Urinary Metabolites of Organophosphate Flame Retardants: Temporal Variability and Correlations with House Dust Concentrations

Background: A reduction in the use of polybrominated diphenyl ethers (PBDEs) because of human health concerns may result in an increased use of and human exposure to organophosphate flame retardants (OPFRs). Human exposure and health studies of OPFRs are lacking.Objectives: We sought to define the degree of temporal variability in urinary OPFR metabolites in order to inform epidemiologic study design, and to explore a potential primary source of exposure by examining the relationship between OPFRs in house dust and their metabolites in urine.Methods: Nine repeated urine samples were collected from 7 men over the course of 3 months and analyzed for bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP), metabolites of the OPFRs tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), respectively. Intraclass correlation coefficients (ICCs) were calculated to characterize temporal reliability. Paired house dust and urine samples were collected from 45 men.Results: BDCPP was detected in 91% of urine samples, and DPP in 96%. Urinary BDCPP showed moderate-to-strong temporal reliability (ICC range, 0.55–0.72). ICCs for DPP were lower, but moderately reliable (range, 0.35–0.51). There was a weak [Spearman r (r_S) = 0.31] but significant (p = 0.03) correlation between urinary BDCPP and TDCPP concentrations in house dust that strengthened when nondetects (r_S = 0.47) were excluded. There was no correlation between uncorrected DPP and TPP measured in house dust (r_S < 0.1).Conclusions: Household dust may be an important source of exposure to TDCPP but not TPP. Urinary concentrations of BDCPP and DPP were moderately to highly reliable within individuals over 3 months.     

Cadmium,Lead, and Other Metals in Relation to Semen Quality: Human Evidence for Molybdenum as a Male Reproductive Toxicant

Background

Evidence on human semen quality as it relates to exposure to various metals, both essential (e.g., zinc, copper) and nonessential (e.g., cadmium, lead), is inconsistent. Most studies to date used small sample sizes and were unable to account for important covariates.

Objectives

Our goal in this study was to assess relationships between exposure to multiple metals at environmental levels and human semen-quality parameters.

Methods

We measured semen quality and metals in blood (arsenic, Cd, chromium, Cu, Pb, manganese, mercury, molybdenum, selenium, and Zn) among 219 men recruited through two infertility clinics. We used multiple statistical approaches to assess relationships between metals and semen quality while accounting for important covariates and various metals.

Results

Among a number of notable findings, the associations involving Mo were the most consistent over the various statistical approaches. We found dose-dependent trends between Mo and declined sperm concentration and normal morphology, even when considering potential confounders and other metals. For example, adjusted odds ratios (ORs) for below-reference semen-quality parameters in the low, medium, and high Mo groups were 1.0 (reference), 1.4 [95% confidence interval (CI), 0.5–3.7], and 3.5 (95% CI, 1.1–11) for sperm concentration and 1.0 (reference), 0.8 (95% CI, 0.3–1.9), and 2.6 (95% CI, 1.0–7.0) for morphology. We also found preliminary evidence for interactions between Mo and low Cu or Zn. In stratified analyses, the adjusted ORs in the high Mo/low Cu group were 14.4 (1.6, 132) and 13.7 (1.6, 114) for below-reference sperm concentration and morphology, respectively.

Conclusions

Our findings represent the first human evidence for an inverse association between Mo and semen quality. These relationships are consistent with animal data, but additional human and mechanistic studies are needed.     

某蓄电池厂铅作业男工血铅、尿铅及血清中性激素水平的调查

目的评价铅作业男性工人的血铅、尿铅水平及其影响因素,研究铅作业男性工人的血清中性激素水平的改变并探讨其机制。方法 2011年1月,选取深圳市某蓄电池厂铅作业男工120名作为接触组,按工作场所空气中铅含量的水平分成高、中、低3个接触浓度组;并选取来自同一家工厂未接触铅作业的40名男工作为对照组,测定4个组人群的血铅、尿铅、血清睾酮、FSH（促卵泡刺激素）及LH（促黄体生成素）的水平并进行统计分析。结果工作场所空气中铅浓度平均为0.29mg/m3,样品超标率为90%;3个接触组血铅、尿铅含量、尿铅异常率均明显高于对照组,差异均有统计学意义,且各接触组间血铅水平及异常率比较,差异也均有统计学意义（均P〈0.01）;随着工龄的增长,工人血铅、尿铅水平和异常率均有升高的趋势;中、高浓度接触组工人的血清睾酮水平均低于对照组和低浓度接触组,而血清FSH水平均高于对照组和低浓度接触组,差异均有统计学意义（均P〈0.01）。结论在该次研究的条件下,工龄增加、工作场所中铅浓度超标是导致血铅、尿铅水平升高的主要危险因素;铅暴露可能对下丘脑—垂体—睾丸轴的性激素分泌功能造成影响,从而对男性工人的生殖系统产生内分泌干扰作用。     

