title: Changes in illicit drug consumption patterns in 2009 detected by wastewater analysis.
abstract: BACKGROUND
  Wastewater analysis can provide estimates of illicit drug (ID) consumption in local communities.
  
  
  METHODS
  We used repeated raw wastewater analysis in urban wastewater treatment plants to estimate loads of cocaine, heroin, methamphetamine, and cannabis consumed daily by the inhabitants of two cities in Northern Italy, Milan and Como, from 2005 to 2009.
  
  
  RESULTS
  Daily cocaine loads did not change in Milan from 2005 to 2008 but fell 45% in 2009 (ANOVA, p<0.001, followed by Tukey-Kramer HSD test [2009 vs. others], p<0.05), and there was a similar drop in Como (41%, p<0.0001, t-test). Heroin also fell from 2008 to 2009 in Milan (66%, ANOVA, p<0.001, followed by Tukey-Kramer [2009 vs. others], p<0.05) and Como (26%, p=0.017, t-test). However, methamphetamine, which had risen in Milan from 2005 to 2008, rose further in 2009 (Kruskal-Wallis test, p<0.001, followed by Steel-Dwass [2009 or 2008 vs. previous], p<0.05), and cannabis, which was falling from 2005 to March 2009, rose again in September 2009 (40%, p=0.027, t-test).
  
  
  CONCLUSIONS
  Results suggest a trend toward a decrease in consumption of costly ID, such as cocaine and heroin. This might be due to a reduction in the number of consumers and/or to a change in their behaviour since there was also an increase in the consumption of less expensive ID. This itself might reflect a drop in consumers' money supply, caused by the economic crisis. Wastewater analysis was useful to estimate ID consumption levels in local communities in real time and promptly identify changes in trends.
authors.affiliation: Department of Environmental Health Sciences, Mario Negri Institute for Pharmacological Research, Via G. La Masa 19, 20156 Milan, Italy. ettore.zuccato@marionegri.it
authors.forename: Ettore
authors.initials: E
authors.lastname: Zuccato
authors.forename: Sara
authors.initials: S
authors.lastname: Castiglioni
authors.forename: Mauro
authors.initials: M
authors.lastname: Tettamanti
authors.forename: Raffaela
authors.initials: R
authors.lastname: Olandese
authors.forename: Renzo
authors.initials: R
authors.lastname: Bagnati
authors.forename: Manuela
authors.initials: M
authors.lastname: Melis
authors.forename: Roberto
authors.initials: R
authors.lastname: Fanelli
mesh_terms: D003042:Cocaine / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D003932:Heroin / Q000032:analysis; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis*; D007558:Italy; D008694:Methamphetamine / Q000032:analysis; D011634:Public Health; D015813:Substance Abuse Detection / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D013287:Illicit Drugs; D014874:Water Pollutants, Chemical; D008694:Methamphetamine; D003932:Heroin; D003042:Cocaine