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Feminisation of fish

10. Potential sources of estrogens and xenoestrogens

In light of the observed feminisation of fish and the increasing evidence that estrogens and/or xenoestrogens in sewage effluent are possible sources to the effects, the following chapters will focus on the sources of the estrogens and xenoestrogens. The fate of the compound in the sewage treatment plants and the effect of different treatment types on the release of estrogens will also be described.

10.1 Estrogens

Estrogens are female steroid sex hormones based on a cholesterol skeleton. Estrogens are produced naturally in vertebrates in the gonads and adrenal cortex of both sexes and the synthesis goes via progesterone and androstenedione or testosterone of which the latter two are male sex hormones (androgens). Both estrogens and androgens are present in both sexes but in males the androgens dominate while estrogens dominate in the females.

The follicle-stimulation hormone controls the excretion of sex hormones in the organism and the luteinizing hormone released from the pituitary gland. The production and excretion of sex hormones change throughout the life of humans. For both male and female the production of sex hormones is small until puberty is reached. After puberty the production of testosterone in men increases gradually until an age of around 40 years is reached, after which it starts to decrease (205). The testosterone is altered to estradiol in some parts of the body, e.g. the brain (74).

10.1.1 Men

Measurements of the total estradiol in the blood stream of three age groups of men showed the following average levels: 36-55 yr men: 0.0073 m g/l, 56-66 yr. men: 0.020 m g/l, and 66-80 yr. men: 0.026 m g/l (206). Estimates of estrogens excreted in male urine are shown in Table 10.1.

Table 10 .1
Excretion of estrogens in urine by males (72)

10.1.2 Women

For women the production of estrogens is more complicated. After sexual maturity the production of estrogens varies during the menstrual cycles and the pregnancy until the menopause is reached.

10.1.2.1 Menstruating women

During the menstrual cycle, plasma concentrations and excretion of estrogens increase from day one to reach a maximum a couple of days before ovulation (day 14). After this period, the excretion declines until a couple of days after ovulation. At that time, the production by corpus luteum causes an increase of the excretion again (luteal phase). If no fertilization of the egg occurs then the corpus luteum degenerates, the estrogen excretion decreases and the woman will menstruate. The excretion of estrogens in urine during the menstrual cycle as found by Brown (1955) is shown in Table 10.2.

Table 10.2
Excretions of estrogens in urine by menstruating women

(207). Average calculated in the present report.

Results from more recent studies of the excretion of estrogens have been collected by Johnson et al. (72), (Table 10.3),

Table 10.3
Average excretion of estrogens in urine by menstruating women (72)

The values of Johnson et al. (88) are used in an estimation of the total emission of estrogens.

10.1.2.2 regnant women

During pregnancy, first the corpus luteum and later the placenta produces large amounts of estrogens and the levels in urine increase. The urine excretion rate of estrogens and progesterone increases steadily during pregnancy reaching maximum at delivery as shown in Table 10.4 (74).

Table 10.4
Excretions of estrogens in urine by pregnant women

(73)

Johnson et al. (72) have reported average values of the excretion as given in Table 10.5.

Table 10.5
Average excretion of estrogens in urine by pregnant women (72)

These values are in agreement with the values reported by Frandsen et al. (73) and are used for estimation of total emission.

10.1.2.3 Post menopausal women

At the menopause, which usually occurs between the age of 45 and 55, in Denmark (on average 51), the menstrual cycles stop and the production of estrogens by the ovaries ceases. Post menopause production of estrogens is very low (74). It has been estimated as shown in Table 10.6.

Table 10.6
Average excretion of estrogens in urine by post menopausal women (72)

10.1.3 Metabolism

Almost all estrogens are emitted as glucuronides, little as sulphates and less than 4 % in unconjugated form.

The estrogens are metabolised mainly in the liver but also elsewhere. Estradiol is both metabolised reversibly and irreversibly. In the reversible metabolism, estradiol is transformed to estrone and estrone sulphate. These circulate in the blood stream and act as estradiol reservoirs. In the irreversible metabolism, estradiol is transformed to cathecol estrogens or estriol. The metabolites from both reversible and irreversible metabolism are, to a large degree, finally conjugated with sulphate and glucuronides and excreted in the urine (Table 10.7). A minor amount of the estrogens are excreted via faeces as un-conjungated metabolites (70;71).

Table 10.7
Distribution of estrogens excreted by non-pregnant women in urine.

