Biological fluids were collected from 15 volunteers recruited in the population of Kinshasa with ages ranging from 25 to 66 years, including 10 men and 5 women. For this small pilot bio-surveillance study, with the aim to conduct the first exploration of pollutant contamination in general population of Kinshasa and covering various exposition profiles, volunteers were selected among business sectors, including market gardeners, pesticide vendors, plastic manufacturers, aluminum utensil makers, mechanics, traders, students, lawyers, painters, drivers, teachers, polices, students, fitters, and sanitation technicians. Each sector, a volunteer was randomly chosen throughout the city. Prior to be enrolled, volunteers were informed about the study merits and were submitted to a questionnaire to record their age, business activity, commonly handled products, and duration of exposure.
Early in the morning, after breakfast, each volunteer was requested to give about 10 mL of whole blood, kept in a plastic tube (without gel but with heparin), 10 mL of whole blood to prepare the serum, kept in a plastic tube (without gel and without heparin), and 50 mL of urine, kept in a polypropylene vial, all together 45 samples for analysis. These samples were collected between March and April 2019 and placed immediately in a dry ice enclosure, while ensuring that tubes with whole blood were not in direct contact with the ice, to avoid the risk of hemolysis and facilitating their transport, for proper storage, to the Clinical Biology Laboratory of the Faculty of Pharmaceutical Sciences at the University of Kinshasa. Tubes with whole blood for the preparation of the serum samples were centrifuged for 5 minutes at 3000 rpm and kept, together with urine samples, in a freezer at -20°C, while tubes of heparinized whole blood were stored in a fridge at 4°C. Toxicological analyses were carried out in the Laboratory of Clinical, Forensic and Environmental Toxicology, at the University of Liege, in Belgium. For a proper transport to Belgium, all samples were stored in a hermetically sealed enclosure with dry ice, while ensuring that the whole blood tubes were not in direct contact with the ice. The current study was approved by the national health ethics committee in the Congo under the series number of 159/CNES/BN/PMMF/2020.
Analysis of metals and metalloids in urine
The inorganic compounds (namely, As, Bi, Cd, Co, Cr, Cu, Mn, Mo, Ni, Sb, Se, Sn, Tl, V and Zn) were analyzed using ICP-MS. Briefly, internal standard (containing Rh, Sc and Ge) was added, at the same time, to the sample, to the quality control sample, and to the standard calibration sample. This mixture was then diluted with an aqueous solution of nitric acid 0.5% before being injected into ICP-MS. For detailed analytical methodology, see supplementary information.
Analysis of glyphosate in urine
Urinary content in glyphosate was investigated following the procedure extensively described in the supplementary information. Briefly, urinary glyphosate in sample, quality control sample, and standard calibration sample was derivatized with fluorenylmethoxycarbonyl chloride (FMOC). A first liquid-liquid extraction was then performed to eliminate residual FMOC and apolar compounds. A second liquid-liquid extraction was performed after acidification to extract the analyte. After evaporation and reconstitution in vial, the sample was analyzed by LC-MS/MS.
Analysis of pyrethroids and organophosphate chlorpyrifos metabolites in urine
Five pyrethroids metabolites (namely, cis- and trans-3-(2,2-dichlorovinyl)-2.2-dimethylcyclopropane carboxylic acid (c- and t-DCCA), 3-phenoxybenzoic acid (3-PBA), 4-fluoro-3-phenoxybenzoic acid (4F-3-PBA) and 3-(2,2-dibromovinyl)-2.2-dimethylcyclopropane carboxylic acid (DBCA)) and one chlorpyrifos metabolite (namely 3,5,6-trichloro-2-pyridinol (TCPY)) were analyzed according to the methodology detailed in Pirard et al. 2020 . Briefly, urinary sample, quality control sample, and standard calibration sample were extracted with diethyl ether. The organic layer was evaporated to dryness and the residue was derivatized with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). The derivatized extract was then analyzed by GC-MS/MS.
Analysis of alkylphosphates in urine
Five dialkylphosphates (DAPs) (nonspecific metabolites of organophosphate pesticides) (namely dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP)) were quantified in urine samples according to the methodology described in Pirard et al., 2020 . In summary, urine sample, quality control sample, and standard calibration sample were extracted on solid phase extraction (SPE) cartridge. The eluate was evaporated to dryness and then derivatized with chloroiodopropane. The derivatized extract was then analyzed by GC-MS/MS.
Analysis of phthalate metabolites, parabens and benzophenone-3 in urine
The urinary concentrations of 7 phthalate metabolites (namely, monoethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (5-OH-MEHP) and mono-2-ethyl-5-oxohexyl phthalate (5-oxo-MEHP)), 4 parabens (namely, methylparaben (MeP), ethylparaben (EP), n-propylparaben (PrP) and n-butylparaben (BP)) and benzophenone-3 were determined according to the methodology developed by Dewalque et al. 2014 . Briefly, urine sample, quality control sample, and standard calibration sample were submitted to an enzymatic hydrolysis, then an extraction was performed using SPE cartridge and finally the extract was analyzed on a LC-MS/MS apparatus.
