Boutrup, S., Kjær, C., Johansson, L.S., Larsen, M.M., Poulsen, M.B., Bossi, R., Christensen, M.R. & Frank-Gopolos, T 2021. Miljøfarlige forurenende stoffer i vandmiljøet. NOVANA. Tilstand og udvikling 2008-2019. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 288 s. - Videnskabelig rapport nr. 466. https://dce2.au.dk/pub/SR466.pdf
In this report, the results of the monitoring of environmentally hazardous pollutants in surface water as well as air and point sources in the period 2008-2019 are described. As a general rule, the report is an update of the corresponding report, which describes the results of the monitoring in the period 2004-2012, but with, among other things, the difference that data from monitoring of environmentally hazardous pollutants in groundwater is not described in this report.
There is an overlap between the period for this report and the previous report. In cases where new data has not become available since the end of the previous report, please refer to the previous report.
The report is structured with a description of the results from control monitoring and operational monitoring during the two six-year periods 2008-2013 and 2014-2019. To the extent that there is a sufficient data basis, an analysis has been conducted of whether there is a statistically significant difference between the concentrations in the two periods.
The report reviews the groups of substances that have been included in the monitoring.
Metals
Throughout the period 2008-2019, metals were included in all the parts of the monitoring described in this report.
Metals occur naturally, but due to their anthropogenic use, some metals occur in the aquatic environment in concentrations, where they can pose an environmental problem.
Sources for the presence of metals in the aquatic environment were studied in different contexts. Jensen and Bak (2018) examined sources of zinc and copper in the freshwater environment. Their study concludes that the loss of zinc and copper from agricultural soils is presumed to constitute a significant source of their presence in the Danish aquatic environment, and that the largest source (80-90%) by far of zinc and copper in Danish soils is agriculture, primarily through the application of pig manure. Ellermann et al. (2021) state that the increasing copper concentration in atmospheric deposition can be attributed to increased road transport due to increased emissions from abrasion of brakes.
The median concentrations in the studied media and matrices of the four metals lead, cadmium, mercury and nickel, which are on the Water Framework directive's list of prioritised substances, as well as zinc are listed in table 1. In rain-related effluents (RRE) from common sewage areas, lead, cadmium and zinc were found with higher median concentrations than in the other aqueous matrices. In effluents from treatment plants with advanced purification, nickel was found with a higher median concentration than in the other aqueous matrices, while mercury was found with the same median concentration in effluents from treatment plants with advanced purification and rain-related effluents from common and separate sewage areas.
The metal content of the effluents from the treatment plants and the rain-related effluents cannot immediately be compared with the environmental quality standards established for the surface water to which they are discharged, as the environmental quality standards are established for the dissolved content of metals (filtered samples), while the total metal content (unfiltered samples) is measured in the effluent samples. With this reservation and assuming that dilution with a factor of 10 takes place in discharge to surface water, copper, mercury, silver and zinc may potentially have resulted in concentrations that are above the environmental quality standards in the surface water to which they are discharged.
When comparing the metal concentrations in the solid matrices, sludge and sediment, the highest median concentrations were found in sludge from basins for rain-based effluents from separate sewage areas, apart from cadmium, which was found with a higher median concentration in sediment from streams (operational monitoring) and lakes.
In rain-related effluents from common sewage areas, aluminium, zinc and copper were found in higher concentrations than in rain-related effluents from separate sewage areas. The concentration level of aluminium and copper in rain-related effluents from common sewage areas was also higher than in effluent from treatment plants with mechanical purification. The higher concentrations in the effluents from common sewage areas may be caused by the discharge of untreated wastewater in connection with overflow at the treatment plants.
In streams, barium was found at the highest concentration level in the water phase, and it was also the metal found most frequently in concentrations above the general environmental quality standards. Among the heavy metals studied, zinc was found at the highest concentration level, followed by copper and nickel, which were found at roughly the same concentration level. In 10 and 50% of the studied samples, zinc and nickel were found in concentrations above the general environmental quality standards. However, in relation to the general environmental quality standards, the assessment is subject to the condition that this environmental quality requirement applies to an annual average of four and 12 tests, respectively. In some cases, the zinc concentrations were above the environmental quality standard’s maximum concentration.
