Environmental Project, 1077 – Survey of Estrogenic Activity in the Danish Aquatic Environment Part B

Survey of Estrogenic Activity in the Danish Aquatic Environment Part B

1 Introduction

1.1 Background
1.2 Objectives
1.3 Project implementation
1.4 Part B vs. Part A reporting

1.1 Background

Within the last decade a number of international studies have described impacts on fish and other aquatic species resulting from exposure to endocrine disrupting chemical substances (in particular substances with estrogenic activity), and supporting preliminary findings of feminisation of fish in a Danish field survey was reported in 2000. The situation raised concern among scientists, politicians and the general public leading to a number of activities and projects aimed to further elucidate the issue including the Danish Environmental Protection Agency's (DEPA) launching of a large study named "Survey of Estrogenic Activity in the Danish Aquatic Environment" in late 2003 (Part A of the current study, published by DEPA as Environmental Project No. 977, 2005).

The survey had the objectives partly to provide data on the state of the Danish aquatic environment with respect to estrogenic activity and partly to identify the likely significant sources of contamination with estrogenic substances. Sampling was carried out at about 150 locations including various categories of streams/rivers and lakes, different types of wastewater treatment plants (WWTPs), drains from manure and sludge amended fields, septic tank effluents, urban rain runoff and fish farm effluents. The almost 350 samples were tested by the genetically modified yeast cell assay called "YES" and about 40% of the samples were additionally analysed chemically for their content of natural and synthetic steroid hormones (E1, E2, α-E2, EE2).

The results of the survey indicated that there was no widespread impact from estrogens in the Danish freshwater environment. However, downstream discharges of poorly treated wastewater to small receiving water courses, or in case of overflow episodes, the resulting environmental concentration would probably exceed effect levels known from the scientific literature.

In 33% of the samples from the aquatic environment the estrogenic activity if present was below the limit of detection. However, low estrogenic activity is found with the YES assay in almost all types of freshwater environments in Denmark, but typically at concentrations lower than 1 ng/L. In almost 70% of the water courses receiving WWTP effluents the level of estrogenic activity immediately downstream the discharge point was higher than the upstream activity. Further downstream of the discharge point the estrogenic activity had decreased to pre-discharge level.

However, due to various circumstances some sub-issues were not elucidated in the survey to the extent necessary for drawing reasonably firm conclusions regarding their possible environmental significance. This was in particular the case for manure or sludge affected field drains, septic tank effluents and the water and sediment quality in small streams receiving discharges from STPs with low treatment efficiency.

Therefore, it was decided that Part B of the survey (the current supplementary investigations) should focus on these issues.

Finally, a general observation in Part A was that most of the estrogenic activity in the different samples was due to the estrogens in their free form (without conjugation) whereas the conjugated forms only accounted for a minor fraction of the potential total activity. Therefore, it was decided to test and analyse only the free forms of the estrogens in Part B of the survey.

1.2 Objectives

The objectives of the supplementary investigation (Estrogen Survey, Part B) can be described as follows:

to study further the significance of estrogen pollution sources in the open land such as drains from fields amended with animal manure or sewage sludge, and sewage from isolated (farm) houses i.e. septic tank effluents, and
to assess the water and sediment quality in small streams receiving discharges from WWTPs with low efficiency in relation to elimination of estrogenic activity (called category C and D WWTPs in Part A of the survey i.e. plants with only mechanical or mechanical/biological treatment processes).

Finally, a few confirmatory tests of new samples from Part A locations were requested by DEPA and were included in the study.

1.3 Project implementation

Part B of the Survey of Estrogenic Activity in the Danish Aquatic Environment was implemented by the same project consortium that carried out Part A of the study:

COWI A/S - Project management, study design, planning and reporting, sampling:
Jesper Kjølholt (project manager from July 2005)
Frank Stuer-Lauridsen (project manager until July 2005)
Linda Høibye
Brian Ahlers.

Danish University of Pharmaceutical Sciences (DFU) - chemical analyses:

Bent Halling-Sørensen
Flemming Ingerslev
Kamilla Bach
Martin Hansen.

Eurofins Denmark A/S - sampling and sample pre-treatment:

Nis Hansen
Benny Køppen.

University of Southern Denmark (SDU) - biological testing:

Poul Bjerregaard
Bente Frost.

The supplementary investigations (including reporting) of the estrogen survey, which were carried out from March to November 2005, were steered by a Committee with the following members:

Jørgen Larsen, Danish Environmental Protection Agency (Chairman)

Lis Morthorst Munk, Danish Environmental Protection Agency

Helle Katrine Andersen, DANVA

Anne Marie Vinggaard, Danish Institute for Foood and Veterinary Research

Christian A. Jensen, Association of Danish Regional Authorities (Counties)

Steen Kristensen, Danish Medicines Agency.

1.4 Part B vs. Part A reporting

The investigations presented in this report are closely linked to the investigations carried out as Part A of the survey of estrogenic activity in the Danish aquatic environment. This was published in 2005 as Environmental Project No. 977: "Survey of Estrogenic Activity in the Danish Aquatic Environment" by the Danish Environmental Protection Agency (DEPA 2005).

As the Part B activities cannot be fully understood without bearing the design, methodologies and results of Part A in mind, this report has not been prepared as a full stand-alone report but rather an addendum to the above report and referring to it (as "Part A") for further details, where relevant.