Phthalates exposure indicators determined by urinary phthalate metabolites in healthy non-obese Czech adults: FANTOM study

Urinary levels of parabens, phthalate metabolites, bisphenol A and plasticizer alternatives in a Belgian population: Time trend or impact of an awareness campaign?

A human biomonitoring study was carried out in 2015 within an adult population living in Liege (Belgium). Some phthalate metabolites and parabens were measured in the urine of 252 participants, and information were collected about their food habits, life styles and home environment to identify some predictors of exposure. Concomitantly, an awareness campaign was initiated by the Provincial Authorities of Liege and spread over 2 years. Three years later (2018), 92 of the initial participants provided again urine samples, and the levels of phthalate metabolites, phthalate substitute (DINCH), parabens, bisphenol-A and bisphenol alternatives (bisphenol-S, -F, -Z, -P) were determined and compared to those obtained in 2015 to assess time trends. In 2015, methyl- and ethylparaben were the most abundant parabens (P50 = 9.12 μg/L and 1.1 μg/L respectively), while propyl- and butylparaben were sparsely detected. Except for mono-2-ethylhexyl phthalate and 6-OH-mono-propyl-heptyl phthalate, all other targeted phthalate metabolites were positively quantified in most of the urine samples (between 89 and 98%) with median concentrations ranging between 2.7 μg/L and 21.3 μg/L depending on the metabolite. The multivariate regression models highlighted some significant associations between urinary phthalate metabolite or paraben levels and age, rural or urban character of the residence place, and the use of some personal care products. However, all determination coefficients were weak meaning that the usual covariates included in the models only explained a small part of the variance. Between 2015 and 2018, levels of parabens and phthalate metabolites significantly decreased (from 1.3 to 2.5 fold) except for monoethyl phthalate which seemed to remain quite constant. Contrariwise, all bisphenol alternatives and DINCH metabolites were measured in higher concentrations in 2018 vs 2015 while BPA levels did not differ significantly. However, it was not feasible to unequivocally highlight an impact of the awareness campaign on the exposure levels of the population.

Phthalates in dormitory dust and human urine: A study of exposure characteristics and risk assessments of university students

Phthalate diesters (PAEs) are prevalent and potentially toxic to human health. The university dormitory represents a typical and relatively uniform indoor environment. This study evaluated the concentrations of phthalate monoesters (mPAEs) in urine samples from 101 residents of university status, and the concentrations of PAEs in dust collected from 36 corresponding dormitories. Di-(2-ethylhexyl) phthalate (DEHP, median: 68.0 μg/g) was the major PAE in dust, and mono-ethyl phthalate (47.9 %) was the most abundant mPAE in urine. The levels of both PAEs in dormitory dust and mPAEs in urine were higher in females than in males, indicating higher PAE exposure in females. Differences in lifestyles (dormitory time and plastic product use frequency) may also affect human exposure to PAEs. Moreover, there were significant positive correlations between the estimated daily intakes of PAEs calculated by using concentrations of PAEs in dust (EDI_D) and mPAEs in urine (EDI_U), suggesting that PAEs in dust could be a significant source of human exposure to PAEs. The value of EDI_D/EDI_U for low molecular weight PAEs (3-6 carbon atoms in their backbone) was lower than that of high molecular weight PAEs. The contribution rate of various pathways to PAE exposure illustrated that non-dietary ingestion (87.8 %) was the major pathway of human exposure to PAEs in dust. Approximately 4.95 % of university students' hazard quotients of DEHP were >1, indicating that there may be some health risks associated with DEHP exposure among PAEs. Furthermore, it is recommended that some measures be taken to reduce the production and application of DEHP.

