Buildings should be places to protect us from the ill affects of the environment -wind, rain, heat and cold -but unless they are designed and managed properly, an inside environment can sometimes be more unhealthy than the outside. Just consider the following, for example.
Radon is a naturally occurring radioactive gas that is responsible for the majority of exposure of the general public to background radiation. It is produced from radioactive decay of uranium. Uranium is found in most places in the Earth’s crust. It escapes the crust through tiny spaces in the ground and then into the atmosphere. Radon is known to accumulate in confined indoor areas, particularly in poorly ventilated houses. Epidemiologic studies have shown an increased risk of lung cancer with proportional increasing exposure to radon.
Radon is measured in units known as becquerels. One Becquerel means that there is one radioactive decay of a radon atom per second for every cubic meter of air (Bq/m3). For example in Antarctic air the concentration is lower that 0.1 while typical indoor exposure is approximately 100. If a home or building is located on soils with a high uranium concentration the levels may be as high as 1000. It is recommended that homes and buildings with levels exceeding 150 - 200 Bq/m3 taken to lower concentrations. This recommendation varies between countries.
Radon levels vary widely with location. For example Australian soils are very low in radon, the average concentration in an Australian home is 12 Bq/m3. In the UK the average in homes is 20 Bq/m3, with the highest concentrations being found in the southwest. Radon levels depend upon several factors such as the amount of uranium in the soils, the soil permeability and soil moisture. Building located on dry, highly permeable soils with fractured bedrock on slopes may have a higher level of radon that otherwise expected from air levels.
Testing for radon can be done by a home owner or by a professional. The availability of detection systems will vary with different locations.
Air Quality and Allergies
As previously mentioned air quality is obviously affected by the local environment. Indoor air quality is also going to be affected by this, however it also affected by additional factors. Poor indoor air quality can lead to allergies.
Allergenic substances can be airborne and inhaled. These include pollen, fungus, and dust. Indoor airborne allergic substances come from two sources:
- Outdoor airborne particles moving indoors
- Allergic components originating from inside the building.
The development of humidity and microclimates within the building will increase the incidence of indoor organisms. Diseases caused by airborne allergenic substances include: asthma, allergic rhinitis, serous otitis media, broncho pulmonary aspergillosis and hypersensitivity pneumonitis. Volatile components from paints, carpets, pesticides, and furnishings may cause stuffy noses, dry throats, chest tightness, lethargy, a loss of concentration, blocked or itchy noses, dry skin, watering or itchy eyes, and headaches in sensitive people. All-in-all the work environment may be similar to a soup of sickness.
Ventilation plays a major role in maintaining air quality. Fresh air circulating into a building increases oxygen levels, and flushes out carbon dioxide build up resulting from human respiration. It also flushes out odours, fumes, dusts, pollutants etc resulting from human activity, the operation of machines, and the by-products of building materials.
Temperature and Humidity
Building temperature is going to be a product of latitude, aspect and building design and insulation. The temperature of a building can be a major contributor to the comfort of the people working in it. Too hot and you can start to feel sweaty and uncomfortable, or lethargic. Too cold and you may start to shiver. Ideal working temperatures will vary from person to person. Generally temperatures in the range of 18-20 degrees C is preferred for offices, with temperatures slightly lower (around 16 degrees C) in factories where light work is carried out. Relative humidity should be in the range of 40 to 70%. If the humidity is too high the atmosphere feels oppressive and natural cooling due to perspiration is reduced. If humidity is too low then dry throats and dry skin can occur.
Interior light can be supplied in several different ways:
- Natural light (e.g. from the sun and moon) radiating from the outside of the building, coming through windows, skylights, etc.
- Combustion systems: open fires, gas lamps, kerosene lamps, candles, etc.
- Electric Lights: incandescent lights, fluorescent lighting, etc. Any flickering lights should be repaired or replaced.
The light intensity required varies from place to place. Work areas require a higher light intensity (e.g. a desk, work bench, or kitchen). Areas where light intensity may need to be lower might include: the bedroom, near a television (to avoid glare), or in a photographic developing room (darkroom). Above all, the brightness of an area should be maintained at a level that is comfortable for those working in the area.
