Measuring the Exposome

ASSESSING THE EXPOSOME

At the moment, external exposure assessment technology provides, at best, snapshots of single exposures. These snapshots are obtained by models or measurements and have limited resolution in time and space. Additionally, data is often not available at individual level. Clearly, better insights are needed into when, where, why (source, activity) and to which combinations of environmental factors people are exposed. As is the case with the assessment of the external exposome, the assessment of the internal exposome is currently performed at defined “static” moments in time. In many cases, this requires the invasive collection of biomaterials (such as blood tests). Other approaches are needed to enable faster, real-time, less invasive read outs of omics and biomonitoring data.

INNOVATIVE TECHNIQUES

Within the Applied Exposome Programme it is our aim to develop innovative exposure measurement techniques, e.g. low cost, wearable, direct reading and/or non-invasive technologies. We are developing, optimising (including validation and calibration) and adapting sensor and other measurement techniques for measuring external exposure levels and internal markers.

EXAMPLE PROJECTS

• Point of care test for benzene: Because of its effects on people’s health, in the (petro-)chemical industry there is a strong focus on benzene in personal-monitoring programmes. Currently, most commonly used bio-monitoring methods are based on laboratory analyses of workers’ urine. These typically have a turn-around time of several weeks and can be logistically challenging in certain parts of the world. To bring the lab to the site, TNO, in partnership with SKC, is developing a “point-of-care” test for benzene metabolites in urine that can be performed on location and provide results within hours, or even minutes. These results will be much more relevant for taking direct risk-management measures and can thus prevent unnecessary (over)exposure to benzene. The oil and gas industry is providing input to this project from an end-user perspective.

• SensA - Mobile air quality sensor network: To explore a new concept of mobile air-quality sensing by large groups of people, a series of 20 sensor boxes, that could be placed on the back of a bicycle, has been developed. The data collected from people involved in two pilot studies in Dutch the city of Eindhoven has provided new insights into the use and applicability of low-cost sensors. It has also uncovered some new challenges on which we are currently working, like the fusion of sensor data and air-quality model calculations.

• Passive sampling: Capturing a wide range of exposures can be challenging. Passive sampling is a technology that has the potential to provide insight into the presence and concentrations of a wide variety of chemicals, and for measurement intervals that can vary from one day to several months. Personal passive sampling devices such as wristbands and broaches have been developed elsewhere. At TNO we are collaborating with the Utrecht Exposome Hub and the University of Toronto to explore which components can be measured with passive sampling devices and the average exposure levels that correspond with a certain concentration level detected by the device.

• Low-cost particle counters: Recent technological developments have led to the availability of relatively low-cost particulate matter (PM) sensors that mainly rely on the optical counting of particles. Together with different partners (RIVM and the Haagse Hogeschool) we evaluate(d) the use of these low-cost particle sensors for assessing workers’ exposure to dust. In addition to this, TNO is working on the next-generation low-cost particle sensors that will be able to measure particulate mass directly and thus enable characterisation of particle composition.