The independent and interactive effects of phthalates exposure and hypertension on the indicators of early renal injury in US adults: Evidence from NHANES 2001-2004

The association between phthalates and early renal injury is largely unknown in adults. We aim to explore the associations of phthalates and hypertension with early renal injury, and the interactive effects of phthalate and hypertension on the early renal injury. This study enrolled 3283 U.S. adults from NHANES 2001-2004. We detected nine phthalate metabolites in spot urine. We also measured the multiple indicators of early renal injury, including albumin-to-creatinine (Cr) ratio (ACR), β2-microglobulin (B2M), cystatin C (CYST), and calculated the estimated glomerular filtration rate (eGFR), including Cr-based eGFR, CYST-based eGFR, and Cr-CYST-based eGFR. Multiple linear regression and multivariable logistic regression were used to explore the associations among urinary phthalate metabolites, hypertension, and the indicators of early renal injury. The results showed that monobenzyl phthalate (MBzP), mono (3-carboxypropyl) phthalate (MCPP), and mono (2-ethylhexyl) phthalate (MEHP) were positively associated with ACR, B2M, CYST and negatively associated with three eGFR. Mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) was positively associated with ACR, with a β value of 0.099 (95% CI: 0.046, 0.152). Meanwhile, MEHP was associated with a higher risk of ACR abnormality, with an OR value of 1.258 (95% CI: 1.067, 1.482). MBzP, MCPP, and MEOHP increased the risks of ACR, B2M, CYST, and eGFR abnormality. Hypertension was positively associated with ACR, with a β value of 0.460 (95% CI: 0.360, 0.561). We also found interactive effects of monoethyl phthalate (MEP), MCPP, MBzP, monobutyl phthalate (MnBP), and hypertension on B2M, CYST, and three kinds of eGFR. Our results indicated that certain phthalate metabolites might contribute to increased risks of early renal injury. The hypertension population may be more sensitive to the early renal injury caused by phthalates exposure than the non-hypertension population.

Exposure to phthalates from personal care products: Urinary levels and predictors of exposure

Phthalates are a large group of chemicals used in many everyday consumer products such as food packaging, household cleaners, cosmetics, fragrances and personal care products (PCPs). A number of diseases such as obesity, hypertension, as well as reproductive system effects and endocrine disorders have been linked to phthalate exposure through the use of PCPs, due to their frequent use and high phthalate content. In this study we review available literature on phthalates and their metabolites in urine and report the various determinants of exposure through the use of PCPs in infants, toddlers, children and adults. The range of creatinine-adjusted concentrations for each phthalate was 1.5-14956.1 μg/g for MEP, 0.4-94.5 μg/g for MEHP, 0.39-425.9 μg/g for MEHHP, 0.5-481.3 μg/g for MEOHP, 0.1-755.1 μg/g for MBzP, and 0.3-401.4 μg/g for MiBP. Time of sampling, frequency of use, race and age are critical factors that influence phthalate concentrations. Using PCPs 48 h before urine collection, using a combination of PCPs (i.e., particularly leave-on versus rinse-off products), being younger (i.e., children compared to their mothers), and being a woman of colour (i.e., Mexican-American and black versus white) leads to higher phthalate levels in urine. The most striking association between any phthalate and PCPs was observed between MEP and perfumes or fragrance-containing products such as shampoos, body lotions and hair products. Future studies should focus on different types and brands of PCPs (i.e., branded versus generic), explore possible ethnic/racial differences and the applicability of non-invasive matrices such as nails and hair for phthalate biomonitoring, as well as intervention studies that explore behavioural changes.

Autistic-like traits in laboratory rodents exposed to phthalic acid esters during early development - an animal model of autism?

Phthalates are chemical substances that are widely used to provide flexibility and durability to plastic materials. They leach from products in which they are mixed and reach living organisms. Results from experimental studies suggest that exposure to phthalates can have a negative impact on an individual's neuronal system and behavior. In this regard, exposure during early ontogenesis seems to be particularly dangerous due to the extensive growth and development of body structures and functions. Disruption during this critical time can result in alterations of behavior and the emergence of neurodevelopmental disorders, such as autism spectrum disorder (ASD). Various animal models have been used to elucidate the pathogenesis of this disease. They are fundamental for research, and although the translation of results to humans is difficult, new animal models are being developed. The aim of this review is to summarize laboratory rodent studies in which early developmental phthalate exposure resulted in brain alterations and autistic-like behavioral traits. We also discuss the possibility of using early developmental phthalate exposure in rodents to create a new animal model of autism.

