Original: English
English only
OSPAR CONVENTION FOR THE PROTECTION OF THE MARINE ENVIRONMENT OF THE NORTH-EAST ATLANTIC
WORKING GROUP ON DIFFUSE SOURCES (DIFF)
HELSINKI: 6-9 OCTOBER 1998
______
Characterisation of Endocrine Disrupting Chemicals
- Selected Examples -
Submitted by World Wide Fund For Nature (WWF)
Background
1.DIFF is expected to examine a report presented by Denmark concerning the selection and prioritisation of substances, which give reasonable grounds for concern that they are endocrine disruptors.
2.WWF has produced a number of technical factsheets describing the characteristics of key endocrine disruptors. This information will be further updated.
Action requested
3.DIFF is invited to make use of the attached information for the selection and prioritisation of endocrine disruptors.
4.DIFF may wish to relate this information to more specific items on the agenda e.g. when considering programmes and measures on particular substances and/or groups of chemicals.
Characterisation of Endocrine Disrupting Chemicals
- Selected Examples
ALKYL PHENOL ETHOXYLATES (APEs)
CHEMICAL NAME, CAS NUMBER AND STRUCTUREBasic structure of alkylphenol ethoxylates consists of an alkylphenol with a side chain of several ethoxylate groups. The alkyl group is typically a branched nonyl-, octyl- or dodecyl-chain.
NPEs chemical formula:C9H19 Nonylphenol, CAS: 9016-45-9
OPEs chemical formula: C8H17 Octylphenol, CAS: 9002-93-1
Metabolites:
Nonylphenol (NP) chemical formula: C15H24O, CAS: 25154-52-3
Octylphenol (OP) chemical formula: C14H22O, CAS: 27193-28-8 and 0027193288
IN VITRO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
p-NP and p-OP induced cell proliferation and increased progesterone receptor levels in human breast tumour MCF-7 cells (Soto, et al., 1991, White et al., 1994).
IN VIVO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
NP induced uterine cornification and endometrial growth in immature female rats (Odum et al., 1997, Lee & Lee, 1996). NP induced vitellogenin production, an egg yolk protein, in male rainbow trout (Lech, et al., 1996). Chronic exposures to NP induced testis-ova (an inter-sex condition characterized by the formation of ovarian tissue, including oocytes, within normal testicular tissue) in Japanese medaka (Gray, & Metcalfe, 1997). Chronic exposures to OP greatly reduced sperm quantity, and adversely influenced the sizes, weights, and histological structures of the testes, epididymides, ventral prostate glands, seminal vesicles, and coagulating glands in adult male rats (Boockfor & Blake, 1997).
RELEASE TO THE ENVIRONMENT
Most releases of alkylphenols to the environment arise from industrial wastewaters directly to ambient surface waters. Releases also occur from vehicle washing, agricultural operations, and via municipals sewage treatment plants (STPs). It is estimated that over 37% of the total APEs used is discharged to aquatic environment. Analysis of drinking water in New Jersy, USA, showed presence of ten NPEs and one OPEs at concentration of 15-29 ng/L (Clark, et al., 1992). Levels of NP and the lower ethoxylates in ambient waters and sediments have also been studied. One American study looked only at rivers, found NP concentrations in ambient water were as high as 0.64 ppb, and NPE up to about 15 ppb. Sediment NP was found at concentrations up to 2.96 ppm (Naylor, et al., 1992).
HUMAN EXPOSURE
APEs are widely used surfactants, which are readily absorbed and rapidly removed from human body. Human exposure occurs through many and varied routes, due to the vast array of applications to which the alkylphenols and their ethoxylates have been put. Examples include: (i) NP leaching into intravenous fluids (Lesko, et al., 1992); (ii) NP leaching from PVC tubing used in milk plants (Junk, et al., 1974); (iii) NP leaching from food-grade PVC used in food packaging (Gilbert et al., 1982); (iv) vaginal spermicides containing octoxynol or nonoxynol as active ingredients; (v) personal products (e.g. lotions, hair colourings, shaving cream, deodorant, etc.); and (vi) drinking water, at approximately 1 ppb (total nonylphenolics), in both New Jersey (Clark, et al., 1992) and Barcelona, Spain (Guardiola et al., 1991). A recent report has demonstrated that NPEs are identifiable in the urine of non-exposed human control subjects, as well as exposed subjects, in a study of detergent-augmented chemotherapy (Charuk, et al., 1998).
