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

Mitochondrial toxicity of triclosan on mammalian cells

Effects of triclosan (5-chloro-2'-(2,4-dichlorophenoxy)phenol) on mammalian cells were investigated using human peripheral blood mono nuclear cells (PBMC), keratinocytes (HaCaT), porcine spermatozoa and kidney tubular epithelial cells (PK-15), murine pancreatic islets (MIN-6) and neuroblastoma cells (MNA) as targets. We show that triclosan (1-10 μg ml-1) depolarised the mitochondria, upshifted the rate of glucose consumption in PMBC, HaCaT, PK-15 and MNA, and subsequently induced metabolic acidosis. Triclosan induced a regression of insulin producing pancreatic islets into tiny pycnotic cells and necrotic death. Short exposure to low concentrations of triclosan (30 min, ≤1 μg/ml) paralyzed the high amplitude tail beating and progressive motility of spermatozoa, within 30 min exposure, depolarized the spermatozoan mitochondria and hyperpolarised the acrosome region of the sperm head and the flagellar fibrous sheath (distal part of the flagellum). Experiments with isolated rat liver mitochondria showed that triclosan impaired oxidative phosphorylation, downshifted ATP synthesis, uncoupled respiration and provoked excessive oxygen uptake. These exposure concentrations are 100-1000 fold lower that those permitted in consumer goods. The mitochondriotoxic mechanism of triclosan differs from that of valinomycin, cereulide and the enniatins by not involving potassium ionophoric activity.

Widespread occurrence and accumulation of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives in human blood and adipose fat

Despite the widespread use of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) in various consumer products, studies on human exposure to these compounds are scarce. In this study, BADGE, BFDGE, and seven of their derivatives were determined in human adipose fat and blood plasma samples collected from New York City, NY. Bisphenol A bis (2,3-dihydroxypropyl) ether [BADGE·2H2O] was the major BADGE derivative found in 60% of the adipose samples and 70% of the plasma samples analyzed. High concentrations and detection frequencies of BFDGE were found in both adipose and plasma samples. BFDGE concentrations in adipose fat ranged from 19.1 to 4500 ng/g wet weight. A significant correlation between BADGE or BFDGE and their derivatives in adipose and plasma samples suggested hydration of these reactive compounds in humans. A significant positive correlation existed between BADGEs (i.e., the sum of BADGE and its five derivatives) and BFDGEs in adipose samples, which suggested similar exposure sources and pathways for these compounds in humans. Bisphenol A (BPA) also was analyzed in adipose fat and plasma, and its concentrations were positively correlated with those of BADGEs, which confirmed coexposure of BADGEs and BPA in humans.

Growth and migration of LNCaP prostate cancer cells are promoted by triclosan and benzophenone-1 via an androgen receptor signaling pathway

Prostate cancer (PCa) is a global health concern in human males. Recently, it has been known that endocrine-disrupting chemicals (EDCs) may act as an exogenous factor to enhance cancer progression. Triclosan (TCS) and 2,4-dihydroxybenzophenone (BP-1) were reported to bioaccumulate in human bodies through the skin absorption. However, there has been insufficient evidence on the findings that the intervention of EDCs may promote the cancer progression in PCa. In the present study, to verify the risk of TCS and BP-1 to a PCa progression, cancer cell proliferation and migration were investigated in LNCaP PCa cells. TCS and BP-1 increased LNCaP cell proliferative activity and migration as did dihydrotestosterone (DHT). This phenomenon was reversed by the treatment with bicalutamide, a well known AR antagonist, suggesting that TCS and BP-1 acted as a xenoandrogen in LNCaP cells via AR signaling pathway by mimicking the action of DHT. A Western blot assay was performed to identify the alterations in the translational levels of cell growth- and metastasis-related markers, i.e., c-fos, cyclin E, p21, and cathepsin D genes. The expressions of genes related with G1/S transition of cell cycle and metastasis were increased by DHT, TCS, and BP-1, while the expression of p21 protein responsible for cell cycle arrest was reduced by DHT, TCS, and BP-1. Taken together, these results indicated that TCS and BP-1 may enhance the progression of PCa by regulating cell cycle and metastasis-related genes via AR signaling pathway.