High Resolution Light Microscopic Evaluation of Boar Semen Quality Sperm Cytoplasmic Droplet Retention in Relationship with Boar Fertility Parameters

The purpose of this study was to investigate the relationship between fertility and quantitative measures of boar semen quality, including various patterns of sperm cytoplasmic droplet (CD) retention, as determined by high power differential interference contrast (DIC) microscopy. A total of 116 ejaculates were collected from a nucleus herd of 18 Large White boars over an eight month period. Semen quality parameters were analyzed for each ejaculate by calculating the percentage of normal spermatozoa, spermatozoa possessing a CD in the proximal, distal, or distal midpiece reflex position, total spermatozoa with an attached cytoplasmic droplet, spermatozoa with non-CD related aberrations and total spermatozoa with abnormalities. Of the 116 ejaculates received, 71 ejaculates from 13 boars had corresponding fertility data from single-sire inseminations of multiparous sows. The fertility data included farrowing rate (FR) and total number born (TNB). The monthly FR encompassed one month before and one month after the date of semen collection. Detection of differences for fertility and semen quality parameters was performed by separating the boars into either an above-average or below-average group based on the mean FR (74.01 ± 1.43%) or TNB (12.34 ± 0.17) for the study. For FR, the boars in the below-average group had a significantly lower percentage of normal spermatozoa and significantly higher percentage of spermatozoa possessing distal CDs, total attached CDs and total abnormalities compared to the boars in the above-average group. Conversely, for TNB there were no significant differences between the above- and below-average groups for the semen quality parameters. These data suggest that the attached CD may negatively affect FR, but not TNB. The detection of relationships between the boar fertility parameters and the retention of the sperm CD after ejaculation, document the advantage of high power DIC microscopy in conventional semen evaluation.     

Spontaneous abortion in spouses of greenhouse workers exposed to pesticides

Objective The aim of this study was to explore the association between exposure to specific pesticides (including endocrine disrupters) of greenhouse workers and spontaneous abortion in their spouses. Methods A group of exposed workers was compared with a non-exposed group. The risk of spontaneous abortion was evaluated using a logistic regression model. Results A significantly higher rate of spontaneous abortion was observed among spouses of workers exposed to specific compounds (atrazine, benomyl-carbendazim, carbaryl and DDT) in comparison with spouses of the unexposed group. The logistic regression model confirmed the increased risk of spontaneous abortion (OR=11.8; 95% CI 2.3–59.6). Conclusions These findings suggest that occupational exposure to pesticides might have an adverse effect on the partner’s reproductive health.     

Predictors and Variability of Urinary Paraben Concentrations in Men and Women,Including before and during Pregnancy

Background: Parabens are suspected endocrine disruptors and ubiquitous preservatives used in personal care products, pharmaceuticals, and foods. No studies have assessed the variability of parabens in women, including during pregnancy.Objective: We evaluated predictors and variability of urinary paraben concentrations.Methods: We measured urinary concentrations of methyl (MP), propyl (PP), and butyl paraben (BP) among couples from a fertility center. Mixed-effects regression models were fit to examine demographic predictors of paraben concentrations and to calculate intraclass correlation coefficients (ICCs).Results: Between 2005 and 2010, we collected 2,721 spot urine samples from 245 men and 408 women. The median concentrations were 112 µg/L (MP), 24.2 µg/L (PP), and 0.70 µg/L (BP). Urinary MP and PP concentrations were 4.6 and 7.8 times higher in women than men, respectively, and concentrations of both MP and PP were 3.8 times higher in African Americans than Caucasians. MP and PP concentrations we CI re slightly more variable in women (ICC = 0.42, 0.43) than men (ICC = 0.54, 0.51), and were weakly correlated between partners (r = 0.27–0.32). Among 129 pregnant women, urinary paraben concentrations were 25–45% lower during pregnancy than before pregnancy, and MP and PP concentrations were more variable (ICCs of 0.38 and 0.36 compared with 0.46 and 0.44, respectively).Conclusions: Urinary paraben concentrations were more variable in women compared with men, and during pregnancy compared with before pregnancy. However, results for this study population suggest that a single urine sample may reasonably represent an individual’s exposure over several months, and that a single sample collected during pregnancy may reasonably classify gestational exposure.     

