Parabens and Their Metabolites in Pet Food and Urine from New York State, United States

Simultaneous and sensitive detection of methylparaben and its metabolites by using molecularly imprinted solid-phase microextraction fiber array technique

BACKGROUND

Methylparaben (MP), a commonly used antibacterial preservative, is widely used in personal care products, foods, and pharmaceuticals. MP and its metabolites are easy to enter the water environment, and their exposure and accumulation have negative effects on the ecological environment and human health, and have endocrine disrupting activity and potential physiological toxicity. It is still the primary issue of environmental analysis and ecological risk assessment to develop simple and reliable methods for simultaneous sensitive detection of these compounds in environmental water.

RESULTS

In this paper, a flexible molecularly imprinted fiber array strategy is proposed for simultaneous enrichment and detection of trace MP and its four main metabolites. The experimental results showed that the three-fiber imprinted fiber array constructed by MP imprinted fiber had the best effect on the simultaneous enrichment of these five target analytes. The enrichment capacity of the imprinted fiber array was 214-456 times, 314-1201 times and 38-685 times that of commercial PA, PDMS and PDMS/DVB fiber arrays, respectively. The limit of detection (LOD) of this method was 0.033 μg L-1. The spiked recovery rate was 86.78-113.96 %, and RSD was less than 9.17 %. In addition, this molecularly imprinted SPME fiber array has good stability, long service life and can be used repeatedly at least 100 times.

SIGNIFICANCE

This molecularly imprinted fiber array strategy can flexibly assemble different molecularly imprinted SPME fibers together, effectively improve the enrichment ability and detection sensitivity, and achieve simultaneous selective enrichment and detection of several analytes. This is an easy, efficient and reliable method for monitoring several trace analytes simultaneously in intricate environmental matrices.

Exposure assessment of dairy cows to parabens using hair samples analysis

Parabens (PBs) are used as preservatives in various products. They pollute the environment and penetrate living organisms, showing endocrine disrupting activity. Till now studies on long-term exposure of farm animals to PBs have not been performed. Among matrices using in PBs biomonitoring hair samples are becoming more and more important. During this study concentration levels of methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP) butyl paraben (BuP) and benzyl paraben (BeP) were evaluated using liquid chromatography-mass spectrometry (LC-MS) in hair samples collected from dairy cows bred in the Kyrgyz Republic. MeP was noted in 93.8% of samples (with mean concentration levels 62.2 ± 61.8 pg/mg), PrP in 16.7% of samples (12.4 ± 6.5 pg/mg) and EtP in 8.3% of samples (21.4 ± 11.9 pg/mg). BuP was found only in one sample (2.1%) and BeP was not detected in any sample included in the study. Some differences in MeP concentration levels in the hair samples depending on district, where cows were bred were noted. This study has shown that among PBs, dairy cows are exposed mainly to MeP, and hair samples may be a suitable matrix for research on PBs levels in farm animals.

Biomonitoring of parabens in wild boars through hair samples analysis

Parabens are compounds widely utilized in the industry as preservative additives to personal care products, cosmetics and food. They pollute the environment and penetrate to the living organisms through the digestive tract, respiratory system and skin. Till now the knowledge about exposure of terrestrial wild mammals to parabens is extremely scarce. Therefore, this study for the first time assessed the concentration levels of five parabens commonly used in industry (methylparaben-MeP, ethylparaben-EtP propylparaben-PrP, benzylparaben -BeP and butylparaben-BuP). Substances have been analyzed in hair samples collected from wild boars using liquid chromatography-mass spectrometry (LC-MS) method. The hair is a matrix, which allows to study long-term exposure of organisms to parabens. During this study MeP was noted in 96.3% of samples with mean 88.3±72.9 pg/mg, PrP in 87.0% of samples with mean 8.5±3.3 pg/mg, BeP in 44.4% of samples with mean 17.2±12.3 pg/mg and EtP in 11.1% of samples with mean 17.2±4.8 pg/mg. In turn BuP was noted only in 3.7% of samples with concentration levels below limit of quantification (2.6 pg/mg). Statistically significant intragender differences in parabens levels have not been noted. Only BeP concentration levels depended on industrialization and density of human population of area, where the animals lived. This study indicates that wild boars are exposed to parabens, especially to MeP and PrP, and analysis of the hair seems to be a useful tool of biomonitoring of parabens in wild mammals.

Occurrence, biomagnification, and risk assessment of parabens and their metabolites in marine fish: The case study of Vietnam

Parabens have emerged as the primary preservative of choice in numerous consumer goods, prompting growing apprehension regarding their potential for human exposure. The study employed the optimized QuEChERs sample extraction method and the UHPLC-Q-Orbitrap HRMS system to generate the initial contamination profiles of seven parabens and their four metabolites in a total of 114 fish samples found along the coastline of Vietnam. The findings of the study indicated that methylparaben was the predominant substance detected, exhibiting the highest concentration in the largehead hairtail (Trichiurus lepturus) species at 32.8 ng g-1 dry weight (dw). Additionally, the metabolites with the highest detectable concentrations in the largehead hairtail were found to be 4-HB and 3,4-DHB, with levels of 8822.0 ng g-1 dw and 3490.8 ng g-1 dw, respectively. Besides, the study reveals notable variations in paraben concentrations across three distinct regions in Vietnam, namely the Central, North, and South (Mann-Whitney U test, p < 0.05). The trophic magnification factors (TMF) for methylparaben, ethylparaben, ethyl protocatechuate, and 4-hydroxybenzoic acid exhibited values exceeding 1, indicating substantial biomagnification of these substances within the marine food web of Vietnam. Additionally, noteworthy positive associations have been observed between methylparaben and ethylparaben, as well as their respective metabolites. Based on the findings of the study, it can be concluded that there is no direct impact of seafood consumption on human health in Vietnam.

