Exposure to phthalate metabolites,phenols and organophosphate pesticide metabolites and blood pressure during pregnancy

Introduction

Hypertensive disorders during pregnancy are one of the leading causes of maternal and offspring mortality and morbidity. Exposure to environmental chemicals is suspected to increase blood pressure (BP) but few studies have investigated the impact of non-persistent chemicals, in particular among pregnant women.

Exposure assessment of phthalates in French pregnant women: Results of the ELFE pilot study

The ubiquitous use of phthalate esters in plastics, building material, medical devices, personal care products and food packaging materials results in a widespread exposure of general population. This study reports measurement of urinary concentration of phthalate metabolites in France and provides a first assessment of the exposure of French pregnant women to this chemical class. For the majority of the phthalate metabolites, concentrations measured in urine were similar to those reported in previous studies except for two phthalates that were characterized by high concentrations of metabolites if compared to previous European and American studies: DiNP (Di-iso-nonylphthalate) and DEHP (Di(2-ethylhexyl)phthalate). In a second part of the study, a pharmacokinetic model was used in order to gain understanding on exposure to DEHP. A high concentration of the primary metabolite of DEHP, MEHP (Mono(2-ethylhexyl)phthalate), was thus identified probably because of a very recent exposure to perfusion materials at the hospital. Pharmacokinetics modelling highlighted that gathering data on the time gap between exposure and biomonitoring is an essential information requirement for reconstructing the dose of non persistent pollutants. Information about exposure pathway is also crucial for conducting effective reverse dosimetry.     

Biological monitoring of carbon disulphide and phthalate exposure in the contemporary rubber industry

Objectives: We studied the range in urinary levels of 2-thiothiazolidine-4-carboxyl acid (TTCA), a metabolite of CS₂ and phthalic acid (PA), a common metabolite of phthalates, across factories and departments in the contemporary rubber manufacturing industry. Methods: Spot urine samples from 101 rubber workers employed in nine different factories were collected on Sunday and during the workweek on Tuesday, Wednesday and Thursday at ∼4 pm. In total, 386 urine samples were successfully analyzed. Results: Levels of both biomarkers increased significantly by a factor 2 (paired t-test P-value <0.05) during the working week as compared to the Sunday biomarker levels with absolute increases of approximately 70 μg/l and 5 μmol/mol creatinine for PA and TTCA, respectively. Levels in both biomarkers did not differ markedly between working days. Increases seemed to be restricted to specific factories and/or departments (e.g. molding and curing). Conclusions: The results of this study demonstrate that rubber workers in the contemporary rubber industry are exposed to phthalates and low levels of CS₂ (∼0.05 ppm) as measured by PA and TTCA, respectively. Exposures to both compounds are largely driven by specific circumstances in factories. Therefore, when estimating exposures to phthalates and CS₂ detailed information should be collected on the type and amount of phthalate containing ester plasticizers, dithiocarbamates and thiurams used. Preferably, personal exposure data should be collected. In this case, biological monitoring seems a reasonable approach. However, in the case of PA attention should be given to individual background levels as this could lead to a substantial overestimation of the occupational contribution to total phthalate exposure.     

Temporal variability in urinary concentrations of phthalate metabolites, phytoestrogens and phenols among minority children in the United States

BACKGROUND: Exposure to endocrine disruptors (EDs), including some phthalates, phytoestrogens and phenols can be quantified using biomarkers of exposure. However, reliability in the use of these biomarkers requires an understanding of the timeframe of exposure represented by one measurement. Data on the temporal variability of ED biomarkers are sparse, especially among children. OBJECTIVE: To evaluate intraindividual temporal variability in 19 individual urinary biomarkers (eight phthalate metabolites from six phthalate diesters, six phytoestrogens (two lignans and four isoflavones) and five phenols) among New York City children. METHODS: Healthy Hispanic and Black children (N=35; 6-10 years old) donated several urine samples over 6 months. To assess temporal variability we used three statistical methods: intraclass correlation coefficient (ICC), Spearman correlation coefficients (SCC) between concentrations measured at different timepoints, and surrogate category analysis to determine how well the tertile categories based on a single measurement represented a 6-month average concentration. RESULTS: Surrogate category analysis indicated that a single sample provides reliable ranking for all analytes; at least three of four surrogate samples predicted the 6-month mean concentration. Of the 19 analytes, the ICC was >0.2 for 18 analytes and >0.3 for 10 analytes. Correlations among sample concentrations throughout the 6-month period were observed for all analytes; 14 analyte concentrations were correlated at 16 weeks. CONCLUSIONS: The reasonable degree of temporal reliability and the wide range of concentrations of phthalate metabolites, phytoestrogens and phenols suggest that these biomarkers are appropriate for use in epidemiologic studies of environmental exposures in relation to health outcomes in children.     

