Urinary phthalate metabolite concentrations among workers in selected industries: a pilot biomonitoring study

Cognitive Functioning and Nail Salon Occupational Exposure among Vietnamese Immigrant Women in Northern California

Introduction: Vietnamese nail salon technicians are continuously exposed to neurotoxins linked to cognitive impairments and Alzheimer’s disease. This study examined the association of occupational exposure with cognitive function and depressive symptoms among Vietnamese nail salon technicians. Methods: The sample included 155 current or former Vietnamese female nail technicians and 145 control group participants. Measures included the Montreal Cognitive Assessment (MoCA) and the Center for Epidemiologic Studies Depression Scale (CES-D). Results: Average cognitive functioning was significantly higher for the control compared to the nail technician group (mean difference = 1.2, p < 0.05). No differences were observed for depression. Multivariate findings revealed that exposure was negatively associated with cognitive functioning (β = −0.29, 95% CI: −0.53, −0.05, p < 0.05). Discussion: Nail salon work and the extent of occupational exposure were associated with lower cognitive functioning among Vietnamese nail technicians. Longitudinal research can further examine the risk for cognitive decline and dementia for this vulnerable population.

Toxicology and carcinogenesis studies of di(2-ethylhexyl) phthalate administered in feed to Sprague Dawley (Hsd:Sprague Dawley SD) rats

Di(2-ethylhexyl) phthalate (DEHP) is a member of the phthalate ester chemical class that occurs commonly in the environment and to which humans are widely exposed. Lifetime exposure to DEHP is likely to occur, including during the in utero and early postnatal windows of development. To date, no carcinogenicity assessments of DEHP have used a lifetime exposure paradigm that includes the perinatal period (gestation and lactation). The National Toxicology Program (NTP) tested the hypothesis that exposure during the perinatal period would alter the DEHP carcinogenic response quantitatively (more neoplasms) or qualitatively (different neoplasm types). Two chronic carcinogenicity assessments of DEHP were conducted in which Sprague Dawley (Hsd:Sprague Dawley SD) rats were exposed to dosed feed containing 0, 300, 1,000, 3,000, or 10,000 ppm DEHP for 2 years using different exposure paradigms. In Study 1, groups of 45 F0 time-mated females were provided dosed feed beginning on gestation day (GD) 6 through lactation. On postnatal day (PND) 21, groups of 50 F1 rats per sex continued on the study and were provided dosed feed containing the same DEHP concentration as their respective dam for 2 years. In Study 2, groups of 50 rats per sex, aged 6 to 7 weeks at study start, were provided dosed feed containing DEHP for 2 years. (Abstract Abridged).

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

Hairdressers may be differentially exposed to phthalates through hair salon services provided and products used, yet no U.S. studies have investigated these exposures in this population. We characterized concentrations and exposure determinants to nine phthalate metabolites in postshift urine samples among 23 hairdressers from three Black and three Dominican salons, as well as a comparison group of 17 female office workers from the Maryland/Washington D.C. metropolitan area. Overall, hairdressers had higher metabolite concentrations than office workers. The geometric mean (GM) for monoethyl phthalate (MEP) was 10 times higher in hairdressers (161.4 ng/mL) than office workers (15.3 ng/mL). Hairdressers providing select services and using certain products had higher GM MEP concentrations than those who did not: permanent waves/texturizing (200.2 vs 115.4 ng/mL), chemical straightening/relaxing (181.6 vs 92.1 ng/mL), bleaching (182.3 vs 71.6 ng/mL), permanent hair color (171.9 vs 83.2 ng/mL), and Brazilian blowout/keratin treatments (181.4 vs 134.6 ng/mL). Interestingly, hairdressers providing natural services had lower GM MEP concentrations than those who did not: twists (129.1 vs 215.8 ng/mL), sister locs/locs (86.0 vs 241.9 ng/mL), and afros (94.7 vs 203.9 ng/mL). Larger studies are warranted to confirm our findings and identify disparities in occupational phthalate exposures.

Application of a combined aggregate exposure pathway and adverse outcome pathway (AEP-AOP) approach to inform a cumulative risk assessment: A case study with phthalates

Advancements in measurement and modeling capabilities are providing unprecedented access to estimates of chemical exposure and bioactivity. With this influx of new data, there is a need for frameworks that help organize and disseminate information on chemical hazard and exposure in a manner that is accessible and transparent. A case study approach was used to demonstrate integration of the Adverse Outcome Pathway (AOP) and Aggregate Exposure Pathway (AEP) frameworks to support cumulative risk assessment of co-exposure to two phthalate esters that are ubiquitous in the environment and that are associated with disruption of male sexual development in the rat: di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP). A putative AOP was developed to guide selection of an in vitro assay for derivation of bioactivity values for DEHP and DnBP and their metabolites. AEPs for DEHP and DnBP were used to extract key exposure data as inputs for a physiologically based pharmacokinetic (PBPK) model to predict internal metabolite concentrations. These metabolite concentrations were then combined using in vitro-based relative potency factors for comparison with an internal dose metric, resulting in an estimated margin of safety of ~13,000. This case study provides an adaptable workflow for integrating exposure and toxicity data by coupling AEP and AOP frameworks and using in vitro and in silico methodologies for cumulative risk assessment.