*Conjugated forms are glucuronides and sulphates

However, the conjugation is reversible. In the organism, conjugated metabolites are to some degree hydrolysed in the intestines and reabsorbed (70). This may very well also take place outside the organism, e.g. in waste water, and unconjugated estriol, estrone etc. may thus be formed.

10.1.4 Hormone therapy

10.1.4.1 Estrogen replacement therapy

Estrogen replacement therapy may be given to women who have entered the menopause or who have had their uterus and ovaries removed.

It may be given in various forms, as outlined in Table 10.8.

Table 10.8
Administration of estrogen replacement drugs (205)

10.1.4.2 Hormone replacement therapy

Hormone replacement therapy includes the administration of two hormones estradiol and progestin (acts like progesterone). It may either be given as combination drugs or progestin may be given supplemental to the estrogen replacement therapy drugs (Table 10.9).

Table 10.9
Administration of hormone therapy drugs (205)

Orally administered estradiol or estrone are mainly excreted in the urine. Recoveries of 50-80 % in the urine have been shown, and up to 18 % in faeces, after 4-6 days (208). The values of 65 % in urine and 15 % in faeces are used for estimation of excretion in this report. Estrone and estradiol constitute 1/3 of the estrogen amount in faeces (209-211).

10.1.4.3 Hormone contraceptives

Birth control pills (oral contraceptives) contain hormones and are taken daily to prevent pregnancy.

Combination birth control pills are the most commonly used. They contain ethinylestradiol and progestin (205). However, the so-called "mini-pills", which only contain progestin, are also used. Several types of emergency contraception pills exist and some contain the hormones: Progestin, ethinyl estradiol and levonorgestrel. Norethisteron and levonorgestrel are often used progestins in contraception pills.

Shortly after administration, ethinylestradiol is found mainly as sulphate conjugated (80 %) in plasma. Part of the compound is metabolised and occurs as 6a -hydroxy, 2-methoxy, 2-hydroxy-3-methylether and 16b -hydroxy derivatives as well as metabolites where the ethinyl group is missing. However, a large part is excreted in un-metabolised but conjugated form. 16.5 % of the dose can be refound in the urine and 9 % in faeces (70;208;212). This is in accordance with the assumptions of a total excretion of 26 % made by Johnson et al. (72). However, larger excretion factors have also been reported (72).

For the estimation of national emission, the value of 26 % ethinylestradiol excretion was used.

10.2 Release of estrogens

The total human excretion of estrogens in Denmark was calculated using the above excretion patterns and estimates of the demographic distribution of women and men in Denmark.

Table 10.10
Demographic figures for Denmark 2001(75)

Estimates of the natural excretion based on the demographic figures in Table 10.10 and on the individual excretion patterns given in previous chapters are presented in Table 10.11.

Table 10.11
Total natural excretion of estrogens in Denmark 2001

In Denmark, 435,000 women are using oral contraceptives (213). The pills taken for 21 days in general contain 30-50 m g ethinylestradiol (214). This gives an average of 12.2 g ethinylestradiol per 24 h in Denmark which corresponds with data from the Danish Medicines Agency (215). With an estimated excretion of 26 %, this corresponds to the excretion shown in Table 10.12.

Table 10.12
Total excretion of ethinylestradiol in Denmark 2001

In Denmark, 80 % of all women suffer from the menopausal symptoms. 25 % still have problems after 5 years and after 10 years, 15 % still have problems. Among these, some will have symptoms for the rest of their postmenopausal life (214). The amount of estradiol sold to relieve menopausal symptoms is stated to be 23 mill. DDD in year 2000 by The Danish Medicines Agency (215). The DDD (equal to the content of one pill, taken each day), range between 1 and 2 mg estradiol or estriol (214). An average of 1.5 mg is used for the estimations. This gives a total use of estradiol and estriol of 97 g per 24 h in Denmark and a total release via faeces and urine at 78 g of estriol, estradiol and metabolites per 24 hours. The distribution between different metabolites is presumably similar to that shown in Table 10.11. If this distribution is used, the excretion from hormone therapy of post-menopausal women is as given in Table 10.13.

Table 10.13
Total excretion of estrogens from hormone therapy in Denmark 2001

The total excretion is given in Table 10.14.

