V. CAUSES OF ILL-HEALTH

 

With the establishment of the correctness of the germ theory of
disease and development of scientific knowledge has come an ever in-~
creasing accumulation of information about the exact causes of ill health,

For purposes of study these causes of ill health may be classified
as to:

{a} Exciting Agents

 

1. Living or animate, as: micro-organisms.

2. Mechenicél, as: automobile accidents, etc.

3. Chemical, as: lead poisoning, etc.

4. Physical, as: heat, cold, or electricity, etc.

or as to:

 

(b} Mode of Transmission

1. Communicable, as: diphtheria, etc.
2. Non-communicable, as: heart disease.

LIVING CAUSES OF ILL HEALTH

 

Our remarkable progress in the control of disease has come as a result
of the proof that certain of our deadliest diseases are caused by living
micro-organisms. For these contributions to the welfare of mankind we have
to thank that remarkable group of scientific workers who founded the science
of bacteriology.

The list of these benefactors is too long for us’ to any more than men-
tion 2° few of the more prominent ones. Pasteur, Koch, Neisser, Laverean,
Eberth, Klebs, Loeffler, Shandim, Hoffman and Noguchi. We are prone to
remember and honor the men of history who were great generals or admirals
and were famous for destroying human life while we are apt to ignore or
forget the men whose fame rests upon preserving human life. Review the
lives of a few of this latter group.

Micro-organisms and Disease

 

Year after year we have seen a gradually lengthening list of micro-
organisms that have been convicted of causing disease in man. These or-
ganisms may be classified in two great groups: (a) Bacteria; (b) Protozoa.

Bacteria-—-The group of bacteria includes a long list of members which
may be considered from the standpoint of their action when taken into the
human body, as:

(a) Pathogenic or disease producing.
(b) Non-pathogenic or non-disease producing.

Non-Pathogens. The importance of non-pathogenic bacteria to humans
and plants is seldom fully realized. The carbon cycle end nitrogen cycle
are necessary for life. They are dependent upon the action of non-patho-
genic bacteria. Commercially these bacteria are essential for the pro-
duction of butter, cheese, tanning hides, curing tobacco, etc.
ait «

Pathogens, The proof that specific bacteria were the cause of :
specific diseases marked the first great step in the rational, scientific
control. of commmicable diseases. The more important members of this
_ group will be cmsidered in connection with the diseases which they cause,

Proof of Disease Production

In’ order to be certain that a given orgenism is the cause of a given
disease, a very exact, scientific method was devised wiich is know as
Koch's Postulates, after their originator:

(a) Same bacteria always found with some disease.
(b) Same bacteria isolated from diseased animal and grown in pure

culture outside the body,
(c) Pure culture must reproduce disease in animal.
(ad) Same organisms recovered from enime1l am grown in pure culture,

Growth and Reproduction of Micro-organisms

The gravth and reproduction of bacteria are dependent upon favorable
conditions adapted to their peculiar needs:

(a) Temperature
(b) Moisture
(c) Rgod supply

bestruction of Micro-Organisms

Sterilization or disinfection is the name applied to the procedure
of destruction of micro-organisms.

Methods: 1, Heat--dry or moist. 2. Sunlight. 35. Chemicals.

Spread of Micro-organisms

A knowledge of the ways by which micro-organisms spread from person
to person is vital to any intelligent defensive hygiene plan against
commmicable diseases. Chapin classifies then as follows:

(a) By cmtact

(b) By fomites (inanimate obj ects)
(c) By air

(a) By food am drink

(e) By insects

Sources of Infection
The chief source of infections is to be found in man and lower animals.
Modes of Infection

The micra-organisms which cause disease enter the body through one
of the following chamels:

(a) Respiratory tract
(b) Digestive tract

(c) Genito-urinary tract
(a) Skin and conjunctiva
8
Exits of Bacteria from Body

From the standpoint of defensive hygiene or prevention it is im
portant to know the mode of exit of the disease producing bacteria from

the body of the infected individual.

{a} Nose and throat

(b) Bowels or bladder

{c) Mucous membranes {fenital)
(a) Blood (indirect by insects)

Fate of Bacteria in the Body

Every human being is constantly taking micro-organisms into his body.
The fate of these orgenisms within the body has a vital relationship to
defensive hygiene. They may:

(a) Live; multiply and produce disease
(bv) Live, multiply without producing disease-—"carriers"
(c) Killed by defensive mechanisms of body.

Determiners of Infection

Whether an individual who takes micro-orgenisms into his body will
develop disease or not depends upon a number of factors:

{a) Type of organism
(bv) Virilence or strength of organism

(c) Number of organisms
(a) Degree of resistance or immmity possessed by the individual.

Course of Infection

A brief outline of a typical infection will serve as a basis for a
better understanding of what is happening in disease caused by micro~-

orgenisms .

(a) Cause--e specific bacteria or protozoa taken into the bodys _
(bo) Incubation period--a battle of resisting forces with infecting

organism. |
(c) Symptoms:
1. Premonitary
2. Onset
5. Fully developed
(d) Results:
1. Recovery
2. Degeneration of organs
3e Death

Mechanism of Infection

We must remember that they,
conditions are favorable
{a} res-

How do micro-orgehisms cause disease?
being living organisms, cannot survive unless
for then: They must carry out their fundamental cycles of life:
piration, {b) nutrition, {c) excretion, (d) reproduction.
« ib =

During the process of nourishing themselves, micro-organisms injure
ian. The manner in which this is brought about is:

(a) By production of soluble toxins or poisons (diphtheria).
(b) By production of insoluble toxins due to splitting up of proteins

of body.

