Concentrations Of Methyl Paraben Research Articles

Tissue-Specific Accumulation and Body Burden of Parabens and Their Metabolites in Small Cetaceans.

Parabens have been of global concern due to their endocrine disrupting properties. However, few studies have reported tissue-specific distribution of parabens in wildlife. In this study, we measured parabens and their metabolites in organs and tissues (blubber, muscle, melon, stomach, kidney, liver, gonad, brain, uterus, and umbilical cord, total n = 94) of common dolphins ( Delphinus capensis) and finless porpoises ( Neophocaena asiaeorientalis), to investigate tissue-specific accumulation and body burden. Among the target compounds, methyl paraben (MeP) and para-hydroxybenzoic acid (4-HB) were detected in all organs. Compared to common dolphins, finless porpoises had significantly higher concentrations of MeP and 4-HB due to their near-shore habitat. Higher concentrations of MeP and 4-HB were found in the kidney, liver, and stomach than in other organs, indicating selective accumulation of parabens in certain organs. Significant correlations between MeP and 4-HB in liver/kidney suggested metabolic transformation of the former to the latter. Detection of parabens in brains, umbilical cords, and uteri suggests that these chemicals cross biological barriers such as the blood-brain and placental barriers. The body burdens of total parabens were in the ranges of 13000-90600 μg and 19800-81500 μg for common dolphins and finless porpoises, respectively.

Transient exposure of methylparaben to zebrafish (Danio rerio) embryos altered cortisol level, acetylcholinesterase activity and induced anxiety-like behaviour

Parabens are widely used as antimicrobial preservatives. Recent studies have reported the endocrine disrupting effects of these chemicals, especially methylparaben. Previously, we have reported the alteration in Vtg gene expression upon exposure to environmentally relevant doses of methylparaben in zebrafish (Danio rerio) embryos. However, studies reporting neurobehavioural outcomes on exposure to methylparaben are limited. Therefore, this study was aimed at investigating the methylparaben-induced effects on developmental and neurobehavioural endpoints. Zebrafish embryos were exposed to sub-lethal concentrations of methylparaben: 0.1 ppb, 1 ppb, 10 ppb and 100 ppb. Alterations in developmental landmarks such as heart rate and hatching percentage were observed in embryos exposed to 10 ppb and 100 ppb of methylparaben. Results obtained from the novel tank diving test established that anxiety-like behaviour is induced in larvae exposed to 0.1 ppb and 1 ppb of methylparaben. A significant inhibition in the acetylcholinesterase (AChE) activity was also recorded in methylparaben-exposed groups. An increase in cortisol levels was observed in the exposed groups, which further supports the observations made in the novel tank diving test, establishing methylparaben as an anxiogenic agent even at sub-lethal concentrations. The underlying molecular mechanism needs further elucidation to investigate whether the behavioural effects are proximally or distally induced by early developmental exposure to methylparaben.

Aqueous methylparaben degradation by dielectric barrier discharge induced non-thermal plasma combined with ZnO-rGO nanosheets

The feasibility of methylparaben (MeP) degradation in aqueous solution by dielectric barrier discharge induced non-thermal plasma combined with zinc oxide-reduced graphene oxide (ZnO-rGO) nanosheets was investigated. The ZnO-rGO nanosheets were synthesized by hydrothermal method and characterized by X-ray diffraction, nitrogen adsorption-desorption isotherm, scanning electron microscope, transmission electron microscope, UV–vis absorption spectroscopy, photocurrent, photoluminescence spectroscopy and X-ray photoelectron spectroscopy. The effects of various factors (discharge power, initial concentration of MeP, initial pH value and air flow rate) on the degradation of MeP were evaluated and the changes of solution pH, conductivity and TOC during the degradation process were discussed. The results showed that when the discharge power was 20 W, the airflow rate was 20 L/h, the ZnO-rGO nanosheets dosage was 0.015 g/L, the initial concentration of MeP was 20 mg/L, and the initial pH value was 7.0, the degradation efficiency of MeP achieved 99% at 15 min. The adding of ZnO-rGO nanosheets to the non-thermal plasma system greatly enhanced the degradation efficiency of MeP. In addition, the role of some reactive species during the degradation process of MeP was also investigated. The degradation process of MeP was well fitted by the pseudo-first-order kinetics. Good stability of the synthetic ZnO-rGO was observed. The degradation intermediates of MeP were determined by gas chromatography-mass spectrometer and the degradation pathways were proposed. Under the attack of reactive species, conjugated structure destruction, hydroxylation, carboxylation and ring-opening reaction occurred during MeP degradation, resulting in the formation of organic acids and alcohols; furthermore, some of the degradation intermediates were mineralized to H2O and CO2.

