Intake of phthalates and di(2-ethylhexyl)adipate: results of the Integrated Exposure Assessment Survey based on duplicate diet samples and biomonitoring data

Phthalates are ubiquitous environmental chemicals with potential detrimental health effects. The purpose of our study was to quantify dietary intake of phthalates and of DEHA (Di-ethylhexyl adipate) using duplicate diet samples and to compare these data with the calculated data based on urinary levels of primary and secondary phthalate metabolites. 27 female and 23 male healthy subjects aged 14-60 years collected daily duplicate diet samples over 7 consecutive days. Overall, 11 phthalates were measured in the duplicates by GC/MS and LC/MS methods. Urinary levels of primary and secondary phthalate metabolites are also available. The median (95th percentile) daily intake via food was 2.4 (4.0) microg/kg b.w. (Di-2-ethylhexyl phthalate, DEHP), 0.3 (1.4) microg/kg b.w. (Di-n-butyl phthalate, DnBP), 0.6 (2.1) microg/kg b.w. (Di-isobutyl phthalate, DiBP) and 0.7 (2.2) microg/kg b.w. for DEHA. MEPH (Mono-2-ethylhexyl phthalate) was detectable only in minor concentrations in the samples, thus conversion of DEHP to MEHP and dietary intake of MEHP were negligible. When comparing back-calculated intake data of the DEHP metabolites with dietary DEHP intake from the day before significant correlations were observed for most of the metabolites. No correlation was found for DnBP and only a weak but significant correlation for DiBP. The median and 95th percentile daily dietary intake of all target analytes did not exceed the recommended tolerable daily intake. Our data indicated that food was the predominant intake source of DEHP, whilst other sources considerably contributed to the daily intake of DnBP and DiBP in an adult population.     

Phthalates in German daycare centers: Occurrence in air and dust and the excretion of their metabolites by children (LUPE 3)

Phthalates have been used for decades in large quantities, leading to the ubiquitous exposure of the population.In an investigation of 63 German daycare centers, indoor air and dust samples were analyzed for the presence of 10 phthalate diesters. Moreover, 10 primary and secondary phthalate metabolites were quantified in urine samples from 663 children attending these facilities. In addition, the urine specimens of 150 children were collected after the weekend and before they went to daycare centers.Di-isobutyl phthalate (DiBP), dibutyl phthalate (DnBP), and di-2-ethylhexyl phthalate (DEHP) were found in the indoor air, with median values of 468, 227, and 194 ng/m³, respectively. In the dust, median values of 888 mg/kg for DEHP and 302 mg/kg for di-isononyl phthalate (DiNP) were observed. DnBP and DiBP were together responsible for 55% of the total phthalate concentration in the indoor air, whereas DEHP and DiNP were responsible for 70% and 24% of the total phthalate concentration in the dust.Median concentrations in the urine specimens were 44.7 μg/l for the DiBP monoester, 32.4 μg/l for the DnBP monoester, and 16.5 μg/l and 17.9 μg/l for the two secondary DEHP metabolites. For some phthalates, we observed significant correlations between their concentrations in the indoor air and dust and their corresponding metabolites in the urine specimens using bivariate analyses. In multivariate analyses, the concentrations in dust were not associated with urinary metabolite excretion after controlling for the concentrations in the indoor air.The total daily “high” intake levels based on the 95th percentiles calculated from the biomonitoring data were 14.1 μg/kg b.w. for DiNP and 11.9 μg/kg b.w. for DEHP. Compared with tolerable daily intake (TDI) values, our “high” intake was 62% of the TDI value for DiBP, 49% for DnBP, 24% for DEHP, and 9% for DiNP. For DiBP, the total daily intake exceeded the TDI value for 2.4% of the individuals. Using a cumulative risk-assessment approach for the sum of DEHP, DnBP, and DiBP, 20% of the children had concentrations exceeding the hazard index of one. Therefore, a further reduction of the phthalate exposure of children is needed.     

