*2.1. Sampling*

In 2019, autopsy tissue samples were collected from 20 individuals who—at the time of death—had been residing near the Constantí HWI at least during the previous 10 years. These individuals were not occupationally exposed, being five of them smokers. The samples were collected in close collaboration with forensic doctors from the Tarragona Division of the Institute of Legal Medicine and Forensic Sciences of Catalonia. Samples were obtained from 19 men and one woman, with an average age of 56 years. From each subject, samples (1 g) of the following tissues were obtained: kidney, liver, brain, bone tissue, and lung. One hundred samples (five tissues per individual) were collected. Autopsies and sample collection were performed within the first 24 h after the death. Samples were stored in hermetically sealed polyethylene containers and frozen at −20 ◦C for processing [20–22]. The protocol of the biological surveillance program, number 07/2017, was reviewed and approved by the Ethical Committee for Clinical Research (CEIm) of the Pere Virgili Health Research Institute (IISPV), Reus/Tarragona, Spain, in 20 March 2017. Furthermore, the specific protocol for the biomonitoring study of autopsy tissues, number PR164/19, was complementarily evaluated and approved by the Clinical Research Ethics Committee (CEIC) of the Bellvitge University Hospital, Barcelona, Spain, in 9 May 2019.

### *2.2. Chemical Analysis*

The concentrations of arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl) and vanadium (V) were determined in all samples. In order to obtain fully comparable data, the same experimental procedure as that used in previous studies of the surveillance program [21,22], was followed. Briefly, 0.5 g of each sample were treated in Teflon vessels containing 5 mL of nitric acid (65%, Suprapur, E. Merck, Darmstadt, Germany) during 8 h at room temperature. Afterwards, samples were heated for 8 h more at 80 ◦C. After cooling, samples were filtrated, made up to 25 mL with deionized water and properly stored −20 ◦C until the chemical determination. The analysis of the 11 trace elements was conducted by means of inductively coupled plasma-mass spectrometry (ICP-MS) using an Elan 6000 instrument (Perkin Elmer, Waltham, MA, USA). The limits of detection (LODs) were 0.025 μg/g for Cd, Pb and Tl; 0.05 μg/g for Mn; 0.10 μg/g for As, Be and Hg; 0.25 μg/g for Ni; and 0.50 μg/g for Cr, Sn and V. The quality of the experimental procedure was controlled and assured by analyzing reference materials

(Lobster Hepatopancreas, TORT 2, NRC Canada, Ottawa, ON, Canada) and blanks in every batch of samples Reproducibility was assured as reported in previous investigations [22]. Recovery percentages ranged between 84% and 121%.
