Assessing the Discharge of Pharmaceuticals Along the Dutch Coast of the North Sea - Reviews of Environmental Contamination and Toxicology - page 3

Because pharmaceuticals are biologically active, are designed to induce
pharmacological effects at low concentrations, and are present in seawater, it is
possible that they affect nontarget organisms in the aquatic environment (Rijs
et al. 2003). Once emission sources and fluxes of pharmaceuticals to the DCZ
are known and quantified, it will be possible to design contamination prevention
measures for specific (groups of) pharmaceuticals.
In this chapter, we assess the input of both human and veterinary pharmaceuticals
along the DCZ. Initially, we collected and assembled all public data on pharmaceu-
ticals known to exist in the Dutch aquatic environment that may end up in the water
of the DCZ. Then we performed emissions calculations to determine the riverine
input and direct discharge (point source discharge at the end of a pipe into an aquatic
environment) of circa 100 active pharmaceutical agents to the North Sea.
The sources, presence, and impact of pseudo hormones and hormones in the
Dutch aquatic environment are published elsewhere (Belfroid et al. 1999; Vethaak
et al. 2002).

2 Methods: Data Inventory and Emissions Calculations

2.1 Data Inventory

An inventory was assembled on existing pharmaceutical concentrations in surface-,
sewage-, industrial-, and marine-water in the Netherlands; the inventory was
sourced from scientific publications, and from other sources, mainly “grey” litera-
ture and unpublished data, from research institutes, for example, Netherlands
Organization for Applied Scientific Research (TNO), Centre for Water Management
(WD), National Institute for Public Health and the Environment (RIVM) and
Applied Research for Water Management (STOWA), and universities (e.g.,
University of Utrecht). In addition to securing information through direct contacts
with these institutes and universities, a literature search was performed on the internet
and in the databases of university libraries.
From these inventoried studies, it appeared that there are several routes by which
human and veterinary pharmaceuticals can enter the environment. The three most
important routes are (1) direct disposal at manufacturing sites, (2) excretion via
urine and feces (sewage water), and (3) dispersion or runoff of manure, etc. from
agricultural land (e.g., Mons et al. 2000).
Human pharmaceuticals are primarily discharged in wastewater from house-
holds, hospitals, and nursing homes, from excreta (urine and feces) (Mons et al.
2000; Derksen et al. 2001). This wastewater enters the sewage system and is treated
in a STP. From a quantitative point of view, excretion of consumed pharmaceuticals
is much more significant than direct disposal from manufacturing activities
(Derksen et al. 2001). Only a small percentage (1-5%) of pharmaceuticals reach
wastewater from manufacturing processes (Mons et al. 2000). Evidence indicates
that Dutch households directly dispose of only a small proportion of pharmaceuticals