Butylparaben weakens female fertility via causing oocyte meiotic arrest and fertilization failure in mice

Butylparaben is an ubiquitous environmental endocrine disruptor, that is commonly used in cosmetics and personal care product due to its anti-microbial properties. Butylparaben has been shown to cause developmental toxicity, endocrine and metabolic disorders and immune diseases. However, little is known about the impact on female fertility, especially oocyte quality. In the present study, we reported that butylparaben influenced female fertility by showing the disturbed oocyte meiotic capacity and fertilization potential. Specifically, butylparaben results in the oocyte maturation arrest by impairing spindle/chromosome structure and microtubule stability. Besides, butylparaben results in fertilization failure by impairing the dynamics of Juno and ovastacin and the sperm binding ability. Last, single-cell transcriptome analysis showed that butylparaben-induced oocyte deterioration was caused by mitochondrial dysfunction, which led to the accumulation of ROS and occurrence of apoptosis. Collectively, our study indicates that mitochondrial dysfunction and redox perturbation is the major cause of the weakened female fertility expoesd to butylparaben.

Co-exposure to parabens and triclosan and associations with cognitive impairment in an elderly population from Shenzhen, China

Parabens and triclosan (TCS) have been extensively applied in personal care products (PCPs) as preservatives and antibacterial agents. However, their potentiality to disrupt the neurological system has induced increasing concern. The elderly population is at a higher risk of neurodegenerative disorder, although research on its association with PCP exposure remains scarce. Here, we measured the urinary levels of four parabens, TCS, and an oxidative stress marker among 540 participants from the Shenzhen aging-related disorder cohort during 2017-2018. The Mini-Mental State Examination (MMSE) was used to assess the cognitive status of participants. Their demographic, dietary, and behavioral factors were collected via questionnaire survey. Among the four paraben analogs, the median concentration of methyl parabens (MeP) was the highest (Low-risk group: 1.21 ng/mL, High-risk group: 1.64 ng/mL). TCS and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were detected in more than 90% of the samples. Weighted quantile sum regression and quantile-based g-computation showed that the combined effect of all analytes was positively associated with the level of 8-OHdG. BtP, EtP and MeP were identified as the major contributors to the joint effect. After stratification by gender, females exhibited more pronounced changes in urinary 8-OHdG level than males. However, the positive correlation between co-exposure to parabens and TCS and cognitive impairment was not significant (p > 0.05) in both models, which warrants investigation with the larger sample size.

New insight into molecular mechanism of P450-Catalyzed metabolism of emerging contaminants and its consequence for human health: A case study of preservative methylparaben

Hydroxylated metabolites in the living body are considered as a potential biomarker of exposure to emerging contaminations (ECs) and breast cancer, but their formation mechanism has not received enough attention. Besides, the adverse impacts of metabolites during the metabolic transformation of ECs largely remain unknown. In this study, we employed a density functional calculation combing with in-vitro incubation of human liver microsomes to explore the bio-transformation of preservative methylparaben (MPB) in human bodies. Our results showed that hydroxylated metabolites of MPB (OH-MPB) were observed experimentally, while a formation mechanism was revealed at the molecular level. That is, hydroxylated metabolite was exclusively formed via the hydrogen abstraction from the phenolic hydroxyl group of MPB followed by the OH-rebound pathway, rather than the direct hydroxylation on the benzene ring. The increasing of hydroxyl groups on ECs could improve the metabolisms. This was confirmed in the metabolism of ECs without hydroxyl group and with multiple-hydroxyl groups, respectively. Furthermore, toxicity assessments show that compared to parent MPB, the hydroxylated metabolites have increased negative impacts on the gastrointestinal system and liver. A semiquinone product exhibits potential damage in the cardiovascular system and epoxides are toxic to the blood and gastrointestinal system. The findings deepen our insight into the biotransformation of parabens in human health, especially by providing health warnings about the potential impacts caused by semiquinone and epoxides.

Within-day variability, predictors, and risk assessments of exposure to parabens among Chinese adult men

BACKGROUND

Parabens, as suspected endocrine disruptors, are widely used in personal care products and pharmaceuticals. However, variability, predictors, and risk assessments of human exposure to parabens are not well characterized.

OBJECTIVE

To evaluate within-day variability, predictors, and risk assessments of exposure to parabens among Chinese adult men.

METHODS

We measured four parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) in repeated urine samples from 850 Chinese adult men. We examined the variability by intraclass correlation coefficients (ICCs) and identified the predictors by multivariable linear mixed models. We assessed risks of paraben exposures based on the estimated daily intake (EDI).

RESULTS

The four parabens were detected in >76% of urinary samples. We observed fair to good to high reproducibility (ICCs: 0.71 to 0.86) for urinary paraben concentrations within one day. Use of facial cleanser was associated with higher four urinary paraben concentrations. Increasing age, taking medicine, intravenous injection, and interior decoration in the workplace were related to higher urinary concentrations of specific parabens. Smoking and drinking were associated with lower urinary concentrations of specific parabens. The maximum EDIs for the four parabens ranged from 13.76 to 848.68 μg/kg bw/day, and 0.9% of participants had the hazard quotient values > 1 driven by PrP exposure.

CONCLUSIONS

Urinary paraben concentrations were less variable within one day. Several lifestyle characteristics including use of facial cleanser and pharmaceuticals may contribute to paraben exposures.

Evaluation of Parabens and Bisphenol A Concentration Levels in Wild Bat Guano Samples

Parabens and bisphenol A are synthetic compounds found in many everyday objects, including bottles, food containers, personal care products, cosmetics and medicines. These substances may penetrate the environment and living organisms, on which they have a negative impact. Till now, numerous studies have described parabens and BPA in humans, but knowledge about terrestrial wild mammals' exposure to these compounds is very limited. Therefore, during this study, the most common concentration levels of BPA and parabens were selected (such as methyl paraben-MeP, ethyl paraben-EtP, propyl paraben-PrP and butyl paraben-BuP) and analyzed in guano samples collected in summer (nursery) colonies of greater mouse-eared bats (Myotis myotis) using liquid chromatography with the tandem mass spectrometry (LC-MS-MS) method. MeP has been found in all guano samples and its median concentration levels amounted to 39.6 ng/g. Other parabens were present in smaller number of samples (from 5% for BuP to 62.5% for EtP) and in lower concentrations. Median concentration levels of these substances achieved 0.95 ng/g, 1.45 ng/g and 15.56 ng/g for EtP, PrP and BuP, respectively. BPA concentration levels did not exceed the method quantification limit (5 ng/g dw) in any sample. The present study has shown that wild bats are exposed to parabens and BPA, and guano samples are a suitable matrix for studies on wild animal exposure to these substances.

