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Graptemys oculifera is endemic to the Pearl River drainage system in Louisiana and Mississippi, and due to this limited range it is vulnerable to environmental changes. Many impacts to this drainage system are due to anthropogenic activities, and alterations may negatively impact the connectivity among populations of G. oculifera. Previous studies show populations below the Ross Barnett Reservoir might be undergoing population declines, suggesting limited movement among populations. In addition to anthropogenic effects, the drainage geomorphology might also play a role in shaping population connectivity, as the sister species of G. oculifera, G. flavimaculata, contains two distinct populations (mainstem Pascagoula and Escatawpa River) and possible subpopulations within the Pascagoula (upper Leaf River, upper Chickasawhay River, and lower sections of the Pascagoula River). We used six polymorphic microsatellite loci to analyze the population genetics of G. oculifera at eight sites in the Pearl River draina...

The Centers for Disease Control and Prevention developed a biomonitoring method to rapidly and accurately quantify chromium and cobalt in human whole blood by ICP-MS. Many metal-on-metal hip implants which contain significant amounts of chromium and cobalt are susceptible to metal degradation. This method is used to gather population data about chromium and cobalt exposure of the U.S. population that does not include people that have metal-on-metal hip implants so that reference value can be established for a baseline level in blood. We evaluated parameters such as; helium gas flow rate, choice and composition of the diluent solution for sample preparation, and sample rinse time to determine the optimal conditions for analysis. The limits of detection for chromium and cobalt in blood were determined to be 0.41 and 0.06 μg L−1, respectively. Method precision, accuracy, and recovery for this method were determined using quality control material created in-house and historical proficiency testing samples. We conducted experiments to determine if quantitative changes in the method parameters affect the results obtained by changing four parameters while analyzing human whole blood spiked with National Institute of Standard and Technology traceable materials: the dilution factor used during sample preparation, sample rinse time, diluent composition, and kinetic energy discrimination gas flow rate. The results at the increased and decreased levels for each parameter were statistically compared to the results obtained at the optimized parameters. We assessed the degree of reproducibility obtained under a variety of conditions and evaluated the method's robustness by analyzing the same set of proficiency testing samples by different analysts, on different instruments, with different reagents, and on different days. The short-term stability of chromium and cobalt in human blood samples stored at room temperature was monitored over a time period of 64 hours by diluting and analyzing samples at different time intervals. The stability of chromium and cobalt post-dilution was also evaluated over a period of 48 hours and at two storage temperatures (room temperature and refrigerated at 4 °C). The results obtained during the stability studies showed that chromium and cobalt are stable in human blood for a period of 64 hours.

In 2012, the Centers for Disease Control and Prevention (CDC) adopted its Advisory Committee on Childhood Lead Poisoning Prevention recommendation to use a population-based reference value to identify children and environments associated with lead hazards. The current reference value of 5 μg/dL is calculated as the 97.5th percentile of the distribution of blood lead levels (BLLs) in children 1 to 5 years old from 2007 to 2010 NHANES data. We calculated and updated selected percentiles, including the 97.5th percentile, by using NHANES 2011 to 2014 blood lead data and examined demographic characteristics of children whose blood lead was ≥90th percentile value. The 97.5th percentile BLL of 3.48 µg/dL highlighted analytical laboratory and clinical interpretation challenges of blood lead measurements ≤5 μg/dL. Review of 5 years of results for target blood lead values

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO REMPAN (Radiation Emergency Medical Preparedness and Assistance Network) and the IAEA RANET (Response and Assistance Network), to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 hours following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response.