Variability of urinary phthalate metabolite and bisphenol A concentrations before and during pregnancy

Background: Gestational phthalate and bisphenol A (BPA) exposure may increase the risk of adverse maternal/child health outcomes, but there are few data on the variability of urinary biomarkers before and during pregnancy.Objective: We characterized the variability of urinary phthalate metabolite and BPA concentrations before and during pregnancy and the ability of a single spot urine sample to classify average gestational exposure.Methods: We collected 1,001 urine samples before and during pregnancy from 137 women who were partners in couples attending a Boston fertility clinic and who had a live birth. Women provided spot urine samples before (n ≥ 2) and during (n ≥ 2) pregnancy. We measured urinary concentrations of monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-iso-butyl phthalate, monobenzyl phthalate (MBzP), four metabolites of di-(2-ethylhexyl) phthalate (DEHP), and BPA. After adjusting for specific gravity, we characterized biomarker variability using intraclass correlation coefficients (ICCs) and conducted several surrogate category analyses to determine whether a single spot urine sample could adequately classify average gestational exposure.Results: Absolute concentrations of phthalate metabolites and BPA were similar before and during pregnancy. Variability was higher during pregnancy than before pregnancy for BPA and MBzP, but similar during and before pregnancy for MBP, MEP, and ΣDEHP. During pregnancy, MEP (ICC = 0.50) and MBP (ICC = 0.45) were less variable than BPA (ICC = 0.12), MBzP (ICC = 0.25), and ΣDEHP metabolites (ICC = 0.08). Surrogate analyses suggested that a single spot urine sample may reasonably classify MEP and MBP concentrations during pregnancy, but more than one sample may be necessary for MBzP, DEHP, and BPA.Conclusions: Urinary phthalate metabolites and BPA concentrations were variable before and during pregnancy, but the magnitude of variability was biomarker specific. A single spot urine sample adequately classified MBP and MEP concentrations during pregnancy. The present results may be related to unique features of the women studied, and replication in other pregnancy cohorts is recommended.     

Temporal variability and predictors of urinary bisphenol A concentrations in men and women

BACKGROUND: Bisphenol A (BPA) is used to manufacture polymeric materials, such as polycarbonate plastics, and is found in a variety of consumer products. Recent data show widespread BPA exposure among the U.S. population. OBJECTIVE: Our goal in the present study was to determine the temporal variability and predictors of BPA exposure. METHODS: We measured urinary concentrations of BPA among male and female patients from the Massachusetts General Hospital Fertility Center. RESULTS: Between 2004 and 2006, 217 urine samples were collected from 82 subjects: 45 women (145 samples) and 37 men (72 samples). Of these, 24 women and men were partners and contributed 42 pairs of samples collected on the same day. Ten women became pregnant during the follow-up period. Among the 217 urine samples, the median BPA concentration was 1.20 microg/L, ranging from below the limit of detection (0.4 microg/L) to 42.6 microg/L. Age, body mass index, and sex were not significant predictors of urinary BPA concentrations. BPA urinary concentrations among pregnant women were 26% higher (-26%, +115%) than those among the same women when not pregnant (p > 0.05). The urinary BPA concentrations of the female and male partner on the same day were correlated (r = 0.36; p = 0.02). The sensitivity of classifying a subject in the highest tertile using a single urine sample was 0.64. CONCLUSION: We found a nonsignificant increase in urinary BPA concentrations in women while pregnant compared with nonpregnant samples from the same women. Samples collected from partners on the same day were correlated, suggesting shared sources of exposure. Finally, a single urine sample showed moderate sensitivity for predicting a subject's tertile categorization.     

