Fragrance, forensics and pheromones

Do we smell sexy? Popular ‘science' suggests yes; plus, in future when police forensics experts smell that something is wrong, this could be more than just a turn of phrase

Human pheromones - we need to talk

Do we smell sexy? Popular ‘science' suggests yes — pheromones, we often hear, send chemical signals about sex and attraction to potential mates. However, there is no conclusive research confirming that humans actually have these smell molecules.

"Sadly, despite the hundreds of web sites selling ‘human pheromones', the molecules they offer don't have any scientific basis. I think it is time to restart our search". So says a senior scientist, Dr Tristram Wyatt from Oxford University, and a leading authority on the topic. He will be speaking on the topic Human Pheromones - we need to talk, at the IFRA UK Fragrance Forum on 16th October.

He adds: "The biggest challenges are probably not finding possible molecules but instead discovering what behaviours pheromones affect - which might not be sex at all. Currently, the most promising lead is the secretion which all mothers produce and which stimulates suckling by any baby. There is so much more for us to discover about human pheromones. I'm sure we'll find them."

Humans are of course mammals and so we, like other primates including the great apes, are smelly. The mystery remains however about whether humans use pheromones - that is, smell signals - for all sorts of behaviours, not just sex. Pheromones are molecules that are characteristic of, for example, all males, not a particular individual. So called ‘pheromone parties' are misnamed, as they are based on our individual smells - known as ‘signature mixtures' - not pheromones.

Dr Tristram Wyatt is a researcher at the Department of Zoology at the University of Oxford and an Emeritus Fellow of Kellogg College, Oxford. He studies how pheromones evolve across the animal kingdom. He is the author of the book Pheromones and animal behavior [sic] (2014, 2nd edition, Cambridge University Press) which includes a chapter devoted to human pheromones. The book has been shortlisted for the Society of Biology's Postgraduate Textbook Award 2014.

He has delivered a TED Talk on the ‘Smelly mystery of the human pheromone' which has received some 900,000 views.

Sniffing out the evidence - fragrance and forensics

In future, when police forensics experts, smell that something is wrong, this could be more than just a turn of phrase. The collection and analysis of natural human scent and applied fragrances could, in the near future, help track criminals, identify victims and solve crimes from sexual assault to child abduction.

The use of smell and fragrance are set to be used in criminal investigations, according to Alison Davidson, a researcher at the Department of Forensic Science and Crime Science based at, Staffordshire University. Dogs have long been used to sniff out crime. However, it seems the laboratory could be about to take over from the Labrador.

Alison Davidson, whose work will be revealed at the IFRA UK Fragrance Forum next week, says: "We know that human 'scent' is a complex chemical mixture including endogenous compounds from skin emanations and exogenous compounds from personal care products. Many aroma chemicals exhibit forensically useful properties such as persistence and transferability and there is increasing evidence for the individuality of human chemical profiles - all of which indicates that there is the potential to use this chemical information as forensic evidence".

She will describe the work currently being done by scent dogs and how chemical analysis would offer significant advantages over existing practices in many criminal investigations - though not all.

Ms Davidson says: "There are operational issues which must be overcome, including preserving and collecting scent evidence from a crime scene and the method for collection of a chemical profile from a suspect in a custody suite. We are also considering the challenges for the forensic laboratory and reviewing some of the possible analytical approaches, which in turn will influence which chemical components are most likely to be detected. It is important to identify which of these would be considered most forensically significant and whether exogenous or endogenous compounds might have more evidential potential".

In her speech she will reflect on what can be learnt from existing forensic practices; how concerns over fingerprint examination and DNA profiling influence the way we might use, store and present ‘scent' evidence in court; and whether the future of forensic scent evidence will provide the reliable answers that forensics experts seek.

The IFRA UK Fragrance Forum will be held at The Royal Society and tickets for the 2014 event are sold out.