Recrutement

A 12 (+12) month post-doctoral position is available at LABERCA (UMR1329 Oniris-INRAE, Nantes, France) in the framework of the PARC project (Partnership for Assessment of Risk of Chemicals, EU Horizon EU Cofund, 2022-2029, https://www.eu-parc.eu/). The earliest possible date for taking up the post is 1^st May 2023.

Background

Food is one of the main sources of exposure to numerous contaminants for the general population. These contaminants are from different origins, some are anthropogenic (Flame retardants, plasticizers etc.), others are from the crust of the earth (heavy metals for example). These substances may be all found in non-trace concentrations in food (See results of total diet studies performed in France, Germany, UK etc.). Estimating the dietary exposure of the population (or sub populations) to these substances individually led, in some cases, to set maximum limits in food (Regulation EC 1881/2006 for PCBs, Cd, Pb etc.). Additionally, mixtures of contaminants are present in food and despite some proposed approaches to assess the risk due to such mixtures, risk assessors face difficulties to draw firm conclusions on the risk related to the mixtures. Other challenges associated with human risk assessment include the proper assessment of long-term chronic exposure, which involves taking into account not only exposure measurements at a given point in time, but also a sufficient number of measurements to reflect the exposure of individuals over their lifetime. We have previously shown that exposure to contaminants changes over a lifetime, highlighting the needs to assess the exposure and risk at different ages that take into account varying lifestyles, as well as socio-economic and environmental factors. This need appears especially for persistent contaminants accumulating in the body over time (e.g. heavy metals, POPs). In our previous and ongoing work, we have applied and confirmed the usefulness of PBPK modelling to reconstruct human internal exposure to individual organic contaminants (PCBs, BPA) or heavy metals (Cd) from external dietary exposure assessments over the life span. This approach is currently pursued to model exposure to mixtures of heavy metals over a lifetime taking into account the different interactions that can occur between them from both a kinetic and dynamic point of view.

Objectives

From this existing conceptual and methodological basis, the aim of the present project, envisaged over 2 years with a post-doctoral fellow, is to extend this PBPK modeling approach to even more complex real life chemical mixtures, combining both organic and inorganic contaminants. This extension better reflects the exposure patterns to which populations are really exposed. Based on the extended PBPK model, the project’s overall objective is to estimate the lifetime exposure of the population to these mixtures and to perform a first risk assessment based on a chronic toxicological endpoint shared by the different substances (developmental neurotoxicants for instance) of the mixture considered.

From this general objective, the project will focus more precisely on:

• Particular co-exposure patterns as observed in selected food items/habits, e.g. high levels of both heavy metals and POPs in biggest consumers of fatty fish.
• Specific sub-populations that are more vulnerable and / or over exposed, e.g. pregnant women…
• Particular health outcomes possibly associated to a given co-exposure, then used as a rationale for prioritizing the chemical mixture (based on external or internal exposures) in the envisaged PBPK modeling work.

Supervisors

Pf. Bruno LE BIZEC (Oniris)

Dr. Gilles RIVIERE (ANSES)

Qualifications

We are looking for a highly motivated scientist with a University PhD and advanced experience in toxicokinetics applied to the characterisation of human exposure to chemicals. More specifically, the candidate is expected to possess:

• A strong background in PBPK modeling
• Knowledge in chemical risk assessment
• Good toxicology skills
• A strong interest for interactivity and interdisciplinary work
• Excellent communication skills in French and in English

Salary

The period of employment is 1 year, open for one additional year, gross salary 2875 €/month.

Application

Please submit your application before 15th of November 2023.
Applications must be submitted to bruno.lebizec(at)oniris-nantes.fr and Gilles.RIVIERE(at)anses.fr as one pdf file containing all materials to be given consideration. The file must include:

• A covering letter
• A curriculum vitae
• Supporting letters