xx Professor Hillel I. Shuval
Another paradox of our modern technological world is the fact that our society "is
hooked" on the use of a vast array of agricultural chemicals and fertilizers to ensure the
plentiful food supply for our growing population. But some of these essential chemicals
are polluting our water resources or leading to unexpected ecological imbalances. The
situation has reached almost crisis dimensions in Israel, a country which is presently
utilizing almost all available ground water. Nitrate levels have been increasing at the rate
of two milligrams per liter per year for the past fifteen years and today some five hundred
wells already show nitrate concentrations equal to or above the standard recommendation
for drinking water by the World Health Organization. It appears from research results
which will be presented at this Conference by an Israeli scientist, that the very high use of
inorganic fertilizers rich in nitrogenous chemicals may be a major factor in this type of
ground water pollution. Can we find a solution to this problem which will both provide
protection of ground water while maintaining the right level of food production essential
to our existence?
Not all water pollution is a result of the disposal of urban and industrial wastes into
the environment. The buildup of naturally occurring inorganic salts in the aquifer as a
result of incautious water resources management could in some cases provide an
extremely serious threat of water pollution, particularly in arid zones. Heavy pumping of
ground water coupled with intensive irrigation practises could cause this problem. While
substantial amounts of water are lost by evaporation in irrigation practise, the dissolved
salts are completely returned to the aquifer resulting in a slow buildup of minerals in the
ground water. Here in Israel, this increase amounts to a few miligrams per liter per year.
The full impact will be felt only in twenty or even fifty years from now, by which time
major portions of our ground water may no longer be suitable for agricultural or domestic
use. Do our water quality management programs face up to the severe implications of
such creeping water pollution, or will we pass this problem on to the next generation
when it may be too late to reverse the process?
It would be a disservice to our profession to imply that we are recklessly riding an
uncontrolled path to total pollution of our water resources and that nothing is being done
to reverse this trend. At this Conference we shall emphasize not only the new and often
ingenious technology developed in our research institutes aimed at overcoming the
problems of pollution, but the real accomplishments achieved with the aid of these
innovations. Many of the papers to be presented here this week will report on real
progress.
An outstanding example is the paper of Gameson and his colleagues of the U.K.
They report on the dramatic improvements in the Thames River over the past
twenty years. In 1950, a reach of some thirty-five kilometers of the river was at times
devoid of oxygen and fish life was extinguished, while today after major investments in
modern wastewater treatment, the river is entirely aerobic once again and more than fifty
species of fish inhabit this rehabilitated waterway. From the other end of the world,
Fujiki of Japan will report later this week that Minamota Bay — once heavily polluted
with deadly mercury wastes has been cleaned up by the construction of plants to remove
mercury from industrial wastewater and by technological changes in other plants which
avoid the use of mercury entirely. Fish caught in the bay in 1961 showed mercury
concentrations of 23 mg/kg, more than forty times the concentration considered safe for
human consumption. By 1970, only 0.2 mg/kg of mercury was found in the fish of that
Another paradox of our modern technological world is the fact that our society "is
hooked" on the use of a vast array of agricultural chemicals and fertilizers to ensure the
plentiful food supply for our growing population. But some of these essential chemicals
are polluting our water resources or leading to unexpected ecological imbalances. The
situation has reached almost crisis dimensions in Israel, a country which is presently
utilizing almost all available ground water. Nitrate levels have been increasing at the rate
of two milligrams per liter per year for the past fifteen years and today some five hundred
wells already show nitrate concentrations equal to or above the standard recommendation
for drinking water by the World Health Organization. It appears from research results
which will be presented at this Conference by an Israeli scientist, that the very high use of
inorganic fertilizers rich in nitrogenous chemicals may be a major factor in this type of
ground water pollution. Can we find a solution to this problem which will both provide
protection of ground water while maintaining the right level of food production essential
to our existence?
Not all water pollution is a result of the disposal of urban and industrial wastes into
the environment. The buildup of naturally occurring inorganic salts in the aquifer as a
result of incautious water resources management could in some cases provide an
extremely serious threat of water pollution, particularly in arid zones. Heavy pumping of
ground water coupled with intensive irrigation practises could cause this problem. While
substantial amounts of water are lost by evaporation in irrigation practise, the dissolved
salts are completely returned to the aquifer resulting in a slow buildup of minerals in the
ground water. Here in Israel, this increase amounts to a few miligrams per liter per year.
The full impact will be felt only in twenty or even fifty years from now, by which time
major portions of our ground water may no longer be suitable for agricultural or domestic
use. Do our water quality management programs face up to the severe implications of
such creeping water pollution, or will we pass this problem on to the next generation
when it may be too late to reverse the process?
It would be a disservice to our profession to imply that we are recklessly riding an
uncontrolled path to total pollution of our water resources and that nothing is being done
to reverse this trend. At this Conference we shall emphasize not only the new and often
ingenious technology developed in our research institutes aimed at overcoming the
problems of pollution, but the real accomplishments achieved with the aid of these
innovations. Many of the papers to be presented here this week will report on real
progress.
An outstanding example is the paper of Gameson and his colleagues of the U.K.
They report on the dramatic improvements in the Thames River over the past
twenty years. In 1950, a reach of some thirty-five kilometers of the river was at times
devoid of oxygen and fish life was extinguished, while today after major investments in
modern wastewater treatment, the river is entirely aerobic once again and more than fifty
species of fish inhabit this rehabilitated waterway. From the other end of the world,
Fujiki of Japan will report later this week that Minamota Bay — once heavily polluted
with deadly mercury wastes has been cleaned up by the construction of plants to remove
mercury from industrial wastewater and by technological changes in other plants which
avoid the use of mercury entirely. Fish caught in the bay in 1961 showed mercury
concentrations of 23 mg/kg, more than forty times the concentration considered safe for
human consumption. By 1970, only 0.2 mg/kg of mercury was found in the fish of that