Phthalates and their metabolites in breast milk--results from the Bavarian Monitoring of Breast Milk (BAMBI)

Phthalates have long been used as plasticizers to soften plastic products and, thus, are ubiquitous in modern life. As part of the Bavarian Monitoring of Breast Milk (BAMBI), we aimed to characterize the exposure of infants to phthalates in Germany. Overall, 15 phthalates, including di-2-ethylhexyl phthalate (DEHP), di-n-butyl phthalate (DnBP), di-isobutyl phthalate (DiBP), di-isononyl phthalate (DiNP), three primary metabolites of DEHP [mono-(2-ethylhexyl) phthalate (MEHP), mono-isobutyl phthalate (MiBP), and mono-n-butyl phthalate (MnBP)], and two secondary metabolites of DEHP were analyzed in 78 breast milk samples. We found median concentrations of 3.9 ng/g for DEHP, 0.8 ng/g for DnBP, and 1.2 ng/g for DiBP, while other parent phthalates were found in only some or none of the samples at levels above the limit of quantitation. In infant formula (n=4) we observed mean values of 19.7 ng/g (DEHP), 3.8 ng/g (DnBP), and 3.6 ng/g (DiBP). For MEHP, MiBP, and MnBP, the median values in breast milk were 2.3 μg/l, 11.8 μg/l, and 2.1 μg/l, respectively. The secondary metabolites were not detected in any samples. Using median and 95th percentile values, we estimated an "average" and "high" daily intake for an exclusively breast-fed infant of 0.6 μg/kg body weight (b.w.) and 2.1 μg/kg b.w., respectively, for DEHP, 0.1 μg/kg b.w. and 0.5 μg/kg b.w. for DnBP, and 0.2 μg/kg b.w. and 0.7 μg/kg b.w. for DiBP. For DiNP, intake values were 3.2 μg/kg b.w. and 6.4 μg/kg b.w., respectively, if all values in milk were set half of the detection limit or the detection limit. The above-mentioned "average" and "high" intake values corresponded to only about 2% to 7%, respectively, of the recommended tolerable daily intake. Thus, it is not likely that an infant's exposure to phthalates from breast milk poses any significant health risk. Nevertheless, other sources of phthalates in this vulnerable phase have to be considered. Moreover, it should be noted that for infants nourished with formula, phthalate intake is of the same magnitude or slightly higher (DEHP) than for exclusively breast-fed infants.     

Transfer of eight phthalates through the milk chain — A case study

This survey determined the levels of eight phthalates – i.e. dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BzBP), di(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-n-octyl phthalate (DnOP) – in several Belgian milk and dairy products. Samples were obtained from various farms, a dairy factory and from different shops in order to investigate phthalate contamination “from farm to fork”. At several stages in the milk chain, product contamination with phthalates – mostly DiBP, DnBP, BzBP and DEHP – was observed. At farm level, the mechanical milking process and the intake of phthalate containing feed by the cattle were found to be possible contamination sources. At industry and retail level, contact materials including packaging materials were additional contamination sources for phthalates in milk and dairy products.     

Phthalates dietary exposure and food sources for Belgian preschool children and adults

Numerous studies have indicated that for phthalates, the intake of contaminated foods is the most important exposure pathway for the general population. Up to now, data on dietary phthalate intake are scarce and – to the authors' knowledge – not available for the Belgian population. Therefore, the purpose of this study was: (1) to assess the long-term intake of the Belgian population for eight phthalates considering different exposure scenarios (benzylbutyl phthalate (BBP); di-n-butyl phthalate (DnBP); dicyclohexyl phthalate (DCHP); di(2-ethylhexyl) phthalate (DEHP); diethyl phthalate (DEP); diisobutyl phthalate (DiBP); dimethyl phthalate (DMP), di-n-octyl phthalate (DnOP)); (2) to evaluate the intake of BBP, DnBP, DEP and DEHP against tolerable daily intake (TDI) values; and (3) to assess the contribution of the different food groups to the phthalate intake. The intake assessment was performed using two Belgian food consumption databases, one with consumption data of preschool children (2.5 to 6.5 years old) and another of adults (≥ 15 years old), combined with a database of phthalate concentrations measured in over 550 food products sold on the Belgian market. Phthalate intake was calculated using the ‘Monte Carlo Risk Assessment’ programme (MCRA 7.0). The intake of DEHP was the highest, followed by DiBP. The intake of BBP, DnBP and DEP was far below the TDI for both children and adults. However, for DEHP, the 99th percentile of the intake distribution of preschoolers in the worst case exposure scenario was equal to 80% of the TDI, respectively. This is not negligible, since other exposure routes of DEHP exist for children as well (e.g. mouthing of toys). Bread was the most important contributor to the DEHP intake and this may deserve further exploration, since the origin of this phthalate in bread remains unclear.     