Table 10.14
Total estimated excretion of estrogens in Denmark 2001

10.2.1 Other sources

10.2.1.1 Phytoestrogens

Though many plants have been shown to contain estrogenically active compounds, only a few contain estradiol and estrone. Examples are liquorice, French bean, date palm, pomegranate and apple (216). The release of estrogens from these plants is not expected to be a major source of estrogens in waste water.

10.3 Alkylphenols

Alkylphenols (AP) consist of a phenol group and an alkane. The compounds may vary both in the relative position of the alkane group and in the length and branching of the alkane. Commercially available alkylphenols are generally mixtures of alkylphenols with different degrees of branching but with the same number of carbon atoms in the chain (76). The largest European producer Sasol offers amyl-, butyl-, cumyl-, dodecyl-, nonyl- and octylphenols for different applications (217). However, nonylphenol (NP) is the most commercially prevalent of the alkylphenol family, representing approximately 85 % of the alkylphenol market. Alkyphenols are mainly used in the production of alkylphenol ethoxylates (APEs), tris(nonylphenyl) phosphite (TNPP) and alkylphenol-formaldehyde condensation resins (77). However, unreacted alkylphenols can be used as plasticizers in plastics.

Table 10.15
The use of nonylphenol in the EU in 1997 (76)

10.3.1 Nonylphenolethoxylates

Nonylphenolethoxylates are relatively easily degraded to nonylphenol (78) and therefore, an important source of alkylphenols. In 1997, 47,000 tonnes of nonylphenol were used for producing 118,000 tonnes of nonylphenolethoxylates in the EU. To our knowledge, this production, performed by seven companies, takes place outside Denmark.

Nonylphenolethoxylates were in 1994 used for the following "EU use categories" in the EU.

Table 10.16
Use of nonylphenolethoxylates in the EU in 1994 (76)

10.3.1.1 Industrial and institutional cleaning

Nonylphenolethoxylates are used in laundries, for floor and surface cleaning in buildings, for car washing, as anti-static cleaners and for metal cleaning. Domestic use of nonylphenol-based cleaners should be virtually zero due to bans and agreements and the use for industrial cleaning should also decrease. The Danish EPA made a voluntary agreement with ‘The Association of Danish Cosmetics, Toiletries, Soap and Detergent industries (SPT)’ in 1987 concerning a reduction of the use of alkylphenolpolyethoxylates. The members of SPT cover 80 to 90% of the Danish market and an analysis carried out by the Danish EPA showed that only one out of 34 cleaning products contained nonylpolyethoxylate or octylpolyethoxylate.

The amount of nonylphenolethoxylate used for industrial and institutional cleaning in the EU was 23,000 tonnes in 1997 (76) and in Denmark, the amount used in 1995 was 1,066 tonnes (218). In view of the voluntary agreements, these numbers probably overestimate the present Danish use of alkylphenolpolyethoxylates which may then be estimated to be between 0 and 1,066 tonnes.

10.3.1.2 Textile auxiliaries

Nonylphenolethoxylates are used in scouring, fibre lubrication and dye levelling in the textile industry. The main use is in wool scouring (76), which is not considered important in Denmark where wool production is small. The total amount of alkylphenol ethoxylates used in textile auxiliaries was 8,000 tonnes in 1997 (76).

10.3.1.3 Leather auxiliaries

Nonylphenolethoxylates may be used for degreasing in the preparation of hides. At present, only very little tanning is taking place in Denmark as Elmo Svendborg is the only functioning tannery. However, a very large tannery is planned on the island of Funen. Within the EU, 3,137 tonnes/year of nonylphenolethoxylates are estimated to be used in leather auxiliaries (76).

10.3.1.4 Agriculture

Nonylphenolethoxylates are used as wetting agents in agrochemical formulations. This decreases the necessary amount of active ingredient. It is also used in tit dips for cows and sheep. In Denmark, the amount used for pesticides in 1995 was 175 tonnes (218), but an agreement was made with the Danish pesticide producers in 1995 to phase out the use of alkylphenolpolyethoxylates in pesticides. Presently, no pesticides on the market contain alkylpolyethoxylates.

10.3.1.5 Emulsion polymers

Nonylphenolethoxylates are added to acrylic esters used for coatings, adhesived and fibre bonding. They act as dispersants and aid in stabilising the formulation. Nonylphenolethoxylates are also thought to be present in the polymerisation reactions used to make polymer solutions for waste water treatment (76). The amount used for this purpose is not known.

