A Civic Biology Part 40
[Ill.u.s.tration: A sensible lunch box, sanitary and compact.]
If you eat your lunch on the street near your school, remember not to scatter refuse. Paper, bits of lunch, and the like scattered on the streets around your school show lack of school spirit and lack of civic pride. Let us learn above all other things to be good citizens.
[Ill.u.s.tration: Dust exhausts on grinding wheels protect lungs of the workmen.]
Inspection of Factories, Public Buildings, etc.--It is the duty of a city to inspect the condition of all public buildings and especially of factories. Inspection should include, first, the supervision of the work undertaken. Certain trades where grit, dirt, or poison fumes are given off are dangerous to human health, hence care for the workers becomes a necessity. Factories should also be inspected as to cleanliness, the amount of air s.p.a.ce per person employed, ventilation, toilet facilities, and proper fire protection. Tenement inspection should be thorough and should aim to provide safe and sanitary homes.
Inspection of Food Supplies.--In a city certain regulations for the care of public supplies are necessary. Foods, both fresh and preserved, must be inspected and rendered safe for the thousands of people who are to use them. All raw foods exposed on stands should be covered so as to prevent insects or dust laden with bacteria from coming in contact with them. Meats must be inspected for diseases, such as tuberculosis in beef, or trichinosis in pork. Cold storage plants must be inspected to prevent the keeping of food until it becomes unfit for use. Inspection of sanitary conditions of factories where products are canned, or bakeries where foods are prepared, must be part of the work of a city in caring for its citizens.
Care of Raw Foods.--Each one of us may cooperate with the city government by remembering that fruits and vegetables can be carriers of disease, especially if they are sold from exposed stalls or carts and handled by the pa.s.sers-by. All vegetables, fruits, or raw foods should be carefully washed before using. Spoiled or overripe fruit, as well as meat which is decayed, is swarming with bacteria and should not be used.
An interesting exercise would be the inspection of conditions in your own home block. Make a map showing the houses on the block. Locate all stores, saloons, factories, etc. Notice any cases of contagious disease, marking this fact on the map. Mark all heaps of refuse in the street, all uncovered garbage pails, any street stands that sell uncovered fruit, and any stores with an excessive number of flies.
In addition to food inspection, two very important supplies must be rendered safe by a city for its citizens. These are milk and water.
[Ill.u.s.tration: Clean cows in clean barns with clean milkers and clean milk pails means clean milk in the city.]
Care in Production of Milk.--Milk when drawn from a healthy cow should be free from bacteria. But immediately on reaching the air it may receive bacteria from the air, from the hands of the person who milks the cows, from the pail, or from the cow herself. Cows should, therefore, be milked in surroundings that are sanitary, the milkers should wear clean garments, put on over their ordinary clothes at milking time, while pails and all utensils used should be kept clean. Especially the surface exposed on the udder from which the milk is drawn should be cleansed before milking.
Most large cities now send inspectors to the farms from which milk is supplied. Farms that do not accept certain standards of cleanliness are not allowed to have their milk become part of the city supply.
Tuberculosis and Milk.--It is recognized that in some European countries from 30 to 40 per cent of all cattle have tuberculosis. Many dairy herds in this country are also infected. It is also known that the tubercle bacillus of cattle and man are much alike in form and action and that _probably_ the germ from cattle would cause tuberculosis in man. Fortunately, the tuberculosis germ does not _grow_ in milk, so that even if milk from tubercular cattle should get into our supply, it would be diluted with the milk of healthy cattle. In order to protect our milk supply from these germs it would be necessary to kill all tubercular cattle (almost an impossibility) or to pasteurize our milk so as to kill the germs in it.
Other Disease Germs in Milk.--We have already shown how typhoid may be spread through milk. Usually such outbreaks may be traced to a single case of typhoid, often a person who is a "typhoid carrier," _i.e._ one who may not suffer from the effects of the disease, but who carries the germs in his body, spreading them by contact. A recent epidemic of typhoid in New York City was traced to a single typhoid carrier on a farm far from the city. Sometimes the milk cans may be washed in contaminated water or the cows may even get the germs on their udders by wading in a polluted stream.
Diphtheria, scarlet fever, and Asiatic cholera are also undoubtedly spread through milk supplies. Milk also plays a very important part in the high death rate from diarrhoeal diseases among young children in warm weather.