(c}) By mechanical action.

Infections may be: (2) Local-—boils; (») Gceneral--typhoid fever,

Infections may spread by (a) etnies Co) blood stream, (c) lymph

strean.

References: Storey--Defensive Hysiene, Book II, Chapters 17 and Lee

Rice, T. Be—Conguest of Disease, Chapter 2.
Bossard——Problems of Social Well-Being, Chapters 8, 9, 15.
Chapin, C. Ve—-Sources and Modes of Infection, Chapters 4-8,
Dekrui Microbe Hunters.
Radot--Life of Pesteur,.

dhe a

DISCUSSION QUESTIONS:

 

1.

Re

Se

4.

Be ee cab

Which one of the groups of exciting causes of ill health do you
consider most important today?

Is there any change going on at the present time in the relative
importance of these groups? What? Why?

What would happen if we destroyed all of the bacteria?

How do bacteriologists proceed when they wish to decide whether a
disease is canmunicable or not?

In what way are disease producing bacteria most frequently spread
from one person to enother?

What information is it necessary to have about a given bacteria in
order to provide defensive measures against it?

What conditions determine whether an individual who takes patho-
genic organisms into his »ody will become ill?

Compare the process of fermentation with microbic disease?

low do bacteria harm the human body?

 

Certain persons who are exposed to communicable diseases do not
come dom with them; other persons recover from them. This raises two
cuestions which are of great practical importance to every individual-—
resistance ard immunity.
a St oe
Resistance. We need to account for:

{a} The already existing resistance to infection.
(b} The resistance which develops during the infection.
(c) The resistance which persists after infection.

These questios can best be answered by a study of the phenomena which
are grouped under the title of immunity.

Immunity is the power which certain living organisms possess of
resisting infection. It is a specific pover.

Virulence or pathogenicity is the ability of a micro-organism to over-
come the” protective méchanisms of the host. The action of these organisms
and reaction of the host results in whet we call disease.

Susceptibility is due to the absence or suppression of the factors
which underlie immunity.

Types of Immunity:

{a) Naturel--mey be inherited by an individual or a whole species.
(pb) Aequired--through artificial means; may be either (a) active, or
(b) passive.
1. Actives
(1) Attack of disease
{2) Introduction of virus or live organisms

(3) Introduction of vaccine or dead organisms
(4) Introductiaom of toxins

2. Passive:
{1) Introduction of anti-bodies from another organism.

Theories of Immnity:

The science of immunology is only 30 years old. The explanation of
it has been a subject of discussion for centuries, ven primitive peoples
have tried to immunize themselves. There have been many theories.

(a) Exhaustion {Pasteur}
(b) Retention
(c) Ehrlichs-~Side-chain

Duration of Immunity

(a) Transient--in a great many infections: diphtheria (from attack of
disease}; tonsillitis; comnon colds; influenza.

{b) Permanent--appears to be for life of the individual: smallpox;
measles: typhoid fever; mumps; poliomyelitis; chicken-pox; etc.

Tests for Immunity

Scientists have developed a number of tests which will determine
whether an individual is susceptible to a specific disease.
(a)

- 12 -

Shick test--for diphtheria

(b) Dick test-—-for scarlet fever

(c)

Skin test—for smail-pox

Artificial Immunization

Some of our most valuable defensive hygiene measures are based upon
methods of producing immunity artificially.

(a)
(»)

Virus--material contcining live organisms
Vaccine or bacterin--contains dead organisms.

Some of the diseases for which we have immnizing methods:

(a)
(b)
(c)
(a)
(e)
(f)
(g)
(h)
(i)
(3)

Diphtheric-—toxin-antitoxin and antitoxin
Tetanus—~-antitoxin

Ravies—-attenvated virus

Epidenic Meningitis--immne serum
Typhoid fever-—bacterin

Scarlet fever-—-—toxin-antitoxin

Small pox-—-attenuated virus

Plague— bacterin

Cholera-——bacterin

Measles——convalescent serum

VII. DEFENSIVE HYGIENE OF COMMUNICABLE DISEASES

In the study of the methods of controlling cammuniceble diseases, the
American Public Health Association has decided that in order to effectively

(a)
(b)
(c)
(a)
(e)
(f)

control a disease we should have the following informtion about it:

Infectious agent

Source of infection

Mode of transmission
Incubation period

Period of cammnicability
Methods of control

1. The infected individual ond his environment.
{1) Recognition of disease
(2) Isolation
(3) Immonization
{4} Disinfection

2. Genéral Measures

Diseases by Sources of Infection

One of the most valuable classificatims of communicable disease is
the one mde with reference to the source of the infecting organisms.

{a)

Diseases Spread by Intestinal Discharges

1. Typhoid fever
2. Cholera

3. Dysentery

4, Food-poisoning
5, Hookeworm
in 73 ie
(b) Saliva Borne Diseases

1. Scarlet fever

*~ Diphtheria

vs Measles

4, Whooping Cough

5« Common Cold and Influenza
6.6 Pneumonia

7. Cerebro-spinal meningitis
84 Infantile Paralysis

9. Tuberculosis
10.6 Leprosy
11. Small-pox
123 Mumps:

(c) Insect Bore Diseases

 

1. Malaria
ke Yellow Fever
Se Plague
4. Typhus Fever

(a) Diseases Transmitted’ to or through Skin or Mucous Membranes

1. Hydrophobia or Rabies
2. Tetanus or Lock-jaw
oe Anthrax

A. Syphilis

5. Gonorrhea

References: Storey--Defensive Hygiene, Chapter 17.
MeLaughlin-~Comnunicable Diseases.
Rice--The Conquest of Disease.
Chapin--Sources and Modes of Infection.
Appleton--Bacterial Infection.
Rosenau-—Preventive Medicin e-Immunity.
Bossard-—Problems of Social Well-Being, Chapters 7-15.
U. S. Public Health Reports--The Control of Communicable

Disease, (Reprint 436--Document Room).