Development and application of simple pharmacokinetic models to study human exposure to di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP)

In a published controlled dosing experiment, a single individual consumed 5 mg each of labeled di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP) on separate occasions and tracked metabolites in his blood and urine over 48 h. Data from this study were used to structure and calibrate simple pharmacokinetic (PK) models for these two phthalates, which predict urine and blood metabolite concentrations with a given phthalate intake scenario (times and quantities). The calibrated models were applied to a second published experiment in which 5 individuals fasted over the course of a 48-h weekend (bottled water only), and their full urine voids were captured and measured for DnBP and DiBP metabolites. One goal of this model application was to confirm the validity of the calibrated models — their validity would be demonstrated if a profile of intakes could be found which adequately duplicated the metabolite concentrations measured in the urine. A second goal was to study patterns of exposure for this group. It was found that all metabolites could be duplicated very well with individual-specific “best-fit” intake scenarios, with one exception. It appears that the model predicted much lower concentrations of the metabolite, 3carboxy-mono-propylphthalate (MCPP), than were observed in all individuals. Modeled as a metabolite of DnBP, this suggests that DnBP was not the major source of MCPP in the urine. For all 5 individuals, the reconstructed dose profiles of the two phthalates were similar: about 6 small bolus doses per day and an intake of about 0.5 μg/kg-day. The intakes did not appear to be associated with diary-reported activities (personal hygiene and medication) of the participants. The modeled frequent intakes suggested one (or both) of two possibilities: ongoing exposures such as an inhalation exposure, or no exposure but rather an ongoing release of body stores of the phthalate metabolites from past exposures.     

Physico-chemical and toxicological characterization of the historic estuarine sediments: a multidisciplinary approach

The accumulation rates, the geochronology of metals and PAH contamination, and the Microtox toxicity are studied in five sediment cores (50 cm length) covering different areas of the Santander Bay, Northern Spain. Chronology given by (210)Pb and (137)Cs reveals significant differences in accumulation rates between sites (0.2-1.1 cm/year), as well as a variable degree of anthropogenic enrichment factors for Fe, Mn, Cu, Pb, Zn, Ni (from 1 to 15) and concentrations of summation Sigma 16PAHs (from 0.01 to 23.84 mg/kg dw) in sediments over the last 90 years. The results indicate the increasing contamination pressure from industrial and urban activities along the Bay. No toxic results from the Microtox test are obtained either with pore water or with normalised sediment aqueous extracts (European Norm EN 12457), suggesting low water solubility and low availability of contaminants in the studied sediments. However, the EC50 values from the Microtox Basic Solid Phase Test (BSPT) ranged from 0.03% to 2.35%, showing vertical toxicity profiles in accordance with metal and PAHs behaviour. The correlation degrees of Microtox BSPT toxicity to chemical concentration in sediment profiles are widely variable showing a high site-dependent toxicity. The oligochaete Limnodrilus hoffmeisteri has been used as a chronic bioassay over surface sediments of two of the studied sites, showing results coherent with the Microtox BSPT acute test results. Global results of the present work provide regional geochemical baselines for metals and PAHs and toxicological data now make it possible to obtain a preliminary quality assessment of the Santander Bay sediment profiles.     

