Determination of benzophenones in human placental tissue samples by liquid chromatography–tandem mass spectrometry

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.

Widespread occurrence of benzophenone-type UV light filters in personal care products from China and the United States: an assessment of human exposure

Benzophenone-3 (BP-3) is a sunscreen agent used in a variety of personal care products (PCPs) for the protection of human skin and hair from damage by ultraviolet (UV) radiation. Concerns have been raised over exposure of humans to BP-3, owing to the estrogenic potential of this compound. Nevertheless, the levels and profiles of BP-3 in PCPs and sources of exposure of humans to this estrogenic compound are not well-known. In this study, concentrations of BP-3 were determined in seven categories of 231 PCPs collected from several cities in China (n = 117) and the United States (U.S.) (n = 114), using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). BP-3 was found in the majority (81%) of the samples analyzed, at concentrations as high as 0.148%. The highest BP-3 concentrations (geometric mean [GM]: 548; median: 530 ng/g) were found in skin lotions (including sunscreen lotions), followed by makeup products (284; 221 ng/g). PCPs collected from the U.S. contained higher concentrations of BP-3 than those collected from China. On the basis of the concentrations measured and daily usage rates of PCPs, we estimated the daily intake of BP-3 through dermal absorption from the use of PCPs. The GM and 95th percentile exposure doses to BP-3 were 0.978 and 25.5 μg/day, respectively, for adult women in China, which were 2 orders of magnitude lower than those found for adult women in the U.S. (24.4 and 5160 μg/day). Skin lotions and face creams contributed to the preponderance of daily BP-3 exposures (>80%).

Benzophenone-type UV filters in urine and blood from children, adults, and pregnant women in China: partitioning between blood and urine as well as maternal and fetal cord blood

Limited information exists on the exposure of benzophenone (BP)-type UV filters (i.e., sunscreen compounds) in children, adults, and pregnant women in China. In this study, we determined the concentrations of five BP derivatives, BP-1, BP-2, BP-3, BP-8, and 4OH-BP in urine (n=101) as well as paired specimens of blood and urine (n=24 pairs) collected from adults; in matched maternal and fetal cord blood (n=20 pairs) collected from pregnant women; and in blood collected from children (n=10). 4OH-BP, BP-1, and BP-3 were found in 61%, 57%, and 25%, respectively, of the urine samples analyzed. 4OH-BP was found in all blood samples; BP-3 was found more frequently in the blood of adults (83%), followed, in decreasing order, by pregnant women (35%) and children (30%). Among all adults, urinary BP-3 concentrations were significantly (p<0.001) positively correlated with urinary BP-1 concentrations. Nevertheless, no significant correlations were found between urinary concentrations of BP-3 (or BP-1) and 4OH-BP. Our results suggest that human exposure to BP-3 and BP-1 is related, whereas 4OH-BP originates from a discrete source. Females had higher urinary concentrations of BP-3, BP-1 and 4OH-BP than males. The distribution profiles of BP-1 and its parent compound (i.e., BP-3) in urine decreased with increasing age of donors (p<0.05). The ratio of concentrations of BP-3 between blood and urine was 0.21 in adults, which was significantly lower than that for 4OH-BP (0.36). The concentration ratio of BPs between cord blood and maternal blood was higher for 4OH-BP (0.61) than that for BP-3 (0.48), which suggested greater trans-placental transfer potential of 4OH-BP. This is the first study to document the occurrence of BPs in paired urine and blood, and in matched maternal and fetal cord blood.

Associations of prenatal exposure to phenols with birth outcomes

Many phenols are known to mimic or antagonize hormonal activities and may adversely affect fetal growth. A study of 567 pregnant women was conducted to investigate the relationship between prenatal phenol exposure and birth outcomes, including birth weight, length, and gestational age. We measured the concentrations of bisphenol A, benzophenone-3, 4-n-octylphenol and 4-n-nonylphenol in maternal urine and examine their association with birth outcomes. Categories of urinary benzophenone-3 concentration were associated with decreased gestational age in all infants (p for trend = 0.03). Between middle and low exposure groups, we also found bisphenol A was negatively associated with gestational duration (βadjusted = -0.48 week; 95% confidence interval: -0.91, -0.05). After stratification by gender, we found the consistent results in infant boys with those in all infants, but we did not observe significant association for girls. In conclusion, we found prenatal phenol exposure was sex-specifically related to birth outcomes.

Methods for the determination of biomarkers of exposure to emerging pollutants in human specimens

Biomonitoring is a very useful tool for assessing human exposure to environmental pollutants. This review discusses recent methods for the quantitative measurement of biomarkers of exposure to different classes of chemicals used in personal-care products (e.g., musk fragrances, preservatives, UV filters, and insect repellents) and consumer products (e.g., organophosphate flame retardants, phthalate esters, perfluorinated compounds, and industrial phenols). The measurements are mainly taken in urine, blood, and breast milk. We also discuss the different procedures commonly used for sample-pretreatment, extraction, and clean up, and chromatographic techniques currently used to determine these compounds. Finally, we present data on the main biomarkers occurring in different human specimens.