Alexandros G. Asimakopoulos

Widespread occurrence of bisphenol A diglycidyl ethers, p-hydroxybenzoic acid esters (parabens), benzophenone type-UV filters, triclosan, and triclocarban in human urine from Athens, Greece.

Biomonitoring of human exposure to bisphenol A diglycidyl ethers (BADGEs; resin coating for food cans), p-hydroxybenzoic acid esters (parabens; preservatives), benzophenone-type UV filters (BP-UV filters; sunscreen agents), triclosan (TCS; antimicrobials), and triclocarban (TCC; antimicrobials) has been investigated in western European countries and North America. Nevertheless, little is known about the exposure of Greek populations to these environmental chemicals. In this study, 100 urine samples collected from Athens, Greece, were analyzed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the determination of total concentrations of five derivatives of BADGEs, six parabens and their metabolite (ethyl-protocatechuate), five derivatives of BP-UV filters, TCS, and TCC. Urinary concentrations of BADGEs, parabens, ethyl-protocatechuate, BP-UV filters, TCS and TCC (on a volume basis) ranged 0.3-20.9 (geometric mean: 0.9), 1.6-1010 (24.2), <2-71.0 (2.1), 0.5-1120 (4.4), <0.5-2580 (8.0) and <0.5-1.9 (0.6) ng/mL, respectively. All 19 target chemicals were found in urine, and the highest detection rates were observed for methyl paraben (100%), bisphenol A bis (2,3-dihydroxypropyl) ether (90%), ethyl paraben (87%), 2,4-dihydroxybenzophenone (78%), propyl paraben (72%), and TCS (71%). Estimated daily intakes (EDIurine), calculated on the basis of the measured urinary concentrations, ranged from 0.023 μg/kg bw/day for Σ5BADGEs to 31.4 μg/kg bw/day for Σ6Parabens.

Contribution of primary and secondary treatment on the removal of benzothiazoles, benzotriazoles, endocrine disruptors, pharmaceuticals and perfluorinated compounds in a sewage treatment plant

The occurrence and fate of 36 emerging contaminants, belonging to five different classes, (benzotriazoles, BTRs; benzothiazoles, BTHs; perfluorinated compounds, PFCs; non-steroidal anti-inflammatory drugs, NSAIDs and endocrine disruptors, EDCs) were investigated in raw, treated wastewater (both particulate and dissolved phases), and in sludge from a sewage treatment plant (STP) in Athens, Greece. The average concentrations of BTRs, BTHs, NSAIDs and EDCs in raw wastewater ranged between 11 ng L(-1) and 7.27 μg L(-1), while PFCs did not exceed 100 ng L(-1). In dewatered sludge, the average concentrations ranged between 0.8 ng g(-1) dw (perfluorohexanoic acid, PFHxA) and 3895 ng g(-1) dw (nonylphenol, NP). The distribution of emerging contaminants between particulate and dissolved phase was different among the compounds. BTRs and BTHs showed lower solid-liquid distribution coefficients (Kd) than all other compounds. For 9 over the 27 compounds detected in influents, the removal efficiency was higher than 70%, while the others either were removed to a lesser extent or detected at higher concentrations in effluents. Based on this, advanced treatment processes should be applied in the future for achieving adequate emerging contaminants removal in STPs. Regarding removal mechanisms, almost 60% of BTRs and 30 to 75% of BTHs were removed in bioreactors, while the contribution of primary and secondary clarifiers was of minor importance. Sorption to primary sludge was a significant mechanism affecting EDCs fate in STP.

Recent trends in biomonitoring of bisphenol A, 4-t-octylphenol, and 4-nonylphenol.

Bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 4-nonylphenol (4-NP) are man-made alkylphenolic environmental contaminants possessing controversial endocrine disruption properties. Nowadays, an increased interest is raised for their accurate determination in biological media in order to estimate the exposure to these compounds and the associated health risk. The aim of this review is to present the available analytical methodologies for biomonitoring these three EDCs in human population. In non-occupational human exposure, they are detected in human matrices in trace level concentrations, commonly lower than 1ng/mL. The use of mass spectrometry based methods is particularly emphasized due to their well known superiority over sensitivity, selectivity and precision, even in difficult matrices, such as blood plasma and serum. Recent and most applicable sample preparation techniques are thoroughly presented. The benefits of solid phase extraction (SPE) and expected developments are demonstrated. Recent results from exposure assessment and epidemiologic studies for BPA, 4-t-OP and 4-NP are summarized and future trends are discussed.