Estimation of the soil hazardous concentration of methylparaben using a species sensitivity approach

Methylparaben, which is known to be an endocrine-disrupting chemical, is added to various personal care products, including cosmetics, and is also used as a food preservative and in pharmaceuticals. However, information on the toxicity of methylparaben in soil ecosystems is limited. Furthermore, unlike other substances such as metals and pesticides, there is no regulation of levels or safe concentrations of methylparaben in soil ecosystems. Therefore, the aims of this study were to evaluate the toxicity of methylparaben on soil species and to derive hazardous concentration (HC) values with respect soil ecosystem protection. We conducted acute bioassays on eight species within six taxonomic groups and chronic bioassays on five species within four taxonomic groups. On the basis of the results obtained, we derived an acute HC5 value of 44 mg/kg soil and a corresponding chronic value of 27 mg/kg soil for methylparaben using species sensitivity distribution methodology following Australian and New Zealand guidelines. Given that there has been no proposed standard value for methylparaben in soil in any country, it was not possible to compare the HC values calculated in this study with regulation standard levels. Nevertheless, to our knowledge, this study is first to assess the toxicity of methylparaben against soil-inhabiting species and to estimate acute and chronic HCs for soil fauna and flora. The results of this study will provide valuable fundamental data for the establishment of acceptable levels of methylparaben in soil.

Efficient remove methylparaben by ozonation process

This study aimed to analyze the factors affecting the degradation of methylparaben solution by ozonation process. Kinetic studies on methylparaben degradation were carried out under different operating conditions, such as ozone concentration, initial pH values of the solution, methylparaben concentration and temperature. Complete degradation was achieved after 15 min of reaction using the methylparaben concentration of 30 mg L−1 at pH 9, 30 mg L−1 dosages of ozone and 20 °C. Methylparaben degradation by ozonation followed the pseudo-first-order kinetic model. The rate of methylparaben degradation increased when increasing pH from 3 to 9 and with the increased concentration of ozone applied. For the best condition, the model predicted an apparent reaction rate constant equal to 0.21 min−1. In addition to the application of the ozonation, ozone-combined processes were studied under the optimal conditions obtained for ozonation. The tested processes were ozonolysis and heterogeneous photocatalytic ozonation. The most efficient method for the degradation and mineralization was photocatalytic ozonation, reaching mineralization rates higher than 93% in 90 min of reaction. Furthermore, in vivo tests using methylparaben solutions previously treated by ozonation and photocatalytic ozonation confirmed there was no toxicity.

Preconception and prenatal urinary concentrations of phenols and birth size of singleton infants born to mothers and fathers from the Environment and Reproductive Health (EARTH) study

