ABSTRACT
AIMS: To perform a wastewater-based analysis to explore the impact of newly legalized retail cannabis sales on its use and to determine if this approach could estimate the size of the legal market place, which began 1 August 2014 in the study area. DESIGN: Laboratory study of raw wastewater samples collected and analyzed over the 3-year period from 2014 to 2016. SETTING AND PARTICIPANTS: Samples obtained from the two wastewater treatment plants that serviced a municipality of 200 000 people in the state of Washington, USA. MEASUREMENTS: Quantitative analysis of 24-hour composite influent samples for the metabolite of the active ingredient in cannabis, 11-nor-9-Carboxy-Δ9-tetrahydrocannabinol (THC-COOH) were performed by liquid chromatography coupled to mass spectrometry. FINDINGS: Wastewater estimates for THC-COOH increased by 9% per quarter, suggesting a doubling in cannabis consumption from 1 December 2013 to 31 December 2016. State-sold THC increased at nearly 70% per quarter, while stores operated from 1 August 2014 to 31 December 2016. Estimating the proportion of the total cannabis market supplied by state-regulated cannabis from these data is not currently achievable. CONCLUSION: A wastewater-based measure of cannabis consumption suggests a significant increase in consumption in Washington, USA following legalization, and that legal sales appear to have displaced a large portion of the illicit market.
Subject(s)
Dronabinol/analogs & derivatives , Marijuana Use/trends , Wastewater-Based Epidemiological Monitoring , Chromatography, Liquid , Commerce/legislation & jurisprudence , Dronabinol/analysis , Humans , Marijuana Use/epidemiology , Marijuana Use/legislation & jurisprudence , Mass Spectrometry , Washington/epidemiologyABSTRACT
Nanoporous gold and silver exhibit strong, omnidirectional broad-band absorption in the far-field. Even though they consist entirely of gold or silver atoms, these materials appear black and dull, in great contrast with the familiar luster of continuous gold and silver. The nature of these anomalous optical characteristics is revealed here by combining nanoscale electron energy loss spectroscopy with discrete dipole and boundary element simulations. It is established that the strong broad-band absorption finds its origin in nanoscale splitting of light, with great local variations in the absorbed color. This nanoscale polychromaticity results from the excitation of localized surface plasmon resonances, which are imaged and analyzed here with deep sub-wavelength, nanometer spatial resolution. We demonstrate that, with this insight, it is possible to customize the absorbance and reflectance wavelength bands of thin nanoporous films by only tuning their morphology.