Benzotriazoles and benzothiazoles in human urine from several countries: A perspective on occurrence, biotransformation, and human exposure

Benzotriazole (BTR) and benzothiazole (BTH) derivatives are high-production-volume chemicals that are mainly used as corrosion inhibitors, and are widely distributed in the environment. BTR derivatives are found in plastics, dishwasher detergents, dry cleaning equipment, and de-icing/anti-icing fluids. BTH derivatives are found in rubber materials, herbicides, slimicides, algicides, fungicides, photosensitizers, azo dyes, drugs, de-icing/anti-icing fluids, and food flavors. However, exposure of humans to BTRs and BTHs is still not known. In this study, six BTRs (1H-benzotriazole, 1-hydroxy-benzotriazole, 4- and 5-hydroxy-benzotriazole [mixture of two isomers], tolyltriazole, xylyltriazole [or 5,6-dimethyl-1H-benzotriazole], and 5-chloro-benzotriazole) and six BTHs (benzothiazole, 2-morpholin-4-yl-benzothiazole, 2-hydroxy-benzothiazole, 2-methylthio-benzothiazole, 2-amino-benzothiazole, and 2-thiocyanomethylthio-benzothiazole) were determined in human urine collected from general populations in seven countries (the U.S., Greece, Vietnam, Korea, Japan, China, and India). The median urinary concentration of the sum of five BTRs (Σ5BTRs; 4- and 5-hydroxy-benzotriazole were not included) ranged from 0.2 (Korea) to 2.8 (India)ng/mL among the countries studied, with the highest concentration of 24.5ng/mL found in a sample from China. Xylyltriazole was found more frequently in urine from all five Asian countries than in urine from the U.S. and Greece. The median concentration of the sum of the six BTHs (Σ6BTHs) ranged from 3.6 (U.S.) to 10.9 (Japan)ng/mL among the countries studied, with a maximum detection rate of 100% in urine samples from Vietnam; BTH was the predominant derivative, accounting for, on average, 43% of the Σ6BTH concentration. Based on the concentrations and detection rates of several BTR and BTH derivatives in urine, possible metabolic transformation pathways of these compounds were presented and human exposure doses calculated. The estimated daily intake doses of BTRs and BTHs were on the order of a few to few tens of micrograms per day.

Benzotriazole, Benzothiazole, and Benzophenone Compounds in Indoor Dust from the United States and East Asian Countries

Organic corrosion inhibitors (OCIs), including ultraviolet light filters, are widely used in plastics, rubbers, colorants, and coatings to increase the performance of products. Derivatives of benzotriazole (BTR), benzothiazole (BTH), and benzophenone (BP) are high-production volume OCIs that have been detected in the environment and human tissues. However, knowledge of their occurrence in indoor environments, as well as human exposure to them, is still lacking. In this study, BTR, BTH, BP and their 12 derivatives were determined in indoor dust for the first time. All three groups of OCIs were found in all 158 indoor dust samples from the U.S. and three East Asian countries (China, Japan, and Korea). The geometric mean (GM) concentration of the sum of six BTRs (GM CΣBTRs) ranged from 20 to 90 ng/g among the four countries studied, with a maximum CΣBTRs of ∼2000 ng/g found in a dust sample from China. Tolyltriazole was the major derivative of BTR measured in dust. GM CΣBTHs in indoor dust from the four countries ranged from 600 to 2000 ng/g. 2-OH-BTH was the predominant BTH in dust from the U.S., Japan, and Korea. GM CΣBPs in dust ranged from 80 to 600 ng/g, with 2-OH-4-MeO-BP and 2,4-2OH-BP, contributing to the majority of ∑BP concentrations. Based on the concentrations of three types of OCIs in indoor dust, human exposure through dust ingestion was calculated. Daily intake of OCIs through dust ingestion was higher for people in the U.S., Japan, and Korea than in China; the residents in urban China are exposed to higher levels of OCIs via dust ingestion than are those in rural China.

A comparative assessment of human exposure to tetrabromobisphenol A and eight bisphenols including bisphenol A via indoor dust ingestion in twelve countries.

