Dr Margaret O'Hara BSC (Hons) PGCE MSc DipIPEM PhD

Dr Margaret O'Hara

School of Physics and Astronomy
Daphne Jackson Trust Fellow

Contact details

School of Physics and Astronomy
University of Birmingham
B15 2TT

Margaret O’Hara is a postdoctoral researcher in Molecular Physics. She is a Daphne Jackson Trust Fellow as she is returning to a scientific career following a career break. She specialises in the use of Proton Transfer Reaction Mass Spectrometry for trace gas analysis. She is a medical physicist by training and her work focuses on medical applications of this technology, particularly breath analysis.

Margaret has several publications in breath analysis and she has been an invited speaker at international conferences on several occasions. Prior to her research career, she was both a hospital physicist and secondary school physics teacher.

Margaret has worked closely with Dr Christopher Mayhew, supporting his research regarding the link between liver disease and higher levels of limonene in the breath by studying patients before and after a liver transplant. Their research has led to the discovery of a reliable and non-invasive test for early-stage liver disease detection that would meet an unmet clinical need. 

She supports campaigns to combat gender stereotyping and to encourage more girls to study physics. She is a STEM ambassador and a member of Sciencegrrl, a grassroots organisation dedicated to providing role models for girls in STEM subjects. She tweets on these issues as @quizicist.



  • PhD in Molecular Physics, University of Birmingham, 2009
  • Associate member of the Institute of Physics and Engineering in Medicine
  • Diploma of the Institute of Physics and Engineering in Medicine, University Hospital Birmingham, 2004
  • Msc in Medical and Radiation Physics, University of Birmingham, 2002
  • Associate member of the Institute of Physics
  • Post Graduate Certificate of Education, Secondary School teaching in Physics and Maths, St Andrew’s College, Bearsden, 1992
  • BSc (Hons) Applied Physics, University of Strathclyde, 1990


Margaret O’Hara completed a BSc in Applied Physics at the University of Strathclyde in 1990. She did teacher training  and taught secondary school physics in Scotland for two years before taking a teaching post in Botswana, where she taught physics and occasionally maths, music and Scottish country dancing. Deciding on a career change, she completed an MSc in Medical and Radiation Physics at the University of Birmingham in 2002. 

She trained as a junior medical physicist at the Queen Elizabeth Hospital in Birmingham for a further two years specialising in radiotherapy, nuclear medicine and diagnostic radiology. Her MSc project was in monte carlo (MCNP) simulations of photo neutrons from a 15 MV clinical linear accelerator. She then did her PhD in the Molecular Physics Group in the School of Physics and Astronomy at the University of Birmingham  measuring VOCs in human breath using Proton Transfer Reaction Mass Spectrometry.

During her PhD and for several years afterwards, she tutored on the Medical and Radiation Physics MSc course. Following her PhD she worked briefly at University Hospital Birmingham radiotherapy physics department running monte carlo simulations of electrons in a linear accelerator, before taking a career break. She is now working as a Daphne Jackson Trust Fellow as a postdoctoral researcher in the Molecular Physics Group headed by Dr Chris Mayhew.

Margaret’s research focuses on  the measurement of volatile organic compounds in breath for medical applications. She is involved in a clinical trial in collaboration with hepatologists at University Hospital Birmingham to use breath analysis to diagnose advanced liver disease and related side effects.

She is also collaborating with Dr Shazia Zafar on a study on breath analysis for assessment of ketosis in patients suffering from hypermesis gravidarum.


Margaret's current research is to measure volatile organic compounds (VOCs) in breath samples from patients suffering from liver disease. In particular, she is interested in finding potential biomarkers for cirrhosis and a side effect of cirrhosis, hepatic encephalopathy. This research is being done in collaboration with Dr Andrew Holt and Dr Tahir Shah, hepatologists at University Hospital Birmingham.

Breath analysis of VOCs has been proposed as a surrogate method of measuring VOCs in blood.In her PhD, Margaret tested this hypothesis by first of all developing a protocol using rebreathing to measure an equilibrium value of volatile organic compounds in human breath. She then measured the VOCs acetone and isoprene in the arterial and venous blood of healthy volunteers and did simultaneous comparisons of concentrations of those VOCs in breath.

Other activities

Margaret is a volunteer for charity Pregnancy Sickness Support which provides support and information for women suffering from severe pregnancy sickness and hyperemesis gravidarum.(HG). She also runs her own website at www.pregnancysicknesssos.co.uk, from where she has conducted survey research on women’s experiences of having HG. Her findings have been presented at two PSS conferences and are available online in the document 'Women’s experience of hyperemesis gravidarum: results of self reported online surveys' (PDF 389 KB). 

She is a member of a Royal College of Obstetricians and Gynaecologists working group which is writing clinical practice guidelines for the treatment of nausea and vomiting of pregnancy and HG.

Margaret is also involved in her local community and actively fundraises for the Moor Pool Heritage Trust, a local Harborne organisation dedicated to preserving the community facilities of Moor Pool Garden Suburb. She writes and administers their fundraising website.