USES
APEs are non-ionic surfactants, their annual world production exceeds 600,000 tonnes. The main APEs used in commercial formulations are nonylphenol ethoxylates (80%) and octylphenol ethoxylates (20%). APEs are extensively used in cleaning products, paints, pesticides, pulp and paper production and textile manufacturing. APEs are also used as intestinal permeability enhancers in drug delivery systems and in spermicides and contraceptive foams.
References
Soto, A.M., Justicia, H., Wray, J.W. and Sonnenschein, C. (1991). p-Nonyl-phenol: An oestrogenic xenobiotic released from "modified" polystyrene. Environmental Health Perspectives 92, 167-173.
White, R., Jobling, S., Hoare, S.A., Sumpter, J.P., Parker, M.G., 1994. Environmentally persistent alkylphenolic compounds are estrogenic. Endocrinology 135, 175-182.
Odum, J., Lefevre, P.A., Tittensor, S., Paton, D., Routledge, E.J., Beresford, N.A., Sumpter, J.P., and Ashby, J. (1997). The rodent uterotrophic assay: Clinical protocol features, studies with nonyl phenols, and comparison with a yeast estrogenicity assay. Regulatory Toxicology and Pharmacology, 25, 176-188.
Lee, P.-C., and Lee, W. (1996). In vivo estrogenic action of nonylphenol in immature female rats. Bull. Environ. Contam. Toxicol. 57, 341-348.
Lech, J.L., Lewis, S.K., and Ren, L. (1996). In vivo estrogenic activity of nonylphenol in rainbow trout. Experimental and Applied Toxicology, 30, 229-232.
Gray, M.A., and Metcalfe, C.D. (1997). Induction of testis-ova in Japanese Medaka (Oryzias latipes) exposed to p-nonylphenol. Environmental Toxicology and Chemistry, 16(5), 1082-1086.
Boockfor, F. R., and Blake, C.A., 1997. Chronic administration of 4-tert-octylphenol to adult male rats caused shrinkage of the testes and male accessory sex organs, disrupts spermatogenesis, and increases the incidence of sperm deformities. Biology of Reproduction, 57, 267-277.
Clark, L.B., Rosen, R.T., Hartman, T.G., Louis, J.B., Suffet, I.H., Lippincott, R.L., and Risen, J.D. (1992). Determination of alkylphenol ethoxylates and acetic acid derivatives in drinking water by particle beam liquid chromatography/mass spectrometry. International Journal of Environmental Analytical Chemistry, 47, 167-180.
Naylor, C.G., Mieure, J.P., Adams, W.J., Weeks, J.A., Castaldi, F.J., Ogle, L.D., and Romano, R.R. (1992). Alkylphenol ethoxylates in the environment. Journal of the American Oil Chemists' Society, 69(7), 695-703.
Lesko, J., Jabukik, T., and Michalkova, A. (1992). Gas chromatographic-mass spectrometric detection of trace amounts of organic compounds in the intravenous fluid Infusio Dario. Journal of Chromatography, 603, 294-297.
Junk, G.A., Svec, H.J., Vick, R.D., and Avery, M.J. (1974). Contamination of water by synthetic polymer tubes. Environmental Science and Technology, 8(13), 1100-1106.
Gilbert, J., Sheperd,, M.J., Startin, J.R., and Wallwork, M.A. (1982). Identification by gas chromatography-mass spectrometry of vinyl chloride oligomers and other low-molecular-weight components in poly(vinyl chloride) resins for food packaging applications. Journal of Chromatography, 237, 249-261.
Guardiola, A., Ventura, F., Matie, L., Caixach, J., and Rivera, J. (1991). Gas chromatographic-mass spectrometric characterization of volatile organic compounds in Barcelona tap water. Journal of Chromatography, 562, 481-492.
