Worldwide estimation of river concentrations of any chemical originating from sewage-treatment plants using dilution factors

Abstract

Dilution factors are a critical component in estimating concentrations of so-called “down-the-drain” chemicals (e.g., pharmaceuticals) in rivers. The present study estimated the temporal and spatial variability of dilution factors around the world using geographically referenced data sets at 0.5° × 0.5° resolution. Domestic wastewater effluents were derived from national per capita domestic water use estimates and gridded population. Monthly and annual river flows were estimated by accumulating runoff estimates using topographically derived flow directions. National statistics, including the median and interquartile range, were generated to quantify dilution factors. Spatial variability of the dilution factor was found to be considerable; for example, there are 4 orders of magnitude in annual median dilution factor between Canada and Morocco. Temporal variability within a country can also be substantial; in India, there are up to 9 orders of magnitude between median monthly dilution factors. These national statistics provide a global picture of the temporal and spatial variability of dilution factors and, hence, of the potential exposure to down-the-drain chemicals. The present methodology has potential for a wide international community (including decision makers and pharmaceutical companies) to assess relative exposure to down-the-drain chemicals released by human pollution in rivers and, thus, target areas of potentially high risk. Environ Toxicol Chem 2014;33:447–452. © 2013 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial, and no modifications or adaptations are made.

A comparison of two methods for the assessment of stress axis activity in wild fish in relation to wastewater effluent exposure

“…Riverine fish are particularly vulnerable to chemical exposure -rivers receive chemicals of anthropogenic origin from a variety of sources, one of the most significant being effluent discharged by wastewater treatment works (WWTWs). Effluent from WWTWs can comprise a substantial proportion of the total flow volume of rivers (Brooks et al, 2006): in 25% of rivers in the United Kingdom the annual median dilution factor of wastewater (total catchment river flow/total domestic wastewater effluent generated) is below 6.3 (Keller et al, 2014). The effluent discharged by WWTWs contains a complex mixture of organic and inorganic chemicals derived from domestic and industrial sources (Henze and Comeau, 2008; 4 Marcogliese et al, 2015) and it is well-established that some of these chemicals may modulate or interfere with the reproductive endocrine system of fish (Mills and Chichester, 2005).…”

Disruption of the stress response in wastewater treatment works effluent-exposed three-spined sticklebacks persists after translocation to an unpolluted environment

“…Effluents from WWTWs can comprise a significant proportion of the total flow in receiving waters (Keller et al 2014) and therefore constitute a potentially substantial challenge to exposed organisms. Most research effort that addresses chemical interference with the function of endocrinedependent processes in aquatic, and terrestrial, vertebrates has focused upon chemicals with adverse effects on the function of the endocrine reproductive axis (Bergman et al 2013;Mills and Chichester 2005).…”

Combined environmental risk assessment for the antiviral pharmaceuticals ganciclovir and valganciclovir in Europe

“…The PNECs derived in the present study for various environmental compartments and receptors may be used for ERAs of GCV and VGCV in other parts of the world. 36,2017No measured environmental concentrations have been located for GCV. Although Peng et al [33] specifically targeted GCV together with other antivirals in wastewater, landfill leachate, river water, reservoirs, and well water in the vicinity of municipal landfills in the Pearl River Delta, China, they could never detect it with limits of quantitation of 19 ng/L for wastewater and 9 ng/L for river water.…”

“…For surface water PEC derivation, the European Medicines Agency and European Union risk assessments assume a default dilution of wastewater treatment effluents by the receiving surface waters of 10 [14]. Keller et al [36] have shown that this default dilution factor covers most of the situations in Europe; but for single countries or regions, the actual median or 25th percentile dilution factor may be less than 10. For instance, this applies for Belgium as a whole country [36], but also for some regions in Spain, Portugal, Italy, Germany, the United Kingdom, and Eastern Europe ( Figure S1 in the Supporting Information in Keller et al [36]).…”

“…Lastly, no significant developmental abnormalities were observed for the F1 fish in the controls and all test concentrations throughout the duration of the test [19]. Therefore, the NOEC for the OECD guideline 210 phase and also for the whole OECD guideline 229/210 partial life cycle test in fathead minnows was 0.012 mg GCV/L mean measured Combined 36,2017concentration, with the F1 generation growth parameters driving this NOEC. Based on the NOECs for the surface water model organisms algae of 109 mg/L mean measured concentration [17], daphnids of 3.3 mg/L mean measured concentration [18], and fish of 0.012 mg/L mean measured concentration [19], the PNEC surface water is 0.0012 mg GCV/L or 1.2 mg GCV/l, using an assessment factor of 10.…”