A fugacity model assessment of ibuprofen, diclofenac, carbamazepine, and their transformation product concentrations in an aquatic environment

Tuomas M A Nurmi,Juha S Knuutinen,Toni K Kiljunen

doi:10.1007/s11356-018-3485-x

Tuomas M A Nurmi, Juha S Knuutinen + Show 1 more

Open Access

https://doi.org/10.1007/s11356-018-3485-x

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Abstract

An updated version of FATEMOD, a multimedia fugacity model for environmental fate of organic chemicals, was set up to assess environmental behaviour of three pharmaceuticals in northern Lake Päijänne, Finland. Concentrations of ibuprofen, diclofenac, and carbamazepine were estimated at various depths at two sites: near a wastewater treatment plant and 3.5 km downstream the plant. When compared with environmental sampling data from corresponding depths and sites, the predicted concentrations, ranging from nanograms to hundreds of nanograms per litre, were found to be in good agreement. Weather data were utilised with the model to rationalise the effects of various environmental parameters on the sampling results, and, e.g. the roles of various properties of lake dynamics and photodegradation were identified. The new model also enables simultaneous assessment of transformation products. Environmentally formed transformation product concentrations were estimated to be at highest an order of magnitude lower than those of the parent compounds, and unlikely to reach a detectable level. However, a possibility that conjugates of ibuprofen are present at higher levels than the parent compound was identified. Simulation results suggest that environmental degradation half-lives of the inspected contaminants under stratified lake conditions are in the range of some weeks to months.

Highlights

A growing variety of chemicals are produced by modern industry and used all over the world (O’Neill 1998)
FATEMOD uses fugacity, fugacity capacity, and reaction rate calculation methods corresponding to the Level III model, but adds the temperature dependence of chemical properties, and supports acids and bases
Almost every modelled water result was between the highest and the lowest value at the corresponding site and depth, and often close to their average. This suggests that the model sufficiently describes the major processes affecting pharmaceutical behaviour in the inspected environment, and the parameters used were valid approximations

Summary

Introduction

A growing variety of chemicals are produced by modern industry and used all over the world (O’Neill 1998). Expanded search efforts and advanced analytical technologies have uncovered the environmental presence of a plethora of anthropogenic chemicals, and many of them are known to be, or are considered potentially harmful. A global effort to assess their risks and to reduce the amounts of contaminants ending up in the environment has been ongoing for decades. Transformation product (TP) and metabolite concentrations and toxicities 2008; Donner et al 2013) may even exceed those of the parent compounds. Many conjugated metabolites can deconjugate back to their respective parent compounds in the environment (Celiz et al 2009; Azuma et al 2017)

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