Maternal and infant exposure to environmental phenols as measured in multiple biological matrices

BACKGROUND

Results of recent national surveys have shown the high prevalence of exposure to bisphenol A (BPA) and triclosan (TCS) among the general population; however biomonitoring data for pregnant women and infants are limited.

METHODS

Women (n=80) were recruited from early prenatal clinics and asked to collect urine samples multiple times during pregnancy and once 2-3 months post-partum. Samples of infant urine and meconium as well as breast milk and infant formula were also collected. Biospecimens were analyzed by GC-MS/MS for BPA, TCS and triclocarban (TCC).

RESULTS

Triclosan was detected in over 80% of the maternal urines (geometric mean (GM): 21.61 μg/L), 60% of the infant urines (GM: 2.8 μg/L), 46% of the breast milk and 80% of the meconium samples. Triclocarban was rarely detected in any of the biospecimens. Median total BPA concentrations were 1.21 and 0.24 μg/L in maternal and infant urines, respectively. Free BPA was detected in only 11% of infant urine samples. The meconium of female infants had significantly higher concentrations of total BPA and TCS than those of males, while no differences were observed in infant urine concentrations by sex.

CONCLUSIONS

We found widespread exposure among pregnant women and infants to environmental phenols, with large inter-individual variability in exposure to triclosan. These data will contribute to the risk assessment of these chemicals, especially in susceptible sub-populations.

The natural degradation of benzophenone at low concentration in aquatic environments

The natural degradation caused by sun irradiation and microbes in aquatic environments is of major significance in the elimination process of benzophenone (BP). In this study, the fate of BP in surface water at a low concentration of 10 μg/L was investigated, including both photodegradation and microbial degradation. The result showed that the photodegradation rate of BP was affected by several parameters such as the initial concentration, continuous input, and the presence of the analogue, ions and small molecules. Meanwhile, the rate of microbial degradation of BP was mainly influenced by the kind and amount of microbes in the environmental water.

Occurrences, toxicities, and ecological risks of benzophenone-3, a common component of organic sunscreen products: a mini-review

Benzophenone-3 (BP-3) has been widely used in sunscreens and many other consumer products, including cosmetics. The widespread use of BP-3 has resulted in its release into the water environment, and hence its potential impact on aquatic ecosystem is of concern. To better understand the risk associated with BP-3 in aquatic ecosystems, we conducted a thorough review of available articles regarding the physicochemical properties, toxicokinetics, environmental occurrence, and toxic effects of BP-3 and its suspected metabolites. BP-3 is lipophilic, photostable, and bioaccumulative, and can be rapidly absorbed via oral and dermal routes. BP-3 is reported to be transformed into three major metabolites in vivo, i.e., benzophenone-1 (BP-1), benzophenone-8 (BP-8), and 2,3,4-trihydroxybenzophenone (THB). BP-1 has a longer biological half-life than its parent compound and exhibits greater estrogenic potency in vitro. BP-3 has been detected in water, soil, sediments, sludge, and biota. The maximum detected level in ambient freshwater and seawater is 125ng/L and 577.5ng/L, respectively, and in wastewater influent is 10,400ng/L. The major sources of BP-3 are reported to be human recreational activities and wastewater treatment plant (WWTP) effluents. BP-3 and its derivatives have been also detected in fish lipid. In humans, BP-3 has been detected in urine, serum, and breast milk samples worldwide. BP-1 has also been detected in placental tissues of delivering women. While sunscreens and cosmetics are known to be major sources of exposure, the fact that BP-3 has been detected frequently among young children and men suggests other sources. An increasing number of in vitro studies have indicated the endocrine disrupting capacity of BP-3. Based on a receptor binding assay, BP-3 has shown strong anti-androgenic and weak estrogenic activities but at the same time BP-3 displays anti-estrogenic activity as well. Predicted no effect concentration (PNEC) for BP-3 was derived at 1.32μg/L. The levels observed in ambient water are generally an order of magnitude lower than the PNEC, but in wastewater influents, hazard quotients (HQs) greater than 1 were noted. Considering limited ecotoxicological information and significant seasonal and spatial variations of BP-3 in water, further studies on environmental monitoring and potential consequences of long-term exposure in aquatic ecosystem are warranted.

