Mellon Institute of Industrial Research and School of Specific
Industries
Robert Kennedy Duncan, Sc.D. Director.
Raymond F. Bacon, Ph.D. Associate Director.
STAFF OF THE SMOKE INVESTIGATION
Raymond C. Benner, Ph.D. Chief Fellow and Chemist.
Joseph A. Beck, LL.B. Attorney.
A. B. Bellows, B.S. Engineer.
W. W. Blair, M.D. Physician.
J. E. Clevenger, M.S. Botanist.
B. A. Cohoe, A.B., M.D. Physician.
E. W. Day, A.M., M.D. Physician.
S. R. Haythorn, M.D. Physician.
W. L. Holman, A.B., M.D. Architect.
Richard Hooker B.S. Architect.
C. T. Ingham Architect.
Richard Kiehnel Architect.
H. H. Kimball, Ph.D. Meteorologist.
Oskar Klotz, M.D., C.M. Physician.
E. B. Lee Architect.
C. H. Marcy, A.B. Bacteriologist.
O. R. McBride, B.S. Engineer.
E. H. McClelland, Ph.B. Bibliographer.
R. T. Miller, Jr., A.B., M.D. Surgeon.
A. F. Nesbit, B.S., A.M. Engineer.
J. J. O’Connor, Jr., A.B. Economist.
K. K. Stevens, B.S. Chemist.
A. A. Straub, M.E. Engineer.
Carlton Strong Architect.
W. W. Strong, Ph.D. Physicist.
J. E. Wallace Wallin, Ph.D. Psychologist.
W. C. White, M.D. Physician.
Ruth E. Gilchrist Secretary.
Mellon Institute of Industrial Research and School of
Specific Industries
Smoke Investigation Bulletin No. 3
Psychological Aspects of the Problem of
Atmospheric Smoke Pollution
By
J. E. Wallace Wallin, Ph. D.
Director of Psychological Clinic, University of Pittsburgh
University of Pittsburgh
Pittsburgh, Pa.
1913
Introduction
All that can be wisely attempted in an article which aims merely to
furnish a preliminary survey of the psychological aspects of the smoke
problem, is to outline the scope of the inquiry, to review briefly
the direct and indirect data, whether impressionistic, observational,
statistical or experimental, which bear on the problem and which
are already available in recorded observations or in literary and
scientific memoirs, and, finally, to suggest certain problems amenable
to statistical or experimental study.
The smoke palls of our industrial centers exert both a direct and
indirect influence upon the human organism. The direct influence is due
to the immediate contact of the smoke-contaminated and poison-laden
air with the skin, mucous membranes and sense organs of the body. The
indirect effects are traceable to the various meteorological states
which are due to smoke products in the atmosphere, and which in turn
directly influence the body. Frequently, possibly always, the smoke
conditions and the state of the atmosphere are so inextricably mixed
that the biological effects must be ascribed to the joint action of
both factors. Only in a controlled experiment would it be possible
absolutely to segregate, and thus separately to measure, the effects of
the smoke and meteorological factors of weather states. This has not
yet been attempted.
The mental effects due to atmospheric smoke and its related weather
states are likewise both direct and indirect. The indirect effects
are due to the influences exerted by smoke clouds and smoke-produced
weather states on the physiological organism--on health, well-being,
energy, freshness, potential reserve, sensori-motor efficiency--and to
the influences thus directly exerted by the changed bodily states on
the mind: on mental tension, balance, inhibition, impulse, inclination,
feeling, emotion, thought, and conduct. On the other hand, the direct
mental effects are traceable to the immediate influences, whether
conscious or unconscious, exerted on the individual’s mental action
by his own experiences--by the thoughts, feelings and impulses which
have been excited in him by various bodily states, sensations and
perceptions produced by cloud and weather conditions--or which have
been directly produced by processes of association and habit formation,
the latter of which have themselves been initiated by thoughts or
responses occasioned, in the first instance, by the physiological
effects of external influences. The action of the mind itself does have
a determining influence upon its own subsequent attitudes, beliefs,
propensities and habits. It is important that these direct effects of
the mind’s own action upon its subsequent behavior be recognized, for
much of the mental gloom and depression occasioned by dismal cosmic
influences has merely been initiated by the external stimuli. Their
peculiar intensity is largely due to the subject’s own introspections,
to his own stream of thought. The mental influences are often more
pronounced than the bodily influences, whether the mental influences
arise from somatic alterations or from introspective changes. Cosmic
states are, perhaps, less to be regarded as _causes_ of mental action
than _factors_ which may upset the emotional balance, lessen inhibition
and alter the train of thought and conduct.
It is also important to emphasize the fact that no hard and fast line
of demarcation can be drawn between the bodily and mental effects of
smoke-clouds or smoke-produced weather states. The human organism is a
psycho-biological unity, and we cannot, except in a purely artificial
and arbitrary fashion, divide the _soma_ and the _psyche_ into two
independent compartments. Bodily states normally influence mental
states and mental states, in turn, normally influence bodily processes,
particularly the functions of the glandular, circulatory, sexual and
neural systems.
