A 2 | Workshop | SPHC 2024

Room

2ème étage - D230


Theme

Biomonitoring


Chair

Céline Fragnière Rime



Title
Biomonitoring in SHeS-pilot: findings and opportunities

Name
Céline Fragnière Rime

Affiliation
BAG

Co-authors

  • Natalie von Götz,
  • Murielle Bochud


Abstract

Background:
As part of the Swiss Health Study - pilot phase, human biomonitoring (HBM) was carried out among healthy adults living in the cantons of Bern and Vaud in 2020-2021.

Methods:
Biological samples were collected from 789 participants and analysed for various chemical substances known to be environmental pollutants. Several substance classes were measured in blood and urine of participants. Substance selection was based on criteria including public interest, health relevance and methodological aspects. The selected substances contain metals, a selection of per- and polyfluoroalkylated substances (PFAS) and glyphosate & AMPA. Pollutant levels were compared to dietary habits and other behavioral components to explore potential sources of exposure of particular relevance. This information is important for proposing and implementing effective risk reduction strategies.  In addition, this data can also be used to establish a baseline exposure distribution for the pilot cantons which can be used to assess abnormal workplace or environmental exposures.

Implication:
The aim of this workshop is to present some of the analytical human biomonitoring results available for the substances selected. The HBM data collected in the pilot phase is representative of a population aged 20-69 in the cantons of interest, but not of Switzerland as a whole. A future long-term national study with healthy participants would allow HBM reference values to be established for other age groups and Switzerland as a whole to monitor pollutant exposure reliably.
SHeS-pilot has participant consent for data and sample re usage and participant recall for downstream research projects.



Title
Biomonitoring in SHeS-pilot: levels of PFASs among the Swiss adult population

Name
Céline Fragnière Rime

Affiliation
BAG

Co-authors

  • Alexandra Jaus
  • Julien Riou
  • Beat Brüschweiler,
  • Murielle Bochud
  • Natalie von Götz


Abstract

Background:
The group of per- and polyfluoroalkyl substances (PFASs) comprises several thousand different chemicals which have been widely used since the 1950s (e.g., in firefighting foams, surface treatments, food packaging, ski wax, textiles). PFASs are extremely persistent and degrade very slowly, often not at all, on their own. They are therefore ubiquitous in the environment. High levels are found at pollution sources such as industrial sites, firefighting training grounds, landfills or contaminated wastewater. Environmental enrichment of PFASs leads to accumulation in the human food chain and the human body.
Some PFASs are known to cause adverse health effects. IARC has recently classified perfluorooctanoic acid PFOA as a Group 1 human carcinogen, based on sufficient evidence of cancer in experimental animals and strong mechanistic evidence that PFOA exhibits key characteristics of a carcinogen in exposed humans. Perfluorooctane sulphonic acid PFOS has been classified as possibly carcinogenic to humans (Group 2B) on the basis of strong mechanistic evidence. The goal of this study is to provide valuable insights into the current human PFAS serum levels in Swiss adult population in the frame of the SHeS-pilot study.

Methods:
30 compounds in the PFAS group, selected on the basis of the EU Recommendation on the control of PFASs in food and feed, were determined in serum samples from SHeS pilot phase. Quantitative analysis of PFASs was performed using LC-MS/MS, after specific sample preparation. The developed method achieved reliable validation parameters for the detection of PFASs in human serum. It achieved stable and robust quantification performance and was considered fit for purpose. Of the 30 substances analysed, PFOA, PFNA, PFDA, PFUnDA, PFHxS, PFHpS and PFOS were present in quantifiable amounts in more than 50% of the samples. PFOS, PFOA and PFHxS were detected in all samples, and were measured at the highest concentrations. Where possible, the concentrations of substances measured by HBM were compared with specific health thresholds and with those found in similar studies conducted in Europe and Canada. Participants were stratified by age and sex, and the most likely sources of exposure were investigated.

Implication:
The HBM data collected provides initial information on PFAS exposure and opens the door to a better understanding of the most likely sources of exposure for SHeS-pilot participants.