DISCUSSION QUESTIONS:

 

1. Define immunity; susceptibility; resistance.

2; How may an individual acquire immunity to disease?
Se Is immunity a general or specific power?

4. Discuss the historical theories of immunity.

5, Of wmt practical importance is the knowledge of the duration of
- immunity?

6. Howare the tests for immmity applied to the control of disease?

7, Outline the basic facts needed about - given disease for its
effective control.

8. Name some of the principal diseases--according to source of infection.
- 14 =.

VIII. PROTOZOA AS CAUSES OF DISEASE

IX.

- Protozoa are classified as animal organisms. There is some uncer-
tainty as to whether some organisms included in this group should not be
considered as vegetable in nature,. The more important point for our pur-
poses is whether they produce disease ani what defensive hygiene methods
are necessary to combat their activities.

Protozoa are simple one-celled organisms. About 7,000 species have
been described. Each of them has a characteristic "life cycle.’ Diseases
caused by a few of the protozoa will be discussed.

Malaria--still an important public health problem.

{a) Cause--Three distinct parasites (plasmodium) .

(b} Source of Infection--Blood of infected individuals.

{c) Mode of Transmission——Anopheles mosquito--parasite undergoes life
cycle in body of mosquito and infection is transmitted to another
individual by vite of mosquito.

Carriers=—Common in infected regions.

Prevention--Screening active cases--quinin prophylaxis and
suppression of mosquitoes.

O Qs

‘Dysentery-~(Amebic)--Most frecuent in Tropics but many cases demon~
strated in United States.

(a) Cause--Endamoeba histolytica.

(b) Mode of Transmission--Intestinal discharges of infected individ-
ual. Transferred by drinking water, contact with fresh dis-
charges, flies, etc.

Trypanosomiasis or Sleeping Sickness--(Africon)--Next to Malaria, the
Trypanosoms are man's most deadly enemies among the protozoa.

(a) Cause--Trypanosoma (two species).
(b) Mode of Transmission--Tsetse fly--Life cycle of parasite in the
body of the fly.

Syphilis--one of the mjor plagues of the world,

(a) Cause~-Spirochaeta pallida or treponema pallidum. A very small
organism, but larger’ than the average bacteria. Discovered by
Schandin and Hoffman, 1905,

(b} Prevalence-~Estimated 8% of poptlatio (Rosenau).

{c) Organisms-~Blood, tissue juices, secretions, and sores of infected
persons,

(d} Modes of Transmission--(a) Directly, most commonly by sexual in-

tercourse, less frequently by kissing, (b) Indirectly, common
drinking cups, instruments, pipes, etc. (c) Congenitally, organ-
isms pass from mother to child.

(e) Prevention and Cure and Social Control.

METOZOA AS CAUSES OF ILL-HEALTH

Metozoa are the so-called’ higher animal parasites that often cause
disease by means of their eggs, enbryoes, and larvae. The more important
members of this group are: (a) Flukes, (b) Tapeworms, (c) Round worms, and
{d) Hook worms.
- 15 =

 

Method of Injury. These organisms injure the individual by:

(a) Taking nourishment from his body
(b) Extraction of blood

(c) Mechanical pressure or obstruction
(d) Toxins

(e) Injury to mucous or skin surfaces

Trichinosis

(2) Cause—-Trichinella spiralis--lives in upper part of intestines.
Female bores into the walls of intestines and deposits ova. They
wander through blood anid lymph stream to striated muscles where
they locate ani become “encysted."

(b) Carriers—-Hogs, wild boars, rats, dogs, and cats. To humans by
undercooked and infected pork.

Tape Worms

(a) Cause--Taenia solium (pork), taenia sagmata (beef), fish.

(b) Transmission--By means of larvae of parasites--taken into body by
eating undercooked infected mat.

(c) Prevention--Thoroughly cooked meats--meat inspection.

Hook Worms. An important public health problem.

(a) Cause--One of many species-—Necator Americanus (New World) from
less virula@t old world form.

(b) Source of Infection--Feces of infected persons—~Infected food and
water. Polluted soil.

(c) Mode of Transmissio--Larwal forms pierce skin--trensported through
circulatory system. :

(d) Prevention--(a) Education, (b) Prevention of soil pollution, (c)
Personal hygiene including shoes.

 

X. CARRIERS OF DISEASE

The recognition and control of the so-called healthy carrier of disease
is one of our most difficult public health problems.

Carrier may be defined as an individual who is not suffering from given

DISEASE, BUT WHO HARBORS Ti = DISEASE PRODUCING ORGANISMS IN HIS BODY AND IS
CAPABLE DIRECTLY OR INDIRECTLY OF INFECTING OTHERS.