BackgroundAlthough pregnancy concentrations of some phenols have been associated with infant size at birth, there is limited data on the effect of preconception exposure. ObjectiveWe aimed to examine paternal and maternal preconception and maternal prenatal urinary phenol concentrations in relation to birth weight and head circumference. MethodsWe evaluated 346 singletons born to 346 mothers and 184 fathers (184 couples) from a prospective preconception cohort of subfertile couples from the Environment and Reproductive Health (EARTH) Study in Boston, USA. We used multiple urine samples collected before the index pregnancy in both men and women to estimate mean preconception urinary benzophenone-3, triclosan, butylparaben, propylparaben, methylparaben, or ethylparaben concentrations. We also estimated mean maternal prenatal urinary phenol concentrations by averaging trimester-specific urine samples. Birth weight and head circumference were abstracted from delivery records. We estimated the association of natural log-phenol concentrations with birth outcomes using multivariable linear regression models, adjusting for known confounders. ResultsIn adjusted models, each log-unit increase in paternal preconception benzophenone-3 concentration was associated with a 137 g increase in birth weight (95% CI: 60, 214). Additional adjustment for prenatal benzophenone-3 concentration strengthened this association. None of the maternal preconception phenol concentrations were associated with birth weight. However, maternal prenatal triclosan concentrations were associated with a 38 g decrease in birth weight (95% CI: −76, 0). Few associations were observed between phenols and head circumference except for a decrease of 0.27 cm (95% CI: −54, 0) in relation to maternal preconception methylparaben concentration. ConclusionsAlthough our findings should be interpreted in light of inherent study limitations, these results suggest potential evidence of associations between some paternal or maternal phenol concentrations and birth size.

Personal care product use as a predictor of urinary concentrations of certain phthalates, parabens, and phenols in the HERMOSA study.

Use of personal care products, such as makeup, soaps, and sunscreen, may expose adolescent girls to potential endocrine disruptors, including phthalates, parabens, and other phenols. We evaluated the relationship between recent self-reported personal care product use and concentrations for urinary metabolites of phthalates, parabens, triclosan, and benzophenone-3 (BP-3) in 100 Latina adolescents. Girls who reported using makeup every day vs. rarely/never had higher urinary concentrations of monoethyl phthalate (MEP) (102.2 ng/mL vs. 52.4 ng/mL, P-value: 0.04), methyl paraben (MP) (120.5 ng/mL vs. 13.4 ng/mL, P-value < 0.01), and propyl paraben (PP) (60.4 ng/mL vs. 2.9 ng/mL, P-value < 0.01). Girls who reported recent use of specific makeup products, including foundation, blush, and mascara, had higher urinary concentrations of MEP, mono-n-butyl phthalate (MBP), MP, and PP. Use of Colgate Total toothpaste was associated with 86.7% higher urinary triclosan concentrations. Use of sunscreen was associated with 57.8% higher urinary concentrations of BP-3. Our findings suggest that personal care product use is associated with higher exposure to certain phthalates, parabens, and other phenols in urine. This may be especially relevant in adolescent girls who have high use of personal care products during a period of important reproductive development.

A global framework to model spatial ecosystems exposure to home and personal care chemicals in Asia

This paper analyzes spatially ecosystem exposure to home and personal care (HPC) chemicals, accounting for market data and environmental processes in hydrological water networks, including multi-media fate and transport. We present a global modeling framework built on ScenAT (spatial scenarios of emission), SimpleTreat (sludge treatment plants), and Pangea (spatial multi-scale multimedia fate and transport of chemicals), that we apply across Asia to four chemicals selected to cover a variety of applications, volumes of production and emission, and physico-chemical and environmental fate properties: the anionic surfactant linear alkylbenzene sulphonate (LAS), the antimicrobial triclosan (TCS), the personal care preservative methyl paraben (MeP), and the emollient decamethylcyclopentasiloxane (D5). We present maps of predicted environmental concentrations (PECs) and compare them with monitored values. LAS emission levels and PECs are two to three orders of magnitude greater than for other substances, yet the literature about monitored levels of LAS in Asia is very limited. We observe a good agreement for TCS in freshwater (Pearson r=0.82, for 253 monitored values covering 12 streams), a moderate agreement in general, and a significant model underestimation for MeP in sediments. While most differences could be explained by uncertainty in both chemical/hydrological parameters (DT50water, DT50sediments, Koc, foc, TSS) and monitoring sites (e.g. spatial/temporal design), the underestimation of MeP concentrations in sediments may involve potential natural sources. We illustrate the relevance of local evaluations for short-lived substances in fresh water (LAS, MeP), and their inadequacy for substances with longer half-lives (TCS, D5). This framework constitutes a milestone towards higher tier exposure modeling approaches for identifying areas of higher chemical concentration, and linking large-scale fate modeling with (sub) catchment-scale ecological scenarios; a major limitation in model accuracy comes from the discrepancy between streams routed on a gridded, 0.5°×0.5° global hydrological network and actual locations of streams and monitoring sites.

