Occupational Exposures to Phthalates among Black and Latina U.S. Hairdressers Serving an Ethnically Diverse Clientele: A Pilot Study

Phthalate and phthalate replacement concentrations in relationship to adiposity in a multi-racial cohort of children

BACKGROUND/OBJECTIVE

Phthalates and phthalate replacements are used in multiple everyday products, making many of them bioavailable to children. Experimental studies suggest that phthalates and their replacements may be obesogenic, however, epidemiologic studies remain inconsistent. Therefore, our objective was to examine the association between phthalates, phthalate replacements and childhood adiposity/obesity markers in children.

SUBJECTS/METHODS

A cross-sectional study was conducted in 630 racial/ethnically diverse children ages 4-8 years. Urinary oxidative metabolites of DINCH and DEHTP, three low molecular weight (LMW) phthalates, and eleven high molecular weight (HMW) phthalates were measured. Weight, height, waist circumference and % body fat were measured. Composite molar sum groups (nmol/ml) were natural log-transformed. Linear regression models adjusted for urine specific gravity, sex, age, race-ethnicity, birthweight, breastfeeding, reported activity level, mother's education and pre-pregnancy BMI.

RESULTS

All children had LMW and HMW phthalate metabolites and 88% had DINCH levels above the limit of detection. One unit higher in the log of DINCH was associated with 0.106 units lower BMI z-score [β = -0.106 (95% CI: -0.181, -0.031)], 0.119 units lower waist circumference z-score [β = -0.119 (95% CI: -0.189, -0.050)], and 0.012 units lower percent body fat [β = -0.012 (95% CI: -0.019, -0.005)]. LMW and HMW group values were not associated with adiposity/obesity.

CONCLUSIONS

We report an inverse association between child urinary DINCH levels, a non-phthalate plasticizer that has replaced DEHP in several applications, and BMI z-score, waist circumference z-score and % body fat in children. Few prior studies of phthalates and their replacements in children have been conducted in diverse populations. Moreover, DINCH has not received a great deal of attention or regulation, but it is a common exposure. In summary, understanding the ubiquitous nature of these chemical exposures and ultimately their sources will contribute to our understanding of their relationship with obesity.

Risk perception and use of personal care products by race and ethnicity among a diverse population

Personal care products can contain phthalates, parabens and other endocrine-disrupting chemicals. However, information on perception of risks from personal care product use and how use varies by race and ethnicity is limited. We evaluated differences in personal care product use and risk perception in a diverse sample of participants recruited from a US college campus and online. A self-administered questionnaire captured information on sociodemographic factors, personal care product use trends and perception of risk associated with them. Pearson's chi-square and Fisher's exact tests were used to determine differences in personal care product use and risk perception by race and ethnicity. Ordered logistic regressions were performed to measure associations between personal care product use frequency across racial/ethnic categories. Participant (n = 770) mean age was 22.8 years [standard deviation ± 6.0]. Daily use of make-up (eye = 29.3%; other = 38.0%; all = 33.7%) and skincare products (55%) was most frequently reported among Middle Eastern and North African participants. Non-Hispanic Black participants reported the highest daily use of hairstyling products (52%) and lotion (78%). Daily make-up use was more frequently reported among females (41%) than males (24.6%). Levels of agreement were similar across racial and ethnic groups, that personal care product manufacturers should be required to list all ingredients (≥87%). There were significant associations between the frequency of use of some personal care products and racial/ethnic categories when the use frequencies of participants from other racial/ethnic categories were compared to the use frequency of non-Hispanic White participants. There were significant differences in daily use frequency, levels of trust, perception of safety and health risks associated with personal care products by race and ethnicity, underscoring that there may be different sources of exposure to chemicals in personal care products by race and ethnicity.

Mechanism of the adverse outcome of Chlorella vulgaris exposure to diethyl phthalate: Water environmental health reflected by primary producer toxicity