10.3.1.6 Paints, adhesives and sealants

Nonylphenolethoxylates are used in the preparation of paints, adhesive and sealant resins. Especially in water-based products (219). In the EU approximately 4,000 tonnes of nonylphenolethoxylate were used for paints and lacquers in 1997 (76) while, in Denmark, 63 tonnes were used for paints and lacquers and 77 tonnes for fillers in 1995 (218).

10.3.1.7 Pulp and paper

Nonylphenolethoxylates may be used in the pulp and paper industry in the wetting of pulp fibres, as anti-foaming agents and as retention aids. The total use of nonylphenolethoxylates in this industry in the EU is estimated to be 800 tonnes/year (76).

10.3.1.8 Metal industry

Nonylphenolethoxylates are used in the cleaning of metal surfaces (iron and steel manufacture), for metal phosphating electronics cleaning and for cleaning of metal product prior to storage. It is also used in cutting and drilling oils (76).

10.3.1.9 Photographic industry

Nonylphenolethoxylates are used as wetting agents in the developing of photographic film, mainly amateur use. The amount used in Europe for this purpose is estimated to be 93 tonnes/year (76).

10.3.1.10 Lubricants and motor oil industry

Nonylphenolethoxylates may be added to motor oil and fuels to make engines meet emission demands. They lubricate and clean engines. In Denmark, products for cooling and lubrication contained 33 tonnes of nonylphenol or nonylphenolethoxylate in 1995 (218).

10.3.1.11 Insulation

In Denmark, 77 tonnes/year were used as additives for insulation materials in 1995 (218). This is assumed to be partly for refrigerator linings.

10.3.2 Other derivatives of alkylphenols

Other important derivatives besides alkylphenolethoxylates are alkylphenol phosphites and nonylphenol-formaldehyde condensation resins (76;77). In the EU, the amount of nonylphenol used for production of these derivatives was 29,000 tonnes in 1997 (76).

10.3.2.1 Alkylphenol phosphites

Alkylphenol phosphites can be used as UV stabilisers in plastics. 4,000 tonnes nonylphenol were used for production of tri(4-nonylphenol)phosphite in 1997 in the EU (76).

10.3.2.2  Nonylphenol-formaldehyde condensation resins

The main use of nonylphenol in the plastics industry is as a monomer in the production of phenol/formaldehyde resins, which are used as adhesives and tackifiers in the rubber industry, as paper coating resins, as resins for printing inks and as resins for contact adhesives and coatings. According to the EU, 22,500 tonnes of nonylphenol were used for nonylphenol-formaldehyde resins in 1997, at 25 sites in the EU (76).

10.3.2.3 Phenolic oximes

Within the EU, 2,500 tonnes of nonylphenol were used for the production of phenolic oximes in 1997. This took place at one site outside Denmark (76). Phenolic oximes are used in extraction and purification of copper from ore, a process that is not performed in Denmark.

10.3.2.4 Nonylphenol amine salts

In the EU, 1,500 tonnes of nonylphenol were used for the production of nonylphenol amine salts. This production is not known to take place in Denmark. Nonylphenol amine salts are used as curing agents or accelerators for epoxy resins. With curing, the nonylphenol is covalently bound inside the epoxy matrix (76). In Denmark, hardeners containing 66 tonnes of nonylphenol were used in 1995 (218).

10.3.2.5 Miscellaneous uses

Apart from the major uses outlined above, a number of miscellaneous uses of nonylphenol derivatives are known: Carbonless copy ink, latex manufacture, and packaging materials (77). The derivatives and amounts used for these purposes were not identified in the present assessment. They are, however, expected to be of minor importance.

10.4 Release of alkylphenols

Nonylphenol is produced at four sites within the EU (76), of which none seems to be in Denmark. Thus, it is believed that there is no release from production in Denmark. Likewise there seems to be no large production of nonylphenolethoxylates or other derivatives and consequently no associated release, in Denmark. Therefore, the release of nonylphenol is expected to be mainly from processing/formulation and use.

10.4.1 Release from processing/formulation

Though neither alkylphenols nor derivatives are produced in Denmark, they may be added to formulations in Denmark. For nonylphenolethoxylates, an emission factor of 0.003 to waste water is used in the EU risk assessment, which is in line with industry reports (76). This leads to a total release of 216 tonnes of nonylphenolethoxylates/year, from formulation, in the EU. In Denmark, a release factor of 0.003 from formulation of cleaning products and tensides with nonylphenolethoxylates corresponds to a release of 4.4 tonnes nonylphenolethoxylates/year to waste water.

