# Characterizing Soil Quality and Assessing Emerging Pollutants in Clusters of Crohn's Disease Incidence in France

LM Wakim, F Occelli, D Cuny, C Lanier, M Paumelle, D Brousmiche, A Deram

Soil quality is an essential component of environmental health, with implications for human health and well-being. Emerging pollutants in soil represent a potential risk to human health, but their link to specific diseases remains largely unexplored. In the context of Crohn's disease (CD), a chronic inflammatory disease of unknown etiology with strong environmental risk indicators, the relationship between soil pollution and disease incidence has never been studied.

The objective of this study was to comprehensively characterize soil quality in Crohn's disease clusters in four French departments. It included an assessment of conventional and emerging pollutants present in the soil matrix.

The methodology employed strategic soil campaigns targeting CD clusters using a hexagonal grid to ensure comprehensive coverage. Site selection aimed at representing diverse land cover types to provide a representative territorial assessment. An analytical method was developed and optimized to detect emerging pollutants in soil at exceedingly low environmental concentrations. A composite index was employed to represent overall soil pollution.

The results of this study showed that heavy metals detected in agricultural soils differed significantly between clusters with high and low incidence of CD. A correlation between the heavy metal composite index and disease incidence was also demonstrated. In addition, emerging pollutants, including endocrine disruptors, antibiotics and human drugs, were assessed using a specialized protocol enabling simultaneous detection of these compounds in soil samples. This protocol, based on QuEChERS and SPE extraction methods, and LC-MS/MS analysis, revealed a heterogeneous distribution of emerging pollutants in the clusters. High concentrations of 21.55 ng/g of 17β-estradiol and 47.16 ng/g for 17α-ethinylestradiol were detected in forest soils. The known sources of these estrogens, both synthetic and natural, in soils come from agricultural practices, which is why their presence in forests, at higher concentrations than in other soil occupations, was not anticipated.

In conclusion, this study sheds light on the evolving nature of Crohn's disease and the increasing indications of its association with agricultural practices. It underlines the correlation between heavy metals in agricultural lands and CD incidence and provides insights into the variability of both emerging and conventional pollutants across different CD clusters. The unexpected presence of hormones, particularly synthetic and natural estrogens, in forested areas where no known sources exist emphasizes the complexity of soil quality and its potential health impacts. This research marks a pioneering effort, being the first large-scale analysis of
emerging pollutants in European soils and the first to integrate various land cover types in a
comprehensive study of this nature.

**Key words:** Crohn's disease, Soil characterization, Emerging pollutants, Hormones

Authors

Lara-Maria WAKIM

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et
géo-environnement (LGCgE)

Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

[Laramaria.wakim@univ-lille.fr](mailto:Laramaria.wakim@univ-lille.fr)

Florent OCCELLI

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et
géo-environnement (LGCgE)

Faculty of Engineering and Health Management (ILIS), Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

Florent.occelli@univ-lille.fr

Damien CUNY

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et
géo-environnement (LGCgE)

Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

Damien.cuny@univ-lille.fr

Caroline LANIER

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et
géo-environnement (LGCgE)

Faculty of Engineering and Health Management (ILIS), Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

Caroline.lanier@univ-lille.fr

Martin PAUMELLE

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et
géo-environnement (LGCgE)

Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

Martin.paumelle.etu@univ-lille.fr
Delphine BROUSMICHE

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et géo-environnement (LGCgE)

delphine.brousmiche.etu@univ-lille.fr

Annabelle DERAM

Univ. Lille, IMT Lille Douai, Univ. Artois, Junia Hauts-de-France – ULR4515 Laboratoire de génie civil et géo-environnement (LGCgE)

Faculty of Engineering and Health Management (ILIS), Faculty of Pharmacy of Lille - Plant and Fungal Sciences Laboratory (LSVF)

Annabelle.deram@univ-lille.fr