The five metals in table 1 were found with median concentrations at the same level in sediment in streams through operational monitoring, lakes through both control and operational monitoring and in marine coastal areas. Concentration levels were lower in sediment from streams studied by control monitoring and marine sediment in open marine areas. In all cases, the detected sediment concentrations of lead and cadmium were below the environmental quality standards. The lower concentrations in the sediment from streams that were examined by control monitoring rather than by the operational monitoring can, among other things, be attributed to the fact that the stations in the operational monitoring were placed in water areas at risk of not meeting the goals. However, the same difference was not detected in sediment in lakes examined by operational and control monitoring, respectively.
Vanadium was detected in lake sediment in concentrations above the environmental quality standards in 10-50% of the lakes studied.
In mussels and fish from marine areas, zinc was detected at the highest concentration level among the studied metals in both livers and muscles. In mussels, copper and arsenic were found at the second-highest concentration level, and copper was also found at the second-highest level in fish livers, while arsenic was found at the second-highest level in fish muscles. In the period 2008-2013, the content of lead in fish muscles was above the environmental quality standard in more than half of the samples studied, and in the period 2014-2019 it was above the environmental quality standard in 10-50% of the studied samples.
In fish from streams and lakes, mercury was detected in concentrations that were above the environmental quality standard in more than 90% of the studied samples. The same applied to fish samples from marine areas in the period 2008-2013 and more than half of the samples in the period 2014-2019.
In the period up to 2000, there was a significant decrease in the concentration of metals in the atmospheric deposition. From 2000 onwards, only a small decrease in the concentrations has been observed, and for copper there has been a tendency in recent years of increased concentration. In wastewater and surface water, certain metals were found in different parts of the monitoring in significantly lower concentrations in 2014-2019 than in2008-2013. This goes for:
In marine areas, the difference between the two periods was examined at station level. Arsenic and silver were found with an increasing trend at some of the stations that were studied, but no stations had a decreasing trend. Arsenic and silver were found with an increasing trend at some of the studied stations, but no stations had a decreasing trend. The remaining metals were detected with both decreasing and increasing trends at the stations where changes were found.
Pesticides
Monitoring of pesticides partly included pesticides that are or have been used in the agricultural sector or for weed control, e.g. in built-up areas, and partly included the so-called "old" chlorinated pesticides, e.g. DDT. The latter were monitored in marine areas, while the remaining pesticides were monitored in fresh surface water, point sources and air. Monitoring of pesticides included both the active substances and a number of degradation products of active substances.
Among the controlled pesticides was prosulfocarb, which is a herbicide that is used on winter crops in the autumn. In 2018, following glyphosate, prosulfocarb was the most sold herbicide in Denmark (the Danish Environmental Protection Agency, 2020). In the calculation of the impact of pesticides, prosulfocarb had the second-largest environmental impact (12.5% of the total environmental impact), while glyphosate, which in 2018 contributed 7.8% of the total environmental impact, was the third most environmentally damaging pesticide.
Glyphosate and its degradation product, AMPA, were the most frequently detected pesticides (83-97%) in rain-related effluents from both separate and common sewage as well as in the water phase in streams. Prosulforcarb was detected in 30-40% of the studied samples taken from rain-related effluents from separate sewage areas, but not in any of the samples from common sewage areas. At the two measuring stations, where precipitation measurements were taken, prosulphocarb was found with the greatest deposition, while in streams it was detected in approx. 15% of the water samples studied in both monitoring and operational monitoring in both 2008-2013 and 2014-2019.
There was no indication that the pesticides examined in the rain-related effluents led to concentrations above the environmental quality standards established for the surface water to which they were discharged. Similarly, there was no indication that pesticides examined in the water phase in streams were present in the studied streams in concentrations above the established environmental quality standards. The concentration of BAM in stream water was significantly lower in 2014-2019 than in 2008-2013.