I. The Pathology of Smoke
THE DIRECT AND INDIRECT EFFECTS OF SMOKE ON BODILY AND MENTAL
WELL-BEING.
_A. The direct effects of smoke on health and conduct._
When it is remembered that the average adult consumes about 30 cubic
inches of air in each inhalation or possibly 864,000 cubic inches
every day, it does not seem an exaggeration to say that more persons
are devitalized, disabled and poisoned by the impurities contained
in smoke-polluted air, than by the noxious ingredients in food and
water. Not only do the solid and vaporous ingredients of smoke-begrimed
air--noxious compounds of carbon, sulphur, nitrogen, chlorine, and
arsenic--irritate the sensitive membranes of the eyes, nose, throat
and lungs, and thus aggravate or cause inflammatory diseases of these
organs, or produce collapse of their sensitive tissues, or increase
their susceptibility to such specific diseases as bronchitis, pneumonia
and subacute forms of phthisis; but the poisonous compounds also
enter the gastro-intestinal tract, and this causes nausea, vomiting,
diarrhea and systemic poisoning. That the gastro-intestinal tract is
affected by inhaled solids has been demonstrated by the experiments
of Saito (19)[1] on dogs and rabbits which were compelled to inhale,
during periods varying from 1 to 33 hours, air charged with white lead
dust. Only from 4 to 24% of the dust was subsequently recovered from
the respiratory organs while the remainder was found in the digestive
organs. In the case of a man who inhaled the air from 10 to 15 minutes
on 20 occasions and who avoided acts of swallowing, 95% of the dust
remained in the body, 50% of which was primarily retained in the nares.
By processes of exclusion 12% probably found its way to the lungs, for
60 to 80% was recovered from the alimentary canal. Thus the principal
portal of entry of soluble inhaled dust appears to be the alimentary
canal.
The deleterious effects on the human system from inhalation of
smoke-polluted air, which contains not only acrid and irritating
solids, but a certain amount of deadly poisons, should be obvious from
a consideration of the comparatively great density of the impurities in
the atmosphere of industrial centers. The weight of the solid matter
in the soot-laden air at Leeds, England, has been found to be 1.2 mg.
per 100 cu. ft. of air, or 200 lbs. per sq. mi. (300 ft. high.) The
soot-fall per square mile per year has amounted to 220 tons in Leeds,
820 tons in Glasgow and 259 tons in London. Moreover, by means of the
dust counter the number of dust particles in the air at Leeds has been
found to vary from 530,000 to 3,736,000 per cu. inch. In manufacturing
cities the number of dust particles often exceeds 300,000 per cu. cm.
even in fine weather, as compared with a few hundred in the country
(Aitken, 4). A large percentage of these particles consists of the
soot from factory, locomotive and domestic fires. Not only are these
conditions, bad as they are, aggravated during foggy weather but on
moderately foggy days the quantity of solid organic impurities may be
increased 700% as compared with fine weather (Russell). During grimy,
opaque fogs, the conditions are still worse.
That the constant inhalation of poison-laden air, largely made up of
the soot particles which abound in manufacturing cities, diminishes the
potential reserve, the productive efficiency and the bodily well-being
of our city dwellers by causing specific diseases, has been abundantly
shown by various studies. The mortality from acute pulmonary diseases,
especially in children and old people, has increased, and the course
of pulmonary tuberculosis has been accelerated in Germany as the
country has become more industrial. The increase in non-tubercular lung
mortality has amounted to 30% in the smoky town of Waldenburg compared
with the nearby textile town of Wusterwaltersdorf (Ascher, 16). The
death rate per 10,000 for the same diseases is 30.6 in the non-smoky
city of Hamm as compared with 57.4 in the smoky city of Gelserkirchen.
In all German towns with a population of over 15,000 the death rate
is 24.0, while in the smoky industrial centers of similar size in
Rhenish Westphalia it is 34.0, and in the industrial districts in upper
Silesia it is 36.0 (Ascher, 4); in rural districts in England it is
17.5 compared with 26.5 in urban industrial districts(4). During the
anthracite strike in this country there was reported an increase of
suspected tubercular cases. In Rochester there was observed an increase
of pulmonary affections with the increase of the smoke nuisance
between 1895-1904. In Pittsburgh a recent investigation by Dr. W. C.
White shows that pneumonia increases with the density of atmospheric
smoke, irrespective of the density of population or of poverty. The
increase is as marked in the well-to-do as in the poorer sections with
relatively the same smoke density. In late years pneumonia has assumed
a very acute and fatal form in Pittsburgh.
That “much of human life, energy and happiness is wasted by the effects
of vapors, noxious because wasted, is now an established certainty”
(Gillespie, 8). It has been estimated that London’s annual smoke
tax amounts to $1,500,000 in death, disease and lowered working
capacity alone. Unfortunately up to the present time there has been
no scientific attempt made to directly measure the degree in which
the producing capacity and the bodily and mental efficiency of city
dwellers may be impaired by atmospheric impurities, nor has any effort
been made to measure the direct or indirect influences of smoke upon
sensory, motor, intellectual, affective and emotional functions, and
on the habits and conduct of human beings. A part of the human waste
caused by smoke-polluted air is certainly due to the irritation caused
by solid smoke particles. The functional efficiency of the visual,
naso-pharyngeal, pulmonary, gastro-intestinal and neural mechanisms,
may be more or less disabled by constant irritation by solid particles.
