Actieve farmaceutische ingrediënten in het terrestrische milieu

: Een procesbeschrijving om accumulatie in landbouwbodems, landbouwgewassen en terrestrische voedselketens te modelleren

Abstract

Since 1990, there has been a continuous increase in investments in the development, production, sales and consumption of medicines. It is estimated that 70% of the administered active pharmaceutical ingredients (APIs) end up in the environment. This study aims to explore possibilities toextend the ePiE model, as part of an exposure model for the terrestrial environment. This research, commissioned by Radboud University, focuses on the study of physical, chemical, biological processes and environmental conditions that influence the accumulation of active pharmaceutical ingredients (APIs) in agricultural soils, crops and terrestrial food chains

Accumulation of APIs in agricultural soils and crops depends on the combination of physiochemical and soil properties. The acidity of the environment and the acid dissociation constant of APIs influence the mobility and reactivity of APIs and determine whether they occur in the ionized state. In addition, the water solubility of a substance and the presence of organic matter, clay minerals and metal (hydr)oxides in the soil influence the accumulation and bioavailability of APIs in agricultural soils. Uptake and accumulation in agricultural crops is influenced by plant physiology, in addition to soil and substance properties, which differs between plant species. Environmental conditions such as climatic influences (temperature and precipitation) also influence the uptake and accumulation by agricultural crops. In the soil matrix, climatic influences and degradation processes influence the mobility, degradation and accumulation of APIs in the soil matrix. Physicochemical properties of substances that play a role in bioaccumulation are the n-octanol / water partition coefficient, ionization and water solubility.

For the accumulation in agricultural soils, a reservoir model approach (according to EMA) can be used as an addition of the ePiE model. The same consumption data from ePiE is used for this model approach, in combination with additional data about the periodic application of sewage sludge or irrigationwith effluent on agricultural land. The plant uptake model of Trapp provides a good basis for modelling the uptake and accumulation of APIs by agricultural crops. The reliability of the model can be increased by more extensive validation studies. A model from the European Food Safety Authority, which describes accumulation of crop protection agents, seems to be applicable to model the concentration of APIs in terrestrial food chains. Using the Henderson-Hasselbalch equation, the unionized and ionized fraction of substances can be calculated, which can be used to extend bioaccumulation models for neutral substances and can be used to model the accumulation of ionizable substances in terrestrial organisms

Date of Award	8 Feb 2021
Original language	Dutch
Supervisor	Jikke van Wijnen (Supervisor), Ad Ragas (Co-assessor) & Angelique Lansu (Examiner)