Classification

(2) Active--one who has had attack of disease md continues to harbor
organisms.
(bo) Passive--one who has never had disease bit harbors organismSe

Diseases--We have been gradually adding to the number of diseases in
which healthy carriers have been demonstrated:

(a) Cholera

(b) Diphtheria

(c} Plague

(ad) Typhoid |

(e) Epidemic meningitis
xi.

ae

(f) Bacillary dysentery
(gz) Poliomyelitis (7?)
(h) Pneumonia

Management of Carriers

(a) Administration by health authorities
(b) Medical ani Surgical Treatment

References: Storey--Defensive Hygiene, Chapters 18, 19, 20.
Rosenau-—Preventive Medicine, See articles on Malaria,
Yellow Fever, Dysentery, Sleeping Sickness, Syphilis,
Trichinosis, Tapeworms and Hook Worms. Also on
Carriers. :
Bossard-—Problens of Social Well-Being, Chapters 10-15.
McLaughlin--Communicable Diseases. .

DISCUSSION QUESTIONS:

 

1. How do protozoa and metozoa differ from bacteria?

2. Are they relatively more or less important to man as causes of
ill-health?

3. Whet are the essential points in the life cycles of.the malarial
parasite?

4, Why is amebic dysentery of special importance to inhabitants of
the Pacific Coast?

5. Discuss our mowledge of the presence of syphilis.

6. Which is the most common method of transmission of syphilis?

7. Should an infection with syphilis be a permanent bar to marriage?
8, Name the most important disease producing metozoa.

9. Discuss the defensive hygiene of metozoa.

10. Discuss the management of healthy disease carriers.

‘WEGHANICAL CAUSES OF ILL HEALTH AND DEATH

The importence of a defensive hygiene program against mechanical
causes of ill health and death is evident when it is noted that approxi-
mately 6% to 8% of the deaths recorded in the Registration Area annually
are caused by accidents of various kinds.

While we have no universal compulsory registration of accidents, the
increasing number of states that require industrial and automobile acci-
dents to be reported is furnishing 1 rapidly increasing basis for more
accurate statistical study.

A considerable number of organizations and government agencies are
engaged in accumulating evidence of the muses of the various mechanical

injuries. Among these my be metioned:
oe 17 =

(a) Bureau of Census-—-U. S. Department of Commerce
(b) State Industrial Accident Boards

(c) State Traffic Departments

(d) Automobile Associations

(e) Insurance Companies

(f} Safety Organizations

Statistical Evidence

 

Mortality--In this field as in the field of disease our most complete
returns are taken from the mortality records. For details as to number and
exact causes of death see references at end of section.

Morbidity—While the deaths from accidents are sufficiently dramatic
the results in now-fatal cases are of equal, if not greater social impor-
tance.

At present we have only partial statistics due to incomplete report-
ing. Sufficiently accurate estimates will be found in the references
(Bossard) to indicate the degree of defensive hygiene problem.

Analysis of the Problem

 

For purposes of discussion, mechanical causes of ill health may be
classified as to their place of occurrence:

{a) Industrial
(b) General--including automobile

Causes

Careful studies are being made to determine the causes responsible
for accidents as a basis for preventive measures. These studies have re-
vealed a great frequency of certain influences:

(a) Carelessness of individuals or groups

(b) Defects of individual (mental or physical)
(c) Fatigue

(d) Faulty machines

Character in Relation to Prevention--Accidents may be classified
from the standpoint of responsibility, in order to plan an effective de-
fensive hygiene program against them.

(a) Personal-—-those in which the action or ability of the individ-
ual is largely responsible:

ie Burne

2. Accidental drowning
3. Accidental shooting
4, Accidental falls

(b) Group--where ma jor responsibility is caused by carelessness or
neglect of the group:

1. Machinery accidents due to lack of safety devices
2 Mine accidénts

Se Railred accidents

4. Street car accidents
- 18 -

(c} Combination--or the accidents where there is a dual responsibil-
ity of the individual and group:

1. Automobile
2-e Machinery
oe obreetcar
4, Railroad

Automobile Accidents--The repid increase of motor propelled vehicles
has led to an enormous number of fatal and non-fatal accidents with all
of their personal and social consequences.

 

The importance of this problen justifies a little closer study of
the causes and methods of prevention of this class of causes of ill health.

Study this problem as a typical example of the facts necessary and
method to be employed in mechanical causes of ill health.

See references at end of section and be prepared to discuss analy-
sis of automobile accidents by cause.

Defense against Accidents--A successful plan of defensive hygiene
must include both education and regulation.

 

Education of Individual

 

(a) Children--Moderm cmditions make it necessary that the education
of the child to protect itself should be begun early. It should
be made an important part of the health program of the schools.

(b) Adults--Safety campaigns in both industry and the general com
munity should be promoted with sufficient freouency and inten-
sity to thoroughly inform every adult of the accident hazards.

 

Regulation--Notwithstanding the soundmess of the educational efforts,
a well-planmed, adequately-enforced set of regulations are necessary.

(c) Automobile Regulations——Adoption and enforcement of standard
eutomobile code--regulation of pedestrian traffic.

 

(bo) Industrial. Regulations--All but five states in the United States
have compensation laws--enforcement of safeguarding.

 

(c) Public Utilities--The regulation of public utilities such as
railroads and steamships is en important part of control of
accidents.

 

References: Storey--Defensive Hygiene, Chapter 14,
Rosenau-—Preventive Medicine.
Bossard-—Problems of Social Well-Being, Chapters 19-20.
(See further references at end of these chapters)

DISCUSSION QUESTIONS:

 

1. What is the estimted annual cost of accidents in the U. S.?

2. Discuss the social problems involved in accidents.
o 19 «

3e Do you agree with the statement that carelessness is the most
important element in accidents? Why?