Subchronic Exposure to Di(2-ethylhexyl) Phthalate and Diisononyl Phthalate During Adulthood Has Immediate and Long-Term Reproductive Consequences in Female Mice

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used in a variety of consumer products. This is concerning because DEHP is an endocrine disruptor and ovarian toxicant. Diisononyl phthalate (DiNP) is a DEHP replacement that is a rising human toxicant due to its increased use as a DEHP substitute. However, little is known about the effects of DEHP or DiNP exposure during adulthood on female reproduction. Thus, this study tested the hypothesis that DEHP or DiNP exposure during adulthood has long-term consequences for female reproduction in mice. Adult female CD-1 mice (39-40 days) were orally dosed with vehicle control (corn oil), DEHP (20 µg/kg/day-200 mg/kg/day), or DiNP (20 µg/kg/day-200 mg/kg/day) for 10 days. Females were paired with untreated male mice for breeding trials immediately post-dosing and again at 3 and 9 months post-dosing. Immediately post-dosing, DEHP and DiNP did not affect fertility. At 3 months post-dosing, DiNP (20 and 100 µg/kg/day and 200 mg/kg/day) significantly disrupted estrous cyclicity, and DiNP and DEHP (20 µg/kg/day) significantly reduced the ability of females to get pregnant. At 9 months post-dosing, DiNP significantly disrupted estrous cyclicity (100 µg/kg/day), reduced time to mating (100 µg/kg/day-200 mg/kg/day), and borderline reduced percent of females who produced offspring (20 mg/kg/day). At 9 months post-dosing, DEHP (200 µg/kg/day and 200 mg/kg/day) and DiNP (100 µg/kg/day and 20 and 200 mg/kg/day) increased numbers of male-biased litters. These data show that DEHP and DiNP exposure has long-term consequences for female reproduction, even long after cessation of exposure.

A Pilot Biomonitoring Study of Cumulative Phthalates Exposure among Vietnamese American Nail Salon Workers

Many California nail salon workers are low-income Vietnamese women of reproductive age who use nail products daily that contain androgen-disrupting phthalates, which may increase risk of male reproductive tract abnormalities during pregnancy. Yet, few studies have characterized phthalate exposures among this workforce. To characterize individual metabolites and cumulative phthalates exposure among a potentially vulnerable occupational group of nail salon workers, we collected 17 post-shift urine samples from Vietnamese workers at six San Francisco Bay Area nail salons in 2011, which were analyzed for four primary phthalate metabolites: mono-n-butyl-, mono-isobutyl-, mono(2-Ethylhexyl)-, and monoethyl phthalates (MnBP, MiBP, MEHP, and MEP, respectively; μg/L). Phthalate metabolite concentrations and a potency-weighted sum of parent compound daily intake (Σandrogen-disruptor, μg/kg/day) were compared to 203 Asian Americans from the 2011-2012 National Health and Nutritional Examination Survey (NHANES) using Student's t-test and Wilcoxin signed rank test. Creatinine-corrected MnBP, MiBP, MEHP (μg/g), and cumulative phthalates exposure (Σandrogen-disruptor, μg/kg/day) levels were 2.9 (p < 0.0001), 1.6 (p = 0.015), 2.6 (p < 0.0001), and 2.0 (p < 0.0001) times higher, respectively, in our nail salon worker population compared to NHANES Asian Americans. Levels exceeded the NHANES 95th or 75th percentiles among some workers. This pilot study suggests that nail salon workers are disproportionately exposed to multiple phthalates, a finding that warrants further investigation to assess their potential health significance.

Late-life consequences of short-term exposure to di(2-ethylhexyl) phthalate and diisononyl phthalate during adulthood in female mice

Di(2-ethylhexyl) phthalate (DEHP) is a known endocrine disruptor and diisononyl phthalate (DiNP) is a common DEHP replacement chemical. However, little is known about late-life consequences due to DEHP or DiNP exposure during adulthood. Thus, this study tested the hypothesis that adult exposure to DEHP or DiNP affects female reproductive parameters during late-life in female mice. Female CD-1 mice (age 39-40 days) were dosed with either vehicle control, DEHP (20 μg/kg/day-200 mg/kg/day), or DiNP (20 μg/kg/day-200 mg/kg/day) for 10 days and breeding trials were conducted at 12 and 15 months post-dosing. Further, ovaries and sera were collected at 12, 15, and 18 months post-dosing. DEHP and DiNP disrupted estrous cyclicity, increased pregnancy loss, decreased fertility, altered the sex ratio of pups, altered ovarian follicle populations, and disrupted hormone levels. Collectively, these data show that short-term exposure to DEHP or DiNP during adulthood has long-term consequences in late-life.

Exposure of Nail Salon Workers to Phthalates, Di(2-ethylhexyl) Terephthalate, and Organophosphate Esters: A Pilot Study

Relatively little is known about the exposure of nail technicians to semivolatile organic compounds (SVOCs) in nail salons. We collected preshift and postshift urine samples and silicone wrist bands (SWBs) worn on lapels and wrists from 10 female nail technicians in the Boston area in 2016-17. We analyzed samples for phthalates, phthalate alternatives, and organophosphate esters (OPEs) or their metabolites. Postshift urine concentrations were generally higher than preshift concentrations for SVOC metabolites; the greatest change was for a metabolite of the phthalate alternative di(2-ethylhexyl) terephthalate (DEHTP): mono(2-ethyl-5-carboxypentyl) terephthalate (MECPTP) more than tripled from 11.7 to 36.6 μg/g creatinine. DEHTP biomarkers were higher in our study participants' postshift urine compared to 2015-2016 National Health and Nutrition Examination Survey females. Urinary MECPTP and another DEHTP metabolite were moderately correlated (r = 0.37-0.60) with DEHTP on the SWBs, suggesting occupation as a source of exposure. Our results suggest that nail technicians are occupationally exposed to certain phthalates, phthalate alternatives, and OPEs, with metabolites of DEHTP showing the largest increase across a work day. The detection of several of these SVOCs on SWBs suggests that they can be used as a tool for examining potential occupational exposures to SVOCs among nail salon workers.