Prostanoid EP receptor agonists are used for a number of clinical indications but may be associated with gastric disturbance. In the present studies we used the ferret and sulprostone (30µg/kg, i.p.) to investigate the role of EP

Iodine is an essential nutrient for normal growth and development. Iodine deficiency, which can cause intellectual impairment and brain damage, affects about 2 billion people worldwide. Severe iodine deficiency can result in a 10%–15% reduction in the IQ of a population. In the United States and many other countries, dairy products contribute the majority of daily iodine intake. According to a review of literature sources from all over the world, iodine nutritional status reflects changes in the dairy industry. Variables affecting the iodine content in dairy products include ration mixture, season, geographic region, sanitizing solutions, and supplements to the feed supply. Studies performed in the United States, Britain, Australia, New Zealand, and Norway showed this impact most noticeably. These studies investigate the relationship between dairy and iodine for various countries over the last six decades. Monitoring the correlation between iodine content in dairy products and population iodine status can help inform public health approaches to ensure adequate, safe, and balanced iodine intake.

Background Despite the public health and toxicologic interest in methyl mercury (MeHg) and ethyl mercury (EHg), these mercury species have been technically difficult to measure in large population studies. Methods Using NHANES 2011–2012 data, we calculated reference ranges and examined demographic factors associated with specific mercury species concentrations and the ratio of MeHg to THg. We conducted several multiple regression analyses to examine factors associated with MeHg concentrations and also with the ratio of MeHg to THg. Results Asians had the highest geometric mean concentrations for MeHg, 1.58 µg/L (95% CI 1.29, 1.93) and THg, 1.86 µg/L (1.58, 2.19), followed by non-Hispanic blacks with MeHg, 0.52 µg/L (0.39, 0.68) and THg, 0.68 µg/L (0.54, 0.85). Greater education attainment in adults and male sex were associated with higher MeHg and THg concentrations. Race/ethnicity, age, and sex were significant predictors of MeHg concentrations, which increased with age and were highest in Asians in all age categories, followed by non-Hispanic blacks. Mexican Americans had the lowest adjusted MeHg concentrations. The ratio of MeHg to THg was highest in Asians, varied by racial/ethnic group, and increased with age in a non-linear fashion. The amount of increase in the MeHg to THg ratio with age depended on the initial ratio, with a greater increase as age increased. Of the overall population, 3.05% (95% CI 1.77, 4.87) had MeHg concentrations >5.8 µg/L (a value that corresponds to the U.S. EPA reference dose). The prevalence was highest in Asians at 15.85% (95% CI 11.85, 20.56), increased with age, reaching a maximum of 9.26% (3.03, 20.42) at ages 60–69 years. Females 16–44 years old had a 1.76% (0.82–3.28) prevalence of MeHg concentrations >5.8 µg/L. Conclusions Asians, males, older individuals, and adults with greater educational attainment had higher MeHg concentrations. The ratio of MeHg to THg varied with racial/ethnic group, increased with age, and was nonlinear. U.S. population reference values for MeHg and the ratio of MeHg to THg can assist in more precise assessment of public health risk from MeHg consumed in seafood.

Quantification of the isotopic composition of uranium in urine at low levels of concentration is important for assessing both military and civilian populations' exposures to uranium. However, until now there has been no convenient, precise method established for rapid determination of multiple uranium isotope ratios. Here, the authors report a new method to measure (234)U/(238)U, (235)U/(238)U and (236)U/(238)U. It uses solid-phase chelation extraction (via TRU columns) of actinides from the urine matrix, followed by measurement using a magnetic sector field inductively coupled plasma mass spectrometer (SF-ICP-MS-Thermo Element XR) equipped with a high-efficiency nebulizer (Apex PFA microflow) and coupled with a membrane desolvating nebulizer system (Aridus II™). This method provides rapid and reliable results and has been used successfully to analyse Certified Reference Materials.

The presence of metals in the environment is ubiquitous and humans are constantly being exposed to them. As such, a general concern exists about potential health consequences that result from the exposure to metals. The continued efforts of environmental scientists to measure metals in clinical specimens are important for defining the extent of human exposure to these chemicals. Laboratory methods to measure the concentration of metals in human blood or urine are available, and they can be used to assess the extent of human exposure to these chemicals. However, several considerations should be reviewed when requesting a laboratory measurement of metals because some factors can affect the test result or its interpretation. These considerations are discussed in this article and include pre-analytical, analytical, and post-analytical factors. Clinicians with this knowledge will be able to request these laboratory tests for their patients with enhanced confidence.