10.4.2 Release from use

The major release of nonylphenol from use is expected to be from nonylphenolethoxylate used as a detergent.

10.4.2.1 Release from use of nonylphenolethoxylate

Industrial and institutional cleaning:

The wastewater release factor for institutional and industrial cleaning is estimated to be 0.9 (76). With a yearly use of 23,000 tonnes, this results in a release of 20,700 tonnes nonylphenolethoxylate/year in the EU and between 0 and 959 tonnes in Denmark.

Car wash:

The release of nonylphenol from car wash in Denmark to waste water has been estimated to be around 891 kg/year (220)

Pesticide:

The usual dose applied with pesticide used to be 50-200 g nonylphenolethoxylate/ha (76). It is assumed that all use of nonylphenolethoxylate in pesticides in Denmark has ceased.

Veterinary tit dips:

There may be some release from the use of nonylphenolethoxylates in tit dips for cows. However, this is not expected to reach the sewage system but rather to be spread on agricultural land with manure.

Leather processing:
The EU release factor for the use of nonylphenolethoxylates in leather processing, to waste water is set to 0.9. Approx. 2,700 tonnes of NPEO are thus released yearly from the leather processing industry. The average release from one large site is estimated to be 2.7 tonnes/year (76).

Metal industry:

In the EU the release of nonylphenolethoxylates from the metal processing industry is estimated to be 632 tonnes/year to waste water (76).

Photographic industry:

Nonylphenolethoxylates used as wetting agents may be released to waste water. With the EU emission factor of 0.8 to waste water, this gives an emission of 74 tonnes/year in the EU (76).

Pulp paper an board industry:

The paper industry is very small in Denmark, why only limited releases from this area can be expected. In the EU, 800 tonnes/year of nonylphenolethoxylates is estimated to be released from the use in this industry (76).

Textile processing industry:

The factor for emission of nonylphenolethoxylate, used in textile processing, to waste water, is set as 0.85 by the EU. This leads to an emission of approx. 4,000 tonnes in 1997. The majority is used for initial wool processing, which is not commonly performed in Denmark.

Paints, lacquers and varnishes industry:

During paint manufacture, release of nonylphenolethoxylate may take place. Estimated emisson factors of 0.005 for emission to waste water have been given by the industry. This leads to an emission of 20 tonnes/year for EU and 0.3 tonnes for Denmark.

Cosmetics:

It is estimated that 50 % of the nonylphenolethoxylate used in cosmetics are released to waste water. The remainder is expected to be disposed of as solid waste. This gives a release of 10 tonnes/year to waste water in Denmark.

Insulation materials:

In Denmark, some use of nonylphenolethoxylate and nonylphenol for insulation (polyurethan) in Denmark has been noted. The loss from this process is not known.

10.4.2.2 Release from use of other alkyphenols

Release from the use of other alkyphenols, mainly in the plastics industry is expected to be low. For example, the loss from use of hardeners is expected to be low. However, this release has not been quantified.

10.4.3 Release from disposal

Most alkylphenol (nonylphenol) is used in products such as detergent formulations, which are not disposed of but emitted to waste water during use. However, alkylphenol incorporated in products such as plastic, paints etc. may be disposed of to landfill or incineration. Alkylphenol will disappear by incineration. No knowledge on the fate in waste deposits is available.

A summary of estimated releases is given in Table 10.17. Where figures for Danish production have been available, these have been used. Since the former use of alkylphenolpolyethoxylates in cleaning products was the largest contributor to the release to the environment, the present release depends strongly on the success of the voluntary agreement between the Danish EPA and ‘The Association of Danish Cosmetics, Toiletries, Soap and Detergent industries (SPT)’.

Table 10.17
Summary of Nonylphenolethoxylate releases to waste water (tonnes/year)

a: Depending on the success of the voluntary agreement

Nonylphenol accounts for 85 % of the alkylphenols sold. The main part of the remaining 15 % is assumed to be octylphenol used in the same way as nonylphenol. The released amounts of alkylphenols could thus probably be enlarged by a factor 1/0.85.

10.5 Bisphenol A

Bisphenol A is used for many purposes in modern society. The major consumption is related to the use of bisphenol A as a chemical building block in the production of polycarbonate plastic and epoxy resins (79). However, bisphenol A is also used for numerous other purposes, as shown in Table 10.18. Formerly, bisphenol A was used as an inactive ingredient in pesticides but this use has ceased (221).