Phthalates Exposure and Occupational Symptoms among Slovakian Hairdressing Apprentices

The objectives of the study were to examine occupational exposure to phthalates of hairdressing apprentices from Slovakia (n = 74, 89.2% females; 10.8% males), outcomes related to body composition and pulmonary functions. We used high-performance liquid chromatography and tandem mass spectrometry to the quantified urinary concentration of phthalates. Pulmonary function test (PFT), anthropometric measurements, and questionnaire were also conducted. We observed a decrease of % of predicted values of forced vital capacity (FVC% of PV) related exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP; p = 0.054) and sum of bis(2-ethylhexyl) phthalate metabolites (∑DEHP; p = 0.037), and a decrease of % of predicted values of vital capacity (VC% of PV) related to exposure to MEOHP, ∑DEHP (p = 0.008), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP; p = 0.014) in females. We detected associations between forced vital capacity (FVC) with weight (p = 0.002) and fat-free mass index (FFMI, p = 0.010). Vital capacity (VC) and VC% of PV increased with weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR), the waist-height ratio (WHtR), fat mass index (FMI) and FFMI in females (p ≤ 0.014). Results of multivariate regression between PFT and anthropometric parameters adjusted to phthalates indicated exposure to MnBP and MEHP, changing body structure (BMI and FMI), subsequently affecting values of FEV1/FVC.

Phthalate and Organophosphate Plasticizers in Nail Polish: Evaluation of Labels and Ingredients

In the 2000s, nail polish manufacturers started promoting "3-Free" products, phasing out three widely publicized toxic chemicals: toluene, formaldehyde, and dibutyl phthalate (DnBP). However, DnBP was sometimes replaced by another endocrine-disrupting plasticizer, triphenyl phosphate (TPHP). Many new " n-Free" labels have since appeared, without any standardization on which n chemicals are excluded. This study aimed to compare measured plasticizer content against nail polish labels. First, we summarized definitions of labels. Then, we measured 12 phthalate and 10 organophosphate plasticizers in 40 nail polishes from 12 brands selected for popularity and label variety. We found labels ranging from 3- to 13-Free; 10-Free was the most inconsistently defined (six definitions). Our samples contained TPHP and bis(2-ethylhexyl) phthalate (DEHP) at up to 7940 and 331 μg/g, respectively. The 5- to 13-Free samples had lower TPHP levels than unlabeled or 3-Free samples (median <0.002 vs 3730 μg/g, p < 0.001). The samples that did not contain TPHP had higher DEHP levels (median 68.5 vs 1.51 μg/g, p < 0.05). We measured plasticizers above 100 μg/g in five brands that did not disclose them and in two that excluded them in labels. This study highlights inconsistencies in nail polish labels and identifies TPHP and DEHP as ingredient substitutes for DnBP.

Improving the knowledge and behavior of workplace chemical exposures in Vietnamese-American nail salon workers: a randomized controlled trial

OBJECTIVES

We assessed the efficacy of trainings with Vietnamese nail salon owners and workers on knowledge and behaviors that could reduce exposures to toxic chemicals in nail products.

METHODS

We trained Vietnamese salon owners in California (n = 77) who then trained their workers (n = 200) on best practices. In a cluster randomized controlled trial, we assessed the efficacy of the training on change in knowledge and self-reported behaviors. Data were collected from 2013 to 2016 and analyzed from 2016 to 2017.

RESULTS

Compared to the control group, the intervention group had significantly greater increases in knowledge about: safer nail polishes [odds ratio (OR) 3.7 (95% confidence interval (CI) 1.9, 7.2)]; proper ventilation methods (OR 4.2; 95% CI 2.2, 8.1); recommended glove types (OR 3.4; 95% CI 1.9, 6.3); and recommended product handling and storage (OR 4.1; 95% CI 1.7, 9.9). The intervention also increased best practices: using safer nail polishes (OR 3.6; 95% CI 1.9, 6.8); reading product labels (OR 2.6; 95% CI 1.3, 5.0); and wearing long sleeves (OR 2.4; 95% CI 1.3, 4.2).

CONCLUSIONS

The owner-to-worker intervention with culturally and linguistically appropriate training for salon owners who then trained workers was effective in promoting knowledge and self-reported behaviors that can reduce workplace chemical exposures.

Occupational exposure to phthalates in relation to gender, consumer practices and body composition

The aim of our work was to find associations between urinary phthalate metabolite concentrations and occupation, consumer practices and body composition. We divided our cohort (n = 129) into occupationally exposed subjects, community service workers (group A; n = 45) and workers from plastic industry (group B; n = 35) and group of general population (control group C, n = 49). To estimate levels of five phthalate metabolites, we used high-performance liquid chromatography and tandem mass spectrometry analysis. We found in plastic industry workers compared to community service workers and subjects of the control group significantly higher urinary concentration mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), mono (2-etylhexyl) phthalate (MEHP), sum di-(2-ethyl-5-oxohexyl) phthalate (DEHP), mono-iso-butyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP). We identified by multivariate analysis of covariance inverse relationship between MEHP and body parameters as waist-to-height ratio, body mass index, waist-to-hip ratio, hip circumference and waist circumference among females, whereas in males, no significant association was found. Results of our study show, despite of variability in terms of occupational exposure to phthalates, that plastic manufactory represents a higher occupational risk in comparison with waste management. The differences in anthropometric parameters between the two occupationally exposed groups and the general population are suggesting a detrimental effect of occupational exposure on body weight homeostasis.