Assessment of exposure to volatile organic compounds through urinary concentrations of their metabolites in pet dogs and cats from the United States

Volatile organic compounds (VOCs) are ubiquitous environmental pollutants, exposure to which is associated with birth defects, neurocognitive and reproductive impairments, and cancer. Little is known, however, about VOC exposure in pet dogs and cats, which represent sentinels for human exposure as well as having value as companion animals. In this study, we determined 38 VOC metabolites (VOCMs) in urine samples collected from 47 dogs and 42 cats from the Albany area of New York State. Seventeen (in cats) to twenty (in dogs) VOCMs were found at detection frequencies (DFs) above 60%. The creatinine-adjusted geometric mean (GM) concentrations of individual VOCMs ranged from 5.43 (EMA) to 761 μg/g (3HPMA) in dog urine and 0.824 (SBMA) to 278 μg/g (ATCA) in cat urine. The ∑20 VOCM concentration in dog urine was 2280 μg/g (geometric mean) and the ∑17 VOCM concentration in cat urine was 847 μg/g. Eight individual VOCMs were significantly more abundant in dog than in cat urine, and the urinary concentrations of several VOCMs in dogs were comparable to those reported for human tobacco smokers. Metabolites of acrolein accounted for 43% of ∑20 VOCM concentration in dogs, whereas those of cyanide and benzene accounted for 60% of ∑17 VOCM concentration in cats. Based on acrylamide exposure doses, calculated hazard quotients were above 1 in 77% of dogs and 50% of cats studied, and cancer risk values (using a benchmark of 10^-6) from exposure to acrylamide exceeded 1 for all dogs and cats. This is the first study to report VOCM concentrations in urine collected from pet dogs and cats and highlights the need to identify sources and health implications of VOCs exposure in these animals.

Monitoring and eco-toxicity effect of paraben-based pollutants in sediments/seawater, north of the Persian Gulf

The current work is documented as the first record of the characteristics, removal efficiency, partitioning behavior, fate, and eco-toxicological effects of paraben congeners in a municipal wastewater treatment plant (WWTP, stabilization ponds) and hospital WWTPs (septic tank and activated sludge), as well as seawater-sediments collected from runoff estuarine stations (RES) and coastal stations (CS) of the north of the Persian Gulf. The median values of Σparabens at the raw wastewater and effluent of the studied WWTPs were 1884 ng/L and 468 ng/L, respectively. The activated sludge system had a greater removal efficiency (56.10%) in removing ∑parabens than the septic tank (45.05%) and stabilization pond (35.54%). The discharge rates of methyl paraben (MeP) was computed to be 2.23, 21.18, and 9.12 g/d/1000 people for stabilization ponds, septic tank, and activated sludge, respectively. Median concentrations of Σparabens in seawater (103.42 ng/L) and sediments (322.05 ng/g dw) from RES stations were significantly larger than from CS stations (61.2 and 262.0 ng/g dw in seawater and sediments, respectively) (P < 0.05). The median of field-based k_oc for Σparabens was 130.81 cm³/g in RES stations and 189.51 cm³/g in CS stations. It was observed that the concentration of parabens could have negative impacts on some living aquatic populations (invertebrates and bacteria), but the risk was not significant for fishes and algae.

An assessment of exposure to several classes of pesticides in pet dogs and cats from New York, United States

Exposure of pet dogs and cats to pesticides used in and around homes (e.g., lawns and gardens) is a significant health concern. Furthermore, some pesticides are directly used on dogs and cats for flea, lice, and tick control. Despite this, little is known regarding the extent of pesticide exposure in pets. In this study, we determined the concentrations of 30 biomarkers of pesticide exposure in urine collected from dogs and cats in New York State, USA: 6 dialkylphosphate (DAP) metabolites of organophosphates (OPs); 14 neonicotinoids (neonics); 3 specific metabolites of OPs; 5 pyrethroids (PYRs); and 2 phenoxy acids (PAs). The sum median concentrations of these 30 pesticide biomarkers (ΣPesticides) in dog and cat urine were 35.2 and 38.1 ng/mL, respectively. Neonics were the most prevalent in dogs (accounting for 43% of the total concentrations), followed by DAPs (17%), PYRs (16%), OPs (13%), and PAs (∼10%). In cat urine, neonics alone accounted for 83% of the total concentrations. Elevated concentrations of imidacloprid were found in the urine of certain dogs (max: 115 ng/mL) and cats (max: 1090 ng/mL). Some pesticides showed gender- and sampling location- related differences in urinary concentrations. We calculated daily exposure doses of pesticides from the measured urinary concentrations through a reverse dosimetry approach. The estimated daily intakes (DIs) of chlorpyrifos, diazinon, and cypermethrin were above the chronic reference doses (cRfDs) in 22, 76, and 5%, respectively, of dogs. The DIs of chlorpyrifos, parathion, diazinon, and imidacloprid were above the cRfDs in 33, 14, 100, and 29%, respectively, of cats. This study thus provides evidence that pet dogs and cats are exposed to certain pesticides at levels that warrant immediate attention.

Determination of bisphenols and parabens in cow urine distillate from India: implication of human exposure and risk assessment

The exposures of a wide range of endocrine-disrupting chemicals to cows have been linked to diseases and are a major concern. In Indian scripts, cow urine is believed to be a treatment for many diseases. Nonetheless, exposure of bisphenols and parabens to cow urine distillates is unknown. Hence, in this study, we determined the concentration of bisphenols and parabens in commercially available cow urine distillate collected from India. The mean concentration of total bisphenols and parabens ranges from the limit of quantification (LOQ) to 149.3 ng/mL and 1479.88 ng/mL, respectively. Predominant bisphenol-F and bisphenol-A were accounted for 88.6% and 6% of total bisphenol concentration, respectively, in marketed cow urine distillate, whereas methyl and propyl parabens were dominant and accounted for 33% and 65%, respectively. The estimated mean daily intake (EDI) of bisphenol for males and females were 45.94 ng/kg-bw/day and 54.29 ng/kg-bw/day, respectively, while for parabens EDI was 455.35ng/kg-bw/day and 538.14 ng/kg-bw/day for males and females, respectively. Hazard quotient, to evaluate the potential risk of exposure, showed no risk in the studied samples. Even though the EDI results from the Monte-Carlo risk assessment analysis did not exceed the acceptable daily intake, their estrogenic actions cannot be ignored in general populations. The estrogenic activities contributed by parabens and bisphenol A measured by estradiol equivalency quotient (EEQ) ranged from 0.00033-42 pg/mL and 2.3 pg/mL, respectively. Our results revealed higher concentrations of bisphenols and parabens in cow urine distillates; hence, special attention should be given to the quality and safety of cow urine distillates. Moreover, strict guidelines should be enforced for the quality of cow urine distillates.