Associations Between Thyroid Hormone Levels and Urinary Concentrations of Bisphenol A,F, and S in 6-Year-old Children in Korea

ObjectivesBisphenol A (BPA) is used in the electrical, mechanical, medical, and food industries. Previous studies have suggested that BPA is an endocrine disruptor. Regulation of BPA has led to increased use of bisphenol F (BPF) and bisphenol S (BPS). However, few studies have investigated the associations of BPF and BPS with thyroid dysfunction in children. Our study investigated the associations of prenatal BPA and early childhood BPA, BPF, and BPS exposure with thyroid function in 6-year-old children.MethodsPrenatal BPA concentrations were measured during the second trimester of pregnancy in an established prospective birth cohort. We measured urinary BPA, BPF, and BPS concentrations and thyroid hormone levels (thyroid-stimulating hormone, total T₃, and free T₄) in 6-year-old children (n=574). We examined the associations between urinary bisphenol concentrations and percentage change of thyroid hormone concentrations using multivariate linear regression. We also compared thyroid hormone levels by dividing the cohort according to BPA, BPF, and BPS concentrations.ResultsThe associations between prenatal BPA and total T₃ levels were statistically significant in all models, except for girls when using a crude model. The associations between urinary BPA and BPS concentrations and levels of all thyroid hormones were not statistically significant. However, we observed that lower free T₄ levels (−1.94%; 95% confidence interval, −3.82 to −0.03) were associated with higher urinary BPF concentrations in girls only.ConclusionsOur findings identified significant associations between prenatal BPA exposure and total T₃ levels in all children and between BPF exposure and free T₄ levels in girls only.     

Plasma Levels of Persistent Organohalogens and Hormone Levels in Adult Male Humans

In this study the authors assessed the possible relationship between high dietary exposure to persistent organohalogens (OHS) through fatty fish from the Baltic Sea and hormone levels in adult men. Blood samples were drawn from 110 men who consumed varying amounts of fish (i.e., 0-32 meals per month) for analysis of plasma levels of 18 polychlorinated biphenyl (PCB) congeners, 5 hydroxy-PCBs, 1,1,1 -trichloro-2,2-bis(4-chlorophenyl)-ethane (p,p'-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE), hexachlorobenzene, and 2,2′,4,4′-tetrabromodiphenyl ether. In addition, plasma levels of follicle-stimulating hormone, luteinizing hormone, prolactin, plasma thyrotropin, free and total T3, free and total T4, and free testosterone were analyzed. The authors adjusted for age, and the only significant associations that remained were negative correlations between 2,2′,4,4′-tetrabro-modiphenyl ether and plasma thyrotropin (p < .001), and between pentachlorophenol and follicle-stimulating hormone (p = .04). The authors expected that there would be some significant correlations that resulted from pure chance. High consumption of organohalogen-polluted fish did not appear to affect plasma concentrations of pituitary, thyroid, or testosterone hormone levels in male adults.     

Sperm Donors in Shanghai,China: A Study of Motivations,Characteristics, and Semen Parameters of Actual Sperm Donors

Objective::To identify the sociodemographic characteristics, motivations, and semen parameters of sperm donors in Shanghai, China.Methods::The participants were...     

Thyroid Hormone Levels of Pregnant Inuit Women and Their Infants Exposed to Environmental Contaminants

Background

An increasing number of studies have shown that several ubiquitous environmental contaminants possess thyroid hormone–disrupting capacities. Prenatal exposure to some of them, such as polychlorinated biphenyls (PCBs), has also been associated with adverse neurodevelopmental effects in infants.

Objectives

In this study we examined the relationship between exposure to potential thyroid hormone–disrupting toxicants and thyroid hormone status in pregnant Inuit women from Nunavik and their infants within the first year of life.

Methods

We measured thyroid hormone parameters [thyroid stimulating hormone (TSH), free thyroxine (fT₄), total triiodothyronine (T₃), thyroxine-binding globulin (TBG)] and concentrations of several contaminants [PCB-153, hydroxylated metabolites of PCBs (HO-PCBs), pentachlorophenol (PCP) and hexachlorobenzene (HCB)] in maternal plasma at delivery (n = 120), in umbilical cord plasma (n = 95), and in infant plasma at 7 months postpartum (n = 130).

