Emerging chemicals

Emerging chemicals are chemicals of emerging concern to human health that can reach human tissues via direct usage of consumer products or uptake via the environment and food. Most emerging chemicals are synthetic and are likely to significantly alter the metabolism of a living being (Sauvé and Desrosiers, 2014). Emerging chemicals are not yet included in existing human biomonitoring programmes, partially due to the lack of analytical methods to measure the chemical or its metabolites in human specimens. There is a lack of knowledge about general population exposure to emerging substances and potential health impacts.

Chemicals can be considered as emerging substances when:

1. they are new synthetic substances, such as recently developed substitutes for regulated substances subject to restrictions on use or bans; or
2. they are substances that have already been present for some time in the environment-food-human continuum, but for which emerging evidence raises new concerns regarding human exposure and/or impacts on health.

Regarding the latter, new concerns can arise due to improvements in the sensitivity of analytical methods, allowing the detection at low concentrations of substances that could not previously be detected in the environment or in humans. In addition, new commercial uses of a known chemical can open up a new routes of exposure. In addition, new toxicological evidence regarding effects on environmental species can be an early warning and call for revisions to the human risk assessment on a given chemical.

HBM4EU work on emerging chemicals aims at providing early warnings of potential chemical risks. The ambition is to minimize the delay between early warnings, human biomonitoring activities to understand exposure and policy efforts to reduce exposure.

In addition, HBM4EU is generating exploratory human exposure data that can guide the prioritisation of substances for monitoring and research under future human biomonitoring activities. Concretely the outputs of this work will contribute to the third and last round of prioritisation under HBM4EU, and so feed into a future European human biomonitoring initiative.

The work is reality-driven, entailing a bottom-up characterization of the current human exposome with the aim of steering further investments toward biomarkers of exposure to chemical of greatest concern. This work is underpinned by state-of-the-art science and entails a significant level of innovation and methodological research.

1. Providing early warning of the presence of known and unknown emerging chemicals in the EU population.
2. Inform the process of substance evaluation and the identification of substances of very high concern under the REACH Regulation.
3. Inform the development of future chemicals policies aimed at protecting human health from chemical risks.

HBM4EU has produced a prioritised list of emerging chemicals. Substances on the list of emerging chemicals will be further prioritised, by considering available exposure, toxicological, and metabolism data, as well as analytical considerations. This inventory is based on expert knowledge from within the HBM4EU consortium, as well as existing lists of emerging chemicals. For example, the European Chemicals Agency (ECHA) leads a systematic process of substance evaluation, to clarify whether the use of certain substances poses a risk to human health or the environment.

The Norman Network lists the currently most frequently discussed emerging substances and emerging pollutants in the field of environment. The network organises the development and maintenance of various web-based databases for the collection & evaluation of data / information on emerging substances, including:

From this important existing knowledge base of emerging substances in environmental matrices (water in particular), the suspect and non-targeted screening of emerging chemicals in human matrices involves a number of specificities that are addressed under the HBM4EU project. Among these are:

1. The lower chemical concentration levels, higher complexity, and/or less possible concentration factor of human matrices compared to environmental and food matrices, leading to additional analytical challenges;
2. The presence in human matrices of sometimes not yet identified biotransformation products (metabolites) rather than pre-identified parent compounds; and
3. The lack of infrastructure, including necessary HBM networks and laboratories compared to other fields.

Another major line of HBM4EU work under Work Package 16 on emerging chemicals, are efforts to build a QA/QC consolidated framework to improve the level of confidence in the identification of the detected markers.

In addition, HBM4EU has produced an inventory of screening methods, as well as a report on direct effect based approaches applied to the screening of emerging substances.

Non-targeted screening approaches are being developed and applied with the aim of revealing and identifying new (i.e. not yet known) markers of exposure related to emerging chemicals. From a methodological point of view, this work is based on the last generation of mass spectrometric technologies, that offer a unique opportunity for such untargeted sample characterization. High resolution mass spectrometry is the main tool used in these investigations, coupled with data processing and analysis.

In the interest of transparency and accountability, HBM4EU invites interested stakeholders to submit comments on the scoping document.

All submitted comments will be made available for download on this webpage and will be taken into consideration by the HBM4EU consortium, where possible.

Please click here to submit your comments.

Please click here to access the Substance Report.

References:

Sauvé, S and Desrosiers, M (2014): A review of what is an emerging contaminant. Chemistry Central Journal 8:15.