Estimation of parabens and bisphenols in maternal products and urinary concentrations in Indian pregnant women: daily intake and health risk assessment

The presence of parabens and bisphenols in maternal products and usage during pregnancy have raised serious concern about their possible harm to pregnant women. The concentrations of six parabens and eight bisphenols were quantified by high-performance liquid chromatography-tandem mass spectrometry in the samples of commercially available herbal-based ayurvedic maternal products and urine of healthy pregnant women from Assam, India. Methyl paraben (MP) and bisphenol AF (BPAF) were found to be more dominant in the maternal products, whereas MP, bisphenol A (BPA), and BPAF were dominant in urine samples of healthy pregnant women. The sum of the mean concentrations of all forms of parabens and bisphenols in maternal products were 48,308.50 ng/g and 542.42 ng/g, respectively, and urine 101.33 ng/mL and 23.42 ng/mL, respectively. The estimated daily intake (EDI) of total parabens and bisphenols in maternal products were 7378.02 and 19.78 ng/kg body weight/day, respectively. EDI of total parabens and bisphenols from urinary concentrations were 690.12 and 111.33 μg/kg body weight/day, respectively. The concentrations of butyl (BP) and heptyl (HP) parabens have a significant positive correlation with birth weight. The hazard quotient (HQ) value of MP, EP, and BPA was less than 1, and margin of exposure (MOE) identified potential risk associated with propyl paraben. Results from Monte-Carlo risk assessment analysis did not exceed the acceptable daily intake (ADI). Our results showed that higher concentrations of parabens and bisphenols are present in maternal products and the urine of healthy pregnant women. Hence maternal products containing bisphenols and parabens should be used cautiously during pregnancy to avoid maternal and fetal complications.

Several typical endocrine-disrupting chemicals in human urine from general population in China: Regional and demographic-related differences in exposure risk

Endocrine-disrupting chemicals (EDCs) are ubiquitous in the environment, and human exposure to these pollutants has caused great public concern. Five groups of EDCs, including parabens, antimicrobials (triclosan (TCS) and triclocarban (TCC)), bisphenols (BPs), tetrabromobisphenol A and its alternatives (TBBPAs), and benzophenones, in urines of general populations from three cities with different economic levels in China were determined simultaneously to evaluate the coexposure levels of such chemicals. The total concentration of target compounds was approximately two times higher in the urines from Chengdu (a first-tier city; geometric mean: 2.50 μg/L) than that from Nantong (a second-tier city; 1.34 μg/L), and was one order of magnitude higher than that from Shehong (a fifth-tier city; 0.73 μg/L). Urinary target compounds were significantly correlated with gender, age, body mass index (BMI), education level, occupation, and diet. The estimated daily intakes of target chemicals ranged from 0.002 (benzophenones) to 10.2 µg/kg-bw/day (parabens). The exposure estimate showed that females were more vulnerable to exposure to these EDCs. This study profiles the regional and demographic-related differences in the concentrations and exposure risks of several typical EDCs in urines from general populations in three cities with different economic levels in China.

Evaluation of human exposure to parabens in north eastern Poland through hair sample analysis

Parabens (PBs) are a group of substances commonly used in industry. They also pollute the environment, penetrate into living organisms and adversely affect various internal organs. During this study, the degree of exposure of people living in Olsztyn, a city in north eastern Poland, to selected parabens most often used in industry was studied. The chemicals under investigation included: methyl paraben—MePB, ethyl paraben—EtPB, propyl paraben—PrPB, benzyl paraben BePB and butyl paraben -BuPB. To this aim, hair samples collected from the scalps of 30 volunteers were analyzed using a liquid chromatography–mass spectrometry technique. All PBs studied were present in a high percentage of analyzed samples (from 76.7% in the case of BePB to 100% in the case of MePB and PrPB). The mean concentration levels were 4425.3 pg/mg for MeBP, 704.0 pg/mg for EtPB, 825.7 pg/mg for PrPB, 135.2 pg/mg for BePB and 154.5 pg/mg for BuPB. Significant differences in PB concentration levels between particular persons were visible. On the other hand, gender, age and artificial hair coloring did not cause statistically significant differences in PB levels. Obtained results have clearly indicated that people living in north eastern Poland are exposed to various PBs, and therefore these substances may affect their health status. However, the evaluation of PBs influence on human health requires further research.

Profiles of parabens, benzophenone-type ultraviolet filters, triclosan, and triclocarban in paired urine and indoor dust samples from Chinese university students: Implications for human exposure

Parabens, benzophenone (BP)-type UV filters, triclosan (TCS), and triclocarban (TCC) are commonly used in personal care products. Human exposure to these compounds has received increasing concern because of their adverse health effects. However, the levels of these chemicals in paired urine and indoor samples have never been simultaneously measured. In this work, eight parabens, eight BP-type UV filters, TCS, and TCC were measured in paired urine and indoor dust samples collected from university students and their dormitories in South China. The target analytes were commonly measured in urine (71%-100%) and indoor dust (30%-98%), with median concentrations ranging from 0.16 ng/mL to 19.3 ng/mL in urine and from <0.01 ng/g to 3700 ng/g in indoor dust samples. Females had high levels of most of these target compounds, and gender-related differences were found in the levels of most target analytes. Positive correlations were found in the levels of methylparaben, ethyl paraben, benzophenone-3, and TCS between urine and indoor dust samples. This finding suggested that indoor dust is an important source for human exposure to these compounds. The estimated daily intake (EDI) of these analytes in paired samples was also evaluated. The median EDI_-urine values of target analytes varied in the range of 4.02-59,280 ng/kg bw/day. Females had higher median EDI_-urine values for most of target analytes than males. In addition, the median EDI_{-indoor dust} values of most target analytes in dust from female dormitories were higher than those in dust from male dormitories. Indoor dust ingestion only had minor contribution (<0.5%) to the total exposure. To the best of the authors' knowledge, this study is the first to simultaneously analyze the concentrations of parabens, BP-type UV filters, TCS, and TCC in the paired urine and indoor samples from university students in South China.