But it is likewise presumptively probable that irritating, acrid soot
particles and poisonous smoke compounds may become factors in causing
premature decay, untimely death, exaggerated fatigue, frequent
sickness, instability of attention, malcontent, irritability, lessened
self-control and possibly psychic disequilibrium. It is probable that
there goes on a gradual process of absorption by the human system of
the poisonous products of imperfect smoke combustion. This insensible
intake may not give rise to any definitely recognizable acute disorder
or specific disabilities. But the process of slow poisoning may
insidiously eat away like a mild canker at vital tissues and thus in
time deplete our potential reserve, thereby making it impossible for
body and brain to function at their points of maximal efficiency.
With an impaired brain the mind cannot reach its highest levels of
creative insight and constructive achievement. It has often been a
matter of comment that people who have lived in relatively smoke-free
cities after coming to live in a city like Pittsburgh, have experienced
a distinct disinclination to work, or a sort of chronic ennui. A
Pittsburgh business man writes that “people coming to Pittsburgh to
reside notice a great depression; likewise many residents of Pittsburgh
on visits find they feel infinitely better and business men working
for periods in cities where there is not the same smoke find they can
do twice as much work. These are not isolated cases but the result of
very general inquiry which I have made for a number of years.[2] People
very frequently remark on the depressed expression not only on the
working men of Pittsburgh, but they also observe it in the clubs. It
is very frequently referred to humidity, but this is entirely wrong as
the humidity in New York ranges much higher than in Pittsburgh. This
certainly is a condition that tends to keep people from coming here and
makes people desirous of leaving at the first opportunity.”
The writer of this essay has now lived in Pittsburgh somewhat over
a year and has experienced during this time a marked distaste or
disinclination to engage in productive authorship. Clear, trenchant,
reflective thinking seems to have been more difficult; and the attempt
to write concisely, incisively and perspicuously has seemed more
labored. Is it possible that the low esteem in which Pittsburgh is
held in the world of productive scholarship--a matter of occasional
remark among medical men and other scientists--is due to the fact that
the air which its scientists must breathe is polluted and poisoned
by smoke? [There are other contributory factors, as we shall see in
the following sections, viz., the various devitalizing weather states
induced by smoke, and possibly the common use of convection heat from
gas stoves in the living rooms. Convection heat from gas stoves, it
is maintained by Scotch investigators, is more injurious than heat by
radiation (21).] Is it possible that the highest spiritual creations
of the citizens of smoke-begrimed cities are being sacrificed on the
altar of commercial greed? Is it possible that, in the interests of
a pseudo-economy, we are impairing the very brains of the people by
permitting our breathing air to be saturated with the poisons of
preventable fumes? Is it possible that the industrial energy for which
Pittsburgh has become famous is less due to the surpassing excellence
of the brain and brawn of its workers than to the munificent bounty
of its mines? We shall probably not be able to offer any satisfactory
answer to questions such as these until a series of controlled
psychological experiments on efficiency, fatigue, and endurance (in
so far as various motor, sensory, and intellectual functions are
concerned), have been carried out under varying degrees of density of
atmospheric smoke.
_B. The indirect influences of smoke on mental and physical well-being;
the meteorological aspects of atmospheric smoke contamination._
I shall first discuss the meteorological variations produced by
smoke, and then the effects of the smoke-produced weather states upon
well-being.
The smoke-clouds of our cities influence a number of weather states
which affect human conduct. The meteorological conditions particularly
affected are: sunshine, clouds, humidity, fogs, temperature, electrical
potential and luminosity. That the smoke from factory and domestic
fires, by filling the atmosphere with opaque clouds of smoke and by
inducing mists and fogs, deprives the city dwellers of the luminous,
vitalizing, cheering, health giving, germicidal rays of the sun, has
been proved by numerous observations and tests. It has been computed
that seven-eighths of the sun’s power is shut out by the smoke in the
manufacturing center of London, and five-eighths in Westminster. The
percentage of sunshine in these two places compared with the rural
stations of Oxford, Cambridge, Marlborough and Gildiston was found to
be as follows (12):
TABLE I.
Winter Summer
From 1881-1885: 17% 83%
” 1906-1910: 38% 92%
It is observable that the amount of sunshine suffers an enormous
reduction in the winter time but only a very slight diminution in
the summer, and that during the last five years the conditions have
considerably improved, due, as we are told, to the considerable
abatement during the last decade or two of London smoke. During one
calendar year the hours of sunshine in the center of Leeds amounted
to 1164 while the corresponding figure for Adel, which is only 4
miles distant, was 1402 (4). Thus the loss of sunshine in Leeds due
to smoke amounted to 17%. The diminution of sunshine in towns near
smoke-producing cities is, again, shown in the following tabulation
of the comparative monthly average duration of bright sunshine for a
period of 20 years (24):
TABLE II.
Station Nov. Dec. Jan. Feb.
