CHAPTER XV Tue COLLECTION AND DisposAL OF REFUSE, THE (Part 3)

collecting bin into which the sweepings are brushed by three further rotating brushes. Another machine similarly sweeps the refuse into a bin mounted on a trailer. Disposal of Street Sweepings. The disposal of street sweepings is generally a troublesome matter. The scrapings from macadam- ised roads can generally, if washed, be used with lime or cement for mortar. Mud is often tipped on waste land, but it should not be placed on possible building sites. It can also be mixed with house refuse and burned in a destructor. Street Watering. Apart from the question of cleansing is the question of watering streets in order to keep down the dust in dry, windy weather. In the case of wood-paved roads the water- ing is also beneficial to the wood itself, making it less subject to DISPOSAL OF REFUSE, ETC. 478 injury by abrasion. In crowded districts, or in times of epidemics, disinfectants should be added to the water. An example would be 1 lb. of permanganate of potash and half a pint of sulphuric acid to 100 gallons of water. Blocks of a disinfectant termed pynezone are also used for this purpose. The road may be watered by a hose or by means of a water cart. In England the latter method is the more usual, both horse and motor-driven carts being used. The water either issues through a perforated pipe or is distributed by falling on two rotating discs or spreaders. A good cart or wagon will spread the water over a width of 20 feet, the quantity used varying from one-tenth to one- fifth of a gallon per square yard of surface. Snow Cleansing. In the case of snow, it is difficult to do any- thing until the fall has ceased, when all available men should be set to work, dealing with the streets in the order of their import- ance. The snow should be banked up at the sides of the road, clear of the channels and gullies, with gangways through where desirable. Snow ploughs, both horse and motor driven, are also used. The disposing of the snow often gives trouble. Sometimes it is tipped down manholes into the sewer, but this is only possible with very large sewers. The best plan is to cart it away to the parks and open spaces and tip it on the land. If the town is on the banks of a river, the snow can be thrown into the river. An application of salt greatly facilitates clearance, since it lowers the freezing temperature of water and therefore causes the snow to melt. The resulting slush, however, must be promptly swept away. The expense of completely clearing streets of snow is very great. For example, it has been said that to clear a 6-inch fall of snow from the streets of London would require more vehicles than exist in that area. Any idea of doing more than to clear the principal streets of any large town, after a heavy fall of snow, is one for the squandering of a large sum of money. Disinfection. A few brief notes on the subject of disinfection will not be out of place in the present volume. The principal infectious diseases are: cholera, chickenpox, diphtheria, erysipelas, influenza, measles, mumps, scarlet fever, smallpox, enteric fever, typhus fever, tuberculosis, and whooping cough. Most diseases are caused by bacteria or micro-organisms, hence the urgent necessity for disinfectants and antiseptics. Distinction Between Disinfectants, Antiseptics, Deodorants and Disinfestants. A disinfectant is an agent which will kill the germs of disease, such as hot air, steam, formaldehyde, sulphur dioxide, ATA DISPOSAL OF REFUSE, ETC. chlorine, chloride of lime, perchloride of mercury, carbolic acid and many proprietary preparations mainly derived from coal-tar. An antiseptic is an agent which will prevent the multiplying of bacteria, such as refrigeration, desiccation, aleohol and, in many cases, a weaker dilution of a disinfectant. A deodorant is an agent which will absorb disagreeable odours sometimes the term is applied also to agents which will mask or hide such odours, though that would not be a true deodorant. Dry earth of suitable type forms a good deodorant, so, too, do proprietary preparations containing a good concentration of chloro- phyl, while oxygen and ozone are also excellent in this respect. A disinfestant is an agent which will destroy disease-carrying pests like rats, mice, fleas, lice, bugs, mosquitoes, flies, ete. Hydro- cyanic gas, mentioned later, is one of the best, but is deadly poison and should be used by an expert and with extreme care. Value of Fresh Air and Sunlight. Fresh air and sunlight have considerable germicidal properties, but quick and complete de- struction of germs, or true disinfection, can only be brought about by either chemical means or heat. In most districts there is a public disinfecting station, where articles can be sent for disinfec- tion. Such a station will be described later. Disinfection of Clothing. Where articles of clothing and bed- ding cannot be sent to a disinfecting station they should be burned if possible; otherwise they should be boiled or soaked for twenty-four hours in some disinfecting liquid, such as a solution of Izal, 5 parts to 100 parts of water; chloride of lime, 2 ounces to a gallon of water; carbolic acid, 5 parts to 100 parts of water; or perchloride of mercury, 4 ounce, hydrochloric acid, 1 ounce, and aniline blue, 5 grains, to 3 gallons of water. Perchloride of mer- cury, or corrosive sublimate as it is often called, is a cheap and very powerful disinfectant, dangerous to use on account of its being colourless, and a very deadly poison; the object of mixing the above ingredients with it is to tint it and make it offensive, so as to avoid mistake. Formaldehyde and Formalin. Coal-tar is the original source of most of the patented disinfecting liquids which are on the market. One of the most powerful disinfectants is that known as