transport.(5 6 The key factors in the transition from biosphere transport to biosphere consequences are the assumptions made concerning man s interaction with his environment. The interactions depend, of course, on man s activities and the presence of nuclides with which he can interact. 

Consequences of Ozone Depletion. Ozone depletion over Antarctica is causing renewed concern about the consequences of increased levels of UV reaching the earth s biosphere. One area of concern involves the free-floating microscopic plants, known collectively as phytoplankton (the grass of the sea), which through the process of photosynthesis, fix carbon dioxide into living organic matter. Phytoplankton forms the basis of the marine food chain on which zooplankton (animal plankton) and all other components of the ecosystem depend for their sustenance. 

The consequences of the massive "loss" of energy accompanying passage from one trophic level to another also include the fact that organisms low in the trophic ladder tend to dominate the cycling of elements through the biosphere. This is especially true on land where vascular plants dominate both the physical structure and... 

Dioxins are of concern because they accumulate in the biosphere, where they have highly deleterious effects. Tests have shown that when the concentration of dioxins in the blood of laboratory animals reaches a critical level, reproductive and immune system defects result. Moreover, recent data indicate that the concentration of dioxins in the blood of the average U.S. resident has nearly reached that level. A major reason is that dioxins are not veiy water-soluble, so they accumulate in the body rather than being readily processed and excreted. Consequently, several groups, including the American Public Health Association, have issued calls for phasing out the use of industrial chlorine. 

The major part of the biosphere is aerobic and consequently priority has been given to the study and assessment of biodegradability under aerobic conditions. Nevertheless, there are environmental compartments that can be permanently (e.g. anaerobic digesters) or temporarily anaerobic (e.g. river sediments and soils) and surfactants do reach these. The majority of surfactants entering the environment is exposed to and degraded under aerobic conditions. This is the predominant mechanism of removal even in cases of absence of wastewater treatment practices (direct discharge) and it is estimated that less than 20% of the total surfactant mass will potentially reach anaerobic environmental compartments [1]. Only in a few cases, however, will the presence of surfactants in these compartments be permanent. The presence of surfactants in anaerobic zones is not exclusively due to the lack of anaerobic degradation. Physico-chemical factors such as adsorption or precipitation play an important role as well as the poor bioavailability of surfactant derivatives (chemical speciation) in these situations. 

Fluorine is ubiquitous in the nature and is consequently an inevitable part of the biosphere and human life. The adequate intake (Al) of fluoride ion from all sources is set at... 

This includes the poorly understood world of soil microorganisms. The consequences of environmental pollution, of depletion of atmospheric ozone or other alterations that affect the radiant energy reaching us, and of the availability to humans of excessive amounts of energy must all be considered. Just as a steady state within cells is often essential to the life of organisms, maintenance of a steady state in the chemical cycles of the biosphere may also be a necessity. 

The biosphere has a complex chemistry and many aspects of the processes and their consequences are not fully understood. However, pollution arises from the cyclic processes being out of balance, or from the accumulation of other undesirable materials. Indeed, a major perception of pollution is the disruption of these cycles. The activities of man are now on such a scale that they significantly affect the environment and its chemistry. 

Humans have always used the environment as a source of resources. However, for a lengthy period of time their activity did not markedly affect the biosphere. Only in the late 19th century did changes in the biosphere induced by human activity drop on human civilization like a ton of bricks. Trying to improve living standards and profit margins, humans continue to step up the rate of material production without little regard for the consequences (Tables 2.2-2.6). With such an approach, most of the resources taken from nature return to nature as waste, often poisonous or unfit for utilization. This threatens the existence of both the biosphere and humankind (Moiseev, 1990 Schwarzenbach, 2002). 

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