Charuk, J.H.M., Grey, A.A., and Reithmeier, R.A.F. (1998) Identification of the synthetic surfactant nonylphenol ethoxylate: a P-glycoprotein substrate in human urine. American Journal of Physiology (in press).
ATRAZINE
CHEMICAL NAME, CAS REGISTRY NUMBER, STRUCTUREAtrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine, C.A.), 1912-24-9, C8H14ClN5
IN VITRO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
Atrazine inhibits binding of 17ß-Oestradiol to the oestrogen receptor in different test systems (Vonier et al., 1996, Tran et al., 1996). However, partly only at submaximal oestradiol concentrations (Tran et al., 1996). It was also found to work anti-androgenic by inhibition of dihydrotestosteron binding to the androgen receptor (Danzo, 1997). It also interfered with binding of androgens to androgen binding proteins (ABP) (Danzo, 1997). Atrazine also inhibited testosterone conversion into active compounds in the brain of the rat (Lyons, 1996).
IN VIVO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
Pseudopregnancies and irregularities in the female cycle were observed in animals (Cooper et al., 1996). Atrazin may also interfere with steroid metabolism. It induced the gonadal-adrenal mesonephros(GAM)-aromatase in the alligator (Crain et al., 1997). A study by the UK ACP found that atrazine increased the occurrence of mammary gland carcinomas in the rat strain studied, but apparently not in other species (ACP, 1994). It was considered likely that atrazine could act as a promotor by altering oestradiol levels (ACP, 1994). It is assumed that atrazine may cause metabolic degradation of oestrogen to favour the route via the more genotoxic 2-hydroxyoestrone (Bradlow et al., 1995). Pre-natal and post-natal treatment with atrazine and metabolites of atrazine decreased the number of androgen specific binding sites in the prostate (Danish EPA, 1995).
EVIDENCE OF MUTAGENITY OR CANCEROGENITY
After feeding experiments with relatively high doses of atrazine (ca. 800 mg/kg) increased damage of the DNA (Pino et al., 1988) and formation of malignant tumors was observed in rats (Pinter et al., 1990). N-nitrosoatrazine which can be formed by reaction of nitrite with atrazine was reported to cause cromosomal abberations in human lymphocytes at concentrations of 0.1 ng/ml (Meisner et al., 1993).
RELEASES TO THE ENVIRONMENT
Atrazine has been used in Germany in high amounts on corn until its ban in 1991 and is still being used in many other countries of the world. It is also assumed to be applied illegally in Germany as it still could be found after 1991 in rain and surface water as well as in soil samples (Dankwardt et al., 1994, 1995, WWF Report, 1998). In the rivers Rhein and Elbe atrazine can be found up to 0.6 µg/L (e.g. in 1995), in smaller streams of agricultural areas concentrations up to 2-3 µg/L could be found in 1992 and 1993 (Dankwardt et al., 1994). US rivers in the corn growing region of the middle west contain up to 100 µg/L atrazine (Dankwardt, unpublished data). In estuaries concentrations of 0.03-2.1 µg/L have been found (van Steenwijk, 1992, Bester and Hühnerfuß, 1993, v. Meerendonk, 1994). In the open sea concentrations up to 0.1 µg/L were observed. About 4-8% of soil samples from the corn growing regions in Bavaria were found to contain more than 100 mg/kg atrazine in 1993-1998 (Dankwardt et al., 1995 and unpublished data). From the soil atrazine may leach into theground water. The bioconcentration factor (BCF) for atrazine predicted from water solubility is 86, experimental log BCF values of 0.3-2 have been reported for different fish species. Atrazine was assumed not to bioconcentrate.
HUMAN EXPOSURE
Dietary exposure to atrazine may arise from drinking water, e.g. well water or untreated ground water. A study from Belgium reported atrazine in tap water up to 0.5 µg/L (Dejonckheere et al., 1996).
USES
Atrazine is a selective pre- and post emergence herbicide used in asparagus, forestry, grasslands, gross crops, maize, pineapple, roses, sorghum, sugarcane and non-crop areas. The main application is on maize (Worthing, 1991).
References
ACP (Advisory Committee on Pesticides) (1994), Annual Report 1993, HMSO, London, cited in G. Lyons, 1996.
