An odour is the detection of a volatile chemical compound in the air with the nose. An odour can be perceived as unpleasant. We can then refer to an odour nuisance (or smell).
Odour nuisance and health risks
Odour can cause a nuisance in the living environment and for this reason also poses health risks. Odour nuisance can lead to physical complaints such as headaches, nausea, disordered breathing and disordered heartbeat. Odour can also cause psychological complaints, e.g. tension, structural dissatisfaction with the living environment and reduction of activities outside the home.
Emission and immission
Odour can cause nuisance and health damage. Companies can emit odour (emissions). The odour spreads through the air and causes an odour load in the living environment (immission).
An odour can enter a home through an open window, door or grate, through ventilation or air treatment systems and through cracks and joints in the home. In homes with a mechanical air supply, there are relatively many complaints about odour nuisance from the local surroundings. Specific sources of odour nuisance outside the dwelling may include:
• businesses (industrial and other businesses, intensive livestock farms, agriculture)
• contaminants in the soil (volatile compounds can evaporate and enter a home);
• traffic (exhaust fumes, tyre and road surface wear);
• vegetable, fruit and garden waste (VFG) bins;
• vegetation (decay processes);
• neighbourhood activities (cooking smells, DIY)
• all-burners and fireplaces;
• sewerage (sewer break due to subsidence, renovation works, overflow after rainfall).
Major indoor environmental odour sources are: pets, kitchen odours, paint odours, tobacco smoke, volatile organic compounds (VOCs) released from a variety of products used in the home, such as paints and detergents, cosmetics, air fresheners and building materials, formaldehyde from building materials, furniture fabrics and flooring. In addition:
• Major indoor environmental odour sources are: pets, kitchen odours, paint odours, tobacco smoke, volatile organic compounds (VOCs) released from a variety of products used in the home, such as paints and detergents, cosmetics, air fresheners and building materials, formaldehyde from building materials, furniture fabrics and flooring. In addition: Due to a production error, the ceiling tiles may contain bacteria that break down the cellulose into butyric acid. This produces a sour, pungent odour.
• • Building and construction defects: absence of or inadequate functioning ventilation or air treatment systems (allowing cooking odours to be dispersed in the home), faulty and/or malfunctioning sewage systems, moisture nuisance, damp cavity wall insulation, improperly installed roofing.
• Combustion gases. A house fire can leave behind an unpleasant fire odour.
• Biological sources: domestic animals, vermin (e.g. shrews), cadavers (e.g. a dead rat in crawl space or cavity walls), VFG bins and plants.
• Use of certain agents: cleaning agents, damp-proofing agents (hydrophobic agents), pesticides and wood preservatives.
• Hobbies or resident behaviour: such as insufficient use of the ventilation facilities.
• Home interior: e.g. furniture or flooring
Indoor air is affected by a large number of chemical, biological and physical factors. Everyone is exposed to this is varying degrees. Usually, exposure to concentrations normally found in homes does not lead to adverse health effects. However, this is not always the case. For example, 'normally' occurring concentrations of radon and thoron (radioactive gases that naturally transform into other radioactive substances) and allergens in homes do have negative health effects. Complaints about the indoor environment usually, however, involve the situation where a person is exposed to elevated concentrations of substances normally found in the indoor environment or to substances not normally found in the indoor environment. In both cases, negative health effects cannot be ruled out.
Many indoor environmental problems are associated with odour nuisance, but odour nuisance can also be an indoor environmental problem in itself.
Individual differences in odour perception
The sensitivity of the sense of smell can vary greatly between individuals for each odour. Although most people have normal odour perception, two per cent of the population is hypersensitive and two per cent is insensitive.
Almost immediately when a smell is perceived, it is instinctively assessed as either pleasant or unpleasant.
Odourants can excite two nerve pathways: the olfactory nerve (nervus olfactorius) and the trigeminal nerve (nervus trigeminus). The two nerve tracts are connected to different parts of the brain. This means that excitation of the two nerves has different consequences for behaviour. The stimulation of the olfactory nerve results in the perception of an odour. Moreover, odourants can be transported directly to the brain via this nerve. The stimulation of the olfactory nerve can cause immediate responses. Some odourants evoke an innate aversion response. This is a reflex of turning away and sometimes disgust or nausea, which occurs, for example, with rotting odours.
A stimulation of the trigeminal nerve manifests as a tingling, irritating or burning sensation. The stimulation of the trigeminal nerve leads to protective reflexes such as sneezing or holding one's breath.
With the advanced filter technology, Clean Air Optima® mobile air purifiers and dehumidifiers transform unhealthy and odour-laden indoor air into clean breathing air.
Activated carbon filters in Clean Air Optima® mobile air purifiers and dehumidifiers effectively filter odours such as pet, mould, kitchen and paint odours, volatile organic compounds (VOCs), formaldehyde, benzene, ammonia, nicotine, cigarette smoke, gases and chemicals, etc. from indoor air. Due to the exceptionally high porosity of the activated carbon filters, unpleasant odours and harmful gases are absorbed and health-threatening chemicals, suspended organic compounds (VOCs) and smog are purified from indoor air.
The unique range includes Clean Air Optima® high-end (SMART) air purifiers with ultra-quiet operation and (SMART) dehumidifiers with an energy-efficient design and a sensor-controlled Airflow System. These effective Clean Air Optima® mobile air purifiers and dehumidifiers can purify up to almost 100 percent of all health-threatening and unpleasant odours, substances, gases, vapours, allergy triggers, bacteria, viruses and Covid-19 aerosols from contaminated indoor air.