Exposure assessment issues in epidemiology studies of phthalates

PurposeThe purpose of this paper is to review exposure assessment issues that need to be addressed in designing and interpreting epidemiology studies of phthalates, a class of chemicals commonly used in consumer and personal care products. Specific issues include population trends in exposure, temporal reliability of a urinary metabolite measurement, and how well a single urine sample may represent longer-term exposure. The focus of this review is on seven specific phthalates: diethyl phthalate (DEP); di-n-butyl phthalate (DBP); diisobutyl phthalate (DiBP); butyl benzyl phthalate (BBzP); di(2-ethylhexyl) phthalate (DEHP); diisononyl phthalate (DiNP); and diisodecyl phthalate (DiDP).MethodsComprehensive literature search using multiple search strategies.ResultsSince 2001, declines in population exposure to DEP, BBzP, DBP, and DEHP have been reported in the United States and Germany, but DEHP exposure has increased in China. Although the half-lives of various phthalate metabolites are relatively short (3 to 18 h), the intraclass correlation coefficients (ICCs) for phthalate metabolites, based on spot and first morning urine samples collected over a week to several months, range from weak to moderate, with a tendency toward higher ICCs (greater temporal stability) for metabolites of the shorter-chained (DEP, DBP, DiBP and BBzP, ICCs generally 0.3 to 0.6) compared with those of the longer-chained (DEHP, DiNP, DiDP, ICCs generally 0.1 to 0.3) phthalates. Additional research on optimal approaches to addressing the issue of urine dilution in studies of associations between biomarkers and different type of health effects is needed.ConclusionsIn conclusion, the measurement of urinary metabolite concentrations in urine could serve as a valuable approach to estimating exposure to phthalates in environmental epidemiology studies. Careful consideration of the strengths and limitations of this approach when interpreting study results is required.     

武汉地区湖泊沉积物重金属的分布及潜在生态效应评价

对武汉地区6个湖泊沉积物重金属元素Hg、Cd、Cu、Pb、Zn、As、Cr、Ni的空间分布特征及其潜在生态效应进行研究。调查区的湖泊底泥重金属含量表现出市区内湖泊沉积物的重金属含量普遍高于郊区湖泊,其中墨水湖中重金属含量最高;湖泊沉积物柱重金属元素垂向分布表现为城区受到一定程度污染的湖泊某些元素表现出表层沉积物显著高于底部沉积物含量的特征,而郊区湖泊除Cd外其它元素垂向含量变化不大,说明郊区湖泊受到人为影响较小。利用潜在生态危害指数法对湖泊沉积物进行生态危害评价,显示武汉地区湖泊元素生态危害排序为：Cd>Hg>As>Cu>Pb>Zn;墨水湖沉积物重金属潜在生态危害相对最高,其次是金银湖;其它湖泊重金属生态危害都比较轻,总体而言武汉湖泊重金属生态危害还是较小的。但参照国外沉积物基准的生态数据库阈值,市区受到人为污染较严重的湖泊沉积物可能会对生物产生负面影响。     

Distribution of PBDEs in air particles from an electronic waste recycling site compared with Guangzhou and Hong Kong, South China

Air samples of total suspended particles (TSP, particles less than 30-60 microm), and particles with aerodynamic diameter smaller than 2.5 microm (PM(2.5)) were collected simultaneously at Guiyu (an electronic waste recycling site), three urban sites in Hong Kong and two urban sites in Guangzhou, South China from 16 August to 17 September 2004. Twenty-two PBDE congeners (BDE-3, -7, -15, -17, -28, -49, -71, -47, -66, -77, -100, -119, -99, -85, -126, -154, -153, -138, -156, -184, -183, -191) in TSP and PM(2.5) were measured. The results showed that the overall average concentrations of TSP and PM(2.5) collected at Guiyu were 124 and 62.1 microg m(-3), respectively. The monthly concentrations of the sum of 22 BDE congeners contained in TSP and PM(2.5) at Guiyu were 21.5 and 16.6 ng m(-3), with 74.5 and 84.3%, contributed by nine congeners (BDE-28, -47, -66, -100, -99, -154, -153, -183 and -191 respectively). This pattern was similar to Tsuen Wan site of Hong Kong. Two urban sites of Guangzhou had the same congener pattern, but were different from Yuen Long and Hok Tsui sites of Hong Kong. The results also showed that the amount of mono to penta brominated congeners, which are more toxic, accounted for 79.4-95.6% of Sigma(22)PBDEs from all sites. All congeners tested in Guiyu were up to 58-691 times higher than the other urban sites and more than 100 times higher than other studies reported elsewhere. The higher concentration in the air was due to heating or opening burning of electronic waste since PBDEs are formed when plastics containing brominated flame retardants are heated.     

