Anders Svenson

Removal of estrogenicity in Swedish municipal sewage treatment plants

The human estrogen receptor alpha-test, hosted in a yeast strain, was used to quantify estrogenicity in three-week composite samples of untreated and treated effluents from 20 Swedish municipal sewage treatment plants. The treatment plants were selected to represent different treatment processes regarding chemical precipitation and microbial procedures. The discharge from Swedish domestic sewage treatment plants contained estrogenic compounds corresponding to <0.1-15 ng estradiol equivalents/L. Low levels of estrogenic activity were also found in a river receiving municipal effluents, 3.5-35 km downstream the outlet from a sewage treatment works. The range of estrogenicity in untreated, raw sewage effluents was found to be 1-30 ng estradiol equivalents/L. Generally, wastewater treatment reduced the estrogenicity and extended biological treatment was most effective in its removal. Activated sludge treatment tended to be more effective than trickling filters, whereas chemical precipitation using iron or aluminium salts without biological treatment showed little effectivity. The study showed that treatment methods in current use are able to eliminate or largely reduce estrogenicity in domestic wastewater.

Toxicity identification and evaluation of nitrification inhibitors in wastewaters

In order to reduce the content of nitrogen in treated wastewater, microbial processes conducting nitrification of nitrogenous compounds and denitrification to gaseous nitrogen are included in the sewage wastewater treatment process. A set of compounds has been found inhibitory to these microorganisms. A procedure is presented for identification of nitrification inhibitors in wastewaters. This includes fractionation of the wastewater sample and location of the inhibitory effect using a nitrification inhibition assay where pure cultures of Nitrobacter are used. A series of unsaturated fatty acids and two monoterpenes were found to constitute the inhibitory effect in a wastewater sample from a plant for drying wood‐derived fuel. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 527–532, 2000

Search for the evidence of endocrine disruption in the aquatic environment: Lessons to be learned from joint biological and chemical monitoring in the European Project COMPREHEND*

Between January 1999 and December 2001, the European Community project COMPREHEND was performed. The overall aim of COMPREHEND was to assess endocrine disruption in the aquatic environment in Europe, consequent to effluent discharge, with emphasis on estrogenic activity. COMPREHEND demonstrated the widespread occurrence of estrogenic effluents across Europe and presented evidence of impacts on a range of wild fish species. Using a variety of bioassays in combination with chemical analytical methods, estrogenic steroids of human origin from domestic wastewater effluents were identified as the most pervasive problem, although alkylphenols may be important estrogenic components of some industrial effluents. New tools have been developed for the identification of estrogenic effluents, and recommendations are made for the improvement of existing techniques. We have shown that individual fish within natural populations may be feminized to varying degrees, but it has not been possible to show, using traditional fish population parameters, that the survival of fish populations is threatened. However, laboratory-based fish life-cycle studies demonstrate the sensitivity of fish to estrogen (and androgen) exposure and how this might lead to complex (and potentially damaging) genetic changes at the population level. New approaches to this problem, utilizing recent advances made in the field of molecular and population genetics, are recommended. Finally, a study of estrogenic and androgenic activity of waste waters during the treatment process has shown that some of the existing wastewater treatment technologies have the potential to eliminate or minimize the hormonal activity of the final effluent.

Occurrence and some properties of the androgenic activity in municipal sewage effluents.

Abstract Androgenicity was tested in municipal effluents before and after treatment in sewage treatment plants using different treatment methods. The activity was tested with a recombinant yeast strain transfected with the gene for the human androgen receptor. Fractionation of effluents showed some basic properties of compounds with androgenic activity. Effluents from Swedish domestic sewage treatment plants contained compounds with androgenic effects. Levels varied from 0–160 ng dihydrotestosterone (DHT) equivalents/L. The androgenicity was higher in untreated effluents and removals of 26 and 42% for STWs without secondary treatment and 96– > 99% were recorded for STWs with secondary and tertiary treatment. As with estrogens in municipal effluents, STWs using biological treatment such as activated sludge and solid supported microbial processes were more effective in reduction of androgenic activity. Plants using only precipitation methods removed less of the activity. The androgens were composed of at least three individual compounds, similarly or less lipophilic than DHT.