Analysis of triclosan and bisphenols in urine
The levels of triclosan and 7 bisphenols (BP) (namely, BPA, BPAF, BPF, BPZ, BPAP, BPP and BPS) in urine samples were measured by using the methodology detailed in the supplementary materials. In summary, the sample, quality control sample, and standard calibration sample were submitted to an enzymatic hydrolysis followed by an extraction on a SPE cartridge. This first extraction was followed by a liquid-liquid extraction and then by a derivatization. The derivatizated extract was then analyzed by a GC-MS/MS .
Analysis of lead in whole blood
Lead was quantified in whole blood. Samples, quality control samples, and standard calibration samples were mixed with internal standard and diluted with a mixture of nitric acid (0.5%), n-butanol (0.2%) and triton (0.1%) in water. The lead content was determined by using an ICP-MS. The procedure has been detailed in supplementary information.
Analysis of polychlorobiphényls (PCBs) and organochlorine pesticides in serum
Fifteen organochlorine pesticides or metabolites, (namely alpha-, beta-and gamma-HCH (α-, β- and γ-HCH), hexachlorobenzene (HCB), aldrin, dieldrin, endrin, trans-chlordane, oxychlordane, trans-heptachlor ep-oxide, cis- and trans-nonachlor, 2,4′- and 4,4′-dichlorodiphenyl-dichloroethylene (DDE), beta-endosulfan) and 3 PCBs (−138, −153, and −180) were quantified in serum. The analytical procedure was extensively detailed in Pirard et al. 2018 . Briefly, sample, quality control sample, and standard calibration sample were denaturized with acetonitrile and a saturated potassium carbonate solution. The mixture was then extracted twice with hexane-acetone mixture (9/1, v/v). The organic phase was cleaned on a SPE cartridge and then evaporated and reconstituted in nonane. The extract was analyzed on a GC-MS/MS apparatus.
Analysis of BFRs in serum
The methodology to quantify 8 polybrominated diphenylethers (PBDEs) (namely, BDE-28, -47, -99, -100, -153, -154, -183 and -209) has been described in Pirard and Charlier, 2018 . In summary, serum sample, quality control sample, and standard calibration sample were denaturized with a glacial acetic acid/water mixture (3/7, v/v) and then extracted twice with a mixture of hexane and acetone (95/5, v/v). The organic phase was then cleaned on a PHREE cartridge, then evaporated and transferred into nonane. The quantification was performed using a GC-MS/MS.
Analysis of perfluorinated alkyl subtances (PFAS) in serum
The quantification of the serum content in 7 PFASs (namely, perfluoro-octane sulfonic (PFOS), perfluoroctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroheptanoic acid (PFHpA) and perfluoroundecanoic acid (PFUdA)) was performed according to the methodology described in Dufour et al. 2018 . Briefly, serum sample, quality control sample, and standard calibration sample were denaturized with formic acid/water mixture (1/1, v/v). Then the sample was extracted on a weak anionic exchange SPE cartridge, the eluate was evaporated to dryness and then reconstituted in 80 µL of a mixture of mobile phases. The extract was then analyzed using a LC-MS/MS apparatus.
Analysis of phenolic organohalogens (POHs) in serum
POHs (namely, pentachlorophenol (PCP), tetrabromobisphenol A (TBBPA), 2,4,6-tribromophenol (2,4,6-TBP), 2,3,6-tribromophenol (2,3,6-TBP), 2,4,5-tribromophenol (2,4,5-TBP), 2,3,4,6-tetrabromophenol (2,3,4,6-TeBP), 6-hydroxy-polybromodiphenylether 47 (6-OH-BDE 47), 5-hydroxy-polybromodiphenylether 47 (5-OH-BDE 47), 5′-hydroxy-polybromodiphenylether 99 (5′–OH–BDE 99), 4-hydroxy-polychlorinated biphenyl 107 (4-OH-CB 107), 3-hydroxy-polychlorinated biphenyl 138 (4-OH-CB 138), 4-hydroxy-polychlorinated biphenyl 146 (4-OH-CB 146), 3-hydroxy-polychlorinated biphenyl 153 (3-OH-CB 153), 4-hydroxy-polychlorinated biphenyl 172 (4-OH-CB 172), 3-hydroxy-polychlorinated biphenyl 180 (3-OH-CB 180) and 4-hydroxy-polychlorinated biphenyl 187 (4-OH-CB 187)) were analyzed according to the method described in Dufour et al. 2016 . In summary, the serum sample, quality control sample, and standard calibration sample were denaturized with a mixture of water/formic acid/2-propanol (50/40/10, v/v) and then extracted on a strong anionic exchange SPE cartridge. The eluate is then extracted with hexane; hexane phase was evaporated to dryness and then derivatized with trimethylsilyldiazomethane. The derivatized extract was then analyzed using a GC-MS/MS.
Analysis of creatinine in urine samples
Adjustment to creatinine was used to normalize pollutant contents in urine samples. In this study, urinary creatinine was evaluated on an ARCHITECT Ci 4100 automate from ABBOTT (Illinois, USA), using an immunoassay.
Quality assurance and statistical analysis
To ensure the results quality, all analyses were covered by internal or external quality control sample and for each analysis, a specific internal standard was used as a recovery indicator and a correction factor. A specific calibration curve was applied for each analysis. All statistical analyses were performed using R programming software (version 3.6.3., CRAN) and Microsoft Excel 2013 (Microsoft, Redmond, WA). For analyses with results lower than the limit of quantification (LOQ), a correction was made by multiplying the LOQ by the detection frequency (DF), in order to valorize the investigation outcomes.