Of the four pesticides studied in sediment from streams and lakes, chlorpyrifos was detected in some samples. The remaining pesticides cypermethrin, isoproturone and tau fluvalinate were not detected or were detected in a few samples.
In marine areas, the studied chlorinated pesticides were found in fish, with higher concentrations in the liver than in the muscle. Hexachlorbenzene, which is one of the few substances for which environmental quality standards have been set in biota, was found in concentrations below the environmental quality standard.
At most of the marine stations examined for chlorinated pesticides, no significant difference was found in the concentrations in fish between the periods 2008-2013 and 2014-2019. In cases where a significant difference was found, the lowest concentration was found in 2014-2019, with the exception of the pp'-DDE, where the concentration was lowest in 2008-2013.
Aromatic hydrocarbons
The monitoring of aromatic hydrocarbons included benzene, toluene and xylene as well as naphthalenes containing two benzene rings. Aromatic hydrocarbons were studied in all parts of the monitoring.
Within this group, naphthalene, dimethylnaphthalene and toluene were the substances that were detected most frequently in the effluents from the wastewater treatment plants with the types of purification that were studied, as well as in rain-related effluents from common sewage areas. In deposition, naphthalene was detected in a higher concentration than methylnaphthalenes. Dimethylnaphthalenes were not studied.
There was no indication that aromatic hydrocarbons in the effluents from purification systems or rain-related effluents have given cause to concentrations above the environmental quality standards established for aromatic hydrocarbons discharged to surface water.
Dimethylnaphthalens were among the studied aromatic hydrocarbons detected at the highest concentration level in sediment from streams, lakes and marine areas with the highest levels of lake sediment. In more than half of the lakes studied and in more than half of the studied coastal marine areas, the content of methylnaphthalenes in sediment was above the environmental quality standard for the sum of methylnaphthalenes. In streams, the sediment concentration of methylnaphthalenes was below the environmental quality standard, and the same applied to the sediment concentration of naphthalene in streams, lakes and marine areas.
The concentration of dimethylnaphthalenes in effluents from wastewater treatment plants with advanced and less advanced purification was significantly higher in 2014-2019 than in 2008-2013, while the concentration of naphthalene in effluents from treatment plants with less advanced purification was significantly lower. In lake sediment, the concentration of trimethylnaphthalenes was significantly higher in 2014-2019 than in 2008-2013. No significant differences were found between the concentrations of aromatic hydrocarbons at treatment plants and in streams in the two studied periods.
Phenols
The monitoring of phenols included the study of the substances phenol, alkylphenols and bisphenol A in point sources, streams, lakes and marine areas.
Bisphenol A and phenol were the most frequently detected phenols in effluents from treatment plants and were, at the same time, the phenols detected at the highest concentration level. The greatest detection frequencies and highest concentration levels were found in the effluents from treatment plants with mechanical purification. More than one-tenth of the measurements for these substances were above the environmental quality standards in the surface water to which they were discharged, under the assumption that dilution took place with a factor of 10.
In stream water, bisphenol A was the most commonly detected phenol, but in all cases in concentrations below the environmental quality standard. Phenol was not studied in stream water.
Nonylphenols and nonylphenolethoxylates were detected in sediment from streams, lakes and marine areas, with the highest frequency in coastal marine areas. The detected sediment concentrations were above the environmental quality standard for nonylphenol in more than 10% of the marine areas studied, both coastal and open areas. Sediment concentrations above the environmental quality standard in the studied streams and lakes were not found. Similarly, octylphenol concentrations were not found above the environmental quality standard in either rivers, lakes or marine areas.
Comparison of the concentration of phenols at stations that were measured in both 2008-2013 and in 2014-2019 showed that the concentration of nonylphenoles was significantly lower in stream water and sea sediment in 2014-2019 than in 2008-2013, and the concentration of nonylphenolmonoethoxylate and 4-tert-octylphenol in sea sediment was also significantly lower. Apart from this, no significant differences were found in the concentrations of the studied phenols in the two periods.