Estrogenicity of domestic and industrial effluents in Sweden

Estrogenicity in Swedish wastewaters was surveyed. Estrogenicity was examined using a recombinant yeast cell test and analyses of the yolk protein precursor in the blood of caged juvenile rainbow trout at sites close to wastewater outlets or in continuous flow tanks of undiluted wastewater. Estrogenic effects corresponding to <0.1 to 15 ng estradiol equivalents were found in municipal effluents. In 9 of 12 industrial effluents, estrogenic effects were below the detection limit of the screen test. None of the six effluents from the pulp and paper industry, from a steel works, and from two chemical industries had a detectable estrogenic effect. Two assays were used for analysis of plasma vitellogenin, a heterologous enzyme-linked immunosorbent assay and a homologous radio immunoassay. Exposure to undiluted municipal wastewater resulted in increased levels of vitellogenin in the plasma of juvenile trout. Using the more sensitive RIA test, increased levels of plasma vitellogenin were detected in cage exposure of rainbow trout in municipal effluent receiving waters. Textile industry effluents mixed with domestic wastewater were estrogenic probably due to contributions from the domestic effluent. In some effluents, toxicity may have masked estrogenic effects.

Antiestrogenicity and estrogenicity in leachates from solid waste deposits.

A great deal of effort has been devoted to developing new in vitro and in vivo methods to identify and classify endocrine disrupting chemicals that have been identified in environmental samples. In this study an in vitro test based on recombinant yeast strains transfected with genes for the human estrogen receptor α was adapted to examine the presence of estrogenic and antiestrogenic substances in six Swedish landfill leachates. Antiestrogenic effects were measured as inhibition of the estradiol induced response with the human estrogen receptor α, and quantified by comparison with the corresponding inhibitory effects of a known antiestrogen, hydroxytamoxifen. The estrogenicity was within the range of that determined in domestic sewage effluents, from below the limit of detection to 29 ng estradiol units L−1. Antiestrogenicity was detected in some of the investigated landfill leachates, ranging between <38 and 3800 μg hydroxytamoxifen equivalents L−1. There was no apparent relation between the type of waste deposited on the landfills and the antiestrogenic effect. Fractionation of a landfill leachate showed that estrogenic compounds were located in two dominant fractions. Three estrogenic compounds were found that accounted for the estrogenic activity in extracts of leachates: bisphenol A, estradiol, and ethinylestradiol. The bisphenol may have been released from decomposing plastic waste and the estrogenic steroids from earlier deposits of municipal sewage sludge and pharmaceutical waste. Fractionation of leachates from three parts of a landfill showed that the antiestrogenic activity was distributed in at least four fractions and somewhat different in different flows of leachate. This indicated a heterogeneous mixture of antiestrogenic substances.

Estrogenicity in bile of juvenile rainbow trout as measure of exposure and potential effects of endocrine disruptors.

Estrogenicity in the bile of juvenile rainbow trout exposed to effluents from municipal sewage treatment plants and various industries was assayed by using a recombinant yeast strain containing the human estrogen receptor alpha gene. Estrogenicity in bile also was measured after deconjugation of steroids to provide an estimate of the exposure and as an endpoint for potential effects on the organism. In unexposed fish or fish exposed for three weeks at control localities, 0.5 to 9 ng of estradiol equivalents (EEq) were found per gram of bile (ng EEq/g bile). Fish exposed for three weeks in cages placed in the receiving waters near outlets of municipal effluent had an average activity of 26 ng EEq/g bile. Fish exposed to undiluted sewage water in aquaria had a bile estrogenicity of 51 to 87,000 ng EEq/g bile. Unconjugated estrogens contributed only 8% or less to the estrogenicity in bile of fish exposed to municipal effluents. Municipal sewage effluents were more estrogenic than the industrial effluents that were investigated. Estrogenicity in bile was compared to that in extracts of wastewater by using the same receptor assay, and to vitellogenin induction in the plasma of the same fish. Bile estrogenicity proved to be a useful and sensitive (internal) measure of exposure and indicated its potential for the display of biological effects as a complement or replacement of more laborious assays.

Assessment of Androgenicity in Leachates from Swedish Landfills and Treatments for its Elimination

Abstract An in vitro recombinant yeast strain, transfected with the human androgen receptor was used to assess androgenic hormone disrupting potencies in leachates from Swedish landfills. It was shown that components in extracts of these affected the androgenic receptor and promoted a response in the β-galactosidase marker system. Levels were within the range of those determined for domestic sewage effluents but lower than the highest levels found in an industrial effluent. These leachates finally enter receiving waters with or without wastewater treatment. Evidence was found for transformation during some of the wastewater treatments.