Contemporary Issues in Exposure Assessment Using Biomonitoring

In environmental epidemiology, use of biomonitoring (i.e., trace-level measurement of environmental chemicals or their metabolites in biospecimens) for exposure assessment has increased considerably in past decades. Although exposure biomarkers should reflect a person's exposure to the target chemicals (or their precursors) within a specific timeframe, timing, duration, and intensity of exposures are normally unknown and likely vary within the study period. Therefore, evaluating exposure beyond a single time point may require collecting more than one biospecimen. Of note, collection and sample processing procedures will impact integrity and usefulness of biospecimens. All of the above factors are fundamental to properly interpret biomonitoring data. We will discuss the relevance of the exposure assessment study protocol design to (a) ensure that biomonitoring specimens reflect the intended exposure, (b) consider the temporal variability of concentrations of the target biomarkers, and

Pollution levels and characteristics of phthalate esters in indoor air in hospitals

The concentrations of phthalate esters (PAEs) in Chinese hospitals were investigated by simultaneously determining concentrations of gas- and particle-phase PAEs. PAEs were detected in two third-class first-grade hospitals, two second-class first-grade hospitals, and a community health service center. Hospital drugstores had the highest concentration (24.19μg/m(3)), which was 1.54 times that of newly decorated houses. The second highest concentration was found in the transfusion rooms, averaging 21.89μg/m(3); this was followed by the concentrations of PAEs in the nurse's workstations, the wards, and the doctor's offices, with mean concentrations of 20.66, 20.0, and 16.92μg/m(3), respectively. The lowest concentrations were found in the hallways (16.30μg/m(3)). Of the six different kinds of PAEs found, major pollutants included diethyl phthalates, dibutyl phthalates, butylbenzyl phthalates and di(2-ethylhexyl) phthalates, comprising more than 80% of all PAEs present. Meanwhile, a comparison between different wards showed that PAE concentrations in the maternity wards were 1.63 times higher than in the main wards. Based on known health hazards, our results suggest that the PAEs seriously influence the health of the pregnant women and babies; therefore, it is of great importance to take the phthalate concentrations in hospitals into consideration. In addition, hospital indoor air was more seriously contaminated than the air of newly decorated houses.

Characterization of Urinary Phthalate Metabolites Among Custodians

Phthalates, a ubiquitous class of chemicals found in consumer, personal care, and cleaning products, have been linked to adverse health effects. Our goal was to characterize urinary phthalate metabolite concentrations and to identify work and nonwork sources among custodians using traditional cleaning chemicals and 'green' or environmentally preferable products (EPP). Sixty-eight custodians provided four urine samples on a workday (first void, before shift, end of shift, and before bedtime) and trained observers recorded cleaning tasks and types of products used (traditional, EPP, or disinfectant) hourly over the work shifts. Questionnaires were used to assess personal care product use. Four different phthalate metabolites [monoethyl phthalate (MEP), monomethyl phthalate (MMP), mono (2-ethylhexyl) phthalate (MEHP), and monobenzyl phthalate (MBzP)] were quantified using liquid chromatography mass spectrometry. Geometric means (GM) and 95% confidence intervals (95% CI) were calculated for creatinine-adjusted urinary phthalate concentrations. Mixed effects univariate and multivariate modeling, using a random intercept for each individual, was performed to identify predictors of phthalate metabolites including demographics, workplace factors, and personal care product use. Creatinine-adjusted urinary concentrations [GM (95% CI)] of MEP, MMP, MEHP, and MBzP were 107 (91.0-126), 2.69 (2.18-3.30), 6.93 (6.00-7.99), 8.79 (7.84-9.86) µg g(-1), respectively. An increasing trend in phthalate concentrations from before to after shift was not observed. Creatinine-adjusted urinary MEP was significantly associated with frequency of traditional cleaning chemical intensity in the multivariate model after adjusting for potential confounding by demographics, workplace factors, and personal care product use. While numerous demographics, workplace factors, and personal care products were statistically significant univariate predictors of MMP, MEHP, and MBzP, few associations persisted in multivariate models. In summary, among this population of custodians, we identified both occupational and nonoccupational predictors of phthalate exposures. Identification of phthalates as ingredients in cleaning chemicals and consumer products would allow workers and consumers to avoid phthalate exposure.