Halogenated aliphatic hydrocarbons
In connection with monitoring, halogenated aliphatic hydrocarbons were examined in point sources and stream water.
Chloroform and tetrachlorylene were the two substances from the group of halogenated hydrocarbons that with collection frequencies of up to 100% were detected most frequently in the effluents from treatment plants, with no significant differences between the three groups of treatment plants. The remaining halogenated hydrocarbons were not detected, or were only detected in a few samples, apart from trichlorethylene, which was detected in up to 19% of the studied samples. Chloroform was also the substance that was detected most frequently in the water phase in streams. Tetrachlorethene was studied in the water phase of streams.
To the extent that environmental quality standards have been established for the halogenated aliphatic hydrocarbons studied, no concentrations were detected that are expected to have given rise to exceedances of the environmental quality standards in streams or the surface water discharged from point sources.
Halogenated aliphatic hydrocarbons
In the monitoring, halogenated aromatic hydrocarbons were examined in point sources.
As the only one of the studied halogenated aromatic hydrocarbons, 2.5-dichloraniline was found in wastewater from treatment plants with advanced purification in the period 2008-2013, but was not detected in the period 2014-2019. Environmental quality standards have not been established for 2.5-dichloraniline.
Chlorine phenols
In connection with the monitoring, chlorphenoles were examined in point sources.
With the exception of 2.4-dichlorphenol, the chlorinated phenols studied in the period 2008-2013 were detected in effluents from treatment plants with advanced purification, but not in effluents from treatment plants with less advanced purification. There is no data from the period 2014-2019.
Environmental quality standards have been established for the two chlorine phenols, pentachlorphenol and 4-chlor-3-methyl-phenol. There was no indication that discharge of wastewater has given rise to exceedances of the quality standards in the surface water discharged from point sources.
Polychlorinated biphenyls (PCBs)
Monitoring of PCBs included the study of a number of PCBs in marine areas.
PCBs were detected to be prevalent in mussels, fish and sediment in marine areas. The PCB congeners PCB#138 and PCB#153 were detected at concentration levels above the background levels set by OSPAR.
At most of the studied marine stations, no significant changes were found in the concentration of the studied PCBs in fish from 2008-2013 to 2014-2019. At one of the seven stations studied, there was a significant maximum concentration of PCB#153 in 2014-2019, and, correspondingly, at a few stations a significantly lower concentration of #PCB101 and PCB#138 in 2014-2019.
Polyaromatic hydrocarbons (PAH)
PAH was studied in all the parts of the monitoring described in this report.
In the effluents from treatment plants, most of the PAHs were not detected or were only detected in a few samples. A few PAHs were found in up to 50% of the studied samples, most frequently in the effluents from treatment plants with mechanical purification. The higher frequency at these treatment plants may be linked to the less advanced purification, but as this group of treatment plants also had the fewest samples, there is greater uncertainty about the result. At the treatment plants, PAH is bound to sludge, which explains the generally low incidence in the effluents from the treatment plants, particularly from treatment plants with advanced and less advanced purification.
In rain-related effluents from common sewage and separate sewage areas, benzo(ghi)perylene, benzo(b+j+k)fluoranthene, chrysene / triphenylene, fluoranthene, phenanthrene and pyrene stood out by being found more frequently than the other PAHs. Benzo(b+j+k)fluoranthene, fluoranthene, phenanthrene and pyrene were, at the same time, the PAHs that contributed the greatest volume in the annual deposition of PAHs, which may be one of the explanations for the higher frequency in rain-related effluents.