Personal care product use and urinary levels of phthalate metabolites in Mexican women

Sources of phthalates other than Polyvinyl chloride (PVC) related products are scarcely documented in Mexico. The objective of our study was to explore the association between urinary levels of nine phthalate metabolites and the use of personal care products. Subjects included 108 women who participated as controls in an ongoing population-based case-control study of environmental factors and genetic susceptibility to breast cancer in northern Mexico. Direct interviews were performed to inquire about sociodemographic characteristics, reproductive history, use of personal care products, and diet. Phthalate metabolites measured in urine by high performance liquid chromatography-isotope dilution tandem mass spectrometry were monoethyl phthalate (MEP), monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), mono-3-carboxypropyl phthalate (MCPP) as well as mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP) that are metabolites of di-ethylhexyl phthalate (DEHP). Detectable urinary concentrations of phthalate metabolites varied from 75% (MEHP) to 100% (MEP, MBP, MEOHP, MEHHP and MECPP). Medians of urinary concentrations of some phthalate metabolites were significantly higher among users of the following personal care products compared to nonusers: body lotion (MEHHP, MECPP and sum of DEHP metabolites (ΣDEHP)), deodorant (MEHP and ΣDEHP), perfume (MiBP), anti-aging facial cream (MEP, MBP and MCPP) and bottled water (MCPP, MEHHP and MEOHP). Urinary concentrations of MEP showed a positive relationship with the number of personal care products used. Our results suggest that the use of some personal care products contributes to phthalate body burden that deserves attention due to its potential health impact.     

Phthalate metabolites in urine from China, and implications for human exposures

Phthalates are esters of phthalic acid and are mainly used as plasticizers (added to plastics to increase their flexibility, transparency, durability, and longevity). Humans are exposed to phthalates through several routes. Urinary phthalate metabolites can be used as biomarkers of human exposures to phthalates. In this study, 14 phthalate metabolites were analyzed in 183 urine samples collected in 2010 from Shanghai, Guangzhou, and Qiqihaer, China. Phthalate metabolites were found in all urine samples and their total concentrations ranged from 18.6 to 3160 ng/mL (median: 331 ng/mL). Mono-n-butyl phthalate (mBP) and mono-2-isobutyl phthalate (miBP) were the major metabolites found in urine, and their respective median concentrations were 61.2 and 51.7 ng/mL; concentrations of miBP were higher than the concentrations reported for other countries, to date. Based on the urinary concentrations of phthalate metabolites, we estimated the daily intake rates in the Chinese population. The estimated daily intakes of dibutyl phthalate (DBP), diethyl phthalate (DEP), and di-(2-ethylhexyl) phthalate (DEHP) in China were 12.2, 3.8, and ~5 μg/kg bw/day, respectively. Thirty nine percent of the samples exceeded the tolerable daily intake of 10 μg/kg bw/day, proposed for DBP, by the European Food Safety Authority, but none of the estimated daily intake values exceeded the reference dose recommended by the U.S. Environmental Protection Agency.     