Determination of Serum Methylparaben Concentrations of Bangladeshi Breast Cancer Patients by RP-HPLC

Breast cancer is one of the two major cancers of females. The mortality rate for breast cancer is significantly high in Bangladesh (about 15.4% among the female cancer patients). There are many possible reasons for breast cancer, among those, the environmental estrogen is considered as one of the potential factors. Parabens, which are widely used as antimicrobial preservatives in cosmetics, pharmaceuticals, food and beverage processing; has a tendency to act as environmental estrogens. In the present study we have estimated and compared the serum methylparaben concentration for control and breast cancer patients (stage III + IV). The serum concentration of methylparaben was determined by using reverse phase high performance liquid chromatography (RP-HPLC). The number of participants for this study was 45 and they were divided into two main groups named as the control group which consisted of 22 healthy females and the case group consisted of 23 breast cancer patients. The results of HPLC data demonstrated there is no existence of methylparaben in the control samples. There was only one sample from breast cancer patients, which had been found to contain traces of methylparaben. Though we are exposed to methylparaben extensively, very limited evidence has been found towards its relationship with breast cancer.

Furosemide ethanol-free oral solutions for paediatric use: formulation, HPLC method and stability study

BackgroundOral liquid solutions of the diuretic active ingredient furosemide (FUR) marketed across Europe do not comply with recent requirements for paediatric preparation owing to their ethanol content and, moreover, in...

Determination of Six Paraben Residues in Fresh-cut Vegetables Using QuEChERS with Multi-walled Carbon Nanotubes and High-Performance Liquid Chromatography–Tandem Mass Spectrometry

In this study, an optimized QuEChERS sample preparation method was developed to analyze residues of six parabens: methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, and isobutylparaben in five fresh-cut vegetables (potato, broccoli, carrot, celery, and cabbage) with high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Homogenized samples were extracted using acetonitrile, and the extracts were cleaned with the novel sorbent multi-walled carbon nanotubes (MWCNTs). MWCNTs provided 84–94% removal of chlorophyll and lower matrix effects (MEs) compared to commonly used primary-secondary-amine (PSA) sorbent. Selected parabens were separated by HPLC with isocratic elution using acetonitrile and 0.1% (v/v) formic acid solution and determined by triple quadrupole MS/MS. The method validation results showed that recoveries were at 70–120% with RSDs 0.99. Fifty fresh-cut vegetable samples from different farmer markets in Beijing, China were collected to measure the paraben residues, and only one sample was tested positive with methylparaben concentration at 81 μg/kg.

A comparative approach of methylparaben photocatalytic degradation assisted by UV-C, UV-A and Vis radiations

ABSTRACTDue to the widespread use of methylparaben (MEP) and its high chemical stability, it can be found in wastewater treatment plants and can act as an endocrine disrupting compound. In this study, the photocatalytic degradation and mineralization of MEP solutions were evaluated under UV-A, UV-C and Vis radiations in the presence of the photocatalyst TiO2. In this sense, the effects of the catalyst load, pH and MEP initial concentration were studied. Remarkably higher reaction rates and total photodegradation were achieved in systems assisted by UV-C radiation. The complete degradation was achieved after 60 min of reaction using the MEP concentration of 30 mg L−1 at pH 9 and 500 mg L−1 TiO2. The experimental data apparently followed a Langmuir-Hinshelwood kinetic model, which could predict 88–98% of the reaction behavior. For the best photodegradation condition, the model predicted an apparent reaction rate constant (kapp) equal to 0.0505 min−1 and an initial reaction rate of 1.5641 mg (L min)−1. Mineralization analyses showed high removal for MEP and derived compounds from the initial solution when using UV-C after 90 min of reaction. The lower toxicity was also confirmed by in vivo tests using MEP solutions previously treated by photocatalysis.