Biomonitoring and emergency response measurements are an important aspect of the Division of Laboratory Sciences of the National Center for Environmental Health, Centers for Disease Control and Prevention (CDC). The continuing advancement in instrumentation allows for enhancements to existing analytical methods. Prior to this work, chromium and nickel were analyzed on a sector field inductively coupled plasma-mass spectrometer (SF-ICP-MS). This type of instrumentation provides the necessary sensitivity, selectivity, accuracy, and precision but due to the higher complexity of instrumentation and operation, it is not preferred for routine high throughput biomonitoring needs. Instead a quadrupole based method has been developed on a PerkinElmer NexION™ 300D ICP-MS. The instrument is operated using 6.0 mL min−1 helium as the collision cell gas and in kinetic energy discrimination mode, interferences are successfully removed for the analysis of 52Cr (40Ar12C and 35Cl16O1H) and 60Ni (44Ca16O). The limits of detection are 0.162 μg L−1 Cr and 0.248 μg L−1 Ni. Method accuracy using NIST SRM 2668 level 1 (1.08 μg L−1 Cr and 2.31μg L−1 Ni) and level 2 (27.7 μg L−1 Cr and 115 μg L−1 Ni) was within the 95% confidence intervals reported in the NIST certificate. Among-run precision is less than 10% RSDs (N = 20) for in house quality control and NIST SRM urine samples. While the limits of detection (LOD) for the new quadrupole ICP-UCT-MS with KED method are similar to the SF-ICP-MS method, better measurement precision is observed for the quadrupole method. The new method presented provides fast, accurate, and more precise results on a less complex and more robust ICP-MS platform.

The alligator snapping turtle (Macrochelys temminckii) is under consideration for listing as a federally endangered species. Distributional data and estimates of population sizes are needed to make a sound decision regarding listing, but this information is largely unavailable due to the immense effort required for M. temminckii trapping surveys. To alleviate difficulty in detection and to help inform subsequent field-intensive survey efforts, we developed an environmental DNA (eDNA) method capable of providing presence data even in systems with high turbidity and suspended organic material. The assay we developed utilizes probe-based quantitative polymerase chain reaction and reliably amplifies M. temminckii eDNA in both lentic and lotic systems, with no amplification observed in other nontarget, sympatric turtle species. The novel eDNA method developed, optimized, and field-tested in this study provides a promising tool for detection of alligator snapping turtles, with resultant presence data likely to prove beneficial for the management and conservation of this species.

Background and objectives Some blood centers provide health screening as a public health measure and to encourage donation. The goal of the current study was to provide cardiovascular disease (CVD) screening to donors using high-throughput testing and web-based communications. Materials and methods CVD risk screening was offered to donors at selected mobile drives in a large metropolitan area. Risk factors were determined by donor questionnaire, laboratory testing (total cholesterol, HDL levels and hemoglobin A1c), and blood pressure measurement. Results were reported to participants via mail and website. A 60-day follow up web-based survey was sent to participants via email to assess the impact of the program on donor’s behavior. Results 9435 donors, 17–75 years old participated with the following risk factors: 61.3% BMIs > 25, 28.8% high total cholesterol, and 31.4% lower than recommended HDL levels. 25.3% of donors that responded to the follow up survey went to see their health care provider based on screening results and 9% of these received new or modified treatment. Conclusion In our sample, blood donors are healthier than the general population, but many still have CVD risk factors, particularly obesity. CVD screening can be successfully used to make donors aware of this important health information and some donors act on this information.

Background: Very high levels of prenatal maternal mercury have adverse effects on the developing fetal brain. It has been suggested that all possible sources of mercury should be avoided. However, although seafood is a known source of mercury, little is known about other dietary components that contribute to the overall levels of blood mercury. Objective: Our