# Biobio Sentinel: Two years of illicit drug surveillance in South-Central Chile. > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/wastewater-cannabis-surveillance-population-drug-trends-chile/ > **Published:** 2026-04-28T23:02:23-04:00 | **Last Modified / Clinically Audited:** 2026-09-28T09:59:43-04:00 > **Clinical Summary:** Chilean wastewater surveillance shows 90% cannabis decline and 1000% cocaine increase over two years, demonstrating environmental drug monitoring capabilities. --- CED Clinical Relevance  #56Monitored Relevance Evidence Brief | CED ClinicTwo-year wastewater surveillance in Chile reveals dramatic tenfold increase in cocaine consumption while [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) declined by 90%. SurveillanceCannabisCocaineEpidemiology[Public Health](https://cedclinic.com/cannabis-mold-contamination-risks-recall-safety/) Two-year wastewater surveillance in Chile reveals dramatic tenfold increase in cocaine consumption while [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) declined by 90%. What This Study Teaches Us This surveillance methodology demonstrates that wastewater-based epidemiology can detect dramatic shifts in community-level drug consumption patterns over time. The opposing trends for different substances suggest distinct market or behavioral dynamics affecting cocaine versus cannabis use in this Chilean region. Why This Matters These findings provide objective, population-level data on drug consumption trends that can inform [public health](https://cedclinic.com/cannabis-mold-contamination-risks-recall-safety/) policy and resource allocation. The methodology offers a non-invasive way to monitor community drug use patterns that doesn’t rely on self-reporting or arrest data. Study Snapshot Study Type Longitudinal Surveillance Study Population Community populations served by 33 wastewater treatment plants in Biobío Region, Chile Intervention Wastewater-based epidemiological monitoring of drug metabolites Comparator Temporal trends over 24 months (September 2022 – August 2024) Primary Outcome Drug consumption levels measured via metabolite detection in wastewater Key Finding Cocaine use increased 1019%, cannabis use decreased >90%, ketamine emerged as detectable substance Journal Journal of Hazardous Materials Year 2024 Clinical Bottom Line Wastewater surveillance provides reliable population-level monitoring of drug consumption trends. The dramatic increase in cocaine use alongside decreased cannabis use suggests significant shifts in drug market dynamics or user preferences that warrant public health attention. What This Paper Does Not Show This study cannot determine individual consumption patterns, reasons for the dramatic shifts in drug use, or health outcomes associated with these consumption changes. The methodology provides population aggregates but not individual-level data or clinical consequences. Where This Paper Deserves Skepticism The study period coincided with significant global events that could confound trends, and wastewater analysis assumes consistent metabolite excretion patterns across populations. The methodology cannot distinguish between occasional and chronic users or account for tourism or temporary population changes. Dr. Caplan's Take While this surveillance data is fascinating from an epidemiological perspective, it doesn’t directly inform my [clinical cannabis](https://cedclinic.com/entourage-effect-cannabis-clinical-breeding-benefits/) practice. However, it does validate that population-level cannabis consumption can be objectively measured and shows significant variability over time, which may reflect changing legal or social contexts. What a Careful Reader Should Take Away Wastewater-based epidemiology provides valuable objective data on community drug consumption patterns. The opposing trends for different substances suggest complex factors influencing drug markets and user behavior that require further investigation to understand fully. Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan →](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion →](https://cedclinic.com/interact/discussion-forums/forum/cannabis-industry/) Have thoughts on this? Share it: [X Share on X](https://twitter.com/intent/tweet?text=Just%20read%20this%20on%20CEDclinic.com%3A%20Biobio%20Sentinel%3A%20Two%20years%20of%20illicit%20drug%20surveillance%20in%20South-Central%20Chile.%20%40drcaplan&url=https%3A%2F%2Fcedclinic.com%2Fwastewater-cannabis-surveillance-population-drug-trends-chile%2F)[in Share on LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fwastewater-cannabis-surveillance-population-drug-trends-chile%2F)[🦅 Share on BlueSky](https://bsky.app/intent/compose?text=Just%20read%20this%3A%20Biobio%20Sentinel%3A%20Two%20years%20of%20illicit%20drug%20surveillance%20in%20South-Central%20Chile.%20via%20%40drcaplan.bsky.social%20https%3A%2F%2Fcedclinic.com%2Fwastewater-cannabis-surveillance-population-drug-trends-chile%2F)[📷 Follow on Instagram](https://www.instagram.com/drbenjamincaplan)[📝 Read more on Substack](https://doctorapprovedcannabis.substack.com/)[🔔 Subscribe via RSS](https://cedclinic.com/feed/) Table of Contents - [FAQ](#FAQ)[What is wastewater-based epidemiology and how reliable is it for monitoring drug consumption?](#What_is_wastewater-based_epidemiology_and_how_reliable_is_it_for_monitoring_drug_consumption) - [What dramatic changes in drug consumption patterns were observed in this Chilean study?](#What_dramatic_changes_in_drug_consumption_patterns_were_observed_in_this_Chilean_study) - [How should clinicians interpret the 90% decline in cannabis consumption detected through wastewater?](#How_should_clinicians_interpret_the_90_decline_in_cannabis_consumption_detected_through_wastewater) - [What clinical implications does the tenfold increase in cocaine consumption have for healthcare providers?](#What_clinical_implications_does_the_tenfold_increase_in_cocaine_consumption_have_for_healthcare_providers) - [How can wastewater surveillance data inform clinical practice and public health responses?](#How_can_wastewater_surveillance_data_inform_clinical_practice_and_public_health_responses) - [Related](#Related) ## FAQ #### What is wastewater-based epidemiology and how reliable is it for monitoring drug consumption? Wastewater-based epidemiology (WBE) monitors community-level drug use by analyzing drug metabolites excreted into sewage systems. This study used validated SPE/LC-MS/MS methods to analyze 3,198 samples from 33 treatment plants, providing objective, population-level data that complements traditional surveillance methods like surveys and arrests. #### What dramatic changes in drug consumption patterns were observed in this Chilean study? The two-year surveillance revealed striking contrasting trends: cocaine use increased more than tenfold (+1019%), while cannabis consumption declined by over 90%. Ketamine also emerged as a new concern, rising from undetectable to measurable levels during the study period. #### How should clinicians interpret the 90% decline in cannabis consumption detected through wastewater? This dramatic decline may reflect changes in consumption patterns, product potency, or detection methods rather than actual cessation of use. Clinicians should continue screening patients for cannabis use as wastewater data represents population trends, not individual patient [risk assessment](https://cedclinic.com/ethical-legal-dilemmas-cannabis-use/). #### What clinical implications does the tenfold increase in cocaine consumption have for healthcare providers? The dramatic rise in cocaine use suggests increased risk of cardiovascular emergencies, psychiatric complications, and [substance use disorders](https://cedclinic.com/cannabinoid-clinical-trials-mental-disorders-evidence-2/) in the population. Healthcare providers should maintain high clinical suspicion for cocaine-related presentations and consider enhanced screening protocols in emergency and primary care settings. #### How can wastewater surveillance data inform clinical practice and public health responses? WBE provides early warning systems for emerging drug trends, allowing healthcare systems to prepare for changing patterns of substance-related presentations. This objective, real-time monitoring can guide resource allocation, treatment program development, and clinical training priorities before individual case presentations become apparent. [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).