Serum metal levels in a population of Spanish pregnant women

ObjectiveTo describe serum levels of calcium, copper, selenium, magnesium, iron and zinc and evaluate their relationship with maternal socio-demographic characteristics and dietary variables in women in the first trimester of pregnancy.MethodCross-sectional study with 1279 participants from the INMA cohorts.ResultsThe concentrations of the elements analyzed were within the normal range. Associations with higher levels of these metals were found for calcium with white meat intake (p = 0.026), for copper with excess body weight (p < 0.01), low social class (p = 0.03) and being multipara (p < 0.01), for magnesium with being over 35 years old (p = 0.001), high social class (p = 0.044), primiparous status (p = 0.002) and low daily intake of bread (p = 0.009) and legumes (p = 0.020); for zinc with university education (p = 0.039) and residence in Gipuzkoa (p < 0.01), and for selenium with residence in Valencia (p < 0.01), university education (p = 0.001), vitamin B₆ supplementation (p = 0.006), fish intake (> 71 g/day) (p = 0.014) and having been born in Spain (p = 0.001). Further, lower iron levels were associated with being overweight (p = 0.021) or obese (p < 0.001) and vitamin B₁₂ supplementation (p = 0.006).ConclusionsOur results suggest that trace elements in the analyzed cohorts are adequate for this stage of pregnancy. The variability in these elements is mainly linked to socio-demographic and anthropometric variables.     

不同孕期妇女尿碘水平与甲状腺功能相关性研究

目的研究全民食盐加碘后杭州市孕妇在不同孕期碘营养和甲状腺功能状况,为今后实施孕妇甲状腺功能监测的必要性和可能性提供依据。方法随机抽取杭州市5个调查点395人进行尿碘、水碘、盐碘、促甲状腺素(TSH)、游离三碘甲状腺原氨酸(FT3)、总甲状腺素(FT4)实验室检测,采用酸消化砷-铈接触法测定尿碘、水碘,采用硫代硫酸钠直接滴定法测定盐碘,化学发光法测定TSH、FT3、FT4水平。统计学处理采用SPSS13.0统计软件,率的比较用χ2检验,P0.05为差异有统计学意义。结果①孕早、中、晚期妇女的尿碘中位数分别为170.3,170.2,162.4μg/L,均显著低于对照组(251.9μg/L,均P0.05);②孕中期妇女中FT4低于下限值者占8.7%,FT3低于下限值者占9.6%;孕晚期妇女中FT4低于下限值者占22.7%,FT3低于下限值者占17.5%;③孕晚期甲状腺激素指标异常的妇女尿碘值300μg/L者(36.6%)明显高于正常组(8.8%)(χ2=12.54,P=0.002)。结论①从群体的角度来看,杭州市孕妇的碘营养处于适宜水平;②建议在孕妇中开展尿碘监测,对于尿碘值150μg/L或300μg/L的孕妇要进行甲状腺功能的筛查。     

Theory-based predictors of influenza vaccination among pregnant women

Background

Guidelines recommend influenza vaccination for pregnant women, but vaccine uptake in this population is far below the goal set by Healthy People 2020. The purpose of this study was to examine predictors of seasonal influenza vaccination among pregnant women.

Methods

Between 2009 and 2012, the Vaccines and Medications in Pregnancy Surveillance System (VAMPSS) conducted a prospective cohort study of influenza vaccine safety among pregnant women in the US and Canada that oversampled vaccinated women. Data for the present paper are from an additional cross-sectional telephone survey completed during the 2010–2011 influenza season. We examined predictors of influenza vaccination, focusing on Health Belief Model (HBM) constructs.

Results

We surveyed 199 pregnant women, 81% of whom had received a seasonal influenza vaccine. Vaccination was more common among women who felt more susceptible to influenza (OR = 1.82, 95% CI 1.10–3.01), who perceived greater vaccine effectiveness (OR = 3.92, 95% CI 1.48–10.43), and whose doctors recommended they have flu shots (OR = 3.06, 95% CI 1.27–7.38). Those who perceived greater barriers of influenza vaccination had lower odds of vaccination (OR = 0.19, 95% CI 0.05–0.75). Perceived social norms, anticipated inaction regret, and worry also predicted uptake, though demographic characteristics of respondents did not.

Conclusion

The HBM provides a valuable framework for exploring influenza vaccination among pregnant women. Our results suggest several potential areas of intervention to improve vaccination rates.     