Tetrabromobisphenol A (TBBPA) and eight bisphenol analogues (BPs) including bisphenol A (BPA) were determined in 388 indoor (including homes and microenvironments) dust samples collected from 12 countries (China, Colombia, Greece, India, Japan, Kuwait, Pakistan, Romania, Saudi Arabia, South Korea, U.S., and Vietnam). The concentrations of TBBPA and sum of eight bisphenols (ƩBPs) in dust samples ranged from <1 to 3600 and from 13 to 110,000 ng/g, respectively. The highest TBBPA concentrations in house dust were found in samples from Japan (median: 140 ng/g), followed by South Korea (84 ng/g) and China (23 ng/g). The highest ∑BPs concentrations were found in Greece (median: 3900 ng/g), Japan (2600 ng/g) and the U.S. (2200 ng/g). Significant variations in BPA concentrations were found in dust samples collected from various microenvironments in offices and homes. Concentrations of TBBPA in house dust were significantly correlated with BPA and ∑BPs. Among the nine target chemicals analyzed, BPA was the predominant compound in dust from all countries. The proportion of TBBPA in sum concentrations of nine phenolic compounds analyzed in this study was the highest in dust samples from China (27%) and the lowest in Greece (0.41%). The median estimated daily intake (EDI) of ∑BPs through dust ingestion was the highest in Greece (1.6-17 ng/kg bw/day), Japan (1.3-16) and the U.S. (0.89-9.6) for various age groups. Nevertheless, in comparison with the reported BPA exposure doses through diet, dust ingestion accounted for less than 10% of the total exposure doses in China and the U.S. For TBBPA, the EDI for infants and toddlers ranged from 0.01 to 3.4 ng/kg bw/day, and dust ingestion is an important pathway for exposure accounting for 3.8-35% (median) of exposure doses in China.

Mass Loading and Fate of Linear and Cyclic Siloxanes in a Wastewater Treatment Plant in Greece

The occurrence and fate of 5 cyclic (D3 to D7) and 12 linear (L3 to L14) siloxanes were investigated in raw and treated wastewater (both particulate and dissolved phases) as well as in sludge from a wastewater treatment plant (WWTP) in Athens, Greece. Cyclic and linear siloxanes (except for L3) were detected in all influent wastewater and sludge samples at mean concentrations of (sum of 17 siloxanes) 20 μg L(-1) and 75 mg kg(-1), respectively. The predominant compounds in wastewater were L11 (24% of the total siloxane concentration), L10 (16%), and D5 (13%), and in sludge were D5 (20%) and L10 (15%). The distribution of siloxanes between particulate and dissolved phases in influents differed significantly for linear and cyclic siloxanes. Linear siloxanes showed higher solid-liquid distribution coefficients (log K(d)) than did cyclic compounds. For 10 of the 16 compounds detected in influents, the removal efficiency was higher than 80%. Sorption to sludge and biodegradation and/or volatilization losses are important factors that affect the fate of siloxanes in WWTPs. The mean total mass of siloxanes that enter into the WWTP via influent was 15.1 kg per day(-1), and the mean total mass released into the environment via effluent was 2.67 kg per day(-1).

Accumulation of 19 environmental phenolic and xenobiotic heterocyclic aromatic compounds in human adipose tissue.

The extensive use of environmental phenols (e.g., bisphenol A) and heterocyclic aromatic compounds (e.g., benzothiazole) in consumer products as well as widespread exposure of humans to these compounds have been well documented. Biomonitoring studies have used urinary measurements to assess exposures, based on the assumption that these chemicals are metabolized and eliminated in urine. Despite the fact that some of these chemicals are moderately lipophilic, the extent of their accumulation in adipose fat tissues has not been convincingly demonstrated. In this study, human adipose fat samples (N=20) collected from New York City, USA, were analyzed for the presence of environmental phenols, including bisphenol A (BPA), benzophenone-3 (BP-3), triclosan (TCS), and parabens, as well as heterocyclic aromatic compounds, including benzotriazole (BTR), benzothiazole (BTH), and their derivatives. BPA and TCS were frequently detected in adipose tissues at concentrations (geometric mean [GM]: 3.95ng/g wet wt for BPA and 7.21ng/g wet wt for TCS) similar to or below the values reported for human urine. High concentrations of BP-3 were found in human adipose tissues (GM: 43.4; maximum: 4940ng/g wet wt) and a positive correlation between BP-3 concentrations and donors age was observed. The metabolite of parabens, p-hydroxybenzoic acid (p-HB), also was found at elevated levels (GM: 4160; max.: 17,400ng/g wet wt) and a positive correlation between donors age and sum concentration of parabens and p-HB were found. The GM concentrations of BTR and BTH in human adipose tissues were below 1ng/g, although the methylated forms of BTR (i.e., TTR and XTR) and the hydrated form of BTH (i.e., 2-OH-BTH) were frequently detected in adipose samples, indicating widespread exposure to these compounds. Our results suggest that adipose tissue is an important repository for BP-3 and parabens, including p-HB, in the human body.