Exposure to phenols, parabens and UV filters: Associations with loss-of-function mutations in the filaggrin gene in men from the general population

BackgroundFilaggrin is an epidermal protein that is important for normal skin barrier functions. Up to 10% of Europeans and Asians carry filaggrin gene (FLG) loss-of function mutations that appear to facilitate trans-epidermal penetration of certain chemicals. We previously showed that mutation carriers have higher internal exposure to certain phthalates, compared to controls, and hypothesized that they could have increased trans-epidermal penetration of other chemicals. ObjectivesWe investigated exposure to non-persistent chemicals in young Danish men with and without FLG mutations. MethodsConcentrations of eight simple phenols, six parabens and nine UV filters were analysed in urine from 65 FLG loss-of-function mutation carriers and 130 non-carriers (controls). Regression analyses, controlling for urinary dilution and confounders, were performed to estimate associations between FLG mutation status and chemical concentrations in urine. ResultsFLG mutation carriers had 80% (13–180%) higher urinary concentrations of methyl paraben (MeP) and 91% (13–219%) higher concentrations of n-propyl paraben (n-PrP) than controls. For 13 compounds, levels were higher in FLG mutation carriers, although differences were only statistically significant for MeP and n-PrP. Combined statistical analysis of concentrations of all the 18 compounds that were detectable in >10% of subjects, suggested that concentrations were generally higher in mutation carriers (p=0.03). ConclusionFLG loss-of-function mutation carriers have a higher internal exposure to some non-persistent chemicals, independently of atopic dermatitis. This may be due to increased trans-epidermal absorption and/or higher exposure, and mutation carriers may constitute a group susceptible to increased absorption of chemicals and topical medication.

Histopathological evaluation of the Zebrafish (Danio rerio) testis following exposure to methyl paraben

Methyl paraben (MP) is widely used as a preservative in various products. It frequently enters into aquatic environment and renders potential threat to fish. The aim of this study was to evaluate reproductive toxicity of MP on zebrafish ( Danio rerio ) under laboratory conditions. Male zebrafish were exposed to four concentrations of MP (0.001, 0.01, 1, and 10 mg L -1 ) for 21 days in semi-static condition. Changes in mean length, mean weight, gonadosomatic index (GSI) and histology of testis were studied. Treatment at 0.001 to 10 mg L -1 MP had no significant effect on the survival, mean length and mean weight of fish. But, GSI decreased in a dose dependent manner and the decrease was significant in the group that received the highest dose. Histological alteration of testis consisted of general testicular atrophy, multi-nucleated gonocytes (MNGs), impaired germ cell, spermatogonial proliferation, Leydig cell hyperplasia, interstitial fibrosis and apoptosis of Sertoli cells. It was concluded that sub-chronic exposures of MP could adversely affect GSI, disrupt the histology of testis and produce estrogenic and antispermatogenic activity in male zebra fish.

Aqueous phase degradation of methyl paraben using UV-activated persulfate method

Methyl paraben (MP), a widely used preservative, exhibits endocrine-disrupting properties with estrogenic activities. The aqueous phase degradation of MP, using UV-activated persulfate method, was investigated in the present study. The combination of UV irradiation and persulfate anion successfully degraded MP showing 98.9% removal within 90min. A quenching experiment using ethanol (EtOH) and tert-butyl alcohol (TBA) showed the presence of both radicals (OH and SO4–) in the system; near neutral pH SO4– radical was the major species. The influence of various factors such as persulfate dose, initial MP concentration, solution pH, and water matrix components on the degradation kinetics was examined in view of the practical applications of the developed process. The degradation rate of MP was considerably increased as the amount of persulfate increased. The degradation of MP in the UV/persulfate system was pH dependent and more promising near neutral pH (6.5) conditions. The presence of anions such as Cl−, HPO42− and HCO3− showed inhibitory effect towards MP degradation. The presence of humic acid also suppressed the degradation efficiency of MP. The reaction rate followed pseudo-first-order kinetics for all of the degradations. The degradation of MP by UV/persulfate treatment led to the production of seven transformation byproducts, which were identified using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS). A degradation pathway for MP degradation was also proposed. The results of the present study reveal that the UV/persulfate process could be an effective approach to remove MP from aqueous solutions.