Considerable exposure to the endocrine disrupting chemicals phthalates and bisphenol-A in intensive care unit (ICU) patients

Critical care medicine has largely benefited from plastic-containing medical devices. However, bisphenol-A (BPA) and phthalates present in the plastics can leach from such devices. We hypothesized that intensive care unit (ICU) patients are exposed to BPA and phthalates through (plastic) medical devices. Serum (n = 118) and urine (n= 102) samples of adult ICU patients (n = 35) were analyzed for total BPA and phthalate metabolites (PMs). Our results showed that adult ICU patients are continuously exposed to phthalates, such as di(2-ethylhexyl)phthalate (DEHP), as well as to BPA, albeit to a lesser extent. This exposure resulted in detectable high serum and urinary levels in almost every patient and at every studied time point. Moreover, these levels were significantly higher than in controls or compared to referenced literature. The chronology of exposure was demonstrated: pre-operative urinary and serum levels of the DEHP metabolites were often below the detection limit. Plastic-containing medical devices were the main source of DEHP exposure: post-operative patients on hemofiltration, extracorporeal membrane oxygenation or both showed serum levels 100-or 1000-fold higher than the levels in the general population reported in the literature. The serum and some of the urinary levels of the DEHP metabolites are the highest ever reported in humans; some at biologically highly relevant concentrations of ≥ 10-50 μM. Despite the continuously tightening regulations, BPA and DEHP appear to be still present in (some) medical devices. Because patient safety is a concern in the ICU, further research into the (possibly toxic and clinical) effects of these chemicals released from medical devices is imperiously necessary.

Pollution levels and characteristics of phthalate esters in indoor air of offices

The pollution status and characteristics of PAEs (phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration (sum of the gas phase and the particulate phase) was 4748.24 ng/m3, ranging between 3070.09 and 6700.14 ng/m3. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the ∑6PAEs. Dividing the particulate-phase PAEs into four size ranges (<2.5, 2.5-5, 5-10, >10 μm), the result indicated that PAEs in PM2.5 were the most abundant, with the proportion of 72.64%. In addition, the PAE concentration in PM2.5 correlated significantly with the total particulate-phase PAEs (R2=0.85). Thus, the amount of PAEs in PM2.5 can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating.

Health hazard assessment of occupationally di-(2-ethylhexyl)-phthalate-exposed workers in China

Di-(2-ethylhexyl)-phthalate (DEHP) is a potential hazard to human health. The effects of occupational high level DEHP exposure on human health were evaluated by measuring the plasma cholinesterase, residues, renal and hepatic biochemical markers. The study was conducted in three representative polyvinyl chloride manufacturing facilities from large size (S1), medium side (S2) to small size (S3). Total 456 adult males including 352 exposed workers (occupational) and 104 control workers (background) were selected. The average DEHP concentrations in respirable particulate matter were 233, 291, and 707 μg m(-3) for S1-S3, respectively, compared with 0.26 μg m(-3) in the background atmosphere (labeled by S4). The results showed significant decreases in post exposure plasma cholinesterase (PChE) levels (<30%) from the exposed workers as compared to baseline. These exposed workers had been evaluated for plasma DEHP residues. Regression analyses explored that PChE decreased significantly with increasing plasma DEHP residues. Serum aspartate aminotransferase, alanine aminotransferase, creatinine, urea, gamma glutamyltransferase, malondialdehyde, total antioxidant and C-reactive protein were significantly raised as compared to the controls. Of the 352 exposed workers, 116 (33.0%) had a daily DEHP intake 22.7 μg kg bw(-1)d(-1) , which is more than 20 μg kg bw(-1)d(-1) specified by the US Environmental Protection Agency. The study demonstrated that occupational phthalate exposure produces health hazards.

Relationship between variation of seasonal temperature and extent of occupational exposure to phthalates

Spot urine samples were collected in summer and winter season to examine the association between temperature variation and phthalate concentration in an occupationally exposed group. We analysed samples by high-performance liquid chromatography with mass spectrometry (HPLC-MS/MS) to determine the concentrations of four phthalate metabolites: mono (2-ethylhexyl) phthalate (MEHP), monobutyl phthalate (MnBP), monoethyl phthalate (MEP), and monoisononyl phthalate (MiNP). We observed significantly higher urinary concentrations of all monitored phthalate metabolites collected during the summer in occupationally exposed group (MEP p < 0.0015, MiNP p < 0.0001, MnBP p < 0.00019, and MEHP p < 0.05); however, in general, population was noticed this difference only for MEHP (p < 0.05) in winter season. We conclude that increasing indoor and outdoor temperature is related to phthalate exposure in specific types of work environment.

Adverse birth outcomes and maternal complications in licensed cosmetologists and manicurists in California

PURPOSE

Due to concerns around occupational chemical exposures, this study sought to examine whether women working as cosmetologists (providing hair and nail care services) and manicurists (providing only nail care services) have an elevated risk for adverse pregnancy outcomes.

METHODS

In this population-based retrospective study of cosmetologists and manicurists in California, we linked cosmetology licensee and birth registry files to identify births during 1996-2009. We compared outcomes among cosmetologists and manicurists to those of the general female population and to women from other industries. We also conducted restricted analyses for Vietnamese women, who comprise a significant proportion of the workforce.

RESULTS

There was little evidence of increased risk for adverse birth outcomes, but we observed an association for small for gestational age (SGA) among Vietnamese manicurists (OR 1.39; 95 % CI 1.08-1.78) and cosmetologists (OR 1.40; 95 % CI 1.08-1.83) when compared to other working women. Some maternal complications were observed, notably an increased risk for gestational diabetes (OR 1.28; 95 % CI 1.10-1.50 for manicurists; OR 1.19; 95 % CI 1.07-1.33 for cosmetologists) compared with the general population, which further elevated when restricted to Vietnamese workers (OR 1.59; 95 % CI 1.20-2.11 for manicurists; OR 1.49; 95 % CI 1.04-2.11 for cosmetologists). Additionally, we observed an association for placentia previa among manicurists (OR 1.46; 95 % CI 1.08-1.97) and cosmetologists (OR 1.22; 95 % CI 1.02-1.46) compared with the general population.

