Dataset of illicit drugs consumption through wastewater during and post COVID-19 in San Pedro de la Paz, Chile.
Description
This dataset was generated to apply the wastewater-based epidemiology (WBE), for the first time, in a Chilean municipality to quantify community-level illicit drug consumption using standardized sampling and analytical procedures. The study selected four metabolites (benzoylegnonine, THCCOOH, Anfetamine and MDMA) of illicit drugs present in wastewater to measure in LC–MS/MS and converted, through back-calculation, into normalized estimates of consumption that are comparable across time when similar protocols are used. To evaluate this, 24 h composite samples were collected at the San Pedro de la Paz Wastewater Treatment Plant (WWTP) in two distinct periods: (i) during COVID-19: twelve days in August 2021 and; (ii) Pos-COVID-19: weekly sampling from September 2022 to October 2023. All samples were collected, preserved with sodium metabisulfite, stored at 4 °C, and processed within three days to ensure consistency across both sampling periods. The data were then normalized using wastewater flow rates and the estimated population served by the WWTP to obtain consumption estimates expressed as mg/day/1000 inhabitants. The data show the presence and quantification in population-normalized mass load (PNML) of drug metabolites in each sampling event. Users can examine the data as a normalized consumption values for population-level comparisons. These data can be interpreted as measurements of metabolite loads entering the WWTP during defined 24 h periods. Researchers may use the provided normalization approach to compare with other WBE studies. The dataset can also be reused to integrate with epidemiological information, or perform temporal and cross-regional comparisons using standardized WBE metrics.
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Steps to reproduce
Wastewater samples were collected as 24 h composite influent samples at the San Pedro de la Paz Wastewater Treatment Plant (WWTP) in the Biobío Region, Chile. An automated GLS sampler was programmed to collect influent wastewater at flow-proportional intervals, obtaining approximately 2 L per sampling event. Immediately after collection, sodium metabisulfite (Na₂S₂O₅) was added at a concentration of 0.5 g/L to prevent degradation of target compounds. Samples were transported to the laboratory, stored in the dark at 4 °C, and processed within 72 hours. At the laboratory, sample processing involved filtration through glass fiber filters (0.7 μm) followed by solid-phase extraction (SPE) using Bond Elut Plexa SPE cartridges (3 mg, 3 mL, Agilent®, USA). Cartridges were conditioned with methanol and ultrapure water, and analytes were eluted with methanol, evaporated under nitrogen to near dryness, and reconstituted in mobile phase prior to LC–MS/MS analysis. Chromatographic separation was achieved on a Shimadzu Shim-pack XR-ODS C18 column (4.6× 100 mm, 2.2 μm) maintained at 40 °C, with optimized mobile phases consisting of (A) water with 0.1% formic acid and (B) methanol or acetonitrile, depending on the analyte group. Detection was performed on a SCIEX Triple Quad 5500+ mass spectrometer operating in negative for THCCOOH and positive mode for the other metabolites. Limits of detection (LOD) of 3 ng/mL for THCCOOH and 6 ng/mL for the other metabolites and limits of quantification (LOQ) from 10 to 4000 ng/L for THCCOOH and from 20 to 1000 ng/L for the other metabolites. For each sampling date, metadata were compiled, including composite sampling start and end times, wastewater flow rates provided by the WWTP, and the estimated population served. These parameters were used to normalize the concentration data through a back-calculation procedure that converts measured concentrations into population-normalized mass load expressed as mg/day/1000 inhabitants. No correction factors were used in the back-calculation.
Institutions
- Universidad Católica de la Santísima ConcepciónBiobío, Concepción
- Universidad MayorSantiago Metropolitan, Santiago