Four companies within the EU produce bisphenol A but there seems to be no such production in Denmark. Total production within the EU is around 700,000 tonnes/year and consumption is around 690,000 tonnes a year (Table 10.18).

Table 10.18
Use in Europe (221)

10.5.1 Polycarbonate

Polycarbonate is produced by a polymerisation process involving bisphenol A. This process is not takin place in Denmark (222), but at five sites in the EU. Although the bisphenol A in polycarbonate in general is polymerized, there are small amounts of free bisphenol A in the final polycarbonate, between <10 mg/kg and 50 mg/kg (221). Polycarbonate is used for compact disks, reusable bottles, food contact containers, multi-wall sheets for construction, injection moulded structural parts for the electronics and automotive industry, impact-resistant glazing, street-light globes and household appliance parts (79;221).

10.5.2 Epoxy resins

Bisphenol A is used for making epoxy resins at 8 sites in the EU, none of them in Denmark (222). The epoxy is used for protective coatings, food- and beverage-can linings, structural composites, electrical laminates, electrical applications and adhesives (79;221). Some epoxy resin adhesives for domestic use, available on the Danish market, contain bisphenol A (223). Bisphenol A may be ethoxylated for use in special epoxy resins.

10.5.3 Phenoplast resins

Phenoplast resins (tradename bakeliteÒ ) are hard brittle plastic materials used for electrical appliances, kitchen tables and car engine parts. There is no phenolplast production in Denmark (222).

10.5.4 Can coating manufacture

Can coating is produced by reacting an epoxy resin with bisphenol A. According to the EU, only 5 companies in Europe make can coatings containing bisphenol A (221). A Danish company, Glud og Marstrand A/S, performs can coating with bisphenol A epoxy in Denmark.

10.5.5 Thermal paper

Bisphenol A is used in the coating of thermal paper, in which it works as a developing agent. Not totally reacted paper may contain significant amounts of residual bisphenol A. Thermal paper is used for cash registers, thermal faxes and printers, and for other machines in hospitals, laboratories etc. (221). Thermal paper is not produced in Denmark.

10.5.6 PVC

Bisphenol A is used in the PVC industry as a polymerisation inhibitor and as an anti-oxidant. The use as a polymerisation inhibitor does not take place in Denmark as there is no PVC raw material production in Denmark (224). In the rest of the EU, bisphenol A used for this purpose should be voluntarily phased out since 2001 (221).

Bisphenol A is used as an anti-oxidant in the processing of PVC, in the production of plasticisers and in the preparation of additive packages for PVC processing. The production of plasticisers and additive packages is not expected to take place in Denmark, but processing of PVC, involving plasticisers and antioxidants, does.

10.5.7 Other uses

Bisphenol A is used in the production of polyols, which are used in the production of polyurethane and in the production of unsaturated polyester resin. None of these productions takes place in Denmark (222). In Denmark, bisphenol polyester resin is used in toners for printers and photocopiers, and polyurethane is used for insulation (225).

10.5.8 Brake fluid

Bisphenol A is added to brake fluid as an anti-oxidant at one site in the EU (221) but not in Denmark.

10.5.9 Tyre manufacture

Bisphenol A is used as an antioxidant in the process of tyre manufacturing, but bisphenol A is not expected to be present in the finished tyre in significant concentrations (221). No tyre production takes place in Denmark.

10.5.10 Fire retardant

Bisphenol A was previously used for the production of tetra-bromobisphenol, which has been used as a fire retardant, but this production is probably not relevant any more within the EU (221).

10.6 Release of bisphenol A

There is no release to the environment from the production of bisphenol A in Denmark, as there is no production. Likewise there is no production of polycarbonate, epoxy resin or other plastic raw materials and thus no related release.

In Denmark, releases of bisphenol are thus expected to arise from processing, use and disposal of bisphenol A-containing materials.

10.6.1 Release from processing

Studies have shown that the release of unreacted monomers during processing of polycarbonate in general is very small (undetectable). However, if the correct procedures are not followed, released amounts may be larger (221).