Levels and determinants of urinary phthalate metabolites in Chinese community-dwelling older adults

BACKGROUND

Biomonitoring studies have demonstrated extensive exposure of infants, children, and pregnant women to phthalates, but data on phthalate exposure and their determinants in Chinese older adults remain insufficient. This study aims to assess urinary phthalate metabolite levels, individual and cumulative exposure risk, and their determinants in Chinese community-dwelling older adults.

METHODS

A total of 987 individuals aged 60 years or over were included in this study. The urinary levels of seven phthalate metabolites were measured using high-performance liquid chromatography-tandem mass spectrometry. The estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) of phthalates were calculated based on urinary metabolite levels. The associations between phthalate metabolite levels and potential determinants were examined using multiple linear regressions.

RESULTS

Detection rates of seven phthalate metabolites from the study population ranged from 63.83% to 99.39%. The highest median concentration was 43.64 μg/L (42.59 μg/g creatinine) for mono-butyl phthalate (MBP). The highest median EDI was 1.55 μg/kg-bw/day for diethyl phthalate (DBP). Nearly 5% of participants had high HI values exceeding 1, mainly attributed to DBP and di-2-ethylhexyl phthalate (DEHP). Furthermore, we found that females, higher body mass index (BMI), smoking, having two or more chronic diseases, and vegetable-based diets were significantly associated with higher levels of parts of phthalate metabolites. More interestingly, higher urine levels of high-molecular-weight (HMW) phthalate metabolites and lower urine levels of low-molecular-weight (LMW) phthalate metabolites were found in rural older adults than in urban older adults.

CONCLUSIONS

Chinese community-dwelling older adults are extensively exposed to phthalates, especially to DBP and DEHP. More attention should be paid to urban-rural differences in exposure to HMW and LMW phthalates and to phthalate exposure among older adults with overweight/obesity, females, and individuals who are current heavy smokers, have two or more chronic diseases, and consume vegetable-based diets.

Biomarkers, matrices and analytical methods targeting human exposure to chemicals selected for a European human biomonitoring initiative

The major purpose of human biomonitoring is the mapping and assessment of human exposure to chemicals. The European initiative HBM4EU has prioritized seven substance groups and two metals relevant for human exposure: Phthalates and substitutes (1,2-cyclohexane dicarboxylic acid diisononyl ester, DINCH), bisphenols, per- and polyfluoroalkyl substances (PFASs), halogenated and organophosphorous flame retardants (HFRs and OPFRs), polycyclic aromatic hydrocarbons (PAHs), arylamines, cadmium and chromium. As a first step towards comparable European-wide data, the most suitable biomarkers, human matrices and analytical methods for each substance group or metal were selected from the scientific literature, based on a set of selection criteria. The biomarkers included parent compounds of PFASs and HFRs in serum, of bisphenols and arylamines in urine, metabolites of phthalates, DINCH, OPFRs and PAHs in urine as well as metals in blood and urine, with a preference to measure Cr in erythrocytes representing Cr (VI) exposure. High performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was the method of choice for bisphenols, PFASs, the HFR hexabromocyclododecane (HBCDD), phenolic HFRs as well as the metabolites of phthalates, DINCH, OPFRs and PAHs in urine. Gas chromatographic (GC) methods were selected for the remaining compounds, e.g. GC-low resolution MS with electron capture negative ionization (ECNI) for HFRs. Both GC-MS and LC-MS/MS were suitable for arylamines. New developments towards increased applications of GC-MS/MS may offer alternatives to GC-MS or LC-MS/MS approaches, e.g. for bisphenols. The metals were best determined by inductively coupled plasma (ICP)-MS, with the particular challenge of avoiding interferences in the Cd determination in urine. The evaluation process revealed research needs towards higher sensitivity and non-invasive sampling as well as a need for more stringent quality assurance/quality control applications and assessments.