Occurrence and removal efficiencies of benzotriazoles and benzothiazoles in a wastewater treatment plant in Greece.

Despite the widespread use of benzotriazoles and benzothiazoles and the occurrence of these compounds in wastewater treatment plants (WWTPs), no earlier study has comprehensively examined their fate in WWTPs. In this study, an integrated liquid chromatography-tandem mass spectrometry (LC-ESI(+)MS/MS) method was developed and validated for simultaneous determination of four benzotriazoles and four benzothiazoles in dissolved and particulate phases of wastewater (raw and treated), and in dewatered sewage sludge. The target benzotriazoles (BTRs) were 1H-benzotriazole, 1-hydroxy-benzotriazole, tolyltriazole, and xylyltriazole (or 5,6-dimethyl-1H-benzotriazole), and the target benzothiazoles (BTHs) were benzothiazole, 2-hydroxy-benzothiazole, 2-methylthio-benzothiazole, and 2-amino-benzothiazole. The limits of detection ranged from 0.08 (2-methylthio-benzothiazole) to 17 ng/L (benzothiazole) for dissolved phase samples, and from 0.04 (2-methylthio-benzothiazole) to 13 ng/g dry weight (dw) (benzothiazole) for particular matter and sludge samples. The method was applied in the analysis of wastewater and sludge samples from the WWTP in Athens, Greece. All target chemicals were detected in wastewater samples, and in some cases the concentrations were significant, on the order of a few μg/L. In sludge samples, benzothiazole and tolyltriazole were present at the highest concentrations (174 and 116 ng/g dw, respectively). For benzotriazole and tolyltriazole, the removal efficiency was below 68%, and for benzothiazoles, the removal efficiency was greater than 64% in the activated sludge treatment process. Both BTRs and BTHs showed low solid-liquid distribution coefficients.

A multi-class bioanalytical methodology for the determination of bisphenol A diglycidyl ethers, p-hydroxybenzoic acid esters, benzophenone-type ultraviolet filters, triclosan, and triclocarban in human urine by liquid chromatography–tandem mass spectrometry

A liquid-liquid extraction (LLE; ethyl acetate) protocol, followed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodology, was developed for the determination of 19 compounds, including bisphenol A diglycidyl ethers (BADGEs; industrial ethers), benzophenone-type UV filters (BP-UV filters; precursors and metabolites), p-hydroxybenzoic acid esters (parabens; preservatives), triclosan (TCS) and triclocarban (TCC) in human urine. Urine specimens were enzymatically deconjugated with β-glucuronidase (from Helix pomatia) and extracted by a LLE procedure for the measurement of total concentrations (i.e., free+conjugated forms) of target analytes. Absolute recoveries of BADGEs, BP-UV filters, parabens, TCS and TCC ranged 25-135%, 84-125%, 52-126%, 75-118% and 90-124%, respectively. Method precision (absolute values; N=5 replicate analyses at the fortification level of 10 ng, k=5 days) ranged from 5.8 (ethyl paraben) to 24.0% (TCS). The limits of quantification (LOQs) varied depending on the target compound and generally ranged from 0.2 to 2.0 ng/mL. The matrix effects ranged from +11 (2,3,4-trihydroxybenzophenone) to -86% (2,4-dihydroxybenzophenone). A total of 30 urine specimens collected from Athens, Greece, were analyzed for the 19 target compounds to demonstrate the applicability of the developed method. The concentrations of target chemicals in urine were presented on volume-, specific gravity (SG)-, and creatinine-normalization bases. MeP, EtP, PrP, OH-EtP, BADGE·2H2O, BP-1 and TCS were found frequently in urine at concentrations in the range of 2.7-436 ng/mL, <0.5-25.4 ng/mL, <0.5-575 ng/mL, <2-18.4 ng/mL, <0.5-13.8 ng/mL, <1-14.6 ng/mL and <0.5-95.3 ng/mL, respectively.