Parabens as chemicals of emerging concern in the environment and humans: A review

Parabens are one of the most widely used preservatives in food, pharmaceuticals and personal care products (PCPs) because of their advantageous properties and low toxicity based on the early assessments. However, recent research indicates that parabens may act as endocrine-disrupting chemicals (EDCs) and thus, are considered as chemicals of emerging concern that have adverse human health effects. To provide the basis for future human health studies, we reviewed relevant literature, published between 2005 and 2020, regarding the levels of parabens in the consumer products (pharmaceuticals, PCPs and food), environmental matrices and humans, including susceptible populations, such as pregnant women and children. The analysis showed that paraben detection rates in consumer products, environmental compartments and human populations are high, while the levels vary greatly by country and paraben type. The concentrations of parabens reported in pregnant women (~20-120 μg/L) were an order of magnitude higher than in the general population. Paraben concentrations in food and pharmaceuticals were at the ng/g level, while the levels in PCPs reached mg/g levels. Environmental concentrations ranged from ng/L-μg/L in surface waters to tens of μg/g in wastewater and indoor dust. The levels of human exposure to parabens appear to be higher in the U.S. and EU countries than in China and India, which may change with the increasing production of parabens in the latter countries. The review provides context for future studies to connect paraben exposure levels with human health effects.

Additives in pet food: are they safe?

A good, nutritious diet is essential for the health and well-being of our domestic pets. Today, most pet dogs and cats are fed highly processed food bearing little resemblance to canine and feline ancestral diets. Additives are included in processed pet food to provide nutritional benefits, ensure food safety, and maintain the desirable features of colour, flavour, texture, stability and resistance to spoilage. This paper reviews the safety of various additives in processed pet food. Labelling, safety assessment, and ethical concerns regarding existing toxicity testing procedures are also considered. The adequacy of testing for many additives and the scientific basis for determining safety are questioned. Additives can be synthetic or 'natural' although the distinction can be blurred when naturally derived substances are synthesised in the laboratory, or extracted using a high level of physical and chemical processing. Although additives play important roles in processed food production, updated strategies and technologies may be required to establish their safety in the pet food industry.

Accurate assessment of parabens exposure in healthy Chinese female adults: Findings from a multi-pathway exposure assessment coupled with intervention study

Exposure of humans to parabens is widespread and urinary parabens are widely used as exposure biomarkers. However, are the levels of these chemicals suitable to assess exposure to parabens? We conducted an intervention study by controlling the use of personal care products (PCPs) to explore the exposure of parabens. Ten female participants were recruited who were treated with different types of PCPs during the 18-day study period. The concentrations of parabens and their metabolites in matrices of different exposure pathways (dust, drinking water and dietary food) and urine samples were determined. We demonstrated that PCPs were the major sources of parabens, accounting for >99% of total exposure. The metabolites were nonspecific to individual parabens and could not be used as exposure biomarkers. Urinary paraben concentrations were positively correlated with external exposure levels. However, poor reproducibility was observed, with intraclass correlation coefficients (ICC) ranging from 0.125 to 0.295 in unadjusted urinary concentrations. Creatinine-adjusting could not significantly improve the ICC values in random spot samples. After adjusting for both creatinine and kinetic models, the ICC values ranged from 0.695 to 0.886, indicating a good reproducibility. So, toxicokinetic parameters may be taken into consideration for precise monitoring of exposures for the non-persistent pollutants.

Occurrence, Distribution, and Human Exposure of Several Endocrine-Disrupting Chemicals in Indoor Dust: A Nationwide Study

Parabens, triclosan (TCS), triclocarban (TCC), and bisphenol A and its analogues (BPs) are used in various industrial and consumer products and are typical endocrine-disrupting chemicals (EDCs). In this study, six parabens, TCS, TCC, and eight BPs were determined in 289 indoor dusts collected from different geographical regions in China. Ten of 16 target compounds were found in >50% samples. Concentrations of Σ₆parabens, Σ(TCS+TCC), and Σ₈BPs in indoor dust ranged from 8.66-21,500 (median: 288), 19.6-8940 (104), and 8.80-37,400 (377) ng/g dw, respectively. The Σ(TCS+TCC) concentrations in dust from Northeast China were higher than those from Central South China (p < 0.05). The concentrations of Σ₈BPs in dust from Eastern China were approximately 2 times higher than those found for North China (p < 0.05), whereas there was no significant spatial difference in concentrations of parabens among different geographical regions (p > 0.05). Human exposure to these EDCs through indoor dust ingestion and dermal absorption was evaluated. The median and 95th percentile estimated daily intakes of Σ₁₆EDCs ranged from 0.439 (adults)-4.57 (infants) and 6.26 (adults)-62.1 (infants) ng/kg bw/day, respectively, generally decreasing with increasing age. This nationwide survey establishes a baseline concentration for parabens in the indoor environment in China.

Analysis of methylparaben in cosmetics based on a chemiluminescence H2 O2 -NaIO4 -CNQDs system

In this article, a simple, effective chemiluminescence (CL) method for the detection of methylparaben (MP) in cosmetic samples was developed based on an IO₄ ^- -H₂ O₂ -carbon nitrogen quantum dots (CNQDs) system without a separation process. The results indicated that the redox reaction between periodate and hydrogen peroxide released hydroxide radicals and superoxide radical anions in the presence of bicarbonate. These two radicals were responsible for the formation of excited luminophor CNQD* with a maximum wavelength at 480 nm. Due to the competitive reaction with hydroxide radicals, CL intensity was markedly diminished in the presence of MP. The relative standard deviation in the intraday assay was below 5.5% (n = 9), and the detection limit was as low as 0.50 μmol/L. The proposed method allowed for the successful, selective determination of MP in cosmetics.