Why?
[Ill.u.s.tration: A diagram to show how typhoid may be spread in a city through an infected milk supply. The black spots in the blocks mean cases of typhoid. _A_, a farm where typhoid exists; the dashes in the streets represent the milk route. _B_ is a second farm which sends part of its milk to _A_; the milk cans from _B_ are washed at farm _A_ and sent back to _B_.
A few cases of typhoid appear along _B_'s milk route. How do you account for that?]
Grades of Milk in a City Supply.--Milk which comes to a city may be roughly placed in three different cla.s.ses. The best milk, coming from farms where the highest sanitary standards exist, where the cows are all tubercular tested, where modern appliances for handling and cooling the milk exist, is known as certified or, in New York City, grade A milk. Most of the milk sold, however, is not so pure nor is so much care taken in handling it.
Such milk, known in New York as grade B milk, is pasteurized before delivery, and is sold only in bottles. A still lower grade of milk (dipped milk) is sold direct from cans. It is evident that such milk, often exposed to dust and other dirt, is unfit for any purpose except for cooking. It should under no circ.u.mstances be used for children. A regulation recently made by the New York City Department of Health states that milk sold "loose" in restaurants, lunch-rooms, soda fountains, and hotels must be pasteurized.
Care of a City Milk Supply.--Besides caring for milk in its production on the farm, proper transportation facilities must be provided. Much of the milk used in New York City is forty-eight hours old before it reaches the consumer. During shipment it must be kept in refrigerator cars, and during transit to customers it should be iced. Why? All but the highest grade milk should be pasteurized. Why? Milk should be bottled by machinery if possible so as to insure no personal contact; it should be kept in clean, cool places; and no milk should be sold by dipping from cans. Why is this a method of dispensing impure milk?
Care of Milk in the Home.--Finally, milk at home should receive the best of care. It should be kept on ice and in covered bottles, because it readily takes up the odors of other foods. If we are not certain of its purity or keeping qualities, it should be pasteurized at home. Why?
[Ill.u.s.tration: New York City is spending $350,000,000 to have a pure and abundant water supply. This is the tunnel which will bring the water from the Catskill Mountains to New York City.]
Water Supplies.--One of the greatest a.s.sets to the health of a large city is pure water. By pure water we mean water free from all _organic_ impurities, including germs. Water from springs and deep driven wells is the safest water, that from large reservoirs next best, while water that has drainage in it, river water for example, is very unsafe.
The waters from deep wells or springs if properly protected will contain no bacteria. Water taken from protected streams into which no sewage flows will have but few bacteria, and these will be destroyed if exposed to the action of the sun and the constant aeration (mixing with oxygen) which the surface water receives in a large lake or reservoir. But water taken from a river into which the sewage of other towns and cities flows must be filtered before it is fit for use.
[Ill.u.s.tration: The city of Lowell in 1891 took its water _without filtering_, _i.e._ from the Merrimack River at the point shown on the map.
Typhoid fever broke out in North Chelmsford and about two weeks later cases began to appear in Lowell until a great epidemic occurred. Explain this outbreak. Each black dot is a case of typhoid.]
Typhoid fever germs live in the food tube, hence the excreta of a typhoid patient will contain large numbers of germs. In a city with a system of sewage such germs might eventually pa.s.s from the sewers into a river. Many cities take their water supply directly from rivers, sometimes not far below another large town. Such cities must take many germs into their water supply. Many cities, as Cleveland and Buffalo, take their water from lakes into which their sewage flows. Others, as Albany, Pittsburgh, and Philadelphia, take their drinking water directly from rivers into which sewage from cities above them on the river has flowed. Filtering such water by means of pa.s.sing the water through settling basins and sand filters removes about 98 per cent of the germs. The result of drinking unfiltered and filtered water in certain large cities is shown graphically at right.
In cities which drain their sewage into rivers and lakes, the question of sewage disposal is a large one, and many cities now have means of disposing of their sewage in some manner as to render it harmless to their neighbors.
[Ill.u.s.tration: Filter beds at Albany, N. Y.]
[Ill.u.s.tration: Cases of typhoid per 100,000 inhabitants before filtering water supply (solid) and after (shaded) in _A_, Watertown, N. Y.; _B_, Albany, N. Y.; _C_, Lawrence, Ma.s.s.; D, Cincinnati, Ohio. What is the effect of filtering the water supply?]