As a ubiquitous contaminant in aquatic environments, diethyl phthalate (DEP) is a major threat to ecosystems because of its increasing utilization. However, the ecological responses to and toxicity mechanisms of DEP in aquatic organisms remain poorly understood. To address this environmental concern, we selected Chlorella vulgaris (C. vulgaris) as a model organism and investigated the toxicological effects of environmentally relevant DEP concentrations at the individual, physiological, biochemical, and molecular levels. Results showed that the incorporation of DEP significantly inhibited the growth of C. vulgaris, with inhibition rates ranging from 10.3 % to 83.47 %, and disrupted intracellular chloroplast structure at the individual level, while the decrease in photosynthetic pigments, with inhibition rates ranging from 8.95 % to 73.27 %, and the imbalance of redox homeostasis implied an adverse effect of DEP at the physio-biochemical level. Furthermore, DEP significantly reduced the metabolic activity of algal cells and negatively altered the cell membrane integrity and mitochondrial membrane potential. In addition, the apoptosis rate of algal cells presented a significant dose-effect relationship, which was mainly attributed to the fact that DEP pollutants regulated Ca2+ homeostasis and further increased the expression of Caspase-8, Caspase-9, and Caspase-3, which are associated with internal and external pathways. The gene transcriptional expression profile further revealed that DEP-mediated toxicity in C. vulgaris was mainly related to the destruction of the photosynthetic system, terpenoid backbone biosynthesis, and DNA replication. Overall, this study offers constructive understandings for a comprehensive assessment of the toxicity risks posed by DEP to C. vulgaris.

What a mix! Volatile organic compounds and worker exposure in small business beauty salons in Tucson, Arizona

Introduction

Small business beauty salons have volatile organic compounds (VOCs) in their workplace air. VOCs are present as ingredients in beauty or hair products. They may also form because of chemical reactions, where thermal-styling elements accelerate the volatilization of these compounds. Uncertainties remain about the relationship between air pollutant concentrations and the variety of beauty salon activities in a work shift. Investigating these associations can help determine high-risk services, associated products, and at-risk workers.

Methods

In this exploratory study, female community health workers recruited beauty salons from target zip codes in predominately Latino neighborhoods, including primarily Spanish-speaking small businesses. We collected salon chemical inventories, business characteristics, and participant activity logs to understand how chemicals and activities influence the total and specific VOC concentrations. We sampled personal total VOCs and specific VOCs from the same shop during the participant work shift. We also measured personal total VOCs for four work shifts per shop.

Results

A linear mixed effects model of log VOCs on the fixed effect of activity and the random effects of salon and shift within the salon showed that the variance between salons explains over half (55%) of the total variance and is 4.1 times bigger than for shifts within salons. Summa canisters detected 31 specific VOCs, and hazard scores ranged between 0 and 4.3. 2-Propanol (isopropyl alcohol) was the only VOC detected in all shifts of all salons.

Discussion

In this study, differences in VOC measurements were primarily between salons. These differences may result from differences in ventilation, services rendered, and product lines applied.

Assessment of the plasticizer exposure of hospital workers regularly handling medical devices: A pilot study

Plastic medical devices, e.g. infusion sets, blood bags or tubing material, that are used manifold in the medical treatment of hospital patients, usually contain considerable amounts of plasticizers. Whereas several studies showed highly elevated inner plasticizer levels of patients treated with plasticized medical devices, little is known about the exposure situation of hospital staff. The present pilot study aimed to evaluate the urinary plasticizer metabolite levels of selected hospital workers of the blood bank (medical technical assistants, MTA) and of perfusionists that are regularly handling plasticized medical devices in order to estimate the work-related amount of the inner individual plasticizer exposure. The study subjects were asked to collect pre- and post-shift spot urine samples over the course of a working week, that were subsequently analyzed for selected urinary metabolites of the plasticizers DEHP, DINCH, DEHTP and TEHTM. Although the observed differences were rather low, a differentiated approach revealed a perceptible impact of the respective workplace environment on the individual urinary plasticizer metabolite levels. Thus, the group of blood bank MTA showed significantly elevated increment levels of urinary DEHP and DINCH metabolites, while the group of perfusionists, showed a considerable higher detection frequency of the main urinary TEHTM metabolite. All in all, however, it can be cautiously concluded by the results of the presented pilot study that a regular handling of plasticized medical devices by hospital employees (via inhalation or dermal contact) contributes demonstrably but yet only marginally to the individual internal plasticizer exposure.

Implementing a suspect screening method to assess occupational chemical exposures among US-based hairdressers serving an ethnically diverse clientele: a pilot study

BACKGROUND

There are over 700,000 hairdressers in the United States, and it is estimated that >90% are female and 31% are Black or Hispanic/Latina. Racial and ethnic minorities in this workforce may be exposed to a unique mixture of potentially hazardous chemicals from products used and services provided. However, previous biomonitoring studies of hairdressers target a narrow list of compounds and few studies have investigated exposures among minority hairdressers.

OBJECTIVE

To assess occupational chemical exposures in a sample of US-based Black and Latina hairdressers serving an ethnically diverse clientele by analyzing urine specimens with a suspect screening method.

