This specialist discipline takes into account observation of design,adequacy of structural elements, moisture ingress, building alteration and adaptation. The internal enviroment of a building can be adversely affected by such factors. Poor or defective design, materials, construction methods and supervision can give rise to moisture ingress and poor ventilation. Poor ventilation can create conditions giving rise to condensation.
The effects of condensation are to create a medium in which fungal spores (typically measured as CFU/M3 - Colony Forming Units per cubic metre in a wide range of year round typical occurrence from 100 – 10,000 CFU M3) present in all air will germinate, reproduce and increase in number until a person with a weakened immune system may potentially become seriously ill.
Interstitial condensation is also a potential source of toxic mould. Even fully monitored and cleansed air quality within a building can then be compromised by such continuing hidden and inaccessible threats.
Moisture required to support fungal germination and growth is described as water activity scale 0 – 1. Water Activity of 0 will not support any fungal growth. (BSI 16000-19 covers sampling procedures).
Internal ventilation has to be understood in terms of air movements within a building. In the late 20th and early 21st Century this has to be particularly evaluated within the context of many new materials included within the structure of a building its fixtures, fittings, décor, furnishings and textiles.
Condensation is potentially serious once mould growth becomes visible. Vinyl wall papers and paint encourage growth as absorption and spread on porous surfaces is prevented. Thus modern décor can exacerbate a problem.
In older buildings construction materials such as lime plaster connected with lime joints and ‘sucked’ moisture out of a building. Chimneys would constantly ventilate and cause air movement. Gaps around doors and windows would contribute to ventilation.
Thus failing to identify condensation and undertaking damp proofing works in older properties using sand and cement internal renders would prevent this natural evaporation through masonry. Cement re pointing then sealed in the external wall surface. This would then potentially cause moisture to rise within the wall. Add to this moisture rising via capillary action from the ground below where there is no damp proof course, or drying out following remedial work to install one, and a wall normally dry would potentially become damp.
Use of lime in construction largely died out after the First World War as cement took over from lime due to its quicker setting time. Thus installation of a damp proof course would stop rising damp but may encourage internal condensation and the misidentified cause of the ‘dampness’ would not be cured by a damp proof course.
As well as the chemical pollutants described above, various biological contaminants often contribute to illness. In fact biological factors are reported to be behind the majority of cases. These biological pollutants can cause illness through three different mechanisms:
- Infection
- Allergy/Hypersensitivity
- Toxicosis - symptoms caused by toxins produced by micro-organisms e.g. mycotoxins produced by mould/fungi
The following are the main sources of this form of pollution:
Toxic Black Mould
Viruses & Bacteria 
The House Dust Mite
Pollen 
Radon gas
Why is radon a health concern?
- Formaldehyde - evaporates from cushions, particleboard and the adhesives used to manufacture most inexpensive wood-based products. Carpets and carpet cushions may also release formaldehyde, causing eye and upper respiratory irritation.
- Carbon monoxide – mainly produced by unserviced furnace burning propane, butane or oil;
- Arsenic - is still used in many household pesticides and is increasingly used as a wood preservative.
- Vinyl chloride - "new car smell": The plastic interior of a new car offgasses this known carcinogen. Water sitting in PVC pipes overnight may also contain this toxin. Very large exposures can lead to "vinyl chloride disease," which causes severe liver damage and ballooning of the fingertips;
- Hydrofluoric acid - the active ingredient in many household rust removers and can cause intense pain and damage to tissues and bone if the recommended gloves happen to have holes in them.
- Phenolsincluding biphenyl, phenolics and pentachloraphenol - are found in disinfectants, antiseptics, perfumes, mouthwashes, glues and air fresheners
- Chlordane, aldrin, dieldrin – Used in pesticides, though all banned for nearly two decades, continue to show up airborne in older houses.
- Phthalates – Contained in Shower Curtain Liners, Plastic Tableclothes, Other Soft, Flexible Plastics. These are hormone disruptors. And of biggest risk is exposure for pregnant women.
The risks and the benefits of introducing flame retardants into upholstered furniture.
Risks due to the presence of flame-retardants in upholstered furniture:
1. The risk of exposure to flame-retardants during manufacture of the products (worker acute and chronic toxicity);
2. The risk of exposure to flame-retardants under normal living conditions. This risk mainly results from accumulation of release flame-retardants in indoor air (inhalation) and/or skin contact and migration of substances (chronic toxicity);
3. The environmental risk during recycling or incineration of the products (mainly ecotoxicity);
4. The risk of increasing emissions of toxic gases from accidental fires due to cigarettes or matches on upholstered furniture (acute toxicity).
All upholstered furniture, sold inUKand intended to the general public, need to be fire retardant to ignition by a cigarette, a small flame like match. InUKfor textiles, foams and fabrics, specifications are fixed by standards such as BS 5852 and EN 1021-1 and 1021-2. There requirements can reduce the fire risks, but toxicity risks due to flame retardant systems are not demonstrated.
These risks of toxicity, induced by the introduction of flame retardants in upholstered furniture that are found in dwellings, should be studied according to the recommendation of General Safety Products Directive (2001/95/CE) in order to achieve the required high level of protection for health and safety of people.
The combustion of upholstered furniture made with polyurethane foam and a covering based on cotton coated with polyvinyl chloride (PVC), should mainly lead to the formation of the following toxic effluents: CO, CO2, HCN and HCl.
In a room of 20 m3, the maximum mass loss to reach the incapacitation and the lethality of mice are respectively in our case, 540 g (incapacitation) and 740 g (lethality). The maximum mass loss required to pass the cigarette test was evaluated to 123 g (on the basis of a flexible polyurethane foam with an average density of 35 kg/m3 representative of a furniture of dwelling, with an extended carbonisation on 50 mm on both sides from the cigarette, which is the maximal criteria of material burn to fulfil EN 1021). This value is far lower than the 540 g mentioned above.