Humans, however, have evolved in natural sunlight and generally feel much better when exposed to sunlight rather than artificial light sources. Research in Scandinavia has linked a high incidence of depression during winter months with a lack of sunlight (SAD: seasonal affective disorder). Treatment of depression patients by maximising the amount of sunlight they receive during the winter months or by exposing them to artificial lights that better simulate natural sunlight than does most office lighting, has resulted in a marked decrease in the depressive symptoms.
Electromagnetic Radiation (EMR)
The presence of everyday radiation is well documented. We experience varying degrees of radiation from the atmosphere, our homes, the television, and from most things that we have contact with during the course of a day. Radiation is a physical phenomenon which is a by-product of atomic interaction. Atoms are the smallest building blocks of matter. All matter is composed of atoms.
Electromagnetic radiation is therefore all around us - it can and does affect our environment. Buildings too, it is quickly being realised, are subject to this radiation. This may affect those people who are using the building. The symptoms of an unhealthy building due to earth radiation might be lethargy among workers, an above average incidence of accidents for seemingly no apparent reason, or it could even involve acute illnesses such as cancers or respiratory problems occurring in staff or residents. For these reasons, electromagnetic radiation cannot be taken lightly. The exact science of electromagnetic radiation is still not fully understood.
An obvious case of man-made electromagnetic radiation is power lines, especially large voltage or high intensity lines. These power lines give off high levels of radiation and studies in Sweden and the United States have shown that this can cause increases in blood diseases among populations located within close proximity for extended periods of time. Electromagnetic radiation can also be caused by natural phenomena. Water veins beneath the surface of the earth are often touted as being responsible for radiation fields. Continued exposure to these radiation fields is unhealthy because they act as stimulants upon the body. This has a wearing affect, which in turn leads to a run-down or tired immune system, and hence susceptibility to disease or mishap
As already suggested, electricity can be a subtle health risk. The human body creates and uses electrical impulses in its normal functioning. Electro Magnetic Radiation (EMR) outside of, but near to, the body can interfere with the body’s natural electrical impulses causing ill health.
EMR occurs everywhere, both in natural environments, and in man-made environments. A healthy building should aim to minimise the effects of EMR by:
1. Avoiding building in places where EMR levels are (or are likely to become) unacceptable;
2. Minimising the creation of EMR from the use of appliances, electrical wiring, etc.
Natural sources of EMR may include:
- Radiation from the ground
- Deposits of magnetic, radioactive materials.
Man Made sources of EMR can include:
- Electrical wiring in houses (particularly around the fuse box)
- Water pipes near electrical wiring
- Electrical appliances
- Office machines (e.g. computers, photocopiers)
- Power lines (overhead, underground, railway)
Creation of Electrical Fields
If electricity is flowing along a conductor (e.g. wiring) and changes direction (i.e. moves through at an angle) then EMR will be created across the angle which is created.
Electric wiring is laid inside a wall vertically to the roof and then horizontally to the centre of a room to supply a light fitting. An electric field or an area of EMR is created between the vertical wire and the horizontal wire. Obviously, a person should avoid sitting in that position for any period of time.
The existence of EMR in the home or office does not necessarily need to be totally avoided. Most people can tolerate some EMR without ill effects, but if the cumulative effect becomes too great it can have serious consequences (e.g. cancer).
EMR needs to be managed by giving proper consideration to all of the following:
- Identify all sources of EMR.
- Identify the relative intensity of EMR from each source.
- Relocate the source (or rearrange the building interior) to minimise EMR exposure.
- Arrange electrical wiring to minimise EMR creation.
- Do not leave appliances plugged in and switched on if not in use.
- Minimise the use of electricity.
- Use short electrical chords and locate permanent/frequent use appliances close to the power point.
- Use energy efficient appliances or office machines (e.g. low radiation computer screens reduce the amount of EMR created).
Think about it this way:
- The greater the length of wire and electrical cord which is ‘live’ at any point in time, the more unhealthy the building is.
- The more twists and turns electricity takes as it moves, the more unhealthy the building will be.
- The more electrical currents penetrating beyond the exterior walls, the greater the likelihood of increased EMR.
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