Consumer product exposures associated with urinary phthalate levels in pregnant women

Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18-38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors were statistically significantly associated with phthalate levels. Individuals who used nail polish had higher levels of mono-butyl phthalate (P=0.048) than non-users. Mono-benzyl phthalate levels were higher among women who used eye makeup (P=0.034) or used makeup on a regular basis (P=0.004). Women who used cologne or perfume had higher levels of di-(2-ethylhexyl) phthalate metabolites. Household products, home flooring or paneling, and other personal care products were also associated with urinary phthalates. The proportion of variance in metabolite concentrations explained by questionnaire items ranged between 0.31 for mono-ethyl phthalate and 0.42 for mono-n-methyl phthalate. Although personal care product use may be an important predictor of urinary phthalate levels, most of the variability in phthalate exposure was not captured by our relatively comprehensive set of questionnaire items.     

妊娠晚期尿失禁妇女的尿动力学表现研究

目的研究妊娠晚期尿失禁妇女的尿动力学表现。方法选择63例妊娠晚期志愿接受尿动力学检查的妇女,按产妇产前是否有尿失禁症状分为尿失禁组（17例）和无尿失禁组（46例）,选择同期14例已婚未孕志愿者为正常对照组,分别进行自由尿流率、膀胱压力容积、压力流率测定及静态尿道压力描记检查。结果妊娠晚期尿失禁发生率为26．98％;仅2例孕妇在valsalva动作时漏尿,漏尿点压（VLPP）分别为50cmH2O和67cmH20;妊娠晚期尿失禁妇女的最大尿道闭合压[（83．69±42．55）mmHg]及功能性尿道长度[（30．45±8．42）mm]低于无尿失禁组[（108．09±8．42）mmHg,（37．60±18．45）mm;P〈0．05]。结论妊娠晚期尿失禁的发生与妊娠后增加的最大尿道闭合压未能弥补日益增加的膀胱压有关,与功能性尿道长度未随妊娠继续而增加有关。     

邻苯二甲酸酯及Wnt通路影响配子及胚胎发育的研究进展

邻苯二甲酸酯（PAEs）作为添加剂被广泛应用于食品、建材、医疗等各行各业中。由于PAEs难以形成强力的共价键,PAEs会不断泄露到环境中并通过人们的饮食、日常生活用品接触等在人体中蓄积。作为环境内分泌干扰物中的一大类,PAEs会造成影响深远的生殖内分泌干扰效应,对配子及胚胎发育产生影响。而Wnt家族基因及其产物可通过多环节、多作用位点影响基因表达或促进细胞增殖,从而诱导组织分化来调控生长发育。综述PAEs的生化性质和污染途径以及PAEs的内分泌干扰机制,并综述Wnt及其他可能介导PAEs对配子及胚胎发育造成影响的信号通路或机制。     

Urinary pyrethroid metabolites among pregnant women in an agricultural area of the Province of Jiangsu, China

Pyrethroid pesticides are widely used throughout the world in agriculture to protect crops and in public health to control diseases. Of particular concern is exposure of pregnant women and their fetuses because little is known about the potential developmental hazards of such exposure. Several studies have detected internal pyrethroid exposure in urine both in adults and children, but few published data are available on metabolites in pregnant women. The present paper provides data on pyrethroid pesticides exposure based on questionnaire items and measurement of maternal urinary metabolite levels among 1149 pregnant women living in agricultural area of Jiangsu Province, China in 2009-2010, none of which reported occupational exposure to pyrethroid insecticides during pregnancy. To assess exposure to pyrethroid pesticides, urine specimens were analyzed for three main metabolites of 3-phenoxybenzoic acid (3-PBA), cis-and-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (cis-DCCA and trans-DCCA) using a gas chromatography-mass spectrometry method. The limits of detection for three pyrethroid metabolites were 0.1μg/L. All pyrethroid metabolites were found in more than 94.0% of the urine samples. Median unadjusted and creatinine-adjusted values for urinary pyrethroid metabolites in these females were 1.01μg/L and 1.55μg/g Cre for 3-PBA, 0.44μg/L and 0.69μg/g Cre for cis-DCCA, 1.17μg/L and 1.86μg/g Cre for trans-DCCA, respectively. About half (45.5%) of women reported that they or family members had applied commercially available indoor insecticides during pregnancy. Both the questionnaire and laboratory data revealed that exposure to pyrethroid pesticides was considerably widespread in our subjects. The median values of urinary metabolites in the present study were about 4-10 times higher as those of general population from the developed countries. Interestingly, we found there was a temporal season variation tendency in different months. Especially, the levels of urinary metabolites in summer were significant higher than those in winter. These data indicated the need to assess the potential adverse effects of pyrethroid pesticides exposure on fetuses and infants in order to take adequate measures to protect pregnant women from pesticide exposures during pregnancy.     