There may be some release of bisphenol A in relation to the use as an anti-oxidant and plasticiser in PVC processing in Denmark. In the EU risk assessment report, the use of 3 tonnes per year as anti-oxidant, typical amount for one generic PVC processing site, is estimated to lead to the release of 6.42 kg/year to waste water (221). In the EU, the total loss to waste water, from the use as PVC antioxidant, is estimated to be 1,070 kg/year. The use of bisphenol A as a plasticiser in the processing of PVC may lead to releases to waste water in the order of 140 kg/year for EU (221).

In the EU risk assessment (221), no release of bisphenol A from can coating to surface or waste water has been encountered at five sites. Waste is disposed of by incineration (221). Thus, no significant emission to water from the Danish can coating industry is expected.

10.6.2 Release during use

Studies have shown very low migration of bisphenol A from polycarbonate into foodstuffs (221). The release to the environment through foodstuffs is thus considered negligible. The total release from washing of polycarbonate bottles, reused for beverages, is estimated to be very small, maximally 1.6 kg/year in the EU (221). Likewise, the release from installed multi-wall polycarbonate sheets is very small, estimated to be 1.3 kg/year in the EU and considered insignificant (221).

The release of bisphenol A from epoxy resins is low. The content of unreacted bisphenol A in uncured epoxy resins is lower than 1,000 ppm and the content is reduced when the resin is cured. The release of bisphenol A from can coatings to food is also very small (221).

The release of bisphenol A from phenoplast is expected to be very small (221). The production and use of phenoplast are much smaller than that of polycarbonate and release can be expected to be much lower as e.g. no washing occurs.

Plasticisers containing bisphenol A are mainly used in PVC for roofing and cables, and some release from these items can be expected. Likewise, some release can be expected from PVC products containing bisphenol A for other purposes. These releases are not directly to waste water but in Denmark, most surface run off from industrial and residential areas is still discharged into the sewage system. The emissions from the use of PVC products are given in Table 10.19.

Table 10.19
Emissions from the use of PVC products in the EU (221)

Production of brake fluid is not known in Denmark and releases from use are expected to be small. Bisphenol A is destroyed in use and waste is in general disposed of as chemical waste (221).

No tyre manufacturing takes place in Denmark and no loss of bisphenol A is expected during use (221).

10.6.3 Release from disposal

After end of use, the plastic products containing small amounts of bisphenol A can be disposed of to landfills or incinerated. By incineration, any free bisphenol A is effectively destroyed.

Considerable leaching of bisphenol A from hazardous waste landfills has been measured in Japan (226) and in Germany (221). Conceivably, it may originate from deposited plastics (polycarbonate, PVC, epoxy resins) (226).

Experiments in which pieces of plastic have been soaked in water for a couple of weeks, have shown that leaching from synthetic leather and PVC cords can be high, up to 139 m g/g plastic was measured (227). However, thermal paper could also be an important source. It has not been possible to estimate the release from landfills here.

10.6.4 Release from recycling

There may be a significant loss of bisphenol A to water from recycling of thermal paper. In the deinking process bisphenol A is released to water. Even though the deinking waste water is treated in a sewage treatment plant at the paper mill, a large emission may be expected according to the EU risk assessment (221). Rigol et al. have reported concentrations of up to 100 m g/l in recycling process waters (228) and, in Japan, bisphenol A concentrations ranging from 8 to 370 m g/l have been measured in the final effluents from paper recycling plants (229). In Denmark, paper is reused by the companies Brdr. Hartmann A/S (Tønder), Dalum paper mill (Odense), SCA Djursland (corrugated cardboard) and Skjern papirfabrik (230;231). However, thermal paper is only expected to constitute a small part of the paper reused at these sites. In the EU, a yearly release to waste water, after pre-treatment at paper mill, of 340 tonnes has been estimated (221). Fürhacker et al. found that paper industry was by far the largest contributor to bisphenol A in sewage water led to a STP in Austria (232). Whether the source was thermal paper was not discussed. It should be noted that bisphenol A may be transformed to the more chlorinated bisphenol A if the pulp is bleached with chlorine (229).

The releases relevant for Denmark have been extrapolated from European to Danish amounts below by means of the relative size of the populations and by application of an estimation factor expressing the difference in European and Danish conditions. For example, a relatively smaller amount of thermal paper is expected to be reused in Denmark than in Europe in general and consequently an estimation factor less than 1 was chosen. The relationship between populations is 5.35 mill (DK) to 370 mill (EU).

It must be noted that these are very crude estimates, which should be substantiated by thorough substance flow investigations.

Table 10.20
Summary of bisphenol A releases to wastewater (tonnes/year)

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