Bester and Hühnerfuß (1993), cited in WWF report, 1998.
Bradlow, L.H., Davis, D.L., Lin, G., Sepkovic, D., Tiwari, R. (1995) Effects of pesticides on the ratio of 16a/2 hydroxyoestrone: A biological merker of breast cancer risk, cited in G. Lyons, 1996.
Cooper, R.L., Stoker, T.E., Goldman, J.M., Parrish, M.B., Tyrey, L. (1996) Effect of atrazine on ovarian function nin the rat. Reprod. Toxicol. 10, 257-264.
Crain, D.A., Guillete, L.J., Rooney, A.A., Pickford, D.B. (1997) Alterations in steroidogenesis in Alligators (Alligator mississippiensis) exposed naturally and experimentally to environmental contaminants. Environ. Health Perspect. 105, 528-533.
Danish EPA (1995) Male reproductive health and environmental chemicals with estrogenic effects, Miljoprojekt No. 290, Danish Environmental Protection Agency, Denmark, cited in G. Lyons, 1996.
Dankwardt, A., Wüst, S., Elling, W., Thurman, E.M., Hock, B. (1994) Determination of atrazine in rainfall and surface water by enzyme immunoassay. Environmental Science & Pollution Research 1, 196-204.
Dankwardt, A., Pullen, S., Rauchalles, S., Kramer, K., Just, F., Hock, B., Hofmann, R., Schewes, R., Maidl, F.X. (1995) Atrazine residues in soil two years after the atrazine ban - A comparison of enzyme immunoassay with HPLC. Analytical Letters28, 621-634.
Danzo, B.J. (1997) Environmental xenobiotics may disrupt normal endocrine function by interfering with the binding of physiologiacl ligands to steroid receptors and binding proteins. Environ. Health Perspect. 105, 294-301.
Dejonckheere, W., Steurbaut, W., Drieghe, S., Verstraeten, R., Braeckman, H. (1996) Pesticide residue concentrations in the Belgian Total Diet, 1991-1993. J. AOAC International 79, 520-528.
Lyons, G. (1996) Pesticides posing hazards to reproduction. A report for WWF-UK, Weyside Park, Catteshall Lane, Godalming, Surrey GU7 IXR, England.
Meisner, L.F., Roloff, B.D., Belluck, D.A. (1993) In vitro effects of N-nitrosoatrazine on chromosome breakage. Arch. Environ. Contam. Toxicol. 24, 108-112.
Pino, A., Maura, A., Grillo, P. (1988) DNA damage in stomach, kidney, liver and lung of rats treated with atrazine. Mutation Research 209, 145-147.
Pinter, A., Török, G., Börzsönyi, M., Surjan, A., Csik, M., Kelcsenyi, Z., Kocsis, Z. (1990) Long-term carcinogenicity bioassay of the herbicide atrazine in F344 rats. Neoplasma 37, 533-544.
Tran, D.Q., Kow, K.Y., McLachlan, J.A., Arnold, S.F. (1996) The inhibition of estrogen receptor-mediated responses by chloro-s-triazine derived compounds is dependent on estradiol concentration in yeast. Biochem. Biophys. Res. Comm. 227, 140-146.
Van Steenwijk (1992), cited in WWF report (1998)
Vonier, P.M., Crain, D.A., McLAchlan, J.A., Guilette, L.J., Arnold, S.F. (1996) Interaction of environmental chemicals with the estrogen and progesterone receptors from the oviduct of the Amerivan alligator. Environ. Health Perspect. 104, 1318-1322.
v. Meerendonk (1994), cited in WWF report (1998)
Worthing, C. (1991) The Pesticide Manual. 9th Ed., The British Crop Protection Council, Unwin Brothers Ltd, England.
WWF Report (1998) Pestizidbelastung von Rhein, Elbe, Weser, Ems und der Nordsee, WWF-Deutschland, Franfurt a. Main.
BISPHENOL A (BPA)
CHEMICAL NAME, CAS NUMBER(S) AND STRUCTUREBisphenol A (4,4'-Isopropylidenediphenol), 80-05-7, C15H16O2 - similar structure as DES
IN VITRO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
BPA is oestrogenic in the E-screen (Krishnan et al.,1993). It stimulates cell proliferation and induces expression of estrogen responsive genes (Ben and Steinmetz, 1998).
