Sigmund F. Zakrzewski (ed.)
- Published in print:
- 2002
- Published Online:
- November 2020
- ISBN:
- 9780195148114
- eISBN:
- 9780197565629
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780195148114.003.0016
- Subject:
- Chemistry, Environmental Chemistry
Water covers 70% of the earth’s surface. Only 3% of this is freshwater, which is indispensable in sustaining plant and animal life. The amount of freshwater is ...
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Water covers 70% of the earth’s surface. Only 3% of this is freshwater, which is indispensable in sustaining plant and animal life. The amount of freshwater is maintained constant by the hydrological cycle. This cycle involves evaporation from oceans and inland waters, transpiration from plants, precipitation, infiltration into the soil, and runoff of surface water into lakes and rivers. The infiltrated water is used for plant growth and recharges groundwater reserves. Although the global supply of available freshwater is sufficient to maintain life, the worldwide distribution of freshwater is not even. In some areas the supply is limited because of climatic conditions or cannot meet the demands of high population density. In other places, although there is no shortage of freshwater, the water supply is contaminated with industrial chemicals and is thus unfit for human use. Moreover, fish and other aquatic species living in chemically contaminated water become unfit for human consumption. Thus, water pollution deprives us and other species of two essential ingredients for survival: water and food. An example of hydrologic changes caused by urbanization is given in Figure 11.1. Conditions before and after urbanization were measured in Ontario, Canada, by the Organization for Economic Cooperation and Development (1). In the urban setting, pervious areas are replaced with impervious ones (such as streets, parking lots, and shopping centers). Groundwater replenishment is greatly reduced and runoff is considerably increased by these changes. Thus, urbanization not only contributes to water pollution; it also increases the possibility of floods. Nitrogen is an important element for sustenance of life. However, in order to be incorporated into living matter it has to be converted into an assimilative form—an oxide or ammonia. Until the beginning of the twentieth century most of the atmospheric nitrogen was converted into assimilative form by soil microorganisms and by lightning. Nitrogen compounds which were not utilized by living matter did not accumulate because the denitrifying bacteria decomposed them to elemental nitrogen which was then released back into the atmosphere. In this way the nitrogen cycle was completed.
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Water covers 70% of the earth’s surface. Only 3% of this is freshwater, which is indispensable in sustaining plant and animal life. The amount of freshwater is maintained constant by the hydrological cycle. This cycle involves evaporation from oceans and inland waters, transpiration from plants, precipitation, infiltration into the soil, and runoff of surface water into lakes and rivers. The infiltrated water is used for plant growth and recharges groundwater reserves. Although the global supply of available freshwater is sufficient to maintain life, the worldwide distribution of freshwater is not even. In some areas the supply is limited because of climatic conditions or cannot meet the demands of high population density. In other places, although there is no shortage of freshwater, the water supply is contaminated with industrial chemicals and is thus unfit for human use. Moreover, fish and other aquatic species living in chemically contaminated water become unfit for human consumption. Thus, water pollution deprives us and other species of two essential ingredients for survival: water and food. An example of hydrologic changes caused by urbanization is given in Figure 11.1. Conditions before and after urbanization were measured in Ontario, Canada, by the Organization for Economic Cooperation and Development (1). In the urban setting, pervious areas are replaced with impervious ones (such as streets, parking lots, and shopping centers). Groundwater replenishment is greatly reduced and runoff is considerably increased by these changes. Thus, urbanization not only contributes to water pollution; it also increases the possibility of floods. Nitrogen is an important element for sustenance of life. However, in order to be incorporated into living matter it has to be converted into an assimilative form—an oxide or ammonia. Until the beginning of the twentieth century most of the atmospheric nitrogen was converted into assimilative form by soil microorganisms and by lightning. Nitrogen compounds which were not utilized by living matter did not accumulate because the denitrifying bacteria decomposed them to elemental nitrogen which was then released back into the atmosphere. In this way the nitrogen cycle was completed.
Philippe Grandjean
- Published in print:
- 2013
- Published Online:
- September 2013
- ISBN:
- 9780199985388
- eISBN:
- 9780199346233
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199985388.003.0004
- Subject:
- Philosophy, Moral Philosophy
The first human disaster due to environmental pollution happened in Minamata, Japan, in the 1950s. Hundreds of children were born mentally retarded because of exposures through contaminated local ...
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The first human disaster due to environmental pollution happened in Minamata, Japan, in the 1950s. Hundreds of children were born mentally retarded because of exposures through contaminated local fish later found to originate from industrial mercury pollution. However, there was strong resistance to the conclusion that a food staple would be hazardous to anyone’s health. A key observation was that the mothers were not harmed by the pollution, only the child that shared the mother’s mercury exposure. More refined research documented effects at lower and lower exposure levels. And when the benefit from seafood nutrients were taken into account, the mercury toxicity was even stronger. Because the pollution occurred in fish and seafood, public health action was delayed for several decades. So, the assumption that otherwise healthy food cannot become unhealthy was wrong.Less
The first human disaster due to environmental pollution happened in Minamata, Japan, in the 1950s. Hundreds of children were born mentally retarded because of exposures through contaminated local fish later found to originate from industrial mercury pollution. However, there was strong resistance to the conclusion that a food staple would be hazardous to anyone’s health. A key observation was that the mothers were not harmed by the pollution, only the child that shared the mother’s mercury exposure. More refined research documented effects at lower and lower exposure levels. And when the benefit from seafood nutrients were taken into account, the mercury toxicity was even stronger. Because the pollution occurred in fish and seafood, public health action was delayed for several decades. So, the assumption that otherwise healthy food cannot become unhealthy was wrong.
Marina Sorrentino
- Published in print:
- 2017
- Published Online:
- March 2017
- ISBN:
- 9780199944590
- eISBN:
- 9780190218850
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199944590.003.0002
- Subject:
- Economics and Finance, Economic History
The chapter focuses on how Italy’s economic growth enabled the spread of improvements in the diet of the Italian population. According to mid-nineteenth-century observers, nourishment was likely to ...
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The chapter focuses on how Italy’s economic growth enabled the spread of improvements in the diet of the Italian population. According to mid-nineteenth-century observers, nourishment was likely to be a daily torment for the major part of the population. In contrast, we estimate that in the aftermath of Italy’s unification (1861) the daily calories available to the average Italian exceeded 2,500, a value that is higher than that commonly used today to mark the threshold of undernutrition in developing countries. A high per-capita calorie availability is consistent with the presence of a sizable part of the population trying to make ends meet. In 1861 one person in two (perhaps even two in three) did not consume enough calories to lead a healthy life. In the case of Italy, macroeconomic data hide more than they reveal.Less
The chapter focuses on how Italy’s economic growth enabled the spread of improvements in the diet of the Italian population. According to mid-nineteenth-century observers, nourishment was likely to be a daily torment for the major part of the population. In contrast, we estimate that in the aftermath of Italy’s unification (1861) the daily calories available to the average Italian exceeded 2,500, a value that is higher than that commonly used today to mark the threshold of undernutrition in developing countries. A high per-capita calorie availability is consistent with the presence of a sizable part of the population trying to make ends meet. In 1861 one person in two (perhaps even two in three) did not consume enough calories to lead a healthy life. In the case of Italy, macroeconomic data hide more than they reveal.