4, What has been the effect of the safety campaigns in industry?
In communities (with reference to automobile accidents)?

5. What do you understand by the term “human engineering” in indus-
try?

6. Outline a program of "accident hygiene” for the purpose of con=-
trolling the personal element in an industrial plant having
dangerous machine processes.

XII. CHEMICAL AGENTS AS CAUSES OF ILL HEALTH

Chemical agents have been recognized as important causes of ill
health as a result of the frequency of poisoning in industry. The attempt
to understand ani solve this problem has been me of the influences which
has brought about the development of Industrial Hygiene. Proper cmsider-
ation of this branch of preventive medicine is given in the course on Group
Hygiene. Consideration will be given here to the more important chemical
causes of ill health.

Statistics

Chemical agents as causes of death are relatively infrequent (1577
Registration Area 1924). As a cause of acute or chronic ill health,
they are of considerable importance on account of the rapid development
of new chemical processes in industry.

Classification

These chemical agents may be conveniently classified as to the na-
ture of the substance:

(a) Inorganic
(b) Organic

Inorganic Chemicals

 

The list of inorganic substances ccpable of causing injury to human
beings is a long one. Only a few of the more important ones will be given
consideration.

Lead is one of the most frequent, serious, and insidious of occu-
pational poisons.

Lead is a typical cumulative poison. Frequently a comparatively
large single dose may be taken without noticeable effect; but small
quantities inhaled or ingested, are stored in the body, resulting in chron-
ic poisoning ani sometimes death. Practically all forms of lead are poi-
SONOUS »

sources

There is a long list of possible smyrces both in and out of industry.
Some of the principal ones are:
(a) Pottery and earthenware processes

(bo) Lead mining, smelting, and refining

{c) Gasoline--(Ethyl gas)

(ad) Printing trades

(e) Miscelleneous: drinking water; beer made in lead lined vats;
paint; face powder and cosmetics.

Absorption

Respiratory tract most frequent and serious. Dust or fumes is the
carrier of the substance. Enters blood directly in lungs.

 

Intestinal tract--through liver into the circulation.

 

Skin--not as frequent--though it occurs from paints, cosmetics and
hair dye.

Storage in Body

 

Lead is stored in the bones. Safely stored without ill effects as
long as calcium balance of body is positive amd a normal hydrogen concen=
tration of the blood.

Excretion=—through feces ard urine.

Symptoms
Acute form--Intense colic, diarrhoea, rapidly developing anemia,
convulsions, and mental symptoms.

Chronic form-Anemia, constipation, colic, paralysis (wrist drop),
"blue line" on gums, muscular vain, and swelling of joints.

Maternal and Congenital--Lead is a race poison, causing:

{a) Sterility
(b) Prematurity and still births
{(c) Dwarfing

Prevention rests here, as in control of cammunicable diseases, upon
a knowledge of the sources and modes of infection: {a) dust, (b) fumes,
(c) by hands to gastro-intestinal tract.

(a) Prevention of dust and removal of fumes
(bo) Cleanliness of body clothing and surroundings
{c) Milk drinking

Arsenic is a source of a considerable amount of occupational poison-
ing.
The principal sources of arsenic poisoning are:

{a) Lead smelting

(b) Paris green manufacture

{c) Sheep dip

(d) Hides, feather, and fur processing
(e) Criminal use
«=

Wode of Entrance

 

Inhalation of fumes or dust or swallowing with food or drink.
Symptoms

(a) Acute--conjunctivitis, eczema, ulcers.
{b) Chronic--Anemia, neuritis, degeneration of liver and kidneys.

Mercury

Sources

(a) Mercury mining and smelting

(>) Manufacture of barometers and thermometers
{c

} Hat making (felt)

Mode of Entrance

 

(a) Inhalation of vapor
(b) Skin
(c) Rarely by swallowing
Symptoms

{a} Anemia

{b) Headache ard dizziness

{c) Tremor

(a) “Ptyalism” (fetid breath, soft, swollen, ulcerated gums, with
loosening teeth)

(e) Enlarged glands.

Prevention--Same as for lead.

Phosphorus
Sources--Chiefly match making with white phosphorus.

Mode of Entrance--Swallowing

 

Symptoms

(a) Necrosis of bones of jaw
(b}) Foul odor of breath

Prevention

(a) Prohibition of use of white phosphorus
(b) Mouth hygiene

Carbon Monoxide--is the most important of all gas poisonings.

 

Sources

 

(a) Illuminating gas
{b) Exhaust from autos
{c} Blast furnaces

(ad) Mine gas
« 22 «
Mode of Entrance--Inhalation

_ Action--Reniers red corpuscles of blood incapable of uniting with
oxygene
Symptons
(a) Acute and sudden dizziness
(b} Blurring vision

(c) Nausea
(d) Stupor and loss of consciousness

Organic Chemicals

 

Only a few of the more important organic chanicals that injure
health can be considered. The ones selected are: alcohol; opium; co-
caine; ami tobacco.

Alcohol my be considered as a food, a medicine, or a habit forming

drug.
Varieties:

(2) Methyl (wood alcohol)--very dangerous, used commercially and to
adukterate cheap whiskies.
(b) Ethyl--main component in alcoholic beverages.

Properties--In large amounts a poison. Dispute is about "small" a=
mounts »

(a) Food--Burned body 1 gram produced 7 calories.

(b) Nervous depressant--Acts by removing inhibition. It is not a
true stimulant.

