Social Hygiene of Human Dwellings.

Hygienically, residential premises should be spacious, dry and light. They should be aired regularly. The air in the room should be clean and it should not contain any hazardous substances or pathogenic microorganisms. The microclimate in the room should be favourable. Esthetically, the interior should be pleasing. The person should feel comfortable to have a rest or to work in the room.

1. Orientation of residential premises.

To provide sufficient lighting and heating of the room, one should be aware of the orientation of residential premises. The room should be accessible to sunlight. From 22^nd March till 22^nd September the exposure to direct solar irradiation (insolation) in the territory of Russia should be no less than 2, 5 hours per day long. In this case buildings facing south or south-east are most beneficial. In the torrid zone sun rays fall upright. Therefore, the room is hardly accessible to sunlight. In the frigid zone, however, sun rays are more oblique. Therefore, sun rays penetrate deeper into the room. In the torrid zone residential buildings should not face west, because sun rays penetrate into the room in the afternoon when the air in the room and the walls of the residential buildings are warm enough. It can result in overheating. In the temperate zone meridian orientation of residential buildings should have an angle of deviation of 19 – 22º from the meridian. In this case buildings usually face east or west.

2. Construction materials.

The main hygienic requirement imposed on construction materials is that they should be characterized by poor heat conductivity so that construction materials can protect buildings from over-cooling or overheating. For example, the wood has a heat conductivity factor of 0, 15- 0, 25; the brick – 0, 5- 0, 75; the concrete – 0, 9- 1, 25.

Low sound-conductivity of building materials used in supporting structures is also of great importance.

Beside natural construction materials, such as wood, brick and stone, some polymeric construction materials are commonly used nowadays. They are cheaper, lighter, more solid and waterproof. It is much easier to clean them. However, they can be rather dangerous for human health.

A wide use of polymeric and synthetic construction materials threatens the health of a person due to toxic monomers released from the materials in the course of their wear and tear. Most monomers contain functionally active chemical groups and biologically, they are much more aggressive than polymeric construction materials, which are obtained from them. The toxicity level of polymeric materials depends on the elements added to make the construction materials more commercial. These elements include softeners, stabilizers, coloring agents, etc. They have an unfavourable effect on the environment too. The number of hazardous substances and the terms of their emission from polymeric materials depend upon their physical and chemical properties (volatility, steam tension, etc.), operating conditions (microclimate, sun rays, etc.), rate of their wear and tear (polymer destruction).

On the basis of general hygienic evaluation, which involves sanitary, chemical, physical, physiological, hygienic, toxicological and microbiological research (the scope of research is determined by the conditions in which the materials are used) the Centre for Sanitary & Epidemiological Control regulates the use of polymeric and synthetic construction materials. According to the results of a comprehensive study, the Centre for Sanitary & Epidemiological Control gives permission to the use of polymeric materials (current inspection is carried out every three years). Hygienic research is carried out according to the rules of Sanitary Law (Item № 2.1.2. 729-99 “Polymeric and polymer-impregnated construction materials, goods and constructions. Hygienic requirements imposed on safe construction materials”).

However, in some cases production technologies and the use of these materials are inadequate which results in mass diseases. The doctor who establishes the diagnosis of allergic, acute respiratory and other diseases should consider that the disease can be associated with the contact of people with polymeric and synthetic materials at home or at work. If the effect of the construction materials is not eliminated, the treatment will not be successful.

Thus, the use of rubber linoleum in the wards of a hospital promoted the development of the symptoms of drug allergy. The withdrawal of the drugs did not improve the patients’ condition. The patients were discharged from the hospital and they recovered shortly after the discharge. After changing the floor in the wards of the hospital, the patients did not develop the same symptoms any more.

Beside allergic reactions, substances which are emitted as a result of polymer destruction (such as phenol, formaldehyde, styrene, phtalates, xylyl, benzol, etc.), can have a general toxic effect.

Polymeric construction materials are good dielectrics. They keep electricity from escaping the body and thus, they have an unfavourable effect on metabolic and trophic processes which take place in the human body. Moreover, polymeric construction materials are able to produce static electric fields (dc fields) on their surface. When the fields are discharged, instantaneous electrolyte rearrangement occurs in the human body which results in reflectory changes of the central nervous system. Static electric fields at a level of 500 V/cm2 can have a mutagenic and embryotropic effect.

The specific nature of physical and chemical properties of polymeric construction materials can be the cause of the deterioration of microclimate in human dwellings, of considerable vertical temperature fluctuations and air humidity changes. All these can cause influenza and some other catarrhal diseases as well as peripheral central nervous system diseases, for example radiculitis.

To prevent diseases caused by polymeric and synthetic construction materials, doctors should take the following measures:

1) When taking the history of the patient presenting with the symptoms of allergy, the doctor should find out what polymeric and synthetic building materials are used at home and at work, notably: flooring, interior, decoration, furniture, carpets, etc. The doctor should also find out whether avoiding the contact with polymeric materials improves the patient’s condition.

2) When establishing the polymeric material which provoked the disease in 1 or several patients, the doctor should inform the Centre for Sanitary and Epidemiological Control about the case. He should do it in writing within 3 days from the day the cause of the disease was revealed. The report should be signed by the Principal Doctor of the hospital.

3) The doctor should carry out sanitary and educational work among the population. The doctor should promote the use of natural construction materials for decorating their flats. At the same time they should convince people to reduce the amounts of polymeric and synthetic materials used in construction or to use these materials according to hygienic standards.

4) The doctor should control the use of polymeric and synthetic materials in constructing, reconstructing or redecorating patient care institutions.

Polymer materials which are permitted to be used for building and redecorating various locations are listed in Polymer and polymer-containing materials and structures permitted for use in construction industry.