formaldehyde. It is generally supplied to the public in the form of solution containing 40 per cent. of formaldehyde, the solution being known as formalin. In the same way that the destructive distillation of coal produces coal-tar, so a similar treatment of wood produces wood-tar. In both cases other materials are produced, including, in the latter case, what is known as wood DISPOSAL OF REFUSE, ETC. A475 naphtha or methyl-alcohol, from which, by an oxidising process, the formaldehyde is produced. The use of formaldehyde is apt to produce a painful irritation of the skin and nails, and it is very desirable, therefore, to prevent the hands being wetted by it. Use of Heat and Steam. In the case of articles of small value, the safest way is to burn them, but disinfection may also be secured by exposing them to either dry or moist heat. Exposure to hot air at a temperature of 284° F. for four hours is about equal to the effect of exposure for five minutes to steam at a temperature of 212° F. Steam is therefore much more largely used. Steam Disinfectors. There are many forms of steam disinfecting apparatus. One of the oldest and best known is the “ Washington- Lyons”. The disinfecting chamber is of oval section, encased by a steam jacket, the outer casing being covered with asbestos to assist in retaining the heat. The apparatus is built into a wall which divides a large room into two, and which has no door or other means of communication except a fixed window, through which signals can be given. The infected articles are brought into the room on one side, hence distinguished as the “infected” side, and are put in a cradle or hung on hooks in a light frame on wheels, which is then run into the disinfecting chamber and the door closed and strongly screwed up, a rubber joint making it airtight. Steam, at a pressure of 30 lb. to the square inch, and a temperature of 273° F., is then turned into the outer jacket, so as to raise the temperature of the inner chamber high enough to prevent conden- sation of the moisture, from the clothes, etc. Next, the air is exhausted from the chamber as far as possible, to give space for the steam. This is done by the suction caused by a jet of steam passing over a pipe, with a high velocity, a two-thirds vacuum being obtained in about ten minutes. Steam is then admitted for ten minutes, until a pressure of 80 lb. per square inch is regis- tered, corresponding to a temperature of about 250° F. It is then shut off to see if the pressure gauge shows any fall, due to particles of steam condensing; if so, steam is turned on again until the pressure remains constant. In bad cases, the steam is turned on a second time for a further ten minutes. After the steam is cut off, dry air is passed in through tubes on which steam is playing, in order thoroughly to dry the articles, the cradle being then drawn out through the opposite door of the apparatus, or the “clean” as opposed to the “infected” side of the disinfecting station. The whole process takes from thirty- five to forty minutes. Great care has to be exercised in regulating the temperature, as 476 DISPOSAL OF REFUSE, ETC. the sanitary authority disinfecting is held liable for any damage done to the articles. It is essential that saturated steam should be used, super- heated steam having little greater power of penetration than hot air. Saturated steam is water vapour at the boiling temperature which is normal to the prevailing pressure. Superheated steam is steam whose temperature has been inereased above the boiling- point by passing it through a coil in a furnace, in which form it behaves like other gases. There are a large number of patterns of steam disinfector, and it is difficult to say that one is better than another. One of rather a different type from that just described, however, is the ‘‘ Thresh”’ disinfector. In this, the lower part of the enclosing jacket of the cylinder acts as the boiler, and has a small furnace under it. The steam passes continuously through the disinfecting chamber, escaping up a chimney, and so is not under pressure, as in the case of the Washington-Lyons apparatus. Heated air is then admitted and the articles thus rapidly dried. Infected articles should be brought to the disinfecting station in proper vans, lined with iron and airtight, kept solely for the carriage of infected articles, separate vans being used for carrying away the clean articles and kept for that purpose only. Public Disinfecting Stations. A public disinfecting station con- sists principally of two rooms, the infected and disinfected side, separated by a wall with no possibility of the passage of air from one to the other, such as a door or opening window. The appara- tus is built into this wall. The van used for the carriage of infected goods should be housed at the infected end of the building, and the clear van at the other end. An incinerator, or small refuse destructor, should be installed at the infected end for the destrue- tion of things which are too filthy to clean. Bedclothing and similar things require to be soaked in water and washed before passing through the disinfector, as the steam would fix the stains permanently. It is therefore usual to install a certain amount of laundry apparatus, such as a washer, hydro-extractor (or centri- fugal wringer), drying chamber and mangle, ete. Some things cannot be subjected to steam at all. It is therefore a good plan to provide a formalin chamber, that is to say, a room kept exclusively for submitting articles to the action of formalde- hyde gas, generated by special types of lamp. Verminous Persons. Bathrooms should be provided, one for men and one for women, for the cleansing of verminous persons. The bathrooms should adjoin the infected room, and have special DISPOSAL OF REFUSE, ETC, ATT hoppers, locking each side, in