Runhill Row 22.8% 7.5% 14.1% 30.5%
Westminster 27.7% 13.1% 18.4% 32.8%
Kew 50.8% 38.1% 40.3% 54.6%
Cambridge 61.0% 40.6% 48.9% 72.8%
At Kew, seven miles west of London, the reduction of sunshine due to
the London smoke has been placed at 37% for a whole year.
In the United States of America for the decennium, 1901-1910, the
aggregate hours of sunshine, percentage of possible sunshine, number
of cloudy days, number of partly cloudy days, and number of foggy days
have been found by the Pittsburgh smoke investigators, from a study of
the records gathered by the United States Weather Bureau in various
cities throughout the country, to be as shown in Table III.
TABLE III.
STATISTICS OF SUNSHINE IN 18 CITIES OF THE UNITED STATES
1. 2. 3. 4. 5. 6.
Aggregate Percentage No. of No. of No. of Total
hrs. of of possible cloudy partly foggy of 3
Station. sunshine. sunshine. days. cloudy days. and 4.
days.
Baltimore 26,466 58.7 1440 1018 142 2458
Boston 25,877 56.8 1398 1003 98 2401
Buffalo 23,200 49.7 1713 1324 157 3037
Chicago 26,442 57.9 1238 1282 116 2520
Cincinnati 26,758 58.6 1356 1202 81 2588
Cleveland 22,394 47.8 1584 1187 67 2771
Denver 29,355 65.9 645 1500 45 2145
Detroit 23,201 50.3 1477 1165 133 2642
Los Angeles 31,521 70.9 743 1404 258 2147
Louisville 25,715 56.8 1284 1094 233 2378
New Orleans 26,091 58.6 1045 1365 162 2410
New York 28,762 57.6 1279 1182 120 2461
Philadelphia 25,249 56.6 1369 1071 127 2440
Pittsburgh 22,573 49.0 1385 1294 185 2679
Portland, Me. 26,914 59.4 1321 1040 303 2361
San Francisco 25,453 56.3 900 1136 241 2036
St. Louis 24,957 58.7 1185 1019 42 2204
Washington D. C. 25,078 55.8 1088 1135 115 2223
It is observable that all the cities which have become notorious in the
matter of smoke pollution show a very low percentage of sunshine, the
worst conditions obtaining in the two cities having the most unsavory
reputation for smoke, viz., Cleveland and Pittsburgh. These two cities
consistently have the worst records for sunshine, for percentage of
possible sunshine and for cloudy and partly cloudy days (combined
totals). Unfortunately no meteorological data are available from
stations situated in non-smoke-producing centers whose geographical
conditions are similar to those obtaining in smoke-producing cities
like Pittsburgh, Cleveland, Detroit, Cincinnati and St. Louis. The
above data only enable us to compare the atmospheric conditions of one
smoky city with another smoky city or with cities whose geographical
surroundings are so different as to render the data useless for
comparative purposes. However, the data recently collected by the
Smoke Investigation of the University of Pittsburgh show, in complete
accordance with similar English findings, that the lessened amount of
sunshine in Pittsburgh is due to the smoke factor. Figures based on
the number of tons of coal consumed in Pittsburgh from 1905 to 1911
show a fair degree of parallelism between the quantity of coal consumed
and the number of smoky days. During the years in which an increasing
amount of coal has been burned (owing to the heightened cost of gas)
the hours of sunshine have fallen from about 2800 to 2200. Likewise
the days on which the United States Weather Bureau has observed
light or dark smoke in Pittsburgh, have increased as follows for the
successive years from 1905-1911: 85, 87, 106, 124, 112, 100 and 156
days (O’Connor, 17). With the increase of coal consumption has come
an increase of smoky days. Dr. Benner tells me that the per cent. of
daylight (as chemically determined) in Pittsburgh was reduced for last
November about 32%, for December 23%, January 36% and February 44%
as compared with the town of Sewickley which is only about 12 miles
distant. There can then be no doubt that smoke lessens the amount of
sunshine.
Smoke likewise is directly related to the production of moisture, mist,
clouds, rain or fogs, because it supplies some of the solid particles
which may serve to aid in the formation of suspended drops of water.
Rain drops are often formed around a solid nucleus. Without solid
particles of dust in the atmosphere there would probably be much less
mist, rain and dew (4). We would, therefore, infer on merely _a priori_
grounds that smoke contributes to the production of fogs. That this
is so seems to be shown by actual investigation. An investigation
conducted by the Meteorological Council in 1901-1903 indicated that 20%
of the fogs in London were smoke-induced, (4, 21)--artificially induced
and therefore preventable fogs. Most suggestive, as showing that smoke
is partly responsible for the existence of fogs, are the fog and smoke
statistics gathered in London during the last 30 years, as shown in
Table IV (applicable to the winter months only). The number of days of
fog have been reduced nearly 300% and the hours of bright sunshine have
increased nearly 100% during this 30-year period (10).
TABLE IV.
Date Days of Fog Hours of bright sunshine
1883-1892 29.9% 55.6%
1892-1901 20.7% 70.1%
1901-1910 10.6% 93.5%
Likewise in Westminster the number of days of fog averaged 27 per year
for the lustrum 1902-1906, and 17 per year for the period 1907-1911.