Railroads are often responsible for carrying typhoid and spreading it. It is said that a recent outbreak of typhoid in Scranton, Pa., was due to the fact that the excreta from a typhoid patient traveling in a sleeping car was washed by rain into a reservoir near which the train was pa.s.sing.
Railroads are thus seen to be great open sewers. A sanitary car toilet is the only remedy.
[Ill.u.s.tration: This chart shows that during a cholera epidemic in 1892 there were hundreds of cases of cholera in Hamburg, which used unfiltered water from the Elbe, but in adjoining Altona, where filtered water was used, the cases were very few.]
[Ill.u.s.tration: Stone filter beds in a sewage disposal plant.]
Sewage Disposal.--Sewage disposal is an important sanitary problem for any city. Some cities, like New York, pour their sewage directly into rivers which flow into the ocean. Consequently much of the liquid which bathes the sh.o.r.es of Manhattan Island is dilute sewage. Other cities, like Buffalo or Cleveland, send their sewage into the lakes from which they obtain their supply of drinking water. Still other cities which are on rivers are forced to dispose of their sewage in various ways. Some have a system of filter beds in which the solid wastes are acted upon by the bacteria of decay, so that they can be collected and used as fertilizer. Others precipitate or condense the solid materials in the sewage and then dispose of it. Another method is to flow the sewage over large areas of land, later using this land for the cultivation of crops. This method is used by many small European cities.
[Ill.u.s.tration: Collecting ashes.]
The Work of the Department of Street Cleaning.--In any city a menace to the health of its citizens exists in the refuse and garbage. The city streets, when dirty, contain countless millions of germs which have come from decaying material, or from people ill with disease. In most large cities a department of street cleaning not only cares for the removal of dust from the streets, but also has the removal of garbage, ashes, and other waste as a part of its work. The disposal of solid wastes is a tremendous task. In Manhattan the dry wastes are estimated to be 1,000,000 tons a year in addition to about 175,000 tons of garbage. Prior to 1895 in the city of New York garbage was not separated from ashes; now the law requires that garbage be placed in separate receptacles from ashes. Do you see why? The street-cleaning department should be aided by every citizen; rules for the separation of garbage, papers, and ashes should be kept. Garbage and ash cans should be _covered_. The practice of upsetting ash or garbage cans is one which no young citizen should allow in his neighborhood, for sanitary reasons. The best results in summer street cleaning are obtained by washing or flushing the streets, for thus the dirt containing germs is prevented from getting into the air. The garbage is removed in carts, and part of it is burned in huge furnaces. The animal and plant refuse is cooked in great tanks; from this material the fats are extracted, and the solid matter is sold for fertilizer. Ashes are used for filling marsh land. Thus the removal of waste matter may pay for itself in a large city.
[Ill.u.s.tration: The upper picture shows the stables where millions of flies were bred; the lower picture, the disinfection of manure so as to prevent the breeding of flies.]
An Experiment in Civic Hygiene.--During the summer of 1913 an interesting experiment on the relation of flies and filth to disease was carried on in New York City by the Bureau of Public Health and Hygiene of the New York a.s.sociation for improving the condition of the poor. Two adjoining blocks were chosen in a thickly populated part of the Bronx near a number of stables which were the sources of great numbers of flies. In one block all houses were screened, garbage pails were furnished with covers, refuse was removed and the surroundings made as sanitary as possible. In the adjoining block conditions were left unchanged. During the summer as flies began to breed in the manure heaps near the stables all manure was disinfected. Thus the breeding of flies was checked. The campaign of education was continued during the summer by means of moving pictures, nurses, boy scouts, and school children who became interested.
At the end of the summer it was found that there had been a considerable decrease in the number of cases of fly-carried diseases and a still greater decrease in the total days of sickness (especially of children) in the screened and sanitary block. The table and pictures speak for themselves.
If such a small experiment shows results like this, then what might a general clean-up of a city show?
[Ill.u.s.tration: In the upper picture a little girl can be seen dumping garbage from the fire escape. She was a foreigner and knew no better. The picture below shows the result of such garbage disposal.]
Public Hygiene.--Although it is absolutely necessary for each individual to obey the laws of health if he or she wishes to keep well, it has also become necessary, especially in large cities, to have general supervision over the health of people living in a community. This is done by means of a department or board of health. It is the function of this department to care for public health. In addition to such a body in cities, supervision over the health of its citizens is also exercised by state boards of health. But as yet the government of the United States has not established a Bureau of Health, important as such a bureau would be.
