Sean Semple.JPG

Sean Semple

Senior Lecturer in the Respiratory Group at the University of Aberdeen and BREATHE, Exposure and Bio-markers Theme Leader. 

Sean is based at the Royal Aberdeen Children's Hospital and also holds an honorary scientific appointment at the Institute of Occupational Medicine in Edinburgh where he collaborates with scientists working within the Centre for Human Exposure Science.

The Exposure and Biomarkers Theme of BREATHE aims to bring together those on the project who are interested in finding better ways of understanding and quantifying exposure to household air pollutants. The theme has a funded PhD studentship and we are extremely lucky to have recruited Mr Gabriel Okello to this position. Gabriel is from Uganda and has experience of installing biogas systems in homes across Africa. He joined our team in Aberdeen in August 2015 and spent some months learning about the range of devices available to measure HAP before writing up protocol to gather data from two countries. His work has now received ethical approval and in March 2016 he made a start on data collection in Uganda and will gather final data in Ethiopia. Gabriel will combine his data collected from fieldwork in Uganda and Ethiopia with the generation of a database of all HAP measurements in in Sub -Saharan Africa.  He is currently contacting those involved in HAP research in SSA to see if they will share their measurement database. 

Gabriel Okello

PhD student for Exposure and Bio-markers Theme at the University of Aberdeen.

Assessing personal exposure to biomass fuel smoke in subSaharan Africa

My main objective in the BREATHE project is to ‘’Assess personal exposure to biomass fuel smoke in sub-Saharan Africa’’. I am carrying out this work as part of a PhD at the University of Aberdeen and after receiving training on the exposure monitoring devices and gaining ethics approval earlier this year I have now started on data collection. The data collection is planned for three sites: Kikati-Lugazi in Uganda; Chikwawa in Malawi; and Kumbursa Debreset in Ethiopia. We hope to recruit about 100 people in each site and measure their exposure using different methodologies. Participants will be selected across a range of gender and age groups to gauge average exposure levels in each group . Measurement of personal exposure is currently ongoing in Kikati village in Uganda. Kakati village is located approximately 45 km from Kampala along the Kampala-Jinja highway. The village has approximately 400 households with most using biomass fuel for cooking purposes.

Twenty homes have so far been assessed with personal exposure to biomass fuel smoke measured over a period of 24 hours for 56 participants. During measurement of personal exposure each participant receives either (or both) a particulate matter (PM2.5) monitoring device or carbon monoxide measuring device. The particulate matter (PM2.5) monitoring devices being used in this study include: SidePak AM510, MicroPEM and Dylos DC1700. The PATS+ devices are due to be sent by Berkerely Air Monitoring Group in the 3rd week of May 2016. The Dylos and SidePak devices are attached to Astro Pro2 power banks in order to provide external power so that the devices can operate for 24h periods. The EL USB Lascar loggers are being used to measure carbon monoxide. GPS tracking devices have also been worn by participants to provide location data and to determine if they can quantify the amount of time spent within indoor and outdoor environments. Paper-based time-activity diaries have also been used to establish the main activities performed by the participants and where they spend their time. Short meetings have been held with the participants to find gather data on their experience of using the devices and go through the time-activity diary to check for completeness.


Gabriel, Mama Phoebe and Noreen after completing the feedback form

Gabriel, Mama Phoebe and Noreen after completing the feedback form

Gabriel and Rodney in Kakati after a rainy day

Gabriel and Rodney in Kakati after a rainy day

  • One of the major challenges has been filling in the time-activity diaries (TAD). Some participants don’t know how to read or write. Many of these are not completed and I have had to draw reference diagrams in cases where the participants cannot write. The have included: a hoe meaning digging, chair/man + sun meaning sitting outside, chair + house/hat meaning seated indoors, diagram of bed meaning sleeping, plate + sun meaning eating outdoors etc.
  • There have also been a number of cases where participants indicate that the noise from the SidePak was a disturbance during the night.
  • Some participants - especially women - have also indicated that the SidePak and Dylos devices can feel heavy carrying around when they are doing their daily activities.
  • One household had an issue of blue and green flickering lights from the GPS and SidePak respectively at night. Their religious beliefs don’t allow flickering lights in households.
  • There have been a number of cases where the wire connecting the Dylos to the power bank has become accidentally detached. This has led to measurements of less than 24 hours.
  • Accessing Kikati on a rainy day or the day after it has rained is difficult due to the slippery roads. Sometime I have to spend 2 to 3 more hours travelling per site visit.