Temporal stability of eight phthalate metabolites and their glucuronide conjugates in human urine

Humans are exposed to phthalates due to the ubiquitous use of these chemicals in consumer products. In the body, phthalates metabolize quickly to form hydrolytic and oxidative monoesters which, in turn, can be glucuronidated before urinary excretion. Exposure assessment studies typically report the total urinary concentrations of phthalate metabolites (i.e., free plus glucuronidated species). Nevertheless, because conjugation may potentially reduce the bioactivity of the metabolites by reducing their bioavailability, measuring the concentrations of free species may be of interest. An accurate, quantitative measurement of phthalate monoesters and their conjugated species requires data on the stability of these species in urine after sample collection and before analysis. We studied the stability of eight phthalate metabolites and their glucuronide conjugates at 25, 4, and −70 °C. Interestingly, the total concentrations of phthalate metabolites decreased over time at 25 and 4 °C, but not at −70 °C for up to 1 year and despite several freeze-thaw cycles. We further observed a considerable decrease in the concentrations of the glucuronides of some phthalate metabolites 1 day and 3 days after collection when the samples were stored at 25 and 4 °C, respectively. By contrast, the concentrations of the glucuronide conjugates at −70 °C remained unchanged for the whole duration of the study (1 year). Based on these findings, we recommend transferring urine specimens to a cooler or a refrigerator immediately after collection followed by permanent storage at subfreezing temperatures within hours of sample collection.     

Effect of benzyl butyl phthalate on physiology and proteome characterization of water celery (Ipomoea aquatica Forsk.)

This study examined the effect of benzyl butyl phthalate (BBP), a phthalate ester (PAE) and an endocrine disruptor, on water celery, Ipomoea aquatica Forsk., one of the most popular leaf vegetables in Taiwan. After 28 days of cultivation, treatment with 100 mg L⁻¹ BBP retarded plant growth and decreased biomass and number of mature leaves and caused the accumulation of proline in leaves of water celery, but the concentrations of chlorophyll a and b in the leaves remained constant. 2-D gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the proteome of leaf tissue revealed five protein spots with up- and down-regulated expression. The predicted protein XP_001417439 was down-regulated, which explained inhibition of plant growth, and the proteina XP_001417040, calreticulin, GAI-like protein 1, and (-)-linalool synthase were up-regulated, which indicates interference with the cell cycle and protein synthesis, as well as dwarfism of water celery. BBP is a stressor on the growth of water celery, and proteome analysis revealed the up- and down-regulation of genes involved in plant growth with BBP treatment.     

Determinants of organophosphate pesticide exposure in pregnant women: A population-based cohort study in the Netherlands

Background

In the Netherlands organophosphate (OP) pesticides are frequently used for pest control in agricultural settings. Despite concerns about the potential health impacts of low-level OP pesticides exposure, particularly in vulnerable populations, the primary sources of exposure remain unclear. The present study was designed to investigate the levels of DAP metabolites concentrations across pregnancy and to examine various determinants of DAP metabolite concentrations among an urban population of women in the Netherlands.

Exposure assessment of phthalate esters in Japanese pregnant women by using urinary metabolite analysis

Objectives  Our objectives were (1) to evaluate whether single spot urine is suitable media for longer-term phthalate esters exposure assessment, and (2) to estimate intake level of phthalate esters of Japanese pregnant women using urinary metabolites as an indicator of prenatal exposure level in their offspring. Methods  We analyzed nine metabolites (MMP, MEP, MnBP, MBzP, MEHP, MEOHP, MEHHP, MINP, MnOP) of seven phthalate esters in spot urine samples from 50 pregnant women by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Using four urine samples collected from each of 12 subjects from 50 pregnant women within 5–12 weeks, we compared intra- and interindividual variation in urinary metabolites by calculation of intraclass correlation coefficient (ICC). We estimated daily intakes of 50 pregnant women from their urinary metabolite concentrations. Results  ICCs for seven phthalate metabolite concentrations in single spot urine samples were: MMP (0.57), MEP (0.47), MnBP (0.69), MBzP (0.28), MEHP (0.51), MEHHP (0.43), and MEOHP (0.41) in 12 pregnant women. Phthalate ester metabolites had high detection rates in 50 subjects. The mean daily intake ranged from 0.01 to 2 μg/kg per day. The daily intake levels in all subjects were lower than corresponding tolerable daily intake (TDI) set by the European Food Safety Authority (EFSA), though maximum value for DnBP of 6.91 μg/kg per day accounted for 70% of TDI value. Conclusions  Higher ICCs indicated that phthalate metabolite levels in single spot urine could reflect longer-term exposure to the corresponding diesters of subjects. Although the current exposure level was less than TDIs, further studies and exposure monitoring are needed to reveal the toxicity of phthalate esters to sensitive subpopulation.     