METHODS

Post-shift urine samples were collected from a sample of US female hairdressers (n = 23) and office workers (n = 17) and analyzed via reverse-phase liquid chromatography coupled to high-resolution mass spectrometry. Detected compounds were filtered based on peak area differences between groups and matching with a suspect screening list. When possible, compound identities were confirmed with reference standards. Possible exposure sources were evaluated for detected compounds.

RESULTS

The developed workflow allowed for the detection of 24 compounds with median peak areas ≥2x greater among hairdressers compared to office workers. Product use categories (PUCs) and harmonized functional uses were searched for these compounds, including confirmed compounds methylparaben, ethylparaben, propylparaben, and 2-naphthol. Most product use categories were associated with "personal use" and included 11 different "hair styling and care" product types (e.g., hair conditioner, hair relaxer). Functional uses for compounds without associated PUCs included fragrance, hair and skin conditioning, hair dyeing, and UV stabilizer.

SIGNIFICANCE

Our suspect screening approach detected several compounds not previously reported in biomonitoring studies of hairdressers. These results will help guide future studies to improve characterization of occupational chemical exposures in this workforce and inform exposure and risk mitigation strategies to reduce potential associated work-related health disparities.

Molecular Dynamics Simulation Prediction of the Partitioning Constants (KH, Kiw, Kia) of 82 Legacy and Emerging Organic Contaminants at the Water-Air Interface

The tendency of organic contaminants (OCs) to partition between different phases is a key set of properties that underlie their human and ecological health impacts and the success of remediation efforts. A significant challenge associated with these efforts is the need for accurate partitioning data for an ever-expanding list of OCs and breakdown products. All-atom molecular dynamics (MD) simulations have the potential to help generate these data, but existing studies have applied these techniques only to a limited variety of OCs. Here, we use established MD simulation approaches to examine the partitioning of 82 OCs, including many compounds of critical concern, at the water-air interface. Our predictions of the Henry's law constant (K_H) and interfacial adsorption coefficients (K_iw, K_ia) correlate strongly with experimental results, indicating that MD simulations can be used to predict K_H, K_iw, and K_ia values with mean absolute deviations of 1.1, 0.3, and 0.3 logarithmic units after correcting for systematic bias, respectively. A library of MD simulation input files for the examined OCs is provided to facilitate future investigations of the partitioning of these compounds in the presence of other phases.

Fluorescence Signal Amplification: Red Carbon Dots@SiO2-Induced Ultra-sensitive Immunoassay for Diethyl Phthalate

Carbon dots as new nanomaterials, have been widely used in rapid detection because of their nondestructive, real-time detection characteristics. Improving the sensitivity and selectivity of the method in complex real samples is new challenge and requirement for sensing technology. Here, we report an ultrasensitive fluorescence immunoassay (FIA) for trace diethyl phthalate (DEP) using red carbon dots@SiO₂ (R-CDs@SiO₂) as tags. SiO₂ as a nanocarrier can effectively improve the bio-functionalization and utilization rate of carbon dots. Moreover, several R-CDs embedded in SiO₂ nanospheres can magnify the fluorescence signal and improve sensitivity. R-CDs@SiO₂ conjugate anti-DEP antibody (Ab) as fluorescent immunosensor, which can specifically recognize DEP. Under optimization conditions, the detection limit (LOD) of this FIA was calculated as 0.0011 ng/mL. In addition, the recoveries of this established FIA ranged from 96.8 to 108.5%, showing satisfactory accuracy. Compared with GC-MS/MS (LOD µg/mL), the sensitivity of the FIA was significantly improved. As a result, the FIA developed using R-CDs@SiO₂ as tags has a high potential for determining trace DEP.

Impact of mono(2-ethylhexyl) phthalate (MEHP) on the development of mouse embryo in vitro

Mono(2-ethylhexyl) phthalate (MEHP) is the most studied metabolite of di(2-ethylhexyl) phthalate (DEHP), a phthalate found in cosmetics, flooring, paints, and plastics products, including toys and medical tubing. Humans are frequently exposed to this compound due to its ubiquitous presence in our environment. DEHP and MEHP are known to be endocrine-disrupting chemicals and exposure levels have been associated to decreased reproductive success. However, few studies have focused on the direct effects of MEHP on embryos. The present study investigated effects of MEHP (0.1, 1, 10, 100 and 1000 µM) on mice preimplantation embryonic development, evaluating percentage of blastocyst formation, hatching from zona pellucida, methylation-related genes, cell lineage commitment, micronucleation, and adherens junction marker at different stages of development during in vitro culture for 6 days. We show MEHP negatively impacts embryo competence by reducing blastocyst formation and hatching at 100 and 1000 µM. In addition, 100 µM MEHP increases the expression of Tet3 gene in blastocysts, which is related to a reduction of DNA methylation, an important mechanism regulating gene expression. Exposed embryos that completed the hatching process in groups 0.1, 1 and 10 µM MEHP had similar number of inner cell mass and trophectoderm cells compared to the control, while micronucleation occurrence and E-cadherin expression was not affected in exposed morulae by MEHP at 10 or 100 µM. Our results showed that high concentrations of MEHP can negatively impact embryo development. New studies unveiling the mechanism of toxicity involved and encompassing further developmental stages are warranted for further understanding.