The Functions of a City Board of Health.--The administration of the Board of Health in New York City includes a number of divisions, each of which has a different work to do. Each is in itself important, and, working together, the entire machine provides ways and means for making the great city a safe and sanitary place in which to live. Let us take up the work of each division of the health board in order to find out how we may cooperate with them.
[Ill.u.s.tration: Comparison of cases of illness during the summer of 1913 in two city blocks, one clean and the other dirty. What are your conclusions?]
The Division of Infectious Diseases.--Infectious diseases are chiefly spread through _personal contact_. It is the duty of a government to prevent a person having such a disease from spreading it broadcast among his neighbors. This can be done by _quarantine_ or _isolation_ of the person having the disease. So the board of health at once isolates any case of disease which may be communicated from one person to another. No one save the doctor or nurse should enter the room of the person quarantined.
After the disease has run its course, the clothing, bedding, etc., in the sick room is fumigated. This is usually done by the board of health.
Formaldehyde in the form of candles for burning or in a liquid form is a good disinfectant. In disinfecting the room should be tightly closed to prevent the escape of the gas used, as the object of the disinfection is to kill all the disease germs left in the room. In some cases of infectious disease, as scarlet fever, it is found best to isolate the patients in a hospital used for that purpose. Examples of the most infectious diseases are measles, scarlet fever, whooping cough, and diphtheria.
Immunity.--In the prevention of germ diseases we must fight the germ by attacking the parasites directly with poisons that will kill them (such poisons are called _germicides_ or _disinfectants_), and we must strive to make the persons coming in contact with the disease unlikely to take it.
This insusceptibility or _immunity_ may be either natural or acquired.
Natural immunity seems to be in the const.i.tution of a person, and may be inherited. Immunity may be acquired by means of such treatment as the ant.i.toxin treatment for diphtheria. This treatment, as the name denotes, is a method of neutralizing the poison (toxin) caused by the bacteria in the system. It was discovered a few years ago by a German, Von Behring, that the serum of the blood of an animal immune to diphtheria is capable of neutralizing the poison produced by the diphtheria-causing bacteria. Horses are rendered immune by giving them the diphtheria toxin in gradually increasing doses. The serum of the blood of these horses is then used to inoculate the patient suffering from or exposed to diphtheria, and thus the disease is checked or prevented altogether by the ant.i.toxin injected into the blood. The laboratories of the board of health prepare this ant.i.toxin and supply it fresh for public use.
[Ill.u.s.tration: Ant.i.toxin for diphtheria prepared by the New York Board of Health.]
It has been found from experience in hospitals that deaths from diphtheria are largely preventable by _early use_ of ant.i.toxin. When ant.i.toxin was used on the first day of the disease no deaths took place. If not used until the second day, 5 deaths occurred in every hundred cases, on the third day 11 deaths, on the 4th day 19 deaths, and on the 5th day 20 deaths out of every hundred cases. It is therefore advisable, in a suspected case of diphtheria, to have ant.i.toxin used at once to prevent serious results.
Vaccination.--Smallpox was once the most feared disease in this country; 95 per cent of all people suffered from it. As late as 1898, over 50,000 persons lost their lives annually in Russia from this disease. It is probably not caused by bacteria, but by a tiny animal parasite. Smallpox has been brought under absolute control by vaccination,--the inoculation of man with the substance (called _virus_) which causes cowpox in a cow.
Cowpox is like a mild form of smallpox, and the introduction of this virus gives complete immunity to smallpox for several years after vaccination.
This immunity is caused by the formation of a germicidal substance in the blood, due to the introduction of the virus. Another function of the board of health is the preparation and distribution of vaccine (material containing the virus of cowpox).
Rabies (Hydrophobia).--This disease, which is believed to be caused by a protozoan parasite, is communicated from one dog to another in the saliva by biting. In a similar manner it is transferred to man. The great French bacteriologist, Louis Pasteur, discovered a method of treating this disease so that when taken early at the time of the entry of the germ into the body of man, the disease can be prevented. In some large cities (among them New York) the board of health has established a laboratory where free treatment is given to all persons bitten by dogs suspected of having rabies.