Odour and the human sensory
“Odour and Smell are two words that are often confused when it comes to their meanings and connotations. The word ‘odour’ is generally used in the sense of ‘scent’. On the other hand, the word ‘smell’ is used generally in the sense of ‘aroma’ either good or bad.”
Although the human sense of smell is feeble compared to that of many animals, it is still very acute. We can recognise thousands of different smells, and we are able to detect odours even in infinitesimal quantities.
Our smelling function is carried out by two small odour-detecting patches – made up of about five or six million yellowish cells – high up in the nasal passages and close to our brain. For comparison, a rabbit has 100 million of these olfactory receptors, and a dog 220 million. Humans are nonetheless capable of detecting certain substances in dilutions of less than one part per trillion parts of air.
Smells and our sense of smell plays an important part of life from identifying danger, determining what eat or not eat, and the pleasure of fragrances. When smells become offensive, we will often refer to it as an ODOUR.
Offensive odours lower quality of life of the affected community and habitants. It will set off community confrontation, attract fines and possibly ceasing operations.
Often odours are identified by the highest concentration of the fugitive gas, which in sewer operations is hydrogen sulphide (H2S). An odour is an odour regardless of if its make up. Simply treating one gas such as H2S changes the odour profile and possibly intensity however the residual gas will be odorous.