In rain-related effluents from one station in the common sewage area, pyrene was found in more than 10% of the studied samples in 2014-2019 in concentrations that, assuming a dilution factor of 10, were above the general environmental quality standards in the surface water to which they were discharged. The highest concentration of pyrene was also above the environmental quality standard's maximum concentration after the assumption of dilution. The remaining PAHs were not found in rain-related effluents in concentrations that, after the assumption of dilution, were above the established environmental quality standards for PAH. The assessment of the results from the rain-related effluents was made with the reservation that the studies of PAH for rain-related effluents only comprised a few stations, and the basis for comparison of the concentrations is therefore uncertain.
In sediment from the studied streams, lakes and marine areas, benzo(b+j+k)fluoranthene, fluoranthene and pyrene were detected at the highest concentration levels. In marine areas, higher concentration levels were detected in coastal marine areas than in the open marine areas that were studied in connection with the Marine Strategy Directive.
PAH was found more frequently in sludge from basins to effluents from separate sewage areas than in the water phase in the effluents from common and separate sewage areas, which is attributed to the PAHs' affinity to particles. Eighteen out of a total of 22 PAHs studied in sludge were identified in all the studied samples. The PAHs detected frequently in the water phase in rain-related effluents were also detected at the highest concentration levels in the studied samples of sludge, except for phenanthrene.
1-methylpyrene and dimethylphenanthrene were found with the lowest frequency in sludge from basins for rain-related effluents from separate sewage areas and sediment from streams and lakes. The two PAHs were studied in sediment from marine areas, but were not found with correspondingly significantly lower frequency than the other PAHs.
There was no indication has that PAH was found in the water phase of the studied streams in concentrations above the environmental quality standards. Similarly, there was no indication that the discharge of PAH from wastewater treatment plants has given rise to concentrations above the environmental quality standards established for the surface water to which it was discharged.
Anthracene was detected in sediment from streams, lakes and coastal marine areas in concentrations above the environmental quality standard, while the concentrations in open marine areas were below the environmental quality standard.
When comparing the concentration of PAH at river stations in 2008-2013 and 2014-2019, significantly lower concentrations of two PAHs (dibenzothiophene and dimethylphenanthrene) were found in 2014-2019 than in 2008-2013. Similarly, at most of the studied marine stations, a significantly lowest concentration of a number of PAHs was found in mussels in 2014-2019, while at some stations an increase was found. In lake sediment, a higher concentration of PAH was found in 2014-2019 than in 2011-2013, to the extent that there is significant difference between the concentrations in 2011-2013 and 2014-2019.
Perfluorinated compounds (PFAS)
In connection with monitoring, perfluorinated compounds were examined in point sources, streams and marine areas.
Perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and perfluorononanoic acid (PFNA) were the most frequently detected PFAS in effluents from wastewater treatment plants among the studied perfluorinated compounds. The substances were found with the lowest detection rates in the effluents from treatment plants with mechanical purification, which indicates that wastewater from households is not the most important source. PFOS was found most frequently in rain-related effluents from common sewage areas.
Of the studied perfluorinated compounds, PFOA was detected at the highest concentration level in the effluents from treatment plants. The highest concentrations were found in effluents from treatment plants with advanced purification. In the effluents from treatment plants, PFOS was found in concentrations that may have resulted in concentrations that, assuming dilution by a factor of 10 at discharge, were above the environmental quality standard in the surface water to which they were discharged.
PFOS and PFOA were the most frequently detected perfluorinated compounds in the water phase in streams. It cannot be ruled out that PFOS was present in the studied streams in concentrations above the general environmental quality standard, but below the maximum concentration. Monitoring of streams was part of the operational monitoring and thus included stations that were assessed to be at risk of failing to meet the targets.
PFOS was shown in all the studied samples of livers from fish in marine areas. Perfluordecanoic acid (PFDA), PFNA and perfluorundeanoic acid (PFUnA) were detected with the second highest frequency. The measurements of PFOS in fish livers did not indicate that PFOS occurred in concentrations above the quality standards in the areas studied.
