People and place

John Cherrie

PDC Session: The exposome and exposure in the workplace

Let’s take a minute to think…

�  Work with the person next to you and think about how practical is it to design an exposome study �  From birth to death �  Recording environmental and occupational

exposures �  Is it a practical prospect,

even in a restricted way?

Summary…

�  Issues in tracking internal exposure �  Issues in tracking external exposure �  So what can we do?

�  Location �  Physical activity

�  The core of our exposome (today)

Internal exposure…

�  Biomarkers of exposure �  Half-life and pattern of exposure �  Sensitivity

�  Attribution to factors in the environment �  Necessity to biobank over a lifetime

�  Continuity �  Long-term stability �  Obsolescence

Untargeted analysis cannot reliably measure below 0.1 µM in 50 µL of serum

Rappaport et al (2014). The Blood Exposome and Its Role in Discovering Causes of Disease. Environmental Health Perspectives, 1–6.

External exposure…

�  Plethora of sensors �  Sensitivity �  Specificity �  Cost

�  “Big data” �  Supermarket loyalty data �  Travel smart cards �  etc.

Data management…

�  Data processing and management is a major undertaking

�  Need accurate descriptive metadata �  title, creator, subject, content, date etc...

�  Necessity to store data over a lifetime �  Continuity �  File format obsolescence �  Physical media obsolesce

Criteria for practical exposome data collection…

�  Portable and unobtrusive to the wearer �  “Low-cost”

�  widespread deployment of sensors is a practical �  Able to collect, store and transmit high-time

resolution data �  Useable by anyone �  Need minimal engagement to collect the data �  Connect to the internet for remote storage

Location…

�  GPS or GPS-enabled smartphone �  The importance of indoor/outdoor

assignment �  Use location, light, temperature, cell phone

signal etc. �  Ideally linked to activities

Temperature - in and out

Data processing is a problem…

Moves app…

�  Advantage of Moves is it’s ability to identify locations and activity and summarise the data

�  However… �  Need your phone

with you �  Activity data biased

http://www.moves-app.com

Time  

Example: Moves v Paper log

Moves v pedometer

Activity…

�  Data-logging activity monitors �  Fitbit �  Actigraph, etc.

�  Latest versions measure steps (distance), heart rate, stairs climbed

�  Day-time and night (sleep)

www.fitbit.com

Accuracy and precision…

�  Like all measurements you need to calibrate the device �  Precision is probably

better than accuracy �  How big is a step? �  Calibration not typically

done by consumers

How can we use this type of data?

�  Using activity as an exposure metric �  Modeling exposure using time-activity

data �  Air pollutants �  UV exposure �  Noise

�  Identifying exposure associated with specific activities

Confidentiality? �  Exposome projects will collect sensitive personal

data �  However, we mostly share personal data already �  And sharing data will become commonplace �  Researchers will need to act under

normal rules of medical ethics �  Practitioners may need to develop

clear guidelines

Summary…

�  At the moment activity and location are most amenable to exposome data collection

�  These data are relevant to reconstructing exposure to a number of other factors