IN VIVO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
BPA increases prolactin release and stimulates uterine, vaginal and mammary growth and differentiation. A dose of 2ng/g body weight (2ppb) of bisphenol A permanently increased the size of the preputial glands and reduced the epididymides in male rats exposed in-utero on gestation days 11-17 (vom Saal et al.,1998).
RELEASES TO THE ENVIRONMENT
Data on the US TRI shows that in 1992, some 104 tonnes of BPA were reported to be released to air and water from 107 facilities (Staples,1995). However, these figures do not include the diffuse sources arising from product leaching. Measured concentrations of BPA in streams and rivers in Japan and Europe are reported to be mostly undetectable, with a few samples showing levels from 0.2 micrograms per litre (µg/l) to 1.9µg/l, and with predicted concentrations in receiving waters in the USA ranging up to 14µg/l in worst case conditions (SPI,1996). Measured bioconcentration factors of BPA in fish ranged from 5-68, while calculated bioconcentration factors for fish range up to about 196 (Staples,1995). However, according to some workers, biomagnification up the food chain is not expected to be significant because of metabolism and excretion in mammals (Staples,1995).
HUMAN EXPOSURE
Dietary exposure to bisphenol A arises because epoxy resins are used as plastic coatings in cans for food and drink (Brotons et al.,1995; APME,1995b). Polycarbonate bottles, such as those used for infant feeding, may also be a source, although a UK study does not support this (MAFF,1997). Consumer exposure additionally occurs from microwaved foods using susceptors in the packaging. Human exposure to BPA and some other, more potent, related oestrogenic substances can also arise from dental work using composite resins (Olea et al.,1996).
USES
Annual European production of 504,000 tonnes, but most is then reacted to form polymer. Bisphenol A has extensive use as an intermediate in the production of polycarbonate, epoxy, and corrosion resistant unsaturated polyester-styrene resins. It may be found in a diverse range of products including the interior coatings for cans and drums, reinforced pipes, adhesives, flooring, protective coatings, water main filters, artificial teeth, nail polish, food packaging materials, electronic parts, circuit boards, computer housings, powder paints, bullet proof windows, headlights, lenses, helmets, thermal paper, paper coatings, and dye developers (Staples,1995; NTP,1982).
References
APME (Association of Plastics Manufacturers in Europe), 1995, APME Epoxy Resins Committee Position Paper, Bisphenol A- Oestrogenic Activity, dated August 1995, Brussels.
APME (Association of Plastics Manufacturers in Europe), 1995b, APME Epoxy Resins Committee Position Paper, Estrogenic activity of Bisphenol A: Implications for the use of Bisphenol A Epoxy resins coatings in food cans, dated August 1995, Brussels.
APME (Association of Plastics Manufacturers in Europe) et al., 1995c, Oestrogen Mimics - Bisphenol A, Joint statement of Epoxy Resins Group of APME, CEPE (European Confederation of Paint, Printing Ink and Artists Colours Manufacturers Associations) and SEFEL (European Secretariat of manufacturers of Light Metal Packaging), dated November 1995, Brussels.
Ben J N and Steinmetz R, 1998, Xenoestrogens: The emerging story of bisphenol A, Trends Endocrinol Metab, Volume 9(3), p124-128.
Brotons J A, Olea-Serrano M F, Villalobos M, Pedraza V, Olea N, 1995, Xenoestrogens released from lacquer coating in food cans, Environmental Health Perspectives, Volume 103, Number 6, June,pp608-612.
Krishnan A V, Stathis P, Permuth S F, Tokes L and Feldman D, 1993, Bisphenol A: An oestrogenic substance is released from polycarbonate flasks during autoclaving, Endocrinology, Volume 132, No 6, pp2279-2286.
MAFF, 1997, Food Safety Information Bulletin, No 89, October 1997, London.
NTP (National Toxicology Program), 1982, Carcinogenesis bioassay of Bisphenol A in F344 rats and B6C3F1 mice (feed study), NTP publication number 82-1771, US Department of Health and Human services, NTP, North Carolina, USA.
