3 Industrial Emuents
3.1 General
Industrial effluents are as diverse as industrial products. The many different kinds
and the various effects upon life and water quality are dealt with in textbooks on
water pollution. Much experience from fresh water management can be transformed
to marine conditions.
In this book, only two aspects of industrial effluents are dealt with: mercury and
pesticides. This is because their importance for the development of marine pollution
science is predominant. The more global aspects of marine pollution with mercury and
with chlorinated hydrocarbons are, however, dealt with in Chapters 8 and 9.
3.2 Effluents Containing Mercury
Minamata is a small town of 50,000 inhabitants on the shore of Shiranui Sea, a part
of the inland sea of Japan (Fig. 22). Many of its inhabitants make their living from
fishing. The rest of the city is economically dependent on the Shin Nihon Chisso
Hiryo Company which, along with other products, had been producing vinylchloride
and acetaldehyde since 1952. In 1953, puzzling symptoms of illness began to be
observed in Minamata's human and cat population. Then in 1956, the illness assumed
epidemic proportions. It was assumed to be contagious meningitis, and the patients
were isolated. An investigation committee was established. It found that all patients
had similar symptoms. They experienced numbness in their lips and limbs. After two
weeks, disturbances in their sense of touch, in speech, and hearing became noticeable.
Their gait became irregular; they walked as if drunk, unable to stop suddenly or to
turn around. The most noticeable thing in all patients was, however, a concentric
narrowing of vision. 46 of the 116 officially registered patients died. Only a few were
cured. Most of them experienced permanent disorders.
Judging by the symptoms, Professor Shimanosuke Katsuku of the Kumamoto Uni·
versity assumed it to be a heavy metal poisoning. It was ascertained that all the
patients had eaten a lot of fish. It was also observed that cats showed signs of Mina·
mata Disease. When it was found that the symptoms could be artifically produced in
healthy cats by feeding them fish from the Bay of Minamata for 5-8 weeks, it was
clear that one was not dealing with a contagious disease, but with food contamina·
tion. Fishing was outlawed in that area of the Bay of Minamata at the beginning of
1957. That year, no additional persons became ill; in 1958, only 3 died.
37
3.1 General
Industrial effluents are as diverse as industrial products. The many different kinds
and the various effects upon life and water quality are dealt with in textbooks on
water pollution. Much experience from fresh water management can be transformed
to marine conditions.
In this book, only two aspects of industrial effluents are dealt with: mercury and
pesticides. This is because their importance for the development of marine pollution
science is predominant. The more global aspects of marine pollution with mercury and
with chlorinated hydrocarbons are, however, dealt with in Chapters 8 and 9.
3.2 Effluents Containing Mercury
Minamata is a small town of 50,000 inhabitants on the shore of Shiranui Sea, a part
of the inland sea of Japan (Fig. 22). Many of its inhabitants make their living from
fishing. The rest of the city is economically dependent on the Shin Nihon Chisso
Hiryo Company which, along with other products, had been producing vinylchloride
and acetaldehyde since 1952. In 1953, puzzling symptoms of illness began to be
observed in Minamata's human and cat population. Then in 1956, the illness assumed
epidemic proportions. It was assumed to be contagious meningitis, and the patients
were isolated. An investigation committee was established. It found that all patients
had similar symptoms. They experienced numbness in their lips and limbs. After two
weeks, disturbances in their sense of touch, in speech, and hearing became noticeable.
Their gait became irregular; they walked as if drunk, unable to stop suddenly or to
turn around. The most noticeable thing in all patients was, however, a concentric
narrowing of vision. 46 of the 116 officially registered patients died. Only a few were
cured. Most of them experienced permanent disorders.
Judging by the symptoms, Professor Shimanosuke Katsuku of the Kumamoto Uni·
versity assumed it to be a heavy metal poisoning. It was ascertained that all the
patients had eaten a lot of fish. It was also observed that cats showed signs of Mina·
mata Disease. When it was found that the symptoms could be artifically produced in
healthy cats by feeding them fish from the Bay of Minamata for 5-8 weeks, it was
clear that one was not dealing with a contagious disease, but with food contamina·
tion. Fishing was outlawed in that area of the Bay of Minamata at the beginning of
1957. That year, no additional persons became ill; in 1958, only 3 died.
37