Occurrence of parabens and their metabolites in the paired urine and blood samples from Chinese university students: Implications on human exposure

Parabens, a group of p-hydroxybenzoic acid esters, are extensively used in cosmetics, personal care products, pharmaceuticals, and foodstuff. In the present study, the total forms (free plus conjugated) of four parent parabens, such as methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP), and four metabolites, namely methyl protocatechuate (OH-MeP), ethyl protocatechuate (OH-EtP), p-hydroxy benzoic acid (4-HB), and 3,4-dihydroxy benzoic acid (3,4-DHB), were detected in paired urine and blood samples collected from 196 Chinese university students. The median urinary and blood parabens and their metabolites concentrations ranged from 0.24 to 167 ng/mL and from <0.02 to 2.88 ng/mL, respectively. MeP was the predominant parent parabens, accounting for 68% and 52% of urine and blood samples, respectively. Furthermore, 4-HB predominantly contributed to the parabens and their metabolites in urine (54%) and blood (41%). Significant positive correlations were observed between the urinary levels and blood levels. Moreover, relatively high levels of parabens and their metabolites were detected in urine samples. Our results imply that urinary concentrations are good predictors of human exposure to parabens and metabolites. Gender-related difference in urinary concentrations of parabens and their metabolites were found. The median urinary levels of the tested compounds in females were significantly higher than those in males (Mann Whitney U test, p < 0.05 or 0.01). The estimated daily intakes (EDIs) of MeP, EtP, and PrP were also evaluated. The median values of EDI_MeP, EDI_EtP, and EDI_PrP for all of the university students were estimated to be 25.9, 1.61, and 3.82 μg/kg bw/day, respectively. The median values (μg/kg bw/day) of EDI_MeP, EDI_EtP, and EDI_PrP were higher in females (53.7, 8.65, and 5.22) than in males (8.41, 0.85, and 2.57). This study is the first study to report the occurrence of parabens and their metabolites in paired urine and blood samples in China.

Profiles of parabens and their metabolites in paired maternal-fetal serum, urine and amniotic fluid and their implications for placental transfer

Six parabens and their four metabolites were measured in paired maternal serum (MS) and cord serum (CS) samples collected from 95 pregnant women to elucidate placental transfer of this class of compounds. Matched maternal urine (MU) and amniotic fluid (AF) collected from 13 of 95 pregnant women were also analyzed to examine partition of these chemicals between maternal and fetal tissues. The placental transfer rates (PTRs; concentration ratio of parabens between CS and MS) of methyl- (MeP), ethyl- (EtP), propyl-parabens (PrP) were 0.81, 0.63, and 0.60, respectively. Furthermore, the PTRs of OH-MeP (0.93) and OH-EtP (1.8) were higher than those of their corresponding parent parabens, which suggested that hydroxylation increased placental transfer rates of parabens. Structure-dependent placental transfer mechanisms were observed. A significant negative correlation between molecular weights (or log K_ow) of MeP, EtP, PrP, and p-hydroxy benzoic acid (4-HB) and PTRs suggested passive diffusion as a mechanism of placental transfer of these chemicals. Nevertheless, other hydroxylated metabolites (OH-EtP, OH-MeP, and 3,4-dihydroxy benzoic acid (3,4-DHB)) showed a positive correlation between molecular weight (or log K_ow) and PTRs, which suggested that the placental transfer is mediated by protein binding of these metabolites. The MU to MS concentration ratios of MeP (MU/MS_MeP) and PrP (MU/MS_PrP) were 71 and 81, respectively, and MU/MS_MeP was two orders of magnitude higher than that found for the metabolite (MU/MS_OH-MeP: 0.35), suggesting that hydroxylation metabolite reduced urinary elimination of parabens. To our knowledge, this is the first time to report the occurrence and distribution of parabens and their metabolites in paired maternal-fetal serum, urine, and AF samples in China. Our results provide novel information on placental transfer of parabens and their metabolites.

Biomonitoring of exposure to bisphenols, benzophenones, triclosan, and triclocarban in pet dogs and cats

Similar to humans, pet animals are exposed to environmental contaminants through multiple sources and pathways. Although a few studies have demonstrated exposure of cats and dogs to environmental chemicals, little is known about exposure to bisphenols, benzophenone UV filters, and antibacterial agents. In this study, we measured three bisphenols, three benzophenone-type UV filters, triclosan (TCS), and triclocarban (TCC) in dog (n = 50) and cat urine (n = 50) collected from New York State, USA. Among bisphenols, BPS was found at the highest concentrations (mean ± SD: 3.2 ± 8.5 ng/mL in dogs and 8.85 ± 30.0 ng/mL in cats) with detection frequencies of 96% in dogs and 78% in cats. Among benzophenones, BP-3 (oxybenzone) was the dominant compound in pet urine, followed by BP-1 and BP-8. TCS was found at concentrations higher than those of TCC in both cat and dog urine. There were no significant differences in bisphenol concentrations between sexes or age groups, both in dogs and cats. The calculated hazard quotients (HQ) suggested that the current exposure levels of BPS and BP-3 in pets were 2-5 orders of magnitude below the tentative threshold values available for humans.

Urinary concentrations and distribution profiles of 21 phthalate metabolites in pet cats and dogs

Phthalates are widely used in several consumer products, including plastics, toys, cosmetics, and medical devices. Little is known about phthalate exposure in pet animals, however, even though they share an indoor environment with humans; this is the first study to measure such exposure. We measured 21 phthalate monoester metabolites (PhMs) in the urine of pet cats (n = 50) and dogs (n = 50) collected from New York State, USA. PhMs were widely detected in all samples, and 12 of 21 PhMs had detection frequencies (Dfs) >80%. The median urinary concentrations of total PhMs in pet cats and dogs were 630 ng/mL and 186 ng/mL, respectively. Monoethyl phthalate (mEP) was the most abundant compound in both cats and dogs. Phthalic acid (PA; a non-specific metabolite of phthalates) was found at very high concentrations in cats (median: 520 ng/mL). The estimated daily intake (EDI) and hazard quotient (HQ) for major phthalates in pets showed that DEHP exposures in cats and dogs were only 2-fold less than the US Environmental Protection Agency suggested reference dose (RfD) for humans.