(c) Habit-forming drug.

 

 

Effects

(a) Health
(b) Longevity

Opium ani its Derivatives

 

The problem of the habit forming drugs is one of our major public
health problems. The opium group includes opium, morphine, codein, and
heroin.

Use~-nunber of addicts not accurately known. Estimated in 1924 to
be 110,000.

Physical Effects

 

Lowers ability to withstand pain or distress
Causes gastro-intestinal disturbances
Destroys self-control, will, memory.

Effects reproductive system

aQiae&éno

Sociel Effects
—. 2

(a) Contributes to crimes of violence, poverty, disease, and disor~
ganization of homes.

Control

(a) Federal: Laws--Food & Drug Act, Harrison Law.
le Organization: U. S. Public Health Service, Anti-Narcotic
League.
(b) International: League of Nations, Health Section
(c) State: Departments of Health, Hospitals and Clinics.

 

 

Tobecco

 

The use of tobacco should be considered from the standpoint of its
effects as:

{a) Habit forming substance
{b) An injurious substance
(c) In its relation to efficiency

Composition of Tobacco

While tobacco as used is the leaves of the plant nicotiana tabacum,
our interest from the standpoint of defensive hygiene is in the active
principles in the plant which are possible chemical poisons.

Nicotin is the most important of these, In its pure form, it is
one of our most powerful, fatal, and rapidly acting poisons. The nicotin
content of the various kinds of tobacco vary considerably from 1.3% to
4%, for Havana ani Maryland, to 6% to 8% for Virginia or Kentucky tobacco.

Tobacco contains many other substances which give it a characteris=
tic flavor. One of them, pyridin, on heating gives rise to substances
that are of importence in estimating the physiological effects of tobacco.
Two of them are carbon monoxide and furfural.

Combustion of Tobacco

Our interest lies in understanding what is responsible for its
charm and its ill effects. There can be no debate about the serious ef-
fects of such a powerful poison as nicotin if used in any but the most
minute quantity. It is its effects when taken into the body in such
amounts and forms as are present in smoking and chewing tovacco that
causes much controversy.

The amount of nicotin in the smoke of burning tobacco depends upon
the kind ami formof tobacco, and the amount of moisture present. This
varies fra 14%, to 35%, in cigarettes, to a much higher percentage in ci-
gars and pipes.

It is claimed by some investigators that nicotin is practically des-
troyed in the process of smoking and that the effects of tobacco are lim
ited to the decamposition products resulting from the pyridin. This
does not explain the fact that the same physiological effects are pro-
duced by chewing tobacco.
«~ 2 «

Effects of Tobacco

The important point is what amount of these substances are absorbed
by the body and what are their effects when taken in regularly over long
periods of time. This will vary with whether the user inhales, swallows
the saliva, uses a holder, as well as upon the kind and forms of tobacco
used.

Wicotin causes a brief stimmlation of the brain and spinal cord
followed by depression. The salivary flow is increased temporarily fol-
lowed by a decrease. The heart action is at first slowed and blood pres-
sure increased followed by rapid heart action and lowered b lood pressure.
Its final effects are not that of a stimulant but of a narcotic.

Habit Formation

 

The use of any narcotic is always accompanied by the danger of habit
formation with its consequent dependence upon the substance. This ap-
plies with peculiar force to tobacco. The individual who is miserable
unless he has his given amount of tobacco at a given time comes in the
Same category, psychologically, as the morphine habitue.

Tobacco end Efficiency

 

A large number of experiments have been made to determine the re-
lationship of the use of tobacco to mental and physical efficiency.

In the field of mental accomplishments, the evidence seems to show a
higher accomplishment among non-smokers, thougn many of the experiments
were not conducted with edeqate controls and stendard conditionse

From the physical standpoint, the evidence is clearer both from
practical ani experimental experience. The athletic coach does not per-
mit his teams to smoke, The mortality experience of the insurance com
penies show more favorable death rates among non-users of tobacco.

References: Storey--Defensive Hygiene, Chapter 16.

Rosenau--Preventive Medicine (1927). {Industrial Poi-
sons, page 1232); Alcohol page 515).

U. Se Public Health Service--Bulletin 116 (1921)
(Document Room)

Pearl—-Alcohol and Longevity

Fisher & Fiske--How to Live, (Alcohol and Tobacco) |

Earp--The Student Who Smokes

O'Shea--Tobacco and Mental Efficiency

Eddy, C.--One Million Drug Addicts in U. Se Current
History, July, 1925. :

Waring, J. Je--The Hygiene of Smoking, Hygeia, June,
1925

California Narcotic Commission--Narcotic Habit, (363.99
C153)

DISCUSSION QUESTIONS:

 

1. Is it true that chemical causes of ill health are relatively un-
important in the United States? Why?
- =

o» Be

22 What are the five fundamentals for the prevention of occupational
diseases ani poisons? {Rosenau)

3. Outline a plan for the prevention of lead poisoning in a pottery
using lead.

4. Explain the preventive action of milk drinking in lead workers.
5. Discuss alcohol as a food.
6. Is alcohol a true stimulant? Why not?

7, Explain the function of Pure Food and Drug and the Harrison law
in controiling drug addiction.

8. What are the important active principles contained in the tobacco
plant? Explain the way in which pyridin is said to produce its
ill ervecss on the body.

