Environmental exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans among population living in a contaminated area in Lausanne, Switzerland

Abstract

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are ubiquitous in the environment and the main route of exposure for humans is food. A widespread soil contamination was discovered in 2021 in Lausanne city. Previous human exposure assessment study showed that consumption of home-produced eggs and cucurbits were dominant exposure scenarios. In the absence of recent biomonitoring data on PCDD/Fs in the Swiss general population, we conducted a cross-sectional study in 2023 to assess the difference between control (n = 50) and exposed (n = 51) groups, living in the contaminated area and reporting to consume selected home-produced foods (eggs and cucurbits). We compared the two groups using multivariable modelling. The geometric mean serum PCDD/Fs concentration was 6.1 (Interquartile range (IQR): 4.2) and 6.9 (IQR: 5.0) pg TEQ₀₅/g lipid in the control and exposed groups, respectively. In the exposed group, the serum concentrations were 7.7 (IQR: 4.6) and 6.4 (IQR: 3.8) pg TEQ₀₅/g lipid for those who consumed home-produced eggs or cucurbit, respectively. In unadjusted analysis, control and exposed groups did not significantly differ. However, multivariable analyses showed that older age, female sex, higher body fat mass and consumption of home-produced eggs from contaminated areas were independently and significantly associated with higher PCDD/F concentrations. Health risk for humans living on contaminated areas depends on the land use. These results confirm the importance of dietary factors of animal origin as an important route of PCDD/Fs exposure. Unlike cucurbits, home-produced eggs from contaminated areas represent an important source of exposure to PCDD/Fs, which helps guiding public health recommendations.