By comparing the concentration of PFAS at stations studied in 2008-2013 and 2014-2019, respectively, there was a significantly lower concentration of perfluorohexanoic acid (PFHxA) and PFDA in effluent from the treatment plants with advanced purification in 2014-2019 than in 2008-2013. Fish livers from marine areas also showed significant decreases in these two substances as well as PFOS, while PFOA was found in significantly higher concentrations in 2014-2019 than in 2008-2013.
Plasticizers
The monitoring of plasticizers included the study of phthalates and an adiphate in point sources, streams, lakes and marine areas.
Of the studied plasticizers, DEHP was one of the most frequently detected and at the highest concentration level in effluents from the treatment plants. The highest concentrations were found in effluents from treatment plants with mechanical purification. Diisononylphthalate (DNP) was found with the second highest frequency, followed by diethylphthalate. In rain-related effluents from common sewage and separate sewage areas, as well as in sludge from basins for rain-related effluents from separate sewage areas, DEHP and DNP were also the most frequently found plasticizers. There was no indication that plasticizers in the effluents from treatment plants or rain-related effluents have given cause to concentrations above the environmental quality standards in the surface water to which they were discharged. Likewise, there was no indication that plasticizers were detected in the studied streams in concentrations above the environmental quality standards.
DEHP and diisononylphthalate (DNP) were also the two substances that were detected with the greatest frequency in sediment in both streams and lakes, and at the highest concentration levels. In the water phase in streams, DNP was also detected most frequently among the studied plasticizers. In sediment from coastal marine areas, the studied plasticizers were detected in 50-100% of the samples studied and, generally, with a greater frequency than in sediment from streams and lakes. Diisodecylphthalate was detected at the highest concentration level in open marine areas. Diisodecylphthalate was not studied in sediment from streams and lakes.
By comparing the concentration of PFAS at stations examined in 2008-2013 and 2014-2019, respectively, it was found that there was no statistical difference between the concentrations of plasticizers in the effluents from treatment plants. In addition, there was no data basis for studying any differences.
Organotine compounds
Monitoring of organotine compounds included the study of butyltin compounds and triphenyltin in point sources, streams and lakes, as well as the study of a number of organotine compounds in marine areas.
In the effluents from wastewater treatment plants and rain-related effluents from common sewage areas, monobutyltin was found most frequently among the studied organotine compounds. Monobutyltin was also, together with dibutyltin, the most frequently identified organotine compound in sediment from streams. The same substances were found at the highest concentration levels in wastewater and sediment from streams and lakes.
Environmental quality standards have been established for tributyltin (TBT) in surface water. TBT in the effluents from treatment plants may have resulted in concentrations above the environmental quality standard's maximum concentration in the surface water emitted from the treatment plants, when it is assumed that a dilution factor of 10 occurred during discharge. With the detection limits used in the analysis of water samples from streams, it was not possible to assess whether concentrations occurred above the environmental quality standard.
In sediment from lakes, streams and coastal marine areas, monobutyltin and dibutyltin were among the most frequently identified organotine compounds. In coastal marine areas, TBT was also among the most frequently detected organotine compounds. The organotine compounds studied were not detected, or were only detected in a few samples from the open marine areas studied. In mussels and fish livers from coastal marine areas, TBT, dibutyltin and monobutyltin were the most commonly detected organotine compounds, as were they in sediment. In fish livers, triphenyltin and diphenyltin were found with frequencies at the same level as mono, di and tri-butyltin compounds, and triphenyltin was found at the highest concentration level in fish livers.
By comparing the concentrations of organotine compounds at stations studied in both 2008-2013 and 2014-2019, a significantly lower concentration of monobutyltin was found in 2014-2019 than in 2008-2013 in effluents from treatment plants with less advanced purification, while sediment from both streams and lakes had significantly higher concentrations in 2014-2019. To the extent that there was a significant difference in the concentrations in 2008-2013 and 2014-2019, the marine areas primarily showed a tendency towards decreasing concentration. At a few stations, an increasing concentration of tributyltin and monobutyl was detected. However, these concentrations were close to the detection limit.
Dioxins and furans
Monitoring of dioxins and furans covered sediment and biota in marine areas.