Developmental toxicity and induction of vitellogenin in embryo-larval stages of zebrafish (Danio rerio) exposed to methyl Paraben

MethylParaben (MP), a methyl ester of p-hydroxybenzoic acid, is used as an anti-microbial preservative in foods, drugs and cosmetics for decades. It enters the aquatic environment, and can have toxic effects on aquatic organisms. Little is known on the developmental toxicity of MP exposure to zebrafish during early life stages. In this study, the developmental effects of MP were evaluated in embryo-larval zebrafish (at concentrations ranging from 100μM, 200μM, 400µM, 800μM and 1000μM for 96h post fertilization (hpf). The survival, hatching, heart beat rate and developmental abnormalities were observed in the embryos exposed to MP. MP exposure resulted in decreased heart rate and hatching rate. Defects including pericardial edema blood cell accumulation and bent spine were observed in all the treated concentration, except at 100μM. With increasing concentrations, the frequency of these defects increased. The 96 hpf LC50 of MP was calculated to be 428μM (0.065mg/L). Furthermore, RT-PCR result showed that in larval zebrafish exposed to 100μM (0.015mg/L) of MP till 96 hpf, expression of vitellogenin I (Vtg -I) was significantly upregulated compared to the control group. This data suggest that even though lower concentrations of MP do not cause phenotypic malformations, it leads to dysregulated expression of estrogenic biomarker gene Vtg-I.

Maternal urinary paraben levels and offspring size at birth from a Chinese birth cohort

BackgroundParabens are suspected to impair fetal growth because of their endocrine disrupting effects. Epidemiological studies regarding the effects of prenatal exposure to parabens on birth outcomes are limited. ObjectivesOur aim was to evaluate the association between prenatal paraben exposure and size of infants at birth. MethodsWithin the longitudinal Healthy Baby Cohort (HBC) in Hubei Province, China, we randomly selected 1006 mother-infant pairs recruited in Wuhan City in 2014. Concentrations of parabens were measured in maternal urine collected before delivery. General linear models were used to analyze the associations of maternal parabens exposure levels with birth weight and birth length. ResultsThe specific gravity adjusted geometric means for urinary concentrations of methyl paraben (MeP), ethyl paraben (EtP), and propyl paraben (PrP) were 5.41, 0.11, and 0.94 ng/mL, respectively. Maternal urinary concentrations of parabens tended to be positively associated with birth weight in boys, while opposite trends were found in girls, though these associations were not significant. Higher maternal urinary levels of MeP were positively associated with birth length in boys (β = 0.30, 95% CI: 0.01, 0.58 for the medium tertile, and β = 0.30, 95% CI: 0.01, 0.58 for the highest tertile compared to the lowest tertile); however, no significant associations with birth length were observed in girls. ConclusionsMaternal urinary levels of MeP were positively associated with length at birth in boys. Besides, we did not find strong associations of the current exposure levels of parabens in Chinese pregnant women with size of infants at birth.

Removal of methylparaben from synthetic aqueous solutions using polyacrylonitrile beads: kinetic and equilibrium studies.

