Physiological hazards
Physiological hazards include damp and mould growth, excess cold, excess heat, asbestos and manufactured mineral fibres, biocides, carbon monoxide and fuel combustion products, lead, radiation, uncombusted fuel gas, and volatile organic compounds.
Types of physiological hazards
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1. Damp and mould growth
Most vulnerable: Those under 14
Threats to health associated with increased prevalence of house dust mites and mould or fungal growths resulting from dampness or high humidities. This includes threats to mental health and social well-being which may be caused by living with the presence of damp, damp staining or mould growth.
Effects
- Physiological health effects
- Dust mites
- Mould growth
- Social and mental health effects
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2. Excess cold
Most vulnerable: Those over 65
This category covers the threats to health from sub-optimal indoor temperatures.
Effects
- Cardiovascular conditions, such as heart attacks and strokes
- Respiratory diseases, such as influenza, pneumonia, and bronchitis
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3. Excess heat
Most vulnerable: All age groups
This category includes threats from excessively high indoor air temperatures.
Effects
- Cardiovascular strain and trauma
- Dehydration
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4. Asbestos and Manufactured Mineral Fibres
Most vulnerable: All age groups
This category covers the presence of, and exposure to, asbestos fibres and manufactured mineral fibres within dwellings.
Effects
The health risks from asbestos exposure are associated with inhalation. Risks from ingestion and skin contact are minimal. The inhalation of asbestos fibres can cause pleural disease (pleural plaques and fibrosis), lung cancer and mesothelioma (cancer of the pleura, the lining around the lung, or, less frequently, cancer of the peritoneum).
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5. Biocides
Most vulnerable: All age groups
This category covers threats to health from those chemicals used to treat timber and mould growth in dwellings. While biocides include insecticides and rodenticides to control pest infestations (for example cockroaches, rats or mice), these are not considered for the purposes of the HHSRS .
Effects
Biocides are intended to prevent growth or development of insects, fungi, moulds, and bacteria, or kill those already present. The potential for harm to human health varies depending on the biocide. The main health risk is from inhalation, although skin contact and ingestion may also be an issue, particularly for small children.
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6. Carbon monoxide and fuel combustion products
Most vulnerable: Those over 65
This category includes hazards resulting from the presence of excess levels in the atmosphere within the dwelling of:
- Carbon monoxide
- Nitrogen dioxide
- Sulphur dioxide
- Smoke
Effects
- At high concentrations carbon monoxide can cause unconsciousness and death
- At lower concentrations, it causes a range of symptoms from headaches, dizziness, weakness, nausea, confusion, and disorientation, to fatigue
- All symptoms which are sometimes confused with influenza and sometimes with depression
- In people with ischaemic heart disease, it can result in episodes of increased chest pain
- Carbon monoxide may impair foetal development
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7. Lead
Most vulnerable: Children under 3
This covers the threats to health from the ingestion of lead.
Effects
Lead is a heavy metal, which, when ingested accumulates in the body, and has toxic effects on the nervous system, cognitive development and blood production.
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8. Radiation
Most vulnerable: Those between 60 and 64, who have had lifetime exposure to radon
This category covers the threats to health from radon gas, primarily airborne, and also radon dissolved in water.
Effects
Radon gas is the second most important cause of lung cancer after smoking, and most radon exposure occurs at home. As radon is soluble in water, it can be ingested, resulting in the organs of the gastrointestinal tract receiving the largest dose.
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9. Uncombusted fuel gas
Most vulnerable: All age groups
This category covers the threat of asphyxiation resulting from the escape of fuel gas into the atmosphere within a dwelling.
Effects
Fuel gases can cause asphyxiation. This occurs when the fuel gas builds up within the dwelling, displacing the air to such an extent that the occupants are unable to obtain sufficient oxygen to breathe.
10. Volatile organic compounds
Most vulnerable: All age groups
Volatile organic compounds are a diverse group of organic chemicals including formaldehyde, which are gaseous at room temperature, and are found in a wide variety of materials in the home.
Effects
Most individual volatile organic compounds that may be found in dwellings have no reported health effects. However, some may cause short term irritation and allergic reactions to the eyes, nose, skin, and respiratory tract. Higher concentrations can result in headaches, nausea dizziness and drowsiness. Formaldehyde can be a particular problem, although sensitivity varies. Allergy sufferers and asthmatics are most vulnerable, and may react to exposure at levels below those that would affect others.