Odour Nuisance Assessment

Taken from the Enforceable Planning Conditions course

OBJECTIVE CRITERIA (Issues to help determine impact)

SPREAD

The geographical extent over which the odour can be detected.

POPULATION AFFECTED

The number of households affected (compared to the character of the area i.e. dense or sparsely populated).

DETECTABILITY

The extent or distance over which the complainants claim they can detect odours & that which officers can also detect odours.

RECOGNITION

The distinct characteristics of the odours and comparison of recognition with detection.

QUALITY OF ODOUR

The characteristics of the odour and its acceptability.

WEATHER EFFECTS

The atmospheric conditions which result in odour detection, including wind direction, temperature, wind strength, type of day affected and times of the day.

WEATHER ANALYSIS

The atmospheric conditions which reduce or enhance odour detection and correlation with complaints.

PERSISTENCE & PERVASIVENESS

The duration of odour impact, the times / periods of respite and whether transient or prolonged - whether absorbed on materials and re-emitted.

IMPACT ON COMPLAINANTS

The use or activity affected by odour, i.e. daytime, sleep, use of garden etc.

IMPORTANCE OF ACTIVITY

The activity identified by the odour and its social importance or necessity, including historical significance i.e. muck spreading is an established farming activity.

ODOUR CHARACTER OF AREA

The background olfactory environment, i.e. that which exists in the absence of the source. For example, is it a town centre with lots of take-away odours in the area or is the type of odour wholly unexpected?

ODOUR MEASUREMENT

Are there any instrumental odour analysis methods available that can be used comparatively.

COMPOSITIONAL ANALYSIS

Can the odorous chemical compounds be identified.

COMMUNITY ACCEPTABILITY

Complainants subjective rating of unpleasantness and comparison with odour known odours. Eg.

• Cattle farm
• Tarmac laying
• Off fat
• Manure Heap
• Paint Fumes
• Sickly sweet
• Blocked Drain
• Thinners
• Fruity
• Muck spreading
• Adhesives/Glue
• Mouldy
• Sewage Works
• Malty
• Strong soap
• Musky
• Car fumes
• Disinfectant
• Fish oil
• Lorry Fumes
• Bleach
• Grassy
• Smoking
• Ammonium
• Smokey Bonfire
• Burning Rubber
• Frying smells
• Burning Plastics
• Spicy foods / herbs
• Burnt fat / Oil
• Smell of rotten / stale spicy foods
• Rancidity

EXTREME CARE IS NEEDED IN USE OF THIS APPROACH. IT CAN BE USEFUL TO GAUGE THE REASONABLENESS OF COMPLAINTS AND SEE IF A COMMON VIEW EXISTS
PRACTICAL CONTROLS

Is odour source totally enclosed, partially enclosed or wholly in the open air?

NATURE OF EMISSION SOURCES

What are the points of odour emission (one or multiple) i.e. transport, storage, waste, processing.

CUMULATIVE IMPACT

Are there other impacts on use and amenity from activities at site such as dust, noise or smoke? Does the combined effect result in nuisance?

Public Attitude, Odours and Interesting Facts

Dislike of bad smells = Deeply ingrained within human defence mechanism

DETECTION AT VERY LOW CONCENTRATIONS

ODOURS ARE NOT GENERALLY TOXIC BUT AVERSION REACTIONS = NAUSEA & CHANGES TO PULSE AND RESPIRATION.

Sniffing can increase sensitivity some four fold.

10-30 million Nasal receptor cells in the nose of a human.

Peak ability to smell from teens to mid 40's - slow loss follows.

Psuedo - hallucinations of smell can occur due to physical brain damage, infections, drugs or psychological disorders.

Human perception varies. Just perceptible for one person may = strong to another.

ODOUR HAS:-

• Detectability
• Intensity (Just perceptible, faint moderate, strong, very strong.)
• Quality
• Acceptability

Pervasiveness & persistence may relate to odour absorption and subsequent release from materials.

RULE OF THUMB - for compound odours - Nuisance occurs where dilution to detection is approximately 5 (i.e. one fifth of concentration).

NB: BEWARE THIS CAN VARY DRAMATICALLY

• Not unpleasant odours can become unpleasant
• Fatigue in sense of smell = real phenomenon can be rapid
• Habituation can occur = growing tolerance.
• Human perception depends on custom, habit & attitude.

ODOUR NUISANCE depends on quality of odour, social and regional factors plus air temperature and humidity.

Training

We offer training for anyone who deals with nuisance issues. We have a range of successful courses for Noise Professionals and Environmental Health Officers. Details of all the courses can be found in Training.