Distribution of pesticides, PAHs and heavy metals in prawn ponds near Kolleru lake wetland, India

This paper discussed the distribution of pesticides, polycyclic aromatic hydrocarbons (PAHs) and heavy metals in water, sediment and prawn from intensive prawn ponds (n=8) near the Kolleru lake wetland, India and assessed the quality of prawn for human consumption and also discussed the possible effects of these pollutants on pond environment and aquatic environment. The chemicals and other products used in prawn ponds near the Kolleru lake wetland were documented. The sediment, prawn and water samples were collected six times from selected prawn ponds during the production period of 3 months. Water samples were analyzed for selected physico-chemical parameters. The levels of pesticides, PAHs and heavy metals were found to decrease in the order sediment followed by prawn and water. The maximum concentrations of pesticides in sediment, prawn and water were alpha-BHC (174.2 microg g(-)(1)), gamma-BHC (234 microg g(-)(1)), malathion (256 microg g(-)(1)), chloripyrifos (198.5 microg g(-)(1)), endosulfan (238 microg g(-)(1)), dieldrin (19.6 microg g(-)(1)) and p,p'-DDT (128.6 microg g(-)(1)). Isodrin was found below detectable limit. The maximum concentrations of PAHs in sediment, prawn and water are anthracene (0.901 microg kg(-)(1)), fluranthene (0.601 microg kg(-)(1)), pyrene (0.786 microg kg(-)(1)), chrysene (0.192 microg kg(-)(1)), benzo(a)pyrene (0.181 microg kg(-)(1)) and benzo(ghi)perylene (227 microg kg(-)(1)). Benzo(e)pyrene, perylene, isomers of dibenzoanthracene and coronene were found below detectable limits. The maximum concentrations of heavy metals in sediment, prawn and water and also in prawn feed are Cu (791 microg g(-)(1)), Pb (270 microg g(-)(1)), Cd (1.07 microg g(-)(1)), Mn (4417 microg g(-)(1)), Ni (8.1 microg g(-)(1)), Co (5.8 microg g(-)(1)), Zn (1076 microg g(-)(1)), Cr (36.4 microg g(-)(1)), As (2.9 microg g(-)(1)), Se (6.3 microg g(-)(1)), Th (2.1 microg g(-)(1)) and Mo (0.762 microg g(-)(1)).     

Accumulation of Chernobyl-derived 137Cs in bottom sediments of some Finnish lakes

The amount and vertical distribution of Chernobyl-derived 137Cs in the bottom sediments of some Finnish lakes were studied. Sediment and surface water samples were taken in 2000 and 2003 from 12 stations in nine lakes and the results were compared with those obtained in corresponding surveys carried out in 1969, 1978, 1988 and 1990. Each of the five deposition categories of Chernobyl fallout in Finland were represented. The depth profiles of 137Cs in the sediments showed considerable variety in the lakes studied. The peak values varied between 1.5 and 46 kBq kg(-1) dry wt. The size and shape of the peak did not always correlate with the amount of deposition in the area, but on the other hand, reflected differences in sedimentation processes in different lakes. In some of the lakes the peak still occurred in the uppermost (0-2 cm) sediment layer, but in an extreme case the peak occurred at a depth of 22-23 cm corresponding to a sedimentation rate of 16 mm year(-1) during the 14 years after the Chernobyl accident. The total amounts of 137Cs in sediments varied from 15 to 170 kBq m(-2) at the sampling stations studied. Since 1990, the amounts have continued to increase slightly in two lakes, but started to decrease in the other lakes. In most of the lakes, the total amounts of 137Cs in sediments were about 1.5-2 times higher than in local deposition. In two lakes, the ratio was below 1, but in one case 3.2. Compared with the total amounts of 137Cs at the same stations in the late 1960s and 1970s, the values were now at their highest, at about 60-fold. The most important factors affecting 137Cs values in sediments were the local amount of deposition and the type of the lake and the sediment, but in addition, there were a number of other factors to be considered.     

Quantitative assessment of the long term behaviour of 90Sr in Lake Uruskul,Southern Urals,Russia