In sediment and biota from the studied marine areas, dioxins and furans were demonstrated with varying frequencies. In sediment, the discovery frequency in the studied open marine areas was lower than in the studied coastal areas.
Environmental quality standards have been established for the sum of toxicity equivalents of dioxins, furans and dioxin-like PCBS in biota. There was no indication that the environmental quality requirement was exceeded in marine biota.
With a single exception, the concentration of dioxins and furans in marine areas decreased to the extent that there was a significant development. Despite this, the concentration of dioxins and furans calculated as toxicity equivalents (WHO-TEQ) has increased. In addition, it should be noted that when calculating toxicity equivalents, only one substance with a concentration above the detection limit is required in order to obtain a value for WHO-TEQ, and since some of the dioxin-like PCBs, especially PCB#118, were detected frequently, this means that a toxicity equivalent can be calculated for fish at these stations.
Brominated flame retardants
The monitoring of brominated flame retardants included the study of up to 15 different congeners of bromated diphenyl ethers in point sources and marine areas.
Among the studied brominated flame retardants, BDE#209 was detected in effluents from treatment plants and in rain-related effluents from a common sewage area. The other brominated flame retardants were not detected or were only detected in a single sample.
In mussels as well as in the livers and muscles from fish from marine areas, brominated flame retardants were detected with varying frequencies, from 0 to 100%. The brominated flame retardants that were shown most frequently overall, were BDE#47, BDE#49, BDE#99 and BDE#100.
Environmental quality standards have been established for the sum of six BDEs, BDE#28, #47, #99, #100, #153 and #154, in surface water and biota. There was no indication that discharge of brominated flame retardants from point sources have given rise to concentrations above the environmental quality standards in the surface water to which they were discharged. This may be linked to the slight tendency of brominated flame retardants to occur in aqueous matrices. The content of BDE#47 in fish muscles from marine areas, on the other hand, was above the environmental quality standard for biota in more than 90% of the studied samples. This indicates widespread occurrence of brominated diphenyl ethers in marine areas in concentrations above the environmental quality standard.
To the extent that was possible to demonstrate a significant difference between the concentration of brominated flame retardants in 2008-2013 and 2014-2019, marine areas had the lowest concentration of BDE#47 and BDE 100, and higher concentration of BDE#154 in 2014-2019.
Ethers
The monitoring of ethers included the study of tertiary butylmethyl ether (MTBE) and triclosan in point sources and streams.
MTBE was detected with a higher frequency in effluents from wastewater treatment plants with advanced purification than in the effluents from the treatment plants with mechanical purification. The opposite was the case for triclosan, which was detected most frequently in effluents from treatment plants with mechanical purification. MTBE and triclosan were not detected or were only detected in a few samples in rain-related effluents from areas with common and separate sewage.
MTBE was detected in a few samples of the water phase from the studied streams.
There was no indication that the discharge of MTBE from point sources has given rise to concentrations above the established environmental quality standard for MTBE in the surface water to which it was discharged, and no indication was found that the environmental quality standards were exceeded in streams.
P-triesters
The monitoring of phosphorus triesters (P-triesters) included studies at point sources.
Trichloropropyl phosphate (TCPP) and triphenyl phosphate were the most frequently identified P-triesters in effluents from treatment plants and rain-related effluents from common sewage areas. TCPP was the most frequently identified P-triester in rain-related effluents from separate sewage areas.
TCPP and tributyl phosphate were detected in significantly lower concentrations in effluents from treatment plants with advanced and less advanced purification in 2014-2019 than in 2008-2013.
There was no indication that the discharge of P-triesters from the treatment plants or rain-related effluents have given rise to concentrations above the environmental quality standards for P-triesters in the surface water to which they are discharged, when it is assumed that a dilution of a factor of 10 occured during discharge.
Detergents
Monitoring of detergents included studies in point sources and streams.
Anionic detergents, determined as alkylbenzensulfonate (LAS), were detected more frequently and at higher concentration levels in effluents from treatment plants with mechanical purification than in effluents from treatment plants with advanced or less advanced purification.