The improvement shown above is due, in large part, to the increased use
of gas and electricity and to better stoking (Kershaw, Russell). On the
other hand, if we turn to Pittsburgh where the amount of smoke has been
on the increase in recent years, we find that the number of days of
fog increased from an average of 22.6 per year for the first five year
period to 50.2 for the second five year period, 1907-1911.
Not only is smoke related to the frequency of fogs, but it also
increases both the duration and the density of fogs. The water globules
become coated with a film of black, sticky, tarry soot which retards
evaporation. These soot fogs, or “pea-soup” fogs as they have often
been called because of their grimy opacity, may at times become
practically impervious to the luminous rays of the sun. Even in one
of the lighter varieties of fogs the soot products may increase seven
fold. Many average soot-fogs reduce the amount of light one-half. On
an exceptionally dark day in Berlin the light was only 1/500 of what
it was on an ordinary overcast day and only 1/3000 to 1/4000 of what
is was on an entirely clear day (H. H. Kimball). The smoke in the
center of Leeds on an ordinary day absorbs as much as 25% of the total
daylight as compared with the suburban sections of Leeds, or 40% as
compared with the suburb of Garforth, which is 7 miles distant (4).
That smoke must materially decrease the limits of visibility is patent
from what has been said. The limits of visibility vary with the number
of dust particles in the air: 1,000 particles per cu. cm. render
large objects like mountains invisible at a distance of 100 miles;
100,000 particles render them invisible 1 mile away, and 1,000,000
particles 1/10 of a mile distant (Aitken). Smoke not only fills the
atmosphere with countless numbers, but with extremely opaque particles.
These particles may unite with globules of water and this makes the
atmosphere still more opaque. As was stated above, in large cities even
in fine weather there may be over 300,000 particles per cu. cm., as
against a few hundred in the country. Accordingly, we find in London
that the limit of visibility in the winter time, even during the clear
part of the day, does not exceed one-half mile.
The temperature readings are somewhat unsatisfactory because they
usually include only the maximum and minimum records for each day.
Minimum temperatures are found to be perceptibly higher in the
cities than in the country, partly because of city heat, but chiefly
because the smoke blankets prevent the escape of the heat at night.
In Pittsburgh the minimum temperature averages about 4° higher than
the temperature in the adjacent stations (Kimball). In the day time
the upper surface of the smoke clouds absorbs portions of the sun’s
heat, and this inevitably lessens the heat on the ground surface. The
solar energy has been reduced 40% by smoke clouds (12), and it is
possible that very little heat penetrates to the earth’s surface during
a very dense smoke cloud. In London the surface temperature during a
given reading was 44° F., while 59 ft. directly above it was 51.5°, a
difference of 7.5°. Between 9 A. M. and 3 P. M. the surface temperature
rose 7.5°, while the roof reading rose 16.5°, or more than twice as
much. Although thoroughly satisfactory data are not available it is
undoubted that smoke (which is most abundant in the atmosphere in the
winter time, owing to lessened convection) lowers very perceptibly the
diurnal winter temperature in smoke-producing cities.
Finally, smoke indirectly affects the electrical potential of the
atmosphere. I know of no direct study of this question, but it is
possible that smoke causes a decrease in the potential because it tends
to increase humidity. An increase of humidity decreases the potential
(save possibly during fogs, as noted later, 14). We are also told that
the potential increases with the turbidity (Trubung) of the atmosphere,
and consequently with high barometric pressure. Since smoke tends to
decrease the diurnal temperature, particularly in the winter time, it
apparently tends to increase the diurnal potential, as the potential
decreases with increasing temperature (14).
Having thus discussed the atmospheric changes caused by smoke we now
turn to the second question. How do the various smoke-induced weather
states affect the mental and bodily health and happiness of human
beings? It is evident that the problem can be formulated largely in
terms of sunshine dynamics. On the one hand, we have the psychic and
physiological influences of positive states of sunshine: brightness,
luminosity, warmth, dryness, the presence of the infra-red, spectral
and ultra-violet rays, and high electrical potential (because of
dryness). On the other hand, we have the effects of the negative
states: gloom, darkness, cloudiness, fogginess, rain, moisture, cold
and low electrical potential. It is utterly impossible to separate all
of these components, and it will, therefore, be no easy task to measure
the influences of each component.
Literature, both poetry and prose, contains frequent allusions to the
alleged effects of sunshine or the absence of sunshine on the feelings
of man. Charles Lamb “felt himself immortal” and “a great deal taller”
on bright days. Moore took delight in sitting in the sunshine:
“Blessed power of sunshine! genial day,
What balm, what life are in thy way!
To feel thee is such real bliss,
That, had the world no joy but this,
To sit in sunshine calm and sweet,
It were a world too exquisite
For man to leave it for the gloom,
The deep cold shadow of the tomb.”
Byron felt “more religious on a sunshiny day,” Pope refers to “the
soul’s calm sunshine,” Rousseau sat with bared head in the sun; Shelley
so coveted the most intense sunlight that he did his writing from the
roof, while it is a common observation that people generally, and
particularly the aged, instinctively seek the sunshine. Mrs. Hemans
wrote a rapturous apostrophe to the sunbeam:
“The sunbeam of summer
O! what is like thee;
Hope of the wilderness,
Joy of the sea.”