The present paper is aimed at assessing the long term behaviour of 90Sr migration from water to bottom sediments of Lake Uruskul, Southern Urals, Russia. The lake was contaminated following the nuclear accident at the Mayak nuclear complex in 1957 (the Kyshtym accident). Some transfer parameters relevant to the behaviour of 90Sr in the water-sediment system were evaluated: a) the radionuclide migration velocity from the water column to the bottom sediment, b) the radionuclide migration rate from bottom sediment to water, and c) the radionuclide migration rate from bottom sediment to deep sediment. The estimated values of the above parameters were 6.4 x 10(-1) m s(-1), 5.7 x 10(-10) s(-1) and 5.2 x 10(-10) s(-1), respectively. These values were compared with data obtained for some Italian lakes contaminated by 90Sr after the nuclear weapons tests fallout. The relatively low radionuclide migration from water to sediment of these lakes is reflected by the values of the ratio migration velocity/migration rate from sediment to water (4 m and 12 m) that are significantly lower than the corresponding value in the Russian lake (112 m). The peculiar hydrochemical conditions of Lake Uruskul (high pH, high mineralisation, etc.) are considered to be responsible for the high radionuclide migration from water to sediment.     

Inhibition of oocyte development in Japanese medaka (Oryzias latipes) exposed to di-2-ethylhexyl phthalate

Di-2-ethylhexyl phthalate (DEHP) is a widely used plasticizer known to be a suspected endocrine disrupter, but its precise effects on aquatic organisms are not yet known. When Japanese medaka (Oryzias latipes) were exposed from the time of hatching to 3 months of age to an aqueous DEHP solution at nominal concentrations of 1, 10, and 50 microg/l, DEHP-treated female fish showed distinct reproductive effects as follows. First, blood vitellogenin levels in all treated test subjects markedly decreased. Second, Gonado Somatic Index (GSI) decreased to 33% and 38% of the control GSI in 10 microg/l and 50 microg/l treated female fish, respectively. Third, 54% of female fish in the control treatment had completely matured oocytes in their ovaries, but only 37%, 0% and 22% of female fish matured to the last stage in the 1, 10 and 50 microg/l treated test subjects, respectively. Unlike female fish, no change or adverse effects were observed in the male fish. In summary, DEHP hinders the development of reproductive organs in the female Japanese medaka. In this work, the possibility o f anti-estrogenic activity of DEHP is proposed as the cause.     

The internal exposure of Taiwanese to phthalate--an evidence of intensive use of plastic materials

Phthalates are widely used in industry and consumer products. Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butylphthalate (DBP) show the greatest potency of reproductive toxicants among phthalates. The purposes of this study are to examine the migration level of phthalate from PVC films by simulating food handling and to reveal the body burden of phthalate for Taiwanese. In order to estimate a worst-case of phthalate migration, food was covered with polyvinyl chloride (PVC) films and then microwave heated. Results show that DEHP level in food increased significantly after heating for 3 min. Under the heating condition, the calculated intake of phthalate and the percentage of the tolerable daily intake (TDI, based on body weight of 60 kg) from eating one 400-g meal were 1705.6 microg and 92.2% for DEHP. Determination of urinary metabolites from 60 subjects reveals more than 90% of samples were detectable for mono-methyl phthalate (MMP), mono-butyl phthalate (MBP) and mono-ethylhexyl phthalate (MEHP). Notably, the median value of estimated daily intake of DEHP had reached 91.6% of TDI established by the European Union Scientific Committee for Toxicity, Ecotoxicity and the Environment (CSTEE) (1998). Thirty-seven percent of the study population exceeded the TDI and 85% exceeded the reference dose (RfD) of the US EPA. We conclude that the body burden of DEHP for Taiwanese reflects the intensives use of plastic materials in the region. The regulation of PVC for food preparation is necessary.     

Metallic and organic contaminants in sediments of Sydney Harbour, Australia and vicinity-- a chemical dataset for evaluating sediment quality guidelines