CONCLUSIONS

Women in the nail and hair care industry may be potentially at increased risk for some maternal complications, although further research is warranted. Vietnamese workers may also have increased risk for SGA.

Predictors of urinary bisphenol A and phthalate metabolite concentrations in Mexican children

Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) and phthalates is prevalent among children and adolescents, but little is known regarding important sources of exposure at these sensitive life stages. In this study, we measured urinary concentrations of BPA and nine phthalate metabolites in 108 Mexican children aged 8-13 years. Associations of age, time of day, and questionnaire items on external environment, water use, and food container use with specific gravity-corrected urinary concentrations were assessed, as were questionnaire items concerning the use of 17 personal care products in the past 48-h. As a secondary aim, third trimester urinary concentrations were measured in 99 mothers of these children, and the relationship between specific gravity-corrected urinary concentrations at these two time points was explored. After adjusting for potential confounding by other personal care product use in the past 48-h, there were statistically significant (p<0.05) positive associations in boys for cologne/perfume use and monoethyl phthalate (MEP), mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and in girls for colored cosmetics use and mono-n-butyl phthalate (MBP), mono(2-ethylhexyl) phthalate (MEHP), MEHHP, MEOHP, and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), conditioner use and MEP, deodorant use and MEP, and other hair products use and MBP. There was a statistically significant positive trend for the number of personal care products used in the past 48-h and log-MEP in girls. However, there were no statistically significant associations between the analytes and the other questionnaire items and there were no strong correlations between the analytes measured during the third trimester and at 8-13 years of age. We demonstrated that personal care product use is associated with exposure to multiple phthalates in children. Due to rapid development, children may be susceptible to impacts from exposure to endocrine disrupting chemicals; thus, reduced or delayed use of certain personal care products among children may be warranted.

Reducing chemical exposures in nail salons through owner and worker trainings: an exploratory intervention study

BACKGROUND

Nail salons represent a rapidly growing industry with mainly Vietnamese immigrant workers. Workers routinely handle nail products containing hazardous compounds, yet have limited accessible information to minimize workplace exposures.

METHODS

We conducted a culturally appropriate pilot intervention on workplace chemical exposure reduction strategies. We trained eight Vietnamese owners, who then trained Vietnamese workers in their salons. We conducted pre-, mid-, and post-intervention assessments with workers, including an in-person survey and personal air monitoring of volatile compounds.

RESULTS

Survey results suggested statistically significant increases for chemical knowledge and behavioral changes in glove and mask use, and a reduced prevalence of nose, throat, and skin irritations. Air monitoring results showed a net reduction for methyl methacrylate and total volatile organic compounds, but not for toluene.

CONCLUSIONS

Worker education disseminated through salon owners to their workers can improve work-related knowledge, behavior, health symptoms, and exposures for select air contaminants, although more research is warranted.

Urinary metabolite concentrations of phthalate metabolites in Central Italy healthy volunteers determined by a validated HPLC/MS/MS analytical method

The main objective of this study was to determine the average concentrations for the metabolites of the four more common phthalates, industrial chemicals widely used in commercial products and potential endocrine disruptors, in the urine of a control population living in Central Italy. The study population consisted of 157 healthy subjects, not occupationally exposed to phthalates (74 males and 83 females). Urinary levels of the analytes were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) with isotopic dilution. The reference values (geometric mean) for males and females were estimated for each metabolite:. Females: for MEP was 72.94μg/g creatinine (CI 95% 3.63-149.51), for MEHP was 3.37μg/g creatinine (CI 95% 1.85-4.89), for MEHHP was 12.74μg/g creatinine (CI 95% 9.45-22.19), for MnBP was 20.26μg/g creatinine (CI 95% 8.17-28.43) and for MBzP was 14.74 (CI 95% 2.94-17.68). Males: for MEP was 56.35μg/g creatinine (CI 95% 2.32-110.39), for MEHP was 2.80μg/g creatinine (CI 95% 1.08-4.52), for MEHHP was 10.77μg/g creatinine (CI 95% 6.18-16.95), for MnBP was 17.59μg/g creatinine (CI 95% 5.72-29.45) and for MBzP was 16.44 (CI 95% 7.90-29.45). To obtain reference values for these chemicals is without doubt an important topic for evaluate the exposure of population and their possible health effects. Information from different geographical areas are important to understand the real different background concentrations.

Urinary monitoring of exposure to yttrium, scandium, and europium in male Wistar rats

On the assumption that rare earth elements (REEs) are nontoxic, they are being utilized as replacements of toxic heavy metals in novel technological applications. However, REEs are not entirely innocuous, and their impact on health is still uncertain. In the past decade, our laboratory has studied the urinary excretion of REEs in male Wistar rats given chlorides of europium, scandium, and yttrium solutions by one-shot intraperitoneal injection or oral dose. The present paper describes three experiments for the suitability and appropriateness of a method to use urine for biological monitoring of exposure to these REEs. The concentrations of REEs were determined in cumulative urine samples taken at 0-24 h by inductively coupled plasma atomic emission spectroscopy, showing that the urinary excretion of REEs is <2 %. Rare earth elements form colloidal conjugates in the bloodstream, which make high REEs accumulation in the reticuloendothelial system and glomeruli and low urinary excretion. The high sensitivity of inductively coupled plasma-argon emission spectrometry analytical methods, with detection limits of <2 μg/L, makes urine a comprehensive assessment tool that reflects REE exposure. The analytical method and animal experimental model described in this study will be of great importance and encourage further discussion for future studies.