Results

In pregnant women, we found a positive association between HO-PCBs and T₃ concentrations (β = 0.57, p = 0.02). In umbilical cord blood, PCB-153 concentrations were negatively associated with TBG levels (β = −0.26, p = 0.01). In a subsample analysis, a negative relationship was also found between maternal PCP levels and cord fT₄ concentrations in neonates (β = −0.59, p = 0.02). No association was observed between contaminants and thyroid hormones at 7 months of age.

Conclusion

Overall, there is little evidence that the environmental contaminants analyzed in this study affect thyroid hormone status in Inuit mothers and their infants. The possibility that PCP may decrease thyroxine levels in neonates requires further investigation.     

Urinary,Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A

Background

Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. Importantly, results from a large number of biomonitoring studies are at odds with the results from two toxicokinetic studies.

Objective

We examined several possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions.

Data sources

We examined > 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism.

Data extraction and synthesis

The > 80 biomonitoring studies examined included measurements in thousands of individuals from several different countries, and these studies overwhelmingly detected BPA in individual adults, adolescents, and children. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Some regulatory agencies have relied solely on these toxicokinetic models in their risk assessments.

Conclusions

Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.     

Lack of Sensitivity of Urinary Trans,Trans, -Muconic Acid in Determining Low-Level (ppb) Benzene Exposure in Children

Benzene is a widespread pollutant of which the main source in the outside environment is automotive traffic. Benzene is also present in cigarette smoke, and small quantities exist in drinking water and food; all of these sources contribute to pollution of indoor environments. Benzene exposure may be studied with biologic indicators. In the present study, the authors evaluated whether differences in urinary concentrations of trans, trans-muconic acid (t,t-MA) were detectable in a sample of 150 children and if the chemical was correlated with environmental exposures to low levels of benzene. The children attended primary schools that had significantly different—but low—environmental benzene levels. Analysis of urinary t,t-MA was achieved with high-performance liquid chromatography (photodiode array detector), and analysis of passive air samplers for benzene was performed with gas chromatography-mass spectrometry. Statistical analysis (Kruskal-Wallis test) indicated that differences in urinary levels of t,t-MA in children from urban and rural areas were not statistically significant (p = .07), nor were there significant differences between children with and without relatives who smoked (p = .69). As has been shown in other studies of children and adults, results of our study evidenced (1) the difficulty of correlating concentrations of urinary biomarkers with environmental exposure to benzene at a parts-per-billion level (i.e., traffic and environmental tobacco smoke) and, consequently, (2) the lack of specificity of t,t-MA as a biological indicator for the study of a population's exposure.     

某镉电池厂镉作业女性32人尿镉及血清中性激素的水平

目的了解镉作业女工尿镉及血清中性激素水平改变的影响因素并初步探讨其机制。方法 2010年11月,选取某镉电池工厂镉作业女工100名作为接触组,按工作场所空气中镉含量的水平分成高、低2个接触浓度组;并选取来自同一家工厂未接触镉作业的50名女工作为对照组,测定3组人群的尿镉、促卵泡刺激素（FSH）、促黄体生成素（LH）及雌二醇（E2）的水平并进行统计分析。结果 2个接触组尿镉含量和异常率均明显高于对照组,差异有统计学意义（P〈0.05,P〈0.01）;高浓度接触组工人在月经周期中的月经期血清中FSH水平和E2水平均低于对照组,差异均有统计学意义（P〈0.01）;增殖期血清中LH水平低于对照组,差异有统计学意义（P〈0.01）;分泌期血清中LH和E2水平均低于对照组,差异均有统计学意义（P〈0.01）。结论在该研究的条件下,工作场所中氧化镉浓度超标是导致尿镉水平升高的主要危险因素;镉暴露可能对下丘脑-垂体-卵巢轴的性激素分泌功能造成影响,从而对女性工人的生殖系统产生内分泌干扰作用。     

Determinants and Within-Person Variability of Urinary Cadmium Concentrations among Women in Northern California