Polyethylene Terephthalate and Polycarbonate Microplastics in Pet Food and Feces from the United States

Human exposure to microplastics has been a topic of interest, but measurements of exposure are limited. Pet animals are sentinels of human exposure, as they share a common living environment with humans. In this study, 58 pet (cat and dog) foods and 78 pet feces samples were collected from Albany, NY, USA, for the analysis of polyethylene terephthalate (PET) and polycarbonate (PC) by alkali-assisted thermal depolymerization and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) methods. PET was detected at concentrations in the range of <1,500 ng/g to 12,000 ng/g (median: <1,500 ng/g) and <1,500 to 4,600 ng/g (median: <1,500 ng/g) in cat and dog foods, respectively. The concentrations of PET in cat (<2,300-340,000 ng/g, median: 61,000 ng/g) and dog (7700-190,000 ng/g, median: 30,000 ng/g) feces were 1-2 orders of magnitude higher than those in pet food samples. A significant positive correlation was found between the concentrations of the monomers (i.e., TPA and BPA) and the corresponding MPs in cat feces. The calculated mean estimated daily intake of PET and PC (calculated from pet food) was lower than that of the mean cumulative daily intake (calculated from pet feces), which suggested that diet is a minor source of exposure to PET and PC in pets.

Microwave synthesis of iodine-doped bismuth oxychloride microspheres for the visible light photocatalytic removal of toxic hydroxyl-contained intermediates of parabens: catalyst synthesis, characterization, and mechanism insight

The iodine-doped bismuth oxychloride (I-doped BiOCl) microspheres are synthesized as the visible light photocatalysts for the photocatalytic removal of three toxic hydroxyl-contained intermediates of parabens. With the aid of the unique heating mode of microwave method, the I-doped BiOCl photocatalysts with tunable iodine contents and dispersed energy bands, instead of a mixture of BiOI and BiOCl or solid solution, are synthesized under the controllable conditions. Due to the stretched architectures, high specific surface area, and effective separation of photogenerated carriers, they exhibit high activity to the photocatalytic degradation of methyl 2,4-dihydroxybenzoate (MDB), methyl 3,4-dihydroxybenzoate (MDHB), and ethyl 2,4-dihydroxybenzoate (EDB). As a typical result, it is indicated that though MDB as the most difficult intermediate of parabens to be degraded, a 91.2% removal ratio can still be achieved over the I-doped BiOCl with an energy band of 2.79 eV within 60 min. In addition, it is also confirmed that these photocatalysts remain stable throughout the photocatalytic reaction and can be reused, and more importantly, the photogenerated h⁺ and •O₂^- are the key reactive species, while •OH plays a negligible role in the photocatalytic reaction. Resorcinol was identified as the main photodegraded intermediate. These results demonstrate that this photocatalytic system not only exhibit a high efficiency but also avoid the consequent secondary pollutions due to the no formation of complex hydroxyl derivatives.

Paraben Toxicology

Parabens now being formally declared as the American Contact Dermatitis Society (non)allergen of the year, the allergologic concerns regarding parabens raised during the past century are no longer a significant issue. The more recent toxicological concerns regarding parabens are more imposing, stemming from the gravity of the noncutaneous adverse health effects for which they have been scrutinized for the past 20 years. These include endocrine activity, carcinogenesis, infertility, spermatogenesis, adipogenesis, perinatal exposure impact, and nonallergologic cutaneous, psychologic, and ecologic effects. To assert that parabens are safe for use as currently used in the cosmetics, food, and pharmaceutical industries, all toxicological end points must be addressed. We seek to achieve perspective through this exercise: perspective for the professional assessing systemic risk of parabens by all routes of exposure. The data reviewed in this article strive to provide a balanced perspective for the consumer hopefully to allay concerns regarding the safety of parabens and facilitate an informed decision-making process. Based on currently available scientific information, claims that parabens are involved in the genesis or propagation of these controversial and important health problems are premature. Haste to remove parabens from consumer products could result in their substitution with alternative, less proven, and potentially unsafe alternatives, especially given the compelling data supporting the lack of significant dermal toxicity of this important group of preservatives.

Oxidation of methylparaben (MeP) and p‑hydroxybenzoic acid (p-HBA) by manganese dioxide (MnO2) and effects of iodide: Efficiency, products, and toxicity

It is reported that methylparaben (MeP, a widely used phenolic preservative) and its major metabolite p‑hydroxybenzoic acid (p-HBA) display estrogenic activity and are frequently detected in various environmental settings. Naturally occurring manganese dioxide (MnO₂) plays an important role in attenuation of contaminants released into the environment, and the presence of iodide (I^-) may affect these processes. In this work, it was found that both MeP and p-HBA displayed considerable reactivity towards MnO₂ with their half-lives increased with decreasing MnO₂ concentrations or increasing pH. The presence of I^- obviously accelerated the transformation efficiency of MeP and p-HBA by MnO₂ with stronger enhancement at higher I^- concentrations or lower pH. Dimeric products (e.g., dimeric MeP or p-HBA) were generated from MeP/p-HBA treated by MnO₂, and iodinated aromatic products (e.g., mono-/di-iodinated MeP/p-HBA) were additionally identified in the presence of I^-. Higher concentrations of these iodinated aromatic products were generally formed at higher I^- or lower MnO₂ concentrations or lower pH. Ecotoxicity analysis showed that dimeric and iodinated aromatic products were more eco-toxic than parent MeP/p-HBA. This work shows that MnO₂ may greatly affect the fate of MeP and p-HBA released into the environment, and the presence of I^- can significantly affect these processes.

Widespread occurrence of glyphosate in urine from pet dogs and cats in New York State, USA

Glyphosate is one of the most widely used herbicides in the United States, which has led to its ubiquitous occurrence in food and water and regular detection in human urine at concentrations of 1-10 μg/L. Data pertaining to health risks arising from the ingestion of glyphosate are limited and are the subject of much debate, which demands the need for more exposure information for this herbicide. Very little is known about glyphosate exposure in pets. In this study, we determined concentrations of glyphosate (Glyp) and its derivatives, methyl glyphosate (Me-Glyp) and aminomethylphosphonic acid (AMPA), in urine collected from 30 dogs and 30 cats from New York State, USA. Glyp was the most predominant compound found in pet urine followed by AMPA and Me-Glyp. The mean urinary concentration of ∑Glyp (sum of Glyp + Me-Glyp + AMPA) in cats (mean: 33.8 ± 46.7 ng/mL) was 2-fold higher than that in dogs (mean: 16.8 ± 24.4 ng/mL). Cumulative daily intakes (CDI) of Glyp in dogs and cats estimated from the urinary concentrations were, on average, 0.57 and 1.37 μg/kg bw/d, respectively. The exposure doses were two to four orders of magnitude below the current acceptable daily intake (ADI) suggested by several international health organizations for humans.