Microbiome alterations from volatile organic compounds (VOC) exposures among workers in salons primarily serving women of color

Salon workers, especially those serving an ethnically and racially diverse clientele (i.e., Black/Latina), may experience disparately high levels of workplace exposures to respiratory irritants, including volatile organic compounds (VOCs). Salon workers are also reported to have a greater risk of developing respiratory conditions compared to the general population. Emerging evidence suggests that occupational chemical exposures may alter the human microbiome and that these alterations may be an important mechanism by which workplace VOC exposures adversely impact respiratory health. This preliminary research investigated the potential effects of 28 VOC urinary biomarkers on the 16S rRNA nasal microbiome in 40 workers from salons primarily serving women of color (Black and Dominican salons) compared to office workers. Our exploratory analysis revealed significant differences in microbial composition by worker group; namely dissimilar levels of Staphylococcus species (S. epidermidis and S. aureus, specifically) in salon workers compared to office workers, and higher alpha diversity levels in workers in Dominican salons compared to workers in Black salons. Within-sample alpha diversity levels tended to be decreased with higher VOC urinary biomarker concentrations, significantly for carbon disulfide, acrolein, acrylonitrile, crotonaldehyde, and vinyl chloride biomarkers. Our research highlights that occupational exposures, particularly to chemicals like VOCs, can impact the respiratory microbiome in the vulnerable salon worker group. Further understanding of the potential effects of chemical mixtures on microbial composition may provide key insights to respiratory health and other adverse health outcomes, as well as direct prevention efforts in this largely historically understudied occupational population.

Polyurethane Foam Face Masks as a Dosimeter for Quantifying Personal Exposure to Airborne Volatile and Semi-Volatile Organic Compounds

Airborne volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are commonly quantitated by collecting the analytes on solid sorbent tubes or passive air samplers, followed by solvent extraction and instrumental analysis, or by grab bag/canister measurements. We report herein a user-friendly sampling method by breathing through polyurethane foam (PUF) face masks to collect airborne VOCs and SVOCs for chemical analysis. Specifically, dibasic esters, phthalate esters, polycyclic aromatic hydrocarbons, linalool, and nicotine trapped on PUF masks were quantitated by gas chromatography-mass spectrometry analysis as model VOCs and SVOCs. Results showed that the amount of these model VOCs and SVOCs trapped on PUF masks is proportional to the exposure duration. After cross-validation by parallel sampling using XAD-2 packed sorbent tubes, the method was used to quantitate VOCs and SVOCs in a variety of indoor and outdoor environments with varying air concentrations of analytes, temperature, humidity, and wind speed. Because air pollution is considered a major cause of many human diseases and premature deaths and the developed PUF mask sampling method showed high trapping efficiencies for both VOCs and SVOCs, it is believed that the developed sampling method will find wide application in assessing air pollution-associated disease risks with possible extension to more classes of VOCs and SVOCs when coupled with suitable instrumental detection methods.

Significant changes in follicular fluid phthalate metabolite levels reflect the lifestyle changes brought about by the strict COVID-19 lockdown in India

OBJECTIVE

To assess if the unprecedented changes in lifestyle because of the lockdown initiated by the COVID-19 pandemic, which altered human behavior, and influenced purchase and consumption patterns, may have had an impact on the exposure to phthalates in Indian women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). To evaluate if the effects of the strict and lengthy lockdown in India, which promoted the new norms of stay-at-home and work-from-home, closure of beauty parlors, and restriction on public gatherings, may have contributed to a decrease in the exposure to phthalates like dibutyl phthalate and diethyl phthalate. These chemicals are found in many personal care products (PCPs) which include cosmetics and fragrances. To investigate if the extensive use of flexible single-use plastic in personal protective equipment like face masks/gloves and in plastic packaging used for online purchases, food takeaways, and home deliveries of essentials and groceries during the COVID-19 pandemic, in an attempt to provide a contact-free delivery system may have inadvertently led to an increase in exposure to phthalates like di(2-ethylhexyl) phthalate, di-isononyl phthalate, and di-isodecyl phthalate which are plasticizers used in manufacturing flexible plastic.