9. Wheat is the relation of the use of tobacco to habit formation?
Efficiency?

10. Explain physiologically why the athletic cach prohibits smoking
for men in training.

XIII. PHYSICAL AGENTS AS CAUSES OF ILL HEALTH

Certain physical agents are capable either directly or indirectly of
causing ill health. A few of the more important will be discussed. Atten~
tion will be called to the heaith influences of certain other ones.

Atmospheric Pressure

 

While changes in atmospheric pressure are not usually of much impor~
tance to the average individual, a knowledge of them is essential under
special conditions of work, recreation, or transportation.

Diminished

Due to the rapid growth of aviation, diminished air pressure is be-
caning more and more important,

Occurrence

{a} Mountain Climbing

(b) Aeroplaning and ballooning

Effects

The effects of living at very high altitudes with their low pressure can

only be mentioned.

The acute effects express themselves in headache, lassitude, and some=
times nausea. The extremities are cold, the pulse is weakened, and the
respirations are deeper and more frequent. The face becomes pallid ond lips
and nails blue. Readjustment sometimes is made.
« 2% «

In more severe cases there may be vomiting, fever, fainting, and per-

sistence of the other symptoms.

The physiological effects of low pressure are due to the low partial

tension of oxygen. This causes a deficiency of oxygen in the blood (anox-
emia). The body tries to compensate for this cmdition by:

ass

(a) Increases respiration
(b) Chemical alterations in blood (lowering alkaline reserve)
(c) Increased hemoglobin (increase in red blood cells)

Increased Pressure
Increased pressure is of importance chiefly in the industrial field
(a) Tunnel workers
(b) Deep sea divers

The subjecting of the individual to high pressures results in a con-

dition called Caisson disease or “bends,” the latter name given by workmen
from the excruciating pains causing the individual toe double up his body.

Symptom s

(a) Slow respiration

(b) Slow pulse

(c) Peins in ears

(d}) Headache ami dizziness
(e) Excruciating pains

(f) Vomiting

Death may occur from internal hemorrhage or there may be paralysis

(diverts palsy).

Physiological effects are most marked am dangerous after decom-

pression. Effects are due to:

{a) Increase in amount of gases in blood (nitrogen)
(ob) Increase in chemical absorption of oxygen
{c) Air emboli

Prevention

(a) Gradually increasing pressure
{b) Gradual decompression

{(c) Caref’ 3: medical supervision

Temperature

The relation of temperature and light to health as two of the impor-

tant elements in climate can only be mentioned. The influence of climte on
the vigor and vitality of races is an interesting field of study. At this
time, we will only comsider the acute, extreme variations in temperature.

Low temperatures

(a) Chilblains

.
- 27 =

{b) Frost bites
(c) Freezing

High temperatures .

 

High temperatures are of more immediate interest.

Heat Stroke--the cause of 300 to 400 deaths in the United States ©
annually. 1t is the result of hot moist atmosphere marked by headache,
rapid pulse and respiration, loss of conscioumess, and sometimes death.

Burns--may vary in effect from simple redness to cremation. In 1924,
6895 persons were accidentally burned to death and in addition 1625 lost
their lives in conflagrations.

Cost: (a) Bceonomic, (bd) Vital.

Defensive hygiene of increased temperatures

Light is an important source of both health em ill health,

 

The effects of light my be summed up under tle following heads:

(a) Insufficient light may affect eyes or have relation to rickets
in children.

(ob) Excessive licht-—-"sun stroke," sunburn.

(c) X-Rays or Radium may injure as well as aid health.

Electricity my be an important cause of ill health and death unless
proper defensive hygiene measures are taken.

(a) Lightning
(b) Commercial electricity

Defenses

(<) Safeguarding
(b) Education

References: Storey--Defensive Hygiene, Chapter 15.
Rosenau-—Preventive Medicine--Articles on Pressure, Tom-
perature, and Light.
Huntington--Civilization and Climate.
Sunset Magazine--What Price California Climate, June, 1928.
uckiesh and Pacini--Light and Health

DISCUSSION QUESTIONS:

 

1. Discuss the relation of aviation to health.

2. Why are the respirations quickened when the atmospheric pressure is
diminished?

3. Explain the increased number of red cells produced under same con=
ditions. “

4, Ontline a defensive hygiene program against Caisson's disease.
5. Discuss relation of high temperature to health.
6. Why are burns of so much importance as a problem of defensive hygiene?
7. Discuss relation of insufficient sunlight to rickets?

8. What defensive hygiene measures are particularly indicated in the
University to meet the hazards of insufficient light?

XIV. DEFENSIVE HYGIENE OF HEREDITY

Our knowledge of heredity has been transferred from the realm of spec-
ulation to the realm of experiment. The rediscovery in 1900 of the work
of Mendel furnished the foundation for the rapid growth of the science
of genetics,

Normality and Abnormality

As a result of the statistical and experimental study of heredity,
we have had revealed to us with great vividness the mechanisms by which
‘both normal and abnormal characters can be transmitted from generation
to generation. The knowledge of these mechanisms has uncovered for us
some of the most pressing problems of Defensive Hygiene.

Problems

The principal problems of heredity for which we should adopt a more
intelligent and agressive defensive program are:

(a) Hereditary mental diseases
(vo) Feeblemindedness
(c) Nervous and mental instability.

Extent of Problem

While there is some controversy over whether the large increase in
mental deficiencies of various kinds is an absolute or relative one, there
is no doubt of the immensity and importance of the problem. An intelli-~
gent opinion upon control measures should be based upon a working know-
ledge of the basic and exciting causes of:

(a) Mental diseases
(b) Feeblemindedness.