Title
Abstract # 3: Biomonitoring in SHeS-pilot: population exposure to glyphosate & AMPA

Name
Jean-Pierre Ghobril

Affiliation
Unisanté

Co-authors

  • Julien Riou
  • Roxana Socianu
  • Claire Zuppinger
  • Céline Fragnière Rime
  • Natalie von Götz
  • Murielle Bochud


Abstract

Background:

Since 1974 the usage of glyphosate/Roundup(c) for crop control has been steadily increasing worldwide. Questions on population exposure and toxicity have arisen early on. The usage or banning of glyphosate has become a rallying point for political action against industrialized agriculture worldwide. Population exposure to glyphosate can occur through professional exposure by workers in agriculture, through living in geographical proximity to agricultural land and through the consumption of glyphosate residue-containing foodstuffs. Glyphosate and its metabolite AMPA can routinely be detected in humans and nature. Human urinary glyphosate concentration is only an indicator of recent exposure as the compounds do not accumulate and the biological half life is just about 9h long. Despite evidence linking glyphosate to various health issues including non hodgkin lymphoma, scientific consensus has not yet been reached. In SHeS-pilot we want to evaluate the extent and characterize the origin of the exposure within our cohort.    

Methods:
Within the densely phenotyped SHeS-pilot cohort, urinary glyphosate and AMPA concentrations were measured in 783 participants with LC-MS/MS. Glyphosate was detected in samples from 380 participants and quantifiable in 148. AMPA was detected in samples from 248 participants and quantifiable in 98. Gamma hurdle regression modelling will be used to jointly estimate the association of covariates with the probability of detection of glyphosate or AMPA (expressed as an odds-ratio) and with the quantity of each substance when detected (expressed as a fold-change). Covariates will include socio-demographic information, food consumption especially for the last 48h, geographic information, usage of pesticides in professional or hobbyist capacity,  We will conduct univariable and multivariable analyses, and account for multiple comparisons by using penalized regression.

Implications:
Understanding and addressing the sources of glyphosate exposure is crucial for assessing the need for regulatory measures.



Title
Biomonitoring in SHeS-pilot: sources of PFAS exposure and links with SARS-CoV-2 immunity

Name
Julien Riou

Affiliation
Unisanté

Co-authors

  • Claire Zuppinger
  • Alexandra Jaus
  • Céline Fragnière Rime
  • Natalie von Götz
  • Murielle Bochud


Abstract

Background:
Humans can be exposed to per- and polyfluoroalkyl substances (PFASs) through food, drinking water and inhaled dust. Professional exposure is also important. A better characterisation of the sources of PFAS exposure in the Swiss population is necessary to allow for effective risk reduction measures. Research has linked PFAS exposure to various health issues, including developmental effects, pregnancy complications, obesity, certain cancers, and immune disruption. This latter effect is of particular relevance in the aftermath of the COVID-19 pandemic. The objectives of this work is to precisely characterize the multifaceted sources contributing to PFAS exposure in the Swiss adult population, and to assess the association between PFAS exposure and the immune response to SARS-CoV-2, particularly after vaccination.

Methods:
We use data from 638 randomly-selected participants of the SHeS-pilot, of which 630 had laboratory measurements for 30 PFASs in serum (in two parts: detection of the substance and quantity when detected). We consider PFASs detected in at least 5 participants, resulting in 14 substances. We use hurdle gamma regression models to jointly estimate the association between covariates and (1) the probability of detection of each PFAS (expressed as an odds-ratio) and (2) the quantity of each PFAS when detected (expressed as a fold-change). Covariates include socio-demographic information, propensity to consume specific foods, use of cosmetics, exposure to ski farts and water-repellents, and professional exposures. We conduct univariable and multivariable analyses, and account for multiple comparisons with penalized regression. We then focus on 593 participants with information about SARS-CoV-2 immunity (anti-spike IgG, again in two parts). We use the same approach to estimate the association between PFAS levels and the levels of anti-S IgG antibodies in the general population and among participants reporting having been vaccinated. We also account for potential confounding.

Implications:
Understanding and addressing the sources of PFAS exposure is crucial in safeguarding human health and advocating for regulatory measures to mitigate their impact. Detecting a link between PFAS exposure and SARS-COV-2 immunity may have implications with regards to the targeting of future vaccination or booster campaigns. Results from this study will contribute to the debate on PFASs in Switzerland.