DESIGN

A comparative study of the levels of six phthalate metabolites detected in follicular fluid (FF) of Indian women undergoing IVF/ICSI 1 year before and immediately after the lockdown initiated by the COVID-19 pandemic.

SETTING

In vitro fertilization center in a large referral hospital in India.

PATIENT(S)

A total of 176 Indian women seeking treatment for infertility and undergoing oocyte retrieval were included after obtaining consent. Each woman contributed one FF sample to the study. Group A (n = 96) women (mean age, 34.0 [±3.9] years, and mean BMI, 25.4 [±4.8]) had their FF samples collected and screened between January 2019 and mid-March 2020, 1 year before the lockdown. Group B (n = 80) women (mean age, 33.9 [±4.1] years, and mean BMI, 25.0 [±4.4]) had their FF collected and screened post the lockdown between October 2020 and June 2021. Both groups were matched by age and BMI.

INTERVENTION(S)

The cryopreserved FF samples of 176 women were processed using enzymatic deconjugation as well as the solid-phase extraction technique, and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect the total levels of six phthalate metabolites.

MAIN OUTCOME MEASURE(S)

To evaluate the impact of the COVID-19 lockdown on the change in the phthalate metabolite levels in the FF of Indian women undergoing IVF/ICSI pre and post the lockdown.

RESULT(S)

The median levels of mono-n-butyl phthalate (1.64 ng/ml in group A vs. 0.93 ng/ml in group B; P<.001) and mono-ethyl phthalate (5.25 ng/ml in group A vs. 3.24 ng/ml in group B; P<.001) metabolites of dibutyl phthalate and diethyl phthalate found in PCPs including cosmetics and fragrances were significantly higher in the FF of 96 women (group A) compared with the levels seen in the FF of 80 women (group B). However, the median levels of mono-isononyl phthalate (0.11ng/ml in group A vs. 0.13 ng/ml in group B; P<.001), mono-isodecyl phthalate (0.11 ng/ml in group A vs. 0.14 ng/ml in group B; P<.001), and mono(2-ethyl-5-oxohexyl) phthalate (0.13 ng/ml in group A vs. 0.14 ng/ml in group B; P=.023) metabolites of di-isononyl phthalate, di-isodecyl phthalate, and di(2-ethylhexyl) phthalate used as plasticizers were significantly higher in the FF of women in group B compared with women in group A.

CONCLUSION(S)

The significant drop in mono-n-butyl phthalate and mono-ethyl phthalate levels, accumulated in the FF of 80 Indian women in group B reflects a decrease or absence of usage patterns of PCPs, including cosmetics and fragrances, thereby suggesting that these women may have deprioritized their use during the COVID-19 pandemic giving preference to personal hygiene and safety. Whereas the unprecedented increase in the use of flexible single-use plastic that became our first line of defense against the coronavirus during the COVID-19 pandemic might be responsible for the accumulation of significantly higher levels of mono-isononyl phthalate, mono-isodecyl phthalate, and mono(2-ethyl-5-oxohexyl) phthalate in FF of the same group.

The reaction laws and toxicity effects of phthalate acid esters (PAEs) ozonation degradation on the troposphere

Low-molecular-weight (LMW) phthalate acid esters (PAEs) tend to enter the atmosphere, flying for several kilometers, so it is easy to endanger human health. This work is the first to use quantum chemistry calculations (Gaussian 16 program) and computational toxicology (ECOSAR, TEST, and Toxtree software) to comprehensively study the ozonolysis mechanism of six LMW PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPP), diisopropyl phthalate (DIP), dibutyl phthalate (DBP), and diisobutyl phthalate (DIBP)) in the atmosphere and the toxicity of DMP (take DMP as an example) in the conversion process. The results show that the electron-donating effect of the ortho position of the LMW PAEs has the most obvious influence on the ozonolysis. We summarized the ozonation reaction law of LMW PAEs at the optimal reaction site. At 298 K, the law of initial ozonolysis total rate constant of the LMW PAEs is k_DIP > k_DPP > k_DIBP > k_DMP > k_DEP > k_DBP, and the range is 9.56 × 10^-25 cm³ molecule^-1 s^-1 - 1.47 × 10^-22 cm³ molecule^-1 s^-1. According to the results of toxicity assessment, the toxicity of products is lower than DMP for aquatic organisms after ozonolysis. But those products have mutagenicity, developmental toxicity, non-genotoxicity, carcinogenicity, and corrosiveness to the skin. The proposed ozonolysis mechanism promotes our understanding of the environmental risks of PAEs and provides new ideas for studying the degradation of PAEs in the tropospheric gas phase.