which the person can place his clothes, which are then put through the disinfector and made fit for use again. In some cases, a bottle-washing room is added with special washing machines, sinks, ete. It perhaps need hardly be said that any such building should be exceptionally well lighted and ventilated, and that the walls and floors should be jointless and non-absorbent, the walls being prefer- ably of glazed tiles to facilitate cleansing. All angles should be rounded, with the same object. Disinfection of Living Rooms. We come next to the disinfection of rooms. This can be done in many ways. Assume sulphur dioxide is to be used: Open all cupboards, drawers, boxes, ete., saturate the walls, floor and woodwork with water, and seal up all openings, such as fireplace, windows, doors and ventilators, with brown paper. Place the sulphur on a tin plate, say 2 lb. to every 1000 cubic feet of space and support it in a larger vessel containing water, to guard against fire. Put this in the middle of the room, ignite the sulphur, and make a speedy exit. Shut the door and seal it up by pasting strips of paper round. Leave the room thus for twenty-four hours. Then open the doors and windows, strip the paper off the walls and burn it, wash off the ceiling with limewash, and scrub the floor and all woodwork, furniture, etc., with a solution of perchloride of mercury, 1 part to 1000 parts of water. The sulphur dioxide can also be obtained in tins under pressure, which is a convenient form, as all that is necessary is to cut off the top of the tin and allow the gas to escape. Gilt picture frames, or steel goods, should not be allowed to remain in the room, as the sulphur spoils them. Formaldehyde is largely used for the fumigation of rooms, being either vaporised by means of special lamps, or sprayed over the surfaces of walls, ceilings, floors, ete. Vapour-producing Lamps and Sprays. Many forms of lamp and spray have been introduced, but it is deemed beyond the province of this volume to deal with them. Some important experiments in reference to the spraying of disinfectants were carried out by Drs. Thresh and Lowden, who arrived at the follow- ing conclusions: 1. That for spraying to be efficient, every portion of the surface to be disinfected must be thoroughly moistened with the disinfect- ing solution; merely passing the spray into a room and trusting to its settling upon the surfaces is utterly unreliable. 478 DISPOSAL OF REFUSE, ETC. 2. The whitewashed surfaces require particular attention, being far more difficult to disinfect than surfaces of wood and paper. 3. That solutions containing under 2 per cent. of formaldehyde are not absolutely reliable. Solutions, therefore, of not less than these strengths should be used. 4, That a proper spray, properly used, effects room disinfection in the minimum of time and with the minimum of expense, and is more reliable than disinfection by sulphur or formalin vapour. Some of the forms of disinfecting lamp are arranged so that they can, if desired, work from the outside of the room by spraying through the keyhole. Hydrocyanic Gas for Disinfection and Disinfestation. Hydro- eyanic acid gas, which in solution is commonly known as prussic acid, is a most effective means of fumigation, and destroys bacteria, vermin, bugs, lice and even the eggs of bugs, ete. It does no damage to metal, wood or paintwork, is relatively cheap and there is no danger of fire. The disadvantage of the method is that it is a most deadly poison, so that its application needs skilled operators and the evacuation of the house on either side. The destruction of pests (or “‘ Disinfestation”’) is often particularly important, owing to the diseases which many of them carry, and in this connection, insects such as flies, bugs, lice, beetles, etc., can be conveniently dealt with by a dust or spray containing D.D.T. or by a dust, fumigation or spray of Gammexane, both of which have a valuable residual action lasting some weeks and which act by paralysis rather than direct poison. Smoke Abatement. Another point which may be just referred to under the heading of drainage and sanitation is that of smoke abatement. In large boiler furnaces the chief cause of smoke is improper stoking and an insuflicient air supply. If the furnace is regularly stoked with small quantities of fuel at short intervals, and is provided with proper draught, either natural or forced, there should be no nuisance. The chimney should not, in fact, be looked upon as solely intended to let the smoke out, its main purpose being to produce a draught through the furnace and assist com- bustion, As the hot gases rise up the chimney, air must enter the furnace to take their place. If a forced draught is used injudiciously, it is apt to be productive of considerable smoke, but foreed-draught systems should be capable of regulation, and be put in the hands of competent stokers. At the time of writing (July 1956) it seems likely that the Clean DISPOSAL OF REFUSE, ETC. 479 Air Act 1956 will become law. Before this there were about nineteen local authorities in this country who had taken powers under local acts of parliament to establish “Smokeless Zones” and about forty who had obtained lesser powers under local acts to control smoke from industrial chimneys. These powers generally excepted smoke from domestic chimneys and required industries to abstain from emitting dark smoke only “‘as far as practicable” and gave many loopholes. The Clean Air Act would give all local authorities, by ‘‘Order’’, and without a local act, powers to designate ‘“‘Smoke Control Areas”’, and prohibit the emission of dark smoke from the chimneys of any building (industrial or domestic) in the zone, unless speci- fically excepted. Such “Orders” require confirmation of the Minister. In “designated areas’? owners or