Many writers cannot do satisfactory work unless the weather fits the
mood, motive or scene; unfavorable weather states cause a disagreement
in the thought processes(27).
Southey refers to the depressing influence made upon him by the “vile,
dark, rainy clouds” of Great Britain, when he returned from a sojourn
of 15 months in sunny Italy, where his brain was in a state of high
illumination. An Italian proverb runs thus: “Where comes no sun the
doctor comes.” Similarly a German saw: “The funeral coach turns twice
as often on the shady side of the street as on the sunny side.” J.
Ashby-Sterry has dwelt upon the demoralizing effect of the London fog:
“A London fog when it arises
All London soon demoralizes.”
“It chokes our lungs,
Our heads feel queer,
We cannot see, we cannot hear!
So when this murky pall drops down,
Though dearly loving London town,
We feel we cannot quite revere
A London fog.”
Likewise Walter C. Smith:
“A grey fog in the early prime,
A blue fog by the breakfast hour,
A saffron fog at luncheon time,
At dinner a persistent shower
Of smut, and then a dismal power
Of choking darkness and despair,
Thickening and saddening all the air.”
A special questionnaire investigation on nephelopsychosis made some
years ago by G. Stanley Hall and the writer (9) indicated that heavy
black clouds and fogs may often strike fear or terror into children,
or may make them feel depressed and gloomy or restless. Some children
experience “terrible fear” at times and others feel that “something
dreadful will happen when the horrible black ones appear.” There
are cases on record of actual motor paralysis caused by terrifying
clouds. There is here an interesting parallelism between the emotional
responses called out by clouds in the children of to-day and the
responses called out in primitive races. In his mythopoetic tendency
primitive man read fear and danger in dark clouds, particularly the
black thunder clouds. The smoke clouds of our city probably depress
children just as any dark clouds do, and when particularly black may
also arouse nephelophobias.
Sir Archibald Geikie has ascribed the subdued, grim character of the
Scot to the gloom of his valleys and the canopy of cloud “which for a
large part of the year cuts off the light and heat of the sun.” The
French formerly regarded the Englishmen as “rude, unlettered ... surly,
ill-conditioned men, having lived in an unhappy climate where perpetual
fog, only varied by rain, prevented the sun from ever being seen,
suffering from so deep and inveterate a melancholy that physicians had
called it the English spleen, and under the influence of this cruel
malady constantly committing suicide, particularly in November, when we
were well known to hang and shoot ourselves by the thousands” (2).
On the other hand, there are those who believe that the monotonous
gloom of England has inoculated the Britain against moods of depression
and hypochondria, and made for the evenness of temperament which is
said to characterize him (18). Gloomy weather would thus serve as a
catharsis against the very depressions which it is said to induce. I
must confess that this reasoning seems to me to be quite specious. The
effects of meteorological monotony, particularly of depressing states,
probably do not differ from the general effects of physiological or
psychic monotony: narcosis, hypnosis, fatigue, overstrain, distaste, or
aversion. However that may be, there can be no doubt that many persons
experience an exhilarating, tonic effect on a bright, sunshiny day and
a depressing influence on gloomy days--assertions that have, indeed,
been ridiculed by Dr. Johnson. Fortunately these impressionistic
views on the buoyancy of sunshine and on the depression of gloom
(particularly cold or hot, damp, dark days) find a certain degree of
support in scientific studies.
Deprived of sunshine the human skin assumes a pale greenish hue, like
the skin of the people in the polar regions. This is probably due
to the absence of the blue and ultra-violet rays of the sun which
dilate the blood vessels and bring the blood to the surface, and to
the absence of the infra-red rays which are associated with heat.
Sunshine promotes transpiration and perspiration, and thus favors the
elimination of toxic products through the skin. Bright, sunny days
lessen the strain on the kidneys.
The amount of blood and the per cent. of hemoglobin are increased
by sunlight and decreased by darkness. Oerum, in an experiment on
animals, found that light increased the quantity of blood 25% in 4
hours. Likewise Grawitz and Graffenberger have observed a diminution in
the quantity of blood in animals kept in the dark, while Marti found
under similar conditions that the number of red blood corpuscles was
lessened (13). There is thus a loss of red coloring matter in the blood
of animals kept in the dark. The well-known baker’s anemia points to
the same impoverished state of the blood in night workers (Gardenghi,
13). Not only so: in an examination of 29 persons Finsen (7) found
less hemoglobin in the winter than in the summer, presumably because
of the diminished sunshine in the winter time. Diesing suggests that
the lack of sunlight in northern countries is an essential factor in
the causation of rachitis. The rays of the sun--specifically the blue
and ultra-violet rays--thus exercise a tonic or stimulating action
on the organs of circulation, transpiration and elimination, and
very probably also directly stimulate the nervous system. Finsen has
shown that benumbed or apparently dead insects have been revitalized
by the application of ultra-violet rays. It is doubtful whether this
stimulating effect is due to increased electrical potential, as argued
by Dexter (5), because the more intense the sunshine and the higher the
temperature the lower is the potential (14). The stimulating effect is
probably due to the chemical action of the short rays of light. These
rays probably penetrate the deeper tissues of the body just like the
X-rays. It is well known that persons suffering from chronic joint
disease, particularly from joints affected with tubercular sinuses,
can be greatly benefited or entirely cured by constantly exposing the
affected limbs to the direct rays of the sun. Guggenbuhl, it will be
recalled, attained some success in the treatment of cretinism simply
by removing the cretins from the dark Alpine valley to the sunlit
summit of the Abendberg.
