Is the reliability of wastewater-based epidemiology affected by season? Comparative analysis with pharmaceuticals prescriptions.

Wastewater-based epidemiology (WBE) has been already proposed by several authors for estimating the consumption of drugs, mainly the illicit ones. However, not much information is available about the actual reliability of this tool given the absence of comparison with the actual consumption. This work aims to evaluate the reliability of the WBE as a tool for estimating the consumption of pharmaceuticals in urban area. Measured consumption back-calculated with a WBE approach was compared with prescription of pharmaceutical products as "control." Moreover, seasonal influence on (i) pharmaceutical consumption, (ii) load of pharmaceutical products in the sewer system, and (iii) reliability of WBE was evaluated. Ciprofloxacin, sulfamethoxazole, metoprolol, carbamazepine, and citalopram were estimated by WBE with a difference respect to the "control" value lower than 0.2 order of magnitude while only trimethoprim and sotalol exceeded the 0.5 order of magnitude of difference but below the 1 order of magnitude. Sedatives were the best represented by WBE (on average 0.15 order of magnitude of difference compared to prescription data). However, further studies are suggested to fully estimate the influence of the type of APs on the reliability of the WBE. Seasonal patterns were found for the load of ciprofloxacin in the sewer and for the consumption of sulfamethoxazole and trimethoprim by population but seasonal changes did not have a significant impact (p > 0.05) on the reliability of WBE. Despite some gaps remained to optimize the reliability of the tool, WBE can be considered a valid method to estimate the consumption of prescribed drugs from the analysis of the sewer system.

Pharmaceutical and narcotics monitoring in Brno wastewater system and estimation of seasonal effect on the abuse of illicit drugs by a wastewater-based epidemiology approach.

The presence of pharmaceuticals (PHA) and narcotics (NAR) in wastewater (WW) has attracting growing interest due to concern for aquatic environment and the possibility to exploit their presence to estimate drug consumption by population. This work aims to (i) quantify PHA and NAR in the WW of the Brno metropolitan area, (ii) determine the effectiveness of the current conventional wastewater treatment plant (WWTP), and (iii) estimate the illicit drug (ID) consumption. 23 PHA and 9 NAR were frequently detected in the untreated WW and studied for their removal. One year monitoring was carried out to highlight a possible seasonal pattern with PHA and NAR load in WW, WWTP effectiveness, and illicit consumption. Results highlighted that the most abundant PHA and NAR were caffeine (73.9 ± 6.9 µg L-1) and methamphetamine (2.3 ± 0.1 µg L-1) while oxazepam (0.13 ± 0.05 µg L-1) and EDDP (0.02 ± 0.01 µg L-1) were the lowest ones, respectively. Only paracetamol, caffeine, atenolol, ciprofloxacin, amphetamine, cocaine, morphine, and benzoylecgonine exhibited a high biodegradability being removed almost completely (> 90 %). A predominant illicit use of methamphetamine was estimated (17 ± 0.6 doses 1000.inh-1 d-1) that might suggest a higher number of consumers than previous official estimation. A lower abuse of cocaine (2.7 ± 0.5 doses 1000.inh-1 d-1), amphetamine (2.2 ± 0.3 doses 1000.inh-1 d-1), methadone (1.1 ± 0.2 doses 1000.inh-1 d-1), heroin (0.9 ± 0.2 doses 1000.inh-1 d-1), and MDMA (0.7 ± 0.1 doses 1000.inh-1 d-1) was found. A seasonality pattern was highlighted for some PHA and NAR influent load and removal, and, about ID consumption, only for heroin and methadone. These results will be useful for water utilities, to enhance the knowledge about the presence and removal of PHA and NAR, and local and national authorities to evaluate and counteract the problem of ID abuse.