The removal of methylparaben (MP), a well-known endocrine disruptor, from aqueous solutions using polyacrylonitrile (PAN) beads has been studied under batch conditions, at room temperature and at different initial MP concentrations. The kinetic and equilibrium results have been analyzed. Kinetic modeling analysis has been carried out with three different types of adsorption models: pseudo-first-order, pseudo-second-order, and Elovich model. Kinetic data analysis indicated that the adsorption was a second-order process. The MP adsorption by PAN was also quantitatively evaluated by using the equilibrium adsorption isotherm models of Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin and the applicability of the respective isotherm equations has been compared through the correlation coefficients. Adsorption data resulted well fitted by the Freundlich isotherm model. Data of MP adsorption have also been used to test different adsorption diffusion models. The diffusion rate equations inside particulate of Dumwald-Wagner and the intraparticle diffusion model have been used to calculate the diffusion rate. The actual rate-controlling step involved in the MB adsorption process was determined. The kinetic expression by Boyd gave the right indications. All together, our results indicate that PAN beads are a useful tool to remediate water bodies polluted by endocrine disruptors.

A survey of parabens in commercial pharmaceuticals from China and its implications for human exposure

Parabens are widely used as antimicrobial preservatives during pharmaceutical production. However, little information is available regarding the occurrence of parabens in commercial pharmaceuticals and their implications for human exposure. In this study, six commonly used parabens were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry with 100 commercial pharmaceuticals collected from China. Almost all of the pharmaceutical samples contained at least one kind of parabens with the detection frequency of 97%. The concentrations of Σ6parabens (sum of the six parabens) ranged from below MDL to 1256ng/g, with mean and median values of 94.8 and 119ng/g, respectively. Methyl paraben (MeP), ethyl paraben (EtP) and propyl paraben (PrP) were the predominant compounds. Significant positive correlation was observed between concentrations of MeP and PrP, indicating their co-applications in pharmaceuticals. Levels of Σ6parabens varied in different categories of pharmaceuticals and increased with their shelf lives. Based on the measured concentrations and daily ingestion rates of pharmaceuticals, the estimated daily intake (EDI) of parabens was calculated. The median values of EDIpharmaceutical for male adults, female adults and children were 4.05, 4.75 and 9.73ng/kg-bw/day, respectively, which were three orders of magnitude lower than those from foodstuffs and personal care products (PCPs). It was firstly reported that the total exposure dose was 0.326mg/kg-bw/day via foodstuffs, PCPs, and pharmaceuticals for Chinese female adults.

Accumulation profiles of parabens and their metabolites in fish, black bear, and birds, including bald eagles and albatrosses

Although several studies have reported the ubiquitous occurrence of parabens in human specimens and the environment, little is known about the accumulation of these estrogenic chemicals in fish and birds. In this study, accumulation profiles of six parabens and their metabolites were determined in 254 tissue (including liver, kidney, egg, and plasma) samples from 12 species of fish and seven species of birds collected from inland, coastal, and remote aquatic ecosystems. In addition, liver and kidney tissues from black bears were analyzed. Methyl paraben (MeP) was found in a majority of the tissues, with the highest concentration (796ng/g (wet weight [wet wt])) found in the liver of a bald eagle from Michigan. 4-Hydroxy benzoate (HB) was the major metabolite, found in 91% of the tissue samples analyzed at concentrations as high as 68,600ng/g, wet wt, which was found in the liver of a white-tailed sea eagle from the Baltic Sea coast. The accumulation pattern of MeP and 4-HB varied, depending on the species. The mean concentrations of MeP measured in fishes from Michigan, New York, and Florida waters were <2.01 (fillet), 152 (liver), and 32.0 (liver) ng/g, wet wt, respectively, and the corresponding 4-HB concentrations were 39.5, 10,500, and 642ng/g, wet wt. The mean hepatic and renal concentrations of 4-HB in black bears were 1,720 and 1,330ng/g, wet wt, respectively. The concentrations of MeP and 4-HB were significantly positively correlated with each other in various tissues and species, which suggested a common source of exposure to these compounds in fish and birds. Trace concentrations of MeP and 4-HB also were found in the tissues of albatrosses from Midway Atoll, Northwestern Pacific Ocean, which suggested widespread distribution of these compounds in the marine environment.