Because of the stimulating effect of sunshine, may not an excess of
sunshine be just as detrimental as a deficiency? It has, indeed, been
assumed that the climatic dangers of the tropics are largely due to
the injurious tropical sunlight, particularly to the abundance of the
ultra-violet rays. Woodruff holds that the failure of the white race
to colonize in the tropics is due to the excessive light, and not
to the heat and humidity. The light, he contends, tends to produce
ennui, neurasthenia and ultimate collapse in blond persons (26). This
conclusion is not sustained by recent investigations. Experiments have
shown that monkeys do not succumb from insolation in the tropical
sun if care is taken not to allow the bodily temperature to rise, by
conducting away by brisk air currents the excessive heat (Aron, 23).
The injurious quality of the solar light is thus due to the infra-red
and not the ultra-violet rays. The white man can secure adequate
protection in the shade from the heat rays, and by wearing white
clothing he can be adequately protected from the ultra-violet rays.
Whether the retinal excitation by the sun’s rays exerts any stimulating
influence is not known. It is known, however, that red colors are
stimulating. They excite some animals (for example, cattle, frogs
and turkeys) and increase muscular strength. Thus Fere obtained the
following strength records: with ordinary light, 23 units; with blue,
24; with green, 28; with yellow, 30; and with red, 42 (29). Colors,
as is well known, possess marked affective qualities, due not merely
to the affective tone of the sensation and the sense feeling, but to
the affective elements of consciousness, namely associations, emotions
and sentiments (29). That sunlight does exert psychic influences apart
from any specific retinal influence is a matter of common experience.
Nevertheless, the most important visual influence of sunshine is
perhaps not the emotional satisfaction, cheer or exuberance which
it engenders, but the optical value of good daylight. Daylight is
relatively colorless because it contains both chromatic and achromatic
light. A bright colorless illumination is best from the standpoint of
visual efficiency, health and affective quality. It is less fatiguing
than a colored light or than intense or dull artificial light. Electric
lights are often too intense because of the proximity of the light or
because the rays are thrown directly into the eyes or directly upon the
object under observation. They thus over-stimulate the sensitive layers
of the retina, and this may cause degenerative changes. Mercury vapor
lamps and old Welsbach burners emit a greenish flame whose affective
quality is very disagreeable to many persons. Many of the gas jets in
common use, unless equipped with incandescent burners, not only give a
weak flickering, dirty yellowish light, which is extremely fatiguing
and irritating to the eyes, but they also vitiate the air of the living
rooms, particularly in the homes of the poor in the winter time. Add to
these difficulties the further fact that by habit and association we
have learned to base our visual estimation and discrimination of things
on their appearance in broad daylight, and we begin to appreciate the
baneful optical effects of the frequent obscuration of the sun by smoke
clouds, by smoke-produced water clouds and fogs, and by the filling
of the atmosphere with opaque particles. As stated before, particles
in the air and fogs may reduce the limit of visibility from one mile
to less than one city block. During the dark days which are common in
manufacturing cities the lights must be kept burning in the homes,
schools, shops and factories--anywhere, in fact, where close eye work
must be done--all day. Almost always the lights must be turned on very
early in the evenings. Very frequently the intensity of artificial
illumination does not meet the requirements of visual health. Aside
from this, artificial illumination entails a considerable economic
loss. Worse still is the condition of those who, through financial
limitations, must work in the dark gloom of smoky days without the
aid of artificial light. The writer has shown in a special experiment
on the visual estimation of distances that bright objects are judged
to be nearer the observer than similar black objects when placed at
the same distance (25). This being the case, it is evident, as indeed
common observation indicates, that anything on which the eyes must be
fixated in darkened illumination will be imperfectly envisaged. To
overcome this optical handicap, there is a strong tendency to move the
object too near the eyes. If done repeatedly this entails a severe
strain on the muscles of accommodation, causing increased muscular
fatigue, which may result in muscular paralysis, imbalance or dioptric
distortions. On the other hand, by illuminating an object with good
daylight it will be made to appear nearer to the eye. The result is
that objects will actually be held at a further distance and distant
objects will be seen without eyestrain. If an investigation could be
carried out on a large scale with sufficient accuracy, it is possible
that a greater prevalence of myopia, myopic astigmatism and other eye
disorders would be found in densely smoky cities than in smoke-free
cities, so that a positive correlation would be found to exist between
eyestrain or certain eye disorders and atmospheric smoke.
Dark days repress the infra-red rays and thus diminish solar energy.