Socioeconomic factors and phthalate metabolite concentrations among United States women of reproductive age

INTRODUCTION

Relatively little is known about the socioeconomic correlates of phthalate metabolite urine concentrations among the general population, exposures of increasing public health concern, particularly for women of reproductive age.

METHODS

We pooled data from the 2001-2008 cycles of the National Health and Nutrition Examination Survey to examine the associations between phthalate metabolite concentrations (including the molar sum of four di-2-ethylhexyl phthalate (DEHP) metabolites, the molar sum of two dibutyl phthalate (DBP) metabolites, and metabolites of benzylbutyl phthalate (BzBP) and diethyl phthalate (DEP)) with socioeconomic indicators (including ethnicity, education, income, and food security status) among women 20 to 39 years age. We also derived a socioeconomic status summary measure using factor analysis and investigated its associations with metabolite concentrations.

RESULTS

In fully adjusted models, the lowest quartile of overall socioeconomic status was associated with 1.83 (95% CI=1.54-2.17) times the concentrations of mono-benzyl phthalate (MBzP), and 0.72 (95% CI=0.54-0.98) times the concentrations of (molar sum) DEHP metabolites compared with the highest quartile of overall socioeconomic status. This latter association was driven primarily by educational attainment. All Non-White ethnicities combined had 1.24 (95% CI=1.09-1.40) times the concentrations of (molar sum) DBP metabolites, 1.32 (95% CI=1.12-1.56) times the mono-ethyl phthalate (MEP) concentrations, and 0.82 (95% CI=0.71-0.96) the concentrations of MBzP of Non-Hispanic Whites.

CONCLUSIONS

Biomarkers of phthalate exposure vary with socioeconomic factors in women of reproductive age in the United States. Given the public health concern surrounding phthalate exposure, more research is needed to elucidate the reasons for these differences.

Occupational exposure to chemicals and fetal growth: the Generation R Study

BACKGROUND

Developmental diseases, such as birth defects, growth restriction and preterm delivery, account for >25% of infant mortality and morbidity. Several studies have shown that exposure to chemicals during pregnancy is associated with adverse birth outcomes. The aim of this study was to identify whether occupational exposure to various chemicals might adversely influence intrauterine growth patterns and placental weight.

METHODS

Associations between maternal occupational exposure to various chemicals and fetal growth were studied in 4680 pregnant women participating in a population-based prospective cohort study from early pregnancy onwards in the Netherlands (2002–2006), the Generation R Study. Mothers who filled out a questionnaire during mid-pregnancy (response: 77% of enrolment) were included if they conducted paid employment during pregnancy and had a spontaneously conceived singleton live born pregnancy (n = 4680). A job exposure matrix was used, linking job titles to expert judgement on exposure to chemicals in the workplace. Fetal growth characteristics were repeatedly measured by ultrasound and were used in combination with measurements at birth. Placental weight was obtained from medical records and hospital registries. Linear regression models for repeated measurements were used to study the associations between maternal occupational exposure to chemicals and intrauterine growth.

RESULTS

We observed that maternal occupational exposure to polycyclic aromatic hydrocarbons, phthalates, alkylphenolic compounds and pesticides adversely influenced several domains of fetal growth (fetal weight, fetal head circumference and fetal length). We found a significant association between pesticide and phthalate exposure with a decreased placental weight.

CONCLUSIONS

Our results suggest that maternal occupational exposure to several chemicals is associated with impaired fetal growth during pregnancy and a decreased placental weight. Further studies are needed to confirm these findings and to assess post-natal consequences.

Occupational exposure to diisononyl phthalate (DiNP) in polyvinyl chloride processing operations

PURPOSE

Diisononyl phthalate (DiNP) is primarily used as a plasticizer in polyvinyl chloride (PVC) materials. While information is available on general population exposure to DiNP, occupational exposure data are lacking. We present DiNP metabolite urinary concentrations in PVC processing workers, estimate DiNP daily intake for these workers, and compare worker estimates to other populations.

METHODS

We assessed DiNP exposure in participants from two companies that manufactured PVC materials, a PVC film manufacturer (n = 25) and a PVC custom compounder (n = 12). A mid-shift and end-shift urine sample was collected from each participant and analyzed for the DiNP metabolite mono(carboxy-isooctyl) phthalate (MCiOP). Mixed models were used to assess the effect on MCiOP concentrations of a worker being assigned to (1) a task using DiNP and (2) a shift where DiNP was used. A simple pharmacokinetic model was used to estimate DiNP daily intake from the MCiOP concentrations.

RESULTS

Creatinine-adjusted MCiOP urinary concentrations ranged from 0.42-80 μg/g in PVC film and from 1.11-13.4 μg/g in PVC compounding. PVC film participants who worked on a task using DiNP (n = 7) had the highest MCiOP geometric mean (GM) end-shift concentration (25.2 μg/g), followed by participants who worked on a shift where DiNP was used (n = 11) (17.7 μg/g) as compared to participants with no task (2.92 μg/g) or shift (2.08 μg/g) exposure to DiNP. The GM end-shift MCiOP concentration in PVC compounding participants (4.80 μg/g) was comparable to PVC film participants with no task or shift exposure to DiNP. Because no PVC compounding participants were assigned to tasks using DINP on the day sampled, DiNP exposure in this company may be underestimated. The highest DiNP intake estimate was 26 μg/kg/day.