Biocatalytic Degradation of Parabens Mediated by Cell Surface Displayed Cutinase

Parabens are emerging environmental contaminants with known endocrine-disrupting effects. This study created a novel biocatalyst (named as SDFsC) by expressing the enzyme Fusarium solani pisi cutinase (FsC) on the cell surface of Baker's yeast Sacchromycese cerevisiae and demonstrated successful enzyme-mediated removal of parabens for the first time. Parabens with different side chain structures had different degradation rates by the SDFsC. The SDFsC preferentially degraded the parabens with relatively long alkyl or aromatic side chains. The structure-dependent degradability was in a good agreement with the binding energy between the active site of FsC and different parabens. In real wastewater effluent solution, the SDFsC effectively degraded 800 μg/L of propylparaben, butylparaben, and benzylparaben, either as a single compound or as a mixture, within 48 h. The estrogenic activity of parabens was considerably reduced as the parent parabens were degraded into 4-hydroxybenzoic acid via hydrolysis pathway by the SDFsC. The SDFsC showed superior reusability and maintained 93% of its initial catalytic activity after six rounds of paraben degradation reaction. Results from this study provide scientific basis for developing biocatalysis as a green chemistry alternative for advanced treatment of parabens in sustainable water reclamation.

Evaluation of parabens and their metabolites in fish and fish products: a comprehensive analytical approach using LC-HRMS

Parabens (PBs) are preservatives frequently used in cosmetics and personal care products as well as in the pharmaceutical and food industries due to their extensive defence mechanisms against multiple categories of microorganisms. Although they are considered safe when used within defined concentration limits, concern about their potential toxicity is still particularly active. Revealed as emerging pollutants, their incidence and behaviour in the aquatic environment have been studied, but there is only sporadic information when it comes to their extent and distribution in seafood. This study explores the presence of methyl- (MeP), ethyl-, propyl-, butyl-, and benzylparaben and their main degradation product 4-hydroxybenzoic acid (pHBA) in several fish species and bivalve samples with the aim to evaluate these food matrices as potentially important contamination sources of PB. Additionally, infant food containing fish was also enrolled in this survey: firstly, due to the absence of any information regarding this exceptionally important food item, and secondly, because of the necessity to estimate the PB content in the processed food. For this purpose, a fast, reliable and robust method was developed based on a simple liquid-liquid extraction followed by high-performance LC, coupled with a benchtop Q-Exactive Orbitrap high-resolution MS. The Q-Exactive parameters were carefully scheduled to achieve a balance between the optimal scan speed and selectivity, considering the limitations that are associated with generic sample preparation methodology. The method was validated through specificity, linearity, recovery, intra- and inter-day repeatability, LOD and LOQ. LOD and LOQ reached the ranges 0.65-3.5 and 2.15-11.7 ng g^-1, respectively, while overall recovery ranged from 77% to 118%. The PBs were more frequently present in bivalves than in fish samples with MeP as the main PB detected. No PBs were found in infant food, but pHBA was observed in all samples.

Elevated Concentrations of Bisphenols, Benzophenones, and Antimicrobials in Pantyhose Collected from Six Countries

Pantyhose, a skin-tight item of clothing made of synthetic fibers and worn by women in many countries, is a source of exposure to several endocrine-disrupting chemicals. Little is known regarding the occurrence of and dermal exposure to chemicals present in pantyhose. In this study, concentrations and profiles of 23 endocrine-disrupting chemicals, including bisphenols, benzophenones, chlorophenols, parabens, and triclocarban (TCC), were determined in 74 pantyhose samples collected from 6 countries. Pantyhose samples were analyzed by two extraction methods: complete dissolution and ultrasonic extraction. Dissolution of the fabric in 1,1,1,3,3,3-hexafluoro-2-propanol/chloroform yielded concentrations of several target chemicals that were up to 286 times higher than in the ultrasonic extraction. Bisphenol S (BPS) and bisphenol A (BPA) were found in 100% and 96% of the samples at median concentrations of 1430 and 14.3 ng/g, respectively. Several brands of pantyhose contained BPS, bisphenol F (BPF), benzophenone-1 (BP-1), ethyl-paraben (EtP), and TCC at concentrations of milligrams per gram. Benzophenone-3 (BP-3), 4-hydroxy benzoic acid (4-HB), and methyl- (MeP) and propyl-parabens (PrP) were found in ≥85% of the samples at median concentrations on the order of several tens to hundreds of nanograms per gram of fabric. Pantyhose made in Japan and China with 21-50% Spandex contained the highest concentrations of BPS (2.2 mg/g), BP-1 (2.4 mg/g), and EtP (88 μg/g). Calculated dermal exposure doses to BPS, BP-1, and EtP by women via pantyhose were as high as 45 900, 50 600, and 1800 picograms per kilogram of body weight per day, respectively.

Temporal Trends of Parabens and Their Metabolites in Mollusks from the Chinese Bohai Sea during 2006-2015: Species-Specific Accumulation and Implications for Human Exposure

Parabens are used as preservatives in many consumer products, and human exposure to these chemicals has been a public concern. In this study, mollusks ( n = 186), collected from the Chinese Bohai Sea during 2006-2015, were analyzed for six parabens and their five metabolites. The total concentration of parabens was in the range of 2.66-299 ng/g dw (geometric mean: 24.1). Methyl paraben and 4-hydroxybenzoic acid were the predominant parent and metabolic parabens, respectively found in mollusks. Mollusk species, Mactra veneriformis, Mytilus edulis, and Cyclina sinensis contained elevated concentrations of both parent and metabolic parabens. A gradual increase in paraben concentrations was found in mollusks collected between 2006 and 2012. Principal component analysis suggested the existence of a common source for these chemicals in mollusks. Consumption of mollusks can contribute to human exposures and we estimated daily intakes of parabens through the consumption of mollusks. This is the first study to report temporal trends and accumulation of parabens and their metabolites in a variety of invertebrate species from coastal marine environments.