In fact, on excessively smoky days only a small amount of solar heat
penetrates to the earth’s surface. This circumstance may be rather
welcome to man during the excessive heat of the summer (although
objectionable to plant life), but during the winter time it may cause
much misery, particularly among the poor, because of the excessive
diurnal cold during this season (smoke clouds elevate the nocturnal
temperature). It is also possible that the reduction of the heat
profoundly affects the habits of the community. Thus Dexter (5) has
shown that low temperatures (10°) produce an excess of drunkenness
amounting to 38%, while high temperatures (85°) decrease drunkenness
to the extent of 40%. High winds, which lower the bodily temperature,
also increase dissipation. The increased tendency to dissipate
probably results from an attempt to seek forgetfulness from misery in
alcoholic narcosis, or from an attempt to artificially elevate the body
temperature by indulgence in drink.
Dark days exert a particularly sinister influence upon working people.
One factory head has ventured the opinion that a disagreeable day
yields about 10% less in labor returns than an agreeable day. During
human labor the chemical products of activity are greatly augmented.
The amount of carbon dioxide given off during a day of work is nearly
twice as much as during a day of rest. Observations on the embryos of
frogs also indicate that more carbonic acid is given off when it is
light than when it is dark (Moleschott). Therefore, merely reasoning
from these premises, it would appear that the bodily waste products
from muscular activity, and probably also to a lesser extent from
mental activity, are more injurious on dark than on bright days. Not
only so: dark, sunless days are likely to be moist, rainy or foggy.
During foggy days particularly the poisonous gases are unable to rise
because of the atmospheric stagnation that obtains during fogs. On
these days the amount of carbon dioxide may sometimes be increased
from 200 to 300% as compared with clear days. Dexter (5) attributes
the devitalizing, depleting effects of fogs to lowered electrical
potential. He regards atmospheric states of high electrical potential
as stimulating and vitalizing to animal life. But it has not been
conclusively shown that the electrical potential is decreased during
fogs. On the contrary, it is maintained that fogs, especially thick,
winter fogs, usually raise the potential (14), while the low ground
fogs in late summer and fall have been found to lower the potential.
But then, again, Chauvenau found that thick, city fogs exercised no
influence on the electrical potential. It has, therefore, not been
proved that lowered electrical potential has anything to do with the
depleting effects of fogs; but I am of opinion that the suppression of
the tonic chemical rays of the sunshine is an important factor.
Again, moisture in the atmosphere may become very injurious because it
absorbs the poisonous exhalations of living organisms. Hence the air
which must be breathed on moist, dark days is liable to be surcharged
with toxic waste products which poison the individual.
The effects of moisture _per se_ vary with the temperature. During
warm, moist atmospheric conditions there is diminished evaporation
from the lungs, fewer red corpuscles (because there is less oxygen
in the air), increased tendency towards intestinal troubles, lowered
resistance, and greater mental and bodily fatigue and prostration;
while during cool moist weather catarrhal, respiratory and rheumatic
affections are aggravated (3, 26).
It has been observed that changes in the density of moisture affect the
sensitivity for odors, tastes and touch. Tea-tasters do their best work
on fair days (11).
That the electrical potential decreases with increase of humidity
has, apparently, been established, except under conditions of fog.
It we grant that a state of high electrical potential stimulates and
energizes the organism, then a part of the devitalizing effect of humid
days must be ascribed to a lessened potential.
Not the least detrimental effect of the dark smoke strata of our
cities is the fact that they intercept the bactericidal rays of the
sun, namely, the blue and ultra-violet rays. These rays either check
the growth of, or completely exterminate, various kinds of pathogenic
bacteria (1, 6). Their deadly effect on the tubercle bacilli is
universally recognized. Indeed, as Sternberg points out, sunlight
is one of the most potent and one of the cheapest agents for the
destruction of pathogenic bacteria. Less diseases are found during
sunshiny than foggy or cloudy weather, while the death rate increases
considerably during fogs. Thus during a November fog in Glasgow the
death rate rose to 13.9 while in other Scotch towns free from fog it
was only 3.3. But the increase in the mortality is not merely due to
the fact that the sunless, foggy states lower the temperature and favor
the growth of micro-organisms, but the water globules absorb particles
of dust and acrid smoke and the toxic products of respiratory waste.
(In factories dust particles become vehicles for the products of human
fatigue.) The inhalation of these products irritates and poisons
the mucous membrane. Moisture is particularly injurious in cases of
pathological nasal obstruction. We should not forget, then, that fog
and particularly dense smoke fog may entirely extinguish those rays
of the sun which exert not only a germicidal action, but which also
possess a tonic, vitalizing quality, viz., the short wave lengths.
Now, since smoke diminishes the sunlight, reduces or suppresses the
heat giving infra-red and the tonic ultra-violet rays, and diminishes
the electrical potential (at least during certain states of the
atmosphere); since smoke increases humidity, both during cold and
warm weather, but particularly during cold states; and since it also
increases fogs, and since fogs and humidity tend to increase the
poisonous, bactericidal and solid contents of the air and to decrease
the electrical potential and the heat light rays; it is evident that
smoke must exert an important influence on human health, happiness and
efficiency, and that the smoke nuisance must be regarded as a problem
of very vital concern to any community that would conserve the vital
efficiency of its citizenship.