Control of Human Heredity

Even though we have accumulated considerable knowledge of the mechan-
isms of both normal and abnormal heredity, it is a difficult and complex
problem to apply in the human field.

Any program of applied eugenics to be successful must be practical
and not visionary. In this course we are concerned directly with the pre-
vention side and only indirectly with the constructive side.
«pO

(a) Positive Eugenics (Discussed Course 150)
(b) Negative Eugenics

(1) Laws restricting marriage

(2) Selective mating (with idea of dilution of defects)
(3) Segregation

(4) Sterilization

(5) Undesirable immigration

Program of Defensive Hygiene of Heredity

Every well informed person should have sufficient knowledge of what
Science has shown us about heredity to enable him to act intelligently
himself and to participate wisely in the community's attempts to meet the
problems arising from heredity.

A working program includes many things that can be done at once and
some that are only possible with increased intelligent public opinion.

(a) Community program

(1) Control of procreation of mentally deficient
(2) Institutions and colonies

(3) Exclusion of abnormal immigrants

(4) Restriction of marriage

(o) Personal program

(1) Knowledge of heredity

(2) Pre-nuptial examination

(3) Ideals of responsibility for reproduction of healthy germ
plasm,

References: Storey---Defensive Hygiene, chaps. 2-6.
Guyer---~Being Well-Born, chaps. 8-13-19-20-23,
Conklin--Heredity and Environment, pages 116-120 and 287 (5th ed)
Bossard--Problems of Well-Being, chaps. 21-25.

DISCUSSION QUESTIONS:
1. If the statements of modern biologists and physicians as to the trans-
mission of feeblemindedness and insanity are true, how do you account

for the great opposition to their social application?

2. Are the present day laws restricting marriage likely to influence marked-
ly the reproduction of the unfit? Why?

5. If the upper grades of feebleminded now segregated are sterilized and
released, what other problem does it affect? How?

4. What would you include in a personal program of defensive hygiene of
heredity and constructive program that would make for race improvement ?
XV. DEFENSES AGAINST ENVIRONMENTAL DEFICIENCIES AND EXCESSES

The earlier part of this course has concerned itself with a consid-
eration of the mechanical, physical, chemical, and micro-organismal causes
of ill health. Science has also demonstrated that we have another great
group of causes: sickness, inefficiency, and death. They may be broadly
classified as environmental excesses and deficiencies.

These excesses and deficiencies play an important part in our levels
of health. One might consider them from a chronological point of view on
account of their peculiar effects on every age group.

(a) Pre-natal (d) Maturity
(b) Infaney and pre-school (e) Old age
(c) School or college

The time at our disposal will permit only a consideration of the prin-
ciples involved in the health effects of excesses and deficiencies,

Food Excesses and Deficiencies

No argument is needed to establish the fact that food is one of the
prime essentials of life. The difficulty is to convince the average in-
dividual that we have sufficient scientific knowledge to prove that more
than instinct, taste and the subjective sensation of satisfaction of hun-
ger are necessary to insure the individual an adequate diet and to protect
him against food excesses and insure him against food deficiencies,

Food Deficiencies

From our studies of normal nutrition, we learned that the amount of
food taken in by the individual should be adapted to his age, body weight,
and degree of activity. Further, that this intake should be distributed
properly among proteins, fats, and carbohydrates with an insurance of se-
curing sufficient vitamins and inorganic salts.

If we are to plan successful defensive hygiene of foods, we must know
the correct amounts and distribution of food elements and understand the
Signs of deficiency of each group.

(a) Protein (c) Carbohydrates (e) Water
{(b) Fats (d) Vitamins (f) Inorganic salts

Food Excesses

It is impossible to judge exactly whether an individual is taking
food in excess without a careful study and expert examination. It is
doubtful wisdom to take the unreliable testimony of the feelings and the
scales, It seems almost uncecessary to mention that we should be able to
recognize the signs of excesses of:

(a) Water (c) Fats (e) Inorganic salts
(vo) Proteins (d) Carbohydrates
wBte

Excretory Excesses and Deficiencies

The excesses or deficiencies of the excretory organs are of vital
importance in health maintenance. The lack of knowledge of normal amounts
of various excretions lead to much permanent physical damage.

Deficiencies

(a) Deficiencies of intestinal excretions. Constipation is one of
our major health problems. Relation to diseases.

(vo) Deficiencies of urinary excretions. Knowledge of normal amounts
and character of urinary excretions is fundamental to health.

(c) Deficiencies of skin excretions. Not relatively important.

Excesses

The excesses of excretions are more likely to attract attention but
are none the less important. They include the same organs;

(a) Urine (c) Perspiration
(ob) Intestinal (d) Menstruation

Excesses and Deficiencies of Exercise

Exercise is fundamental to good function. Both deficiency and excess
need to be guarded against.

Deficiency of Exercise
A deficiency of exercise has a serious effect on:
Metabolism

(a)
(bo) Organic growth
(c) Functional growth

The signs of deficient exercise may be summarized:

(a) Weakness and lack of endurance to voluntary muscles
(bo) Weakness and lack of endurance of heart and circulation
(c) Weakness and lack of endurance of muscles of respiration

Excesses of Exercise

Excessive exercise may be a serious matter. The understanding of the
signs of over exertion are among the most important hygienic facts. To
interpret fatigue properly is difficult but possible. Fatigue may be
either local or general. The degree of fatigue and the rate and complete-
ness of recovery are of vital importance.

(a) Normal muscular fatigue (ec) Exhaustion
{b) Acute muscular fatigue