An internally consistent dataset comprising 103 surficial estuarine sediment samples were collected from Sydney Harbour, Australia and locations south of Sydney. This paper describes the chemical characteristics of the dataset and evaluates its suitability for use in evaluating biological effects-based sediment quality guidelines (SQGs). The sediments contained mixtures of chemicals, the most prevalent chemical classes being metals and polycyclic aromatic hydrocarbons, whereas sediments from coastal lakes/estuaries south of Sydney had low concentrations of contaminants. Maximum concentrations of the prevalent contaminants zinc, lead, copper and pyrene were 11,300, 1,420, 1,060 mg kg(-1) and 23,300 microg kg(-1), respectively. For the majority of samples, concentrations of individual chemicals exceeded most effects-based SQGs that have been adopted for use in Australia, implying occasional or frequent adverse biological effects are expected. Comparing mixtures of contaminants to ranges in numbers of SQGs exceeded and mean SQG quotients showed that most samples (57% to 68%) had contamination characteristics associated with moderate probabilities (30% to 52%) of acute toxicity, based on North American data. A smaller proportion of samples (15% to 17%) had contamination characteristics associated with high probabilities (74% to 85%) of toxicity. The wide range of chemicals and concentrations, associated with low, medium and high probabilities of toxicity, indicated that the dataset was suitable for future use in evaluating predictive abilities of SQGs. This is relevant, given the recent introduction of North American-derived SQGs for Australia.     

Natural and synthetic endocrine disrupting compounds (EDCs) in water, sediment and biota of a coastal lagoon

We report a survey on the occurrence and distribution of natural (17beta-estradiol, E2; estrone, E1) and synthetic (nonylphenol, NP; nonylphenol monoethoxylate carboxylate, NP1EC; bisphenol-A, BPA; benzophenone, BP; mestranol, MES; 17alpha-ethinylestradiol, EE2; diethylstilbestrol, DES) endocrine disrupting compounds (EDCs) in water, sediment and biota (Mediterranean mussel, Mytilus galloprovincialis) in the Venice lagoon, a highly urbanized coastal water ecosystem that receives both industrial and municipal wastewater effluents. The survey was preceded by the development of tailor made extraction and clean-up procedures for the simultaneous HPLC-ESI-MS determination of all examined EDCs in sediment and biota samples. Satisfactory extraction performances and method detection limits (MDLs) were obtained for almost all EDCs. Most of the selected compounds were found in water and sediment (concentration range: 2.8-211 ng/L, and 3.1-289 microg/kg, d.w., respectively), while only 17alpha-ethinylestradiol and nonylphenol were recorded in biota samples (conc. range: 7.2-240 ng/g, d.w.). 17beta-estradiol and ethinylestradiol contributed mostly to the water estradiol equivalent concentration (EEQ) (1.1-191 ng/L, average: 25 ng/L), while synthetic EDCs (17alpha-ethinylestradiol, diethylstilbestrol) were mainly responsible of the sediment EEQ (1.1-191 microg/kg, average: 71 microg/kg, d.w.). Whenever diethylstilbestrol was not recorded in the sediment, water EEQs were similar to sediment EEQs. A remarkable increase of nonylphenol was observed in sediments over the last decade.     

Inventories of Pu, Cs, and excess Pb in sediments from freshwater and brackish lakes in Rokkasho, Japan, adjacent to a spent nuclear fuel reprocessing plant

We investigated the vertical profiles of ^239+240Pu, ¹³⁷Cs, and excess ²¹⁰Pb (²¹⁰Pb_ex) in sediment core samples obtained from two freshwater lakes and two brackish lakes situated near the first commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan, before the final test of the plant using actual spent nuclear fuel. The inventory of ^239+240Pu in those lakes was larger than that in soil in Rokkasho, which indicated the inflow of ^239+240Pu from the catchment area in addition to direct deposition on the lake surfaces. The ¹³⁷Cs inventory in sediments of the brackish lakes was lower than that in the soil, which showed that part of the ¹³⁷Cs was removed from the sediments by the brackish water or that it was not deposited into the sediments, because of the high solubility of Cs in brackish water. The ¹³⁷Cs inventory in sediments of the freshwater lakes was higher than that of the brackish lakes, and comparable with that in soil except for one core sample out of four. The ^239+240Pu/¹³⁷Cs ratio in freshwater lake sediments was higher than that in soil, and that indicated that part of the ¹³⁷Cs was lost from the sediments. The low inventory of ¹³⁷Cs may be attributable to competition for absorption sites in sediments with ammonium ions formed in the reducing environment which occurs from summer to fall in the sediments. Those data will be used as background data on the artificial radionuclides in the lakes to assess the effect of released radionuclides on their concentrations.