A survey of alkylphenols, bisphenols, and triclosan in personal care products from China and the United States

Exposure of humans to environmental phenolic compounds such as bisphenol A (BPA) and alkylphenols is a matter of concern, due to these compounds' ubiquitous occurrence and estrogenic potencies. Little is known about the levels of environmental phenolics in personal care products (PCPs). In this study, nonylphenol, two octylphenols, eight bisphenols (BPA and its analogs), and triclosan (TCS) were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in PCP samples (n = 231) collected from China and the United States (U.S.). The concentrations of 4-n-nonylphenol (4-NP), 4-n-octylphenol (4-OP), 4-tert-octylphenol (4-t-OP), and TCS were in the ranges of <0.5-39,100 [geometric mean (GM): 21.5], <0.5-315 (0.680), <1.0-10,100 (2.69), and <0.5-53,900 (3.03) ng/g, respectively. The GM concentrations of individual bisphenols, including BPA, bisphenol S (BPS), and bisphenol F (BPF), were generally at sub-nanogram per gram levels. No significant differences in concentrations of the target compounds were found among various PCP categories or between China and the U.S. The estimated GM daily intakes of 4-NP, ∑OPs (sum of 4-OP and 4-t-OP), ∑BPs (sum of eight bisphenols), and TCS through dermal absorption from the use of PCPs were 0.932, 0.093, 0.072, and 0.016 μg/day, respectively, for adult Chinese women and 0.340, 0.054, 0.120, and 0.068 μg/day, respectively, for adult U.S. women. Body lotions, face creams, and liquid foundations accounted for the majority (>85 %) of the dermal exposure doses of the target phenolics.

Parabens. From environmental studies to human health

Parabens are a group of substances commonly employed as preservatives, mainly in personal care products, pharmaceuticals and food. Scientific reports concerning their endocrine disrupting potential and the possible link with breast cancer raised wide discussion about parabens' impact and safety. This paper provides holistic overview of paraben usage, occurrence in the environment, methods of their degradation and removal from aqueous solution, as well as hazards related to their endocrine disrupting potential and possible involvement in carcinogenesis.

Human fetal exposure to triclosan and triclocarban in an urban population from Brooklyn, New York

Triclosan (TCS) and triclocarban (TCC) are antimicrobial agents formulated in a wide variety of consumer products (including soaps, toothpaste, medical devices, plastics, and fabrics) that are regulated by the U.S. Food and Drug Administration (FDA) and U.S. Environmental Protection Agency. In late 2014, the FDA will consider regulating the use of both chemicals, which are under scrutiny regarding lack of effectiveness, potential for endocrine disruption, and potential contribution to bacterial resistance to antibiotics. Here, we report on body burdens of TCS and TCC resulting from real-world exposures during pregnancy. Using liquid chromatography tandem mass spectrometry, we determined the concentrations of TCS, TCC, and its human metabolites (2'-hydroxy-TCC and 3'-hydroxy-TCC) as well as the manufacturing byproduct (3'-chloro-TCC) as total concentrations (Σ-) after conjugate hydrolysis in maternal urine and cord blood plasma from a cohort of 181 expecting mother/infant pairs in an urban multiethnic population from Brooklyn, NY recruited in 2007-09. TCS was detected in 100% of urine and 51% of cord blood samples after conjugate hydrolysis. The interquartile range (IQR) of detected TCS concentrations in urine was highly similar to the IQR reported previously for the age-matched population of the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2004, but typically higher than the IQR reported previously for the general population (detection frequency = 74.6%). Urinary levels of TCC are reported here for the first time from real-world exposures during pregnancy, showing a median concentration of 0.21 μg/L. Urinary concentrations of TCC correlated well with its phase-I metabolite ∑-2'-hydroxy-TCC (r = 0.49) and the manufacturing byproduct ∑-3'-chloro-TCC C (r = 0.79), and ∑-2'-hydroxy-TCC correlated strongly with ∑-3'-hydroxy-TCC (r = 0.99). This human biomonitoring study presents the first body burden data for TCC from exposures occurring during pregnancy and provides additional data on composite exposure to TCS (i.e., from both consumer-product use and environmental sources) in the maternal-fetal unit for an urban population in the United States.