Background: Cadmium (Cd) is a toxic metal associated with increased morbidity and mortality. Urinary Cd (U-Cd) concentration is considered a biomarker of long-term exposure.Objectives: Our objectives were to evaluate the within-person correlation among repeat samples and to identify predictors of U-Cd concentrations.Methods: U-Cd concentrations (micrograms per liter) were measured in 24-hr urine samples collected from 296 women enrolled in the California Teachers Study in 2000 and a second 24-hr sample collected 3–9 months later from 141 of the participants. Lifestyle and sociodemographic characteristics were obtained via questionnaires. The Total Diet Study database was used to quantify dietary cadmium intake based on a food frequency questionnaire. We estimated environmental cadmium emissions near participants’ residences using a geographic information system.Results: The geometric mean U-Cd concentration was 0.27 µg/L and the range was 0.1–3.6 µg/L. The intraclass correlation among repeat samples from an individual was 0.50. The use of a single 24-hr urine specimen to characterize Cd exposure in a case–control study would result in an observed odds ratio of 1.4 for a true odds ratio of 2.0. U-Cd concentration increased with creatinine, age, and lifetime pack-years of smoking among ever smokers or lifetime intensity-years of passive smoking among nonsmokers, whereas it decreased with greater alcohol consumption and number of previous pregnancies. These factors explained 42–44% of the variability in U-Cd concentrations.Conclusion: U-Cd levels varied with several individual characteristics, and a single measurement of U-Cd in a 24-hr sample did not accurately reflect medium- to long-term body burden.     

SQA—V全自动精子质量分析仪与计算机辅助精液分析系统结果比较

目的评估SQA—V全自动精子质量分析仪与计算机辅助精液分析系统（CASA）分析的精液各项主要参数的可比性。方法 对50份精液标本采用SQA-V全自动精子质量分析仪与CASA同时进行检测。结果在检测精子密度,精子活率,A级精子活力百分率和A＋B级精子活力百分率的结果上,SQA-V全自动精子质量分析仪与CASA的结果差异无统计学意义（P〉0．05）。结论SQA—V全自动精子质量分析仪与CASA在各项主要参数上具有较好的一致性。     

Serum DDT and DDE Levels in Pregnant Women of Chiapas,Mexico

The authors measured the main ingredients of technical DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl [p,p[icaron]-DDT]) and its principal metabolite, 1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene [p,p[icaron]-DDE]) in serum collected from 52 pregnant women in Tapachula, Chiapas, Mexico in 1998. The median lipid-adjusted serum levels for the women were 676 ng/g p,p[icaron]-DDT (range: 56–23,169 ng/g) and 4,843 ng/g p,p[icaron]-DDE (range: 113–41, 964 ng/g). In regression analysis, serum DDT and DDE increased with age (test for trend, p = .022) but decreased with total lactation (test for trend, p < .001). Residence in a house that had ever been sprayed for malaria control was also related to serum DDT and DDE. This study provides evidence of high-level exposure to DDT and DDE among pregnant women living in Chiapas, Mexico, despite countrywide restrictions on its use at the time.     

人类精子DNA氧化损伤与精子质量和精液中镉、铅浓度的关系

用高压液相色谱—光电检测系统和高压液相色谱—紫外线检测器同时检测发现人精子ＤＮＡ８ＯＨｄＧ 和ｄＧ 水平,用原子吸收光谱检测精液中镉、铅浓度。确定５６ 名非吸烟者精子ＤＮＡ８羟脱氧核糖核酸（８ＯＨｄＧ） 水平,探讨人类精子ＮＤＡ氧化性损伤与精子质量和精液中镉、铅浓度的关系。发现８ＯＨｄＧ／１０６ｄＧ平均几何均数为４８．３（９５ ％ ＣＩ：２０．８ － １１１．８ ,ｎ ＝ ５６） ;８ＯＨｄＧ／１０６ｄＧ 与精子密度（ｒ＝ － ０．４６ ,Ｐ＝ ０．００１ ,ｎ ＝ ５６） 和精子总数之间（ｒ＝ － ０．３７ ,Ｐ＝ ０．００５ ,ｎ ＝ ５６） 呈明显的负相关;８ＯＨｄＧ／１０６ｄＧ 与精液镉（ｒ＝ ０．４９ ,Ｐ＝ ０．００１） 、铅（ｒ＝ ０．３０ 、Ｐ＝ ０．０２５） 浓度呈明显的正相关。提示人类精子氧化性损伤影响精子质量,精液中镉、铅浓度可能是人类精子氧化性损伤的重要因素