Scientists in Sweden have developed an application for building 'suspect screening lists' that incorporates exposure parameters, opening the door to rapid prioritisation of emerging chemical pollutants based more on risk than hazard.
Suspect screening is a way of identifying – and monitoring the distribution of – new chemicals of concern, using sampling and high resolution mass spectrometry (HRMS). Scientists analyse environmental samples and compare the results with predefined lists of priority chemicals, or suspect screening lists, to determine what chemicals are present and in what quantities.
Lists are usually built by expert judgement of hazard data. In contrast, the application developed by the scientists, SusTool, provides a means of selecting substances automatically from a database of 32,000 substances with known properties. It also incorporates exposure parameters, such as indices for production and emission, alongside hazard parameters of the kind more commonly used.
The work, published in Chemosphere on 5 February, was led by Wiebke Dürig and Rikard Tröger at the Swedish University of Agricultural Sciences (SLU) in Uppsala, Sweden. The Swedish EPA and Swedish research council Formas provided funding.
SusTool uses a set of 15 parameters, with a weighting function, to derive 'scores' for individual substances. By adjusting these elements, users can adapt the application to their specific research questions or monitoring objectives.
To demonstrate it, the scientists built three lists of 500 substances, one each for:
- organic pollutants in drinking water sources;
- hydrophilic bioaccumulating pollutants; and
- hydrophobic bioaccumulating pollutants.
They then compared these lists with equivalents from the SusDat database hosted by the Norman Network. The comparison showed that the tool can not only "identify highly relevant emerging pollutants … but also other compounds of potential concern [that] have been less studied or not yet investigated."