LAS was detected in a few of the samples from streams.
The concentration of LAS in effluents from treatment plants with mechanical purification was at a level where it may have resulted in concentrations above the environmental quality standard's maximum concentration and the general environmental quality standards for the surface water to which the wastewater was discharged, when it is assumed that a dilution of a factor of 10 took place during discharge. However, there was no indication that PAH was detected in concentrations above the environmental quality standards in the water phase of the studied streams.
Pharmaceuticals
The monitoring of pharmaceuticals included both human and veterinary medicines as well as two degradation products. The pharmaceuticals were studied in point sources and streams.
A number of pharmaceuticals were detected in close to 100% of the samples studied from effluents from treatment plants. These included carbamazepine, citalopram, furosemide, ibuprofen, 2-hydroxyibuprofen, sulfamethiazole and tramadol. Among these, furosemide, ibuprofen and 2-hydroxyibuprofen were found at higher concentration levels in effluents from treatment plants with mechanical purification than from treatment plants with the other two groups of treatment. This is partly due to the less advanced purification technology at treatment plants with mechanical purification, but it may also indicate that wastewater from households is a significant source of these pharmaceuticals in wastewater.
In rain-related effluents from common sewage areas, pharmaceuticals were detected at frequencies at the same level as they were in effluents from treatment plants, but at lower concentration levels.
There was no indication that the studied pharmaceuticals in the effluents from treatment plants or rain-related effluents have led to a concentration above the environmental quality standards in the surface water to which they were discharged, when it is assumed that dilution took place with a factor of 10.
Three of the 19 studied pharmaceuticals were detected with significantly lower concentrations in effluents from treatment plants with advanced purification in 2014-2019 than in 2008-2013 (sulfamethiazole, sulfamethoxazole and trimethoprim). Two pharmaceuticals were found in higher concentrations in 2014-2019 than in 2008-2013 at the treatment plants with advanced purification (salicylic acid) and less advanced purification (paracetamol).
In freshwater fish farms, furosemide, sulfamethoxazole and ibuprofen were the most frequently detected of the eight pharmaceuticals that were studied in influents and effluents from fish farms. The detection frequency and concentration levels were higher in the effluents from fish farms than in the influents. The occurrence of the pharmaceuticals in the influents to fish farms shows that upstream of the fish farms, there were other sources for the occurrence of the substances in the streams.
Sulfadiazine and florfenicol, which are among the pharmaceuticals for which environmental quality standards have been established, were found in the effluents of freshwater fish farms in concentrations above the environmental quality standards' maximum concentrations. However, dilution takes place in the event of discharge to the streams, so that any concentration above the environmental quality requirement in the stream depends on the dilution zone.
In streams, the most frequently identified pharmaceuticals were diclofenac, erythromycin and clarithromycin. There was no indication of pharmaceuticals in the studied streams in concentrations above the environmental quality standards. Sulfadiazine and trimethroprim were detected less frequently in the studied streams than in the influents and effluents from freshwater fish farms.
Estrogens
The monitoring of oestrogens included two natural and one artificial sex hormone studied in point sources and streams.
The natural estrogen, estrone, was among the estrogens studied that was detected with the greatest frequency in effluents from treatment plants. The greatest detection frequencies and highest concentrations were found in the effluents from treatment plants with mechanical purification. The artificial estrogen, ethinyl estradiol, was not detected or was only detected in a few samples of effluents from treatment plants.
In streams, estrone was detected in 94-100% of the studied samples and was the only investigated oestrogen found in the water phase in more than a few samples.
In a few cases, discharge of 17β-estradiol from treatment plants with advanced, less advanced and mechanical purification may have resulted in concentrations above the environmental quality standard's maximum concentration in the surface water to which they were discharged. The same applied to the discharge of ethinyl estradiol from treatment plants with advanced purification. However, no indication was found of concentrations above the environmental quality standards in the studied streams.