Demographic and dietary predictors of urinary bisphenol A concentrations in adults in Israel

Background

To date, there is scarce data on levels of exposure to bisphenol A (BPA) in the general population in Israel and the region. The goal of the current study was to measure urinary levels of BPA in the general adult population in Israel and to determine the demographic and dietary predictors of exposure.

Methods

We recruited 249 individuals (ages 20–74) from five different regions in Israel. We collected urine samples and questionnaire data including detailed dietary data and analyzed urine samples for BPA concentrations.

Results

Eighty nine percent of the study population had urinary BPA concentrations equal to or above the level of quantification (0.3 μg/L). Median creatinine adjusted BPA urinary concentrations in the study population (2.3 μg/g) were slightly higher than those reported for the general population in the US (1.76 μg/g) and Canada (1.47 μg/g), and were comparable to those reported for the general population in Belgium (2.25 μg/g) and Korea (2.09 μg/g). BPA concentrations were higher in Jews compared to Arab and Druze (prevalence ratio (PR) = 2.34; 95%CI 1.56–3.49), in individuals with higher education (PR = 1.70, 1.11–2.62), in individuals consuming mushrooms (PR = 2.08, 1.07–4.05), and in smokers (PR = 1.43, 1.00–2.05).

Conclusions

We found that the general adult population in Israel is widely exposed to BPA. Our findings on higher BPA levels in Jews compared to Arabs and Druze and in individuals with higher education highlights the fact that predictors of BPA exposure vary across populations.     

Identifying sources of phthalate exposure with human biomonitoring: Results of a 48 h fasting study with urine collection and personal activity patterns

Human biomonitoring studies measuring phthalate metabolites in urine have shown widespread exposure to phthalates in the general population. Diet is thought to be a principle route of exposure to many phthalates. Therefore, we studied urinary phthalate metabolite patterns over a period of strict fasting and additionally recorded personal activity patterns with a diary to investigate non-dietary routes of exposure. Five individuals (3 female, 2 male, 27–47 years of age) fasted on glass-bottled water only over a 48-h period. All urine void events were captured in full, and measured for metabolites of the high molecular weight (HMW) di-(2-ethylhexyl) phthalate (DEHP), di-isononyl phthalate (DINP) and di-isodecyl phthalate (DiDP), and the low molecular weight (LMW) di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), butylbenzyl phthalate (BBzP), dimethyl phthalate (DMP), and diethyl phthalate (DEP). In all, 21 metabolites were measured in a total of 118 urine events, including events before and after the fasting period. At the onset of the study all phthalate metabolite concentrations were consistent with levels found in previous general population studies. Metabolites of the HMW phthalates (DEHP, DiNP and DiDP) showed a rapid decline to levels 5–10 times lower than initial levels within 24 h of the fast and remained low thereafter. After food consumption resumed, levels rose again. By contrast, metabolites of the LMW phthalates including DMP, DEP, BBzP, DnBP and DiBP showed a cyclical pattern of rising and declining concentrations suggestive of ongoing non-food exposures. Furthermore, metabolites of most of the LMW phthalates (BBzP, DnBP and DiBP) tracked each other remarkably well, suggesting concurrent exposures. Diary entries could not help explain exposure sources for these phthalates, with one exception: rises in MEP concentrations around males’ showers suggest personal care products as a major source of DEP. Exposure to HMW phthalates in this cohort appears to be driven by dietary intake, while non-dietary routes such as use of personal care products and ubiquitous sources including dust and indoor air appear to explain exposure to LMW phthalates.