Olea N, Pulgar R, Perez P, Olea-Serrano, Rivas A, Novillo-Fertrell A, Pedraza V, Soto A, Sonnenschein, 1996, Estrogenicity of resin-based composites and sealants used in dentistry, Environmental Health Perspectives, Volume 104, Number 3, March, pp298-305.
Sharman M, Honeybone C, Jickels S, Castle L,1995, Detection of residues of the epoxy adhesive component bisphenol A diglycidylether (BADGE) in microwave susceptors and its migration into food, Food additives and contaminants, Volume 12, no 6, pp779-787.
Staples C A,1995, An assessment of the environmental fate and effects of bisphenol A, Studies sponsored by the Society for the Plastics Industry Washington, presentation at Society of Environmental Toxicology and Chemistry, Vancouver, 5-9 November 1995.
Vom Saal F S, Cooke P S, Buchanan D L, Palanza P, Thayer K A, Nagel S C, Parmigiani S, Welshons W V, 1998, A physiologically based approach to the study of bisphenol A and other estrogenic chemicals on the size of reproductive organs, daily sperm production and behaviour, Toxicology and Industrial Health, Volume 14, Nos 1/2, p239-260.
DiButylPhthalate (DBP)
CHEMICAL NAME, CAS NUMBER(S) AND STRUCTUREDi-n-butyl phthalate, 84-74-2, C6H2204
IN VITRO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
DBP weakly interacted with the oestrogen receptor (Jobling et al.,1995). In human breast cancer cell lines DBP increased cell division, and was found to stimulate the activity of the oestrogen receptor directly. When tested in the presence of 17b oestradiol to see if it could compete with estradiol and have an overall dampening effect on oestrogenicity, DBP were shown to act with the "real" hormone - and it was suggested that DBP would therefore enhance the effects of endogenous oestrogens (Jobling et al.,1995).
IN VIVO EVIDENCE FOR AN ENDOCRINE DISRUPTIVE ACTION
DBP impaired the androgen dependent development of the reproductive tract in male offspring of female rats dosed at 250, 500 and 750 mg/kg/day throughout pregnancy and lactation up until offspring were 20 days old. The epididymis was absent or underdeveloped in 9, 50 and 71% of offspring when examined at 100 days old at the 250, 500 and 750 mg/kg/day dose levels respectively. Similarly hypospadias occurred in 3, 21, and 43 % of males exposed at the different dose levels and ectopic or absent testes were noted in 3,6,and 29% of males (Mylchreest et al., 1998).
An NTP continuous breeding study showed an increased sensitivity in F1male rats as compared to the Fo generation, which indicates that altered male reproductive development was due to in utero, neonatal and/or pubertal exposure of the F1 generation (NTP, 1991; Wine et al., 1997). These studies suggests that phthalates produce changes in reproductive organ development by an anti-androgenic endocrine mediated mechanism, in which effects on FSH are believed to play an important part. Phthalates certainly decrease the responsiveness of the Sertoli cells in the testis to FSH stimulation and hence the Sertoli cells may be the primary site of toxicity as receptors for FSH are specific to these cells in the testis (Mylchreest et al. 1998).
RELEASES TO THE ENVIRONMENT
DBP is a frequent and widespread contaminant, and may be found at low levels in air, water and soil. It is taken up from water by a variety of aquatic organisms, and hence has been found in fish, oysters and clams. It has also been found in eggs (ATSDR,1990).
HUMAN EXPOSURE
In the survey of human adipose tissue undertaken in the US in 1986, 76% of the samples were found to be contaminated with DBP, which provides conclusive evidence that widespread exposure has occurred. Human exposure is likely to occur mostly from contaminated air, and from consumption of contaminated water and food, the latter of which may be due to food chain contamination or from leaching from inks and food packaging.
USES
DBP is used as a plasticiser in PVC and in nitrocellulose polyvinyl acetate. It may be found in vinyl compounds, in carpet backing, in perfume oils, in concrete (additive), and as an insect repellent. Widespread use in flexible plastics means it is found in many consumer products including home furnishings, paints, inks, clothing, and cosmetics (ATSDR, 1990).
References