The human health risk of
pharmaceuticals in Dutch waters
Figure 1. Pharmaceutical contamination of water (Mohd Nasir et al., 2019)
Authors Lola Barends (6753434)
Florine Bezoen (6428495)
Merijn Hilhorst (6808247)
Yara Langeveld (6733506)
Course Environmental Chemistry and Health (GEO3-2119)
Case study supervisor Sander Lentz
Course coordinator Rasesh Pokharel
Faculty Geosciences, Utrecht University
Date 11-01-2022
In this research, the main research question is split up into four sub questions that
are separately investigated. After this, a discussion and conclusion are drawn,
containing recommendations for further actions regarding pharmaceutical
contamination in Dutch waters.
1
,Introduction
The use of human and veterinary pharmaceuticals is increasing, as approximately 600 pharmaceutical
compounds have been found in aquatic environments (Wöhler et al., 2020). These compounds have an
impact on human health via several exposure pathways, for example via surface, ground- and drinking
water (van der Hoek et al., 2013). Through the intake of drinking water, dairy products, fish, leaf and
root crops and the inhalation of air, pharmaceuticals are mostly exposed to the body (Kumar et al.,
2010). In the Netherlands, the exposure to pharmaceuticals differs between small and large water
bodies, such as the distinction between Rhine water and polder water (Houtman et al., 2014). It is
important to assess the risk of these pharmaceuticals for humans, since the overall toxic impact on
human health of low doses of pharmaceuticals is currently unknown (de Jongh et al., 2012). Hereby, a
knowledge gap remains with regard to which pharmaceuticals are most present in the environment
and pose the highest risk to human health.
The problem of pharmaceuticals in Dutch drinking water has increased due to several factors.
Firstly, demographic developments, such as an increased consumption of pharmaceuticals due to an
aging population, have contributed to the problem (Claassen et al., 2021). Furthermore, societal
changes, in the form of growing industrial activities and technological improvements, have taken
place. A fourth factor includes regulatory changes, such as phasing out certain contaminants, which
encourages the use of possibly more damaging alternatives (Claassen et al., 2021). Lastly, climate
change contributes to the problem by for example sewage overflows as a result of heavy rain events.
This research aims to answer the research question “To what extent are pharmaceuticals
present in Dutch waters safe for humans?” Hereby, it targets the knowledge gap of what
pharmaceuticals in which Dutch waters should be of key focus to achieve a reduction in aqueous
pharmaceutical contamination in the Netherlands. This question is further specified into four
subquestions. Firstly, an outline of the most prevalent pharmaceuticals in Dutch waters will be given,
after which the difference between small and large Dutch waters is investigated. Furthermore, the
human health effects and risks that consequently arise are outlined and finally the initiatives that have
taken place to reduce pharmaceutical contamination of Dutch waters are delineated. The methodology
section describes the used method for gathering results and drawing conclusions.
Through this research, a theoretical contribution can be made, as it is clarified which
pharmaceuticals pose the greatest threat to human health and what has been done to stop this. As a
result, advice will be formulated as to what actions are necessary to tackle this problem effectively.
Methodology
This research is based on a systematic literature search. Information is gathered through
systematically reviewing scientific articles for their relevance. The table in Appendix 1 entails the
search terms in combination with a search engine and the relevant sources. The search terms are based
on the research question and the individual subquestions. The search engines that are used are Google
Scholar, Pubmed and Web of Science, which ensures external validity, as different sampling methods
are used (Bryman, 2016). In addition, several exclusion criteria are applied, namely, only English and
Dutch articles and review articles, published between January 1980 to December 2021. The articles
must mention all the search terms to be deemed relevant. The search is also geographically restricted
to the Netherlands and Europe. With every search result, the first 10 pages and their conclusion are
screened. Initially, the articles scanned for their title, abstract and keywords. Besides, the resources
used in the articles are also scanned for other relevant references. The articles are firstly reviewed by
all researchers independently and then collectively for investor triangulation, which ensures internal
validity (Bryman, 2016).
2
, After collecting a selection of relevant articles, the articles are read entirely to subtract
relevant information. For each sub question several criteria are used to determine the relevance of the
found literature, which are summarised in Appendix 2. This information is used to answer the sub
questions and thereafter the research question. After sampling, 33 scientific sources remained
available for use in the research.
Which pharmaceuticals have the highest prevalence in Dutch waters
and in what doses do these occur?
Drinking water in the Netherlands is produced from surface water (37%), groundwater (58%) and
bank filtration (6%) (Geudens, 2012). It is estimated that 140 tons of pharmaceuticals are discharged
in surface waters via sewage treatment plants, most of which are human pharmaceuticals. Once
pharmaceuticals enter the water system, they have to be watched carefully and their values should be
measured frequently, so the drinking water does not contain too many pharmaceuticals.
The level of pharmaceuticals is measured via sampling in both surface waters and wastewater
treatment plants (WWTPs). In wastewater treatment plants pharmaceuticals are collected and filtered
as much as possible. Therefore, concentrations in the WWTPs are higher than in surface and
groundwater.
Pharmaceutical levels in Dutch waters are very fluent. The quantities are dependent on their
location, both national and regional, season, as there are higher concentrations during persistent
droughts, river discharge and legislation (Government of the Netherlands, 2019).
It is estimated that by 2035 there will have been an increase in pharmaceuticals in waters in
the Netherlands of 37%, relative to 2019. This is caused by an increase in medicine use and climate
change (Government of the Netherlands, 2019).
Over the years, the Netherlands has spent more on healthcare per capita to increase both
quality of life and life expectancy (Appendix C). As people nowadays tend to become older, medicine
use is also expected to increase. Furthermore, climate change also contributes to higher levels of
pharmaceuticals in water; increase in droughts and sewage overflows lead to higher concentrations
(Government of the Netherlands, 2019).
Occurence of specific pharmaceuticals
3