CONCLUSION

Occupational exposure to DiNP associated with PVC film manufacturing tasks were substantially higher (sixfold to tenfold) than adult general population exposures; however, all daily intake estimates were less than 25% of current United States or European acceptable or tolerable daily intake estimates. Further characterization of DiNP occupational exposures in other industries is recommended.

Biological monitoring of exposure to di(2-ethylhexyl) phthalate in six French factories: a field study

OBJECTIVE

The aim of this study was to assess, by biological monitoring, workers' exposure to di(2-ethylhexyl) phthalate (DEHP) in the flexible-PVC industry in France to provide additional occupational exposure data, which are particularly scarce.

METHOD

Over 5 days of pre-and post-shift sampling, three urinary metabolites of DEHP, mono (2-ethylhexyl) phthalate (MEHP), mono (5-carboxy-2-ethylpentyl) phthalate (5cx-MEPP) and 2-ethylhexanoic acid (2-EHA) were quantified in 62 workers and 29 controls from six factories. Analyses were performed by high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) after on-line extraction.

RESULTS

Median concentrations of the pre- and post-shift urinary samples in the exposed workers were 12.6 and 28.7 μg/l for MEHP, 38.6 and 84.4 μg/l for 5cx-MEPP and 20.4 and 70.6 μg/l for 2-EHA, respectively. In the controls, the corresponding values were 4.8 and 4.7 μg/l for MEHP, 15.1 and 12.4 μg/l for 5cx-MEPP and 21.8 and 20.5 μg/l for 2-EHA, respectively. There was a significant increase (Mann-Whitney U-test, P < 0.05) of post-shift excretion in the exposed workers versus the unexposed controls and in the post-shift versus pre-shift concentrations only in the exposed workers. Values of 250 and 500 μg/l (100 and 280 μ/g creatinine) for MEHP and 5cx-MEPP, respectively, are proposed as guidance values.

CONCLUSION

There is clear evidence of occupational exposure of workers in these factories. The guideline values proposed should prevent high exposures in the soft PVC industry, particularly in factories where DEHP compounds or plastisols are employed. An epidemiological survey is needed to complete the DEHP risk assessment.

Occupation and occupational exposure to endocrine disrupting chemicals in male breast cancer: a case-control study in Europe

OBJECTIVES

Male breast cancer is a rare disease of largely unknown aetiology. In addition to genetic and hormone-related risk factors, a large number of environmental chemicals are suspected of playing a role in breast cancer. The identification of occupations or occupational exposures associated with an increased incidence of breast cancer in men may help to identify mammary carcinogens in the environment.

METHODS

Occupational risk factors for male breast cancer were investigated in a multi-centre case-control study conducted in eight European countries which included 104 cases and 1901 controls. Lifetime work history was obtained during in-person interviews. Occupational exposures to endocrine disrupting chemicals (alkylphenolic compounds, phthalates, polychlorinated biphenyls and dioxins) were assessed on a case-by-case basis using expert judgement.

RESULTS

Male breast cancer incidence was particularly increased in motor vehicle mechanics (OR 2.1, 95% CI 1.0 to 4.4) with a dose-effect relationship with duration of employment. It was also increased in paper makers and painters, forestry and logging workers, health and social workers, and furniture manufacture workers. The OR for exposure to alkylphenolic compounds above the median was 3.8 (95% CI 1.5 to 9.5). This association persisted after adjustment for occupational exposures to other environmental oestrogens.

CONCLUSION

These findings suggest that some environmental chemicals are possible mammary carcinogens. Petrol, organic petroleum solvents or polycyclic aromatic hydrocarbons are suspect because of the consistent elevated risk of male breast cancer observed in motor vehicle mechanics. Endocrine disruptors such as alkylphenolic compounds may play a role in breast cancer.

Occupational and environmental exposures and risk of systemic lupus erythematosus: silica, sunlight, solvents

OBJECTIVES

We examined occupational and non-occupational exposures in relation to risk of SLE in a case-control study conducted through the Canadian Network for Improved Outcomes in SLE (CaNIOS).

METHODS

SLE cases (n = 258) were recruited from 11 rheumatology centres across Canada. Controls (without SLE, n = 263) were randomly selected from phone number listings and matched to cases by age, sex and area of residence. Data were collected using a structured telephone interview.

RESULTS

An association was seen with outdoor work in the 12 months preceding diagnosis [odds ratio (OR) 2.0; 95% CI 1.1, 3.8]; effect modification by sun reaction was suggested, with the strongest effect among people who reported reacting to midday sun with a blistering sunburn or a rash (OR 7.9; 95% CI 0.97, 64.7). Relatively strong but imprecise associations were seen with work as an artist working with paints, dyes or developing film (OR 3.9; 95% CI 1.3, 12.3) and work that included applying nail polish or nail applications (OR 10.2; 95% CI 1.3, 81.5). Patients were more likely than controls to report participation in pottery or ceramics work as a leisure activity, with an increased risk among individuals with a total frequency of at least 26 days (OR 2.1; 95% CI 1.1, 3.9). Analyses of potential respirable silica exposures suggested an exposure-response gradient (OR 1.0, 1.4. and 2.1 for zero, one and two or more sources of exposure, respectively; trend test P < 0.01).

CONCLUSIONS

This study supports the role of specific occupational and non-occupational exposures in the development of SLE.