Urinary metabolites of phthalates and di-iso-nonyl cyclohexane-1,2-dicarboxylate (DINCH)-Czech mothers' and newborns' exposure biomarkers

To assess human exposure to hazardous diesters of phthalic acid and their substitute di-iso-nonyl cyclohexane-1,2-dicarboxylate (DINCH), concentrations of their metabolites in urine should be determined. For the purpose of this biomonitoring study, a quick and easy sample preparation procedure for the simultaneous determination of eight phthalate and four DINCH metabolites in urine has been implemented and validated. Following the enzymatic hydrolysis and dilution with methanol, the sample is ready for the analysis by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The limits of quantification of this method ranged from 0.15 to 0.4 ng/mL urine with recoveries of 60-126% and repeatability in the range of 1-11%. The validated method was subsequently used for the analysis of urine samples collected from mothers and their newborn children living in two localities of the Czech Republic (Karvina and Ceske Budejovice, 2013-2014). Median concentrations of all measured metabolites (∑metabolites) were slightly lower in the urine samples collected from children (77.7 ng/mL urine) compared to their mothers (115.3 ng/mL urine), but no correlation was found between the concentrations of target compounds in children's and mothers' urine samples. The analyte with the highest concentration was monobutyl phthalate (MBP), with the median concentration of 32.1 ng/mL urine in the urine samples collected from mothers and 17.2 ng/mL urine in the samples collected from their children. This compound was also found in almost all of the measured samples. On the other hand, mono-isononyl-cyclohexane-1,2-dicarboxylate (MINCH) was not found in any urine sample. The most contaminated samples were collected from children living in the Karvina locality (median ∑metabolites 103.2 ng/mL urine), where the mono (2-ethyl-5-carboxypentyl) phthalate (cx-MEHP) compound contributed 43% to the total content of phthalate metabolites in newborns' urine. The results from our study are comparable with concentrations of the target compounds from Norway and Germany and lower compared to the results concluded in Sweden.

Urine Levels of Phthalate Metabolites and Bisphenol A in Relation to Main Metabolic Syndrome Components: Dyslipidemia, Hypertension and Type 2 Diabetes. A Pilot Study

AIM

Human exposure to organic pollutants (some of them also called endocrine disruptors) can be associated with adverse metabolic health outcomes including type 2 diabetes. The goal of this study was to compare the urine levels of bisphenol A and phthalate metabolites in subgroups of patients with metabolic syndrome composed of patients with and without three important components of metabolic syndrome (hypertension, dyslipidemia and diabetes).

METHODS

We have investigated 24 hr urine samples of 168 patients with metabolic syndrome from the Metabolic Outpatient Department of General University Hospital in Prague. Using standard metabolic syndrome criteria, we classified patients as dyslipidemic (n=87), hypertensive (n=96), and type 2 diabetic (n=58). Bisphenol A and 15 metabolites of phthalates were evaluated in relation to creatinine excretion. Samples were analysed with enzymatic cleavage of glucuronide using ultra-high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in one laboratory with external quality control.

RESULTS

Four metabolites, mono-n-butyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-carboxypentyl) phthalate showed significantly higher levels in diabetic compared to non-diabetic patients (p<0.001, p=0.002, p=0.002, and p=0.005, respectively). The differences remained significant after adjustment to hypertension, dyslipidemia, age, and BMI. No difference was found between either the hypertensive and non-hypertensive or dyslipidemic and non-dyslipidemic patients. There was no significant relation of bisphenol A level to diabetes, hypertension, dyslipidemia, age, and BMI.

CONCLUSIONS

Urine levels of four phthalate metabolites were significantly higher in type 2 diabetics independently on specified predictors. Phthalate levels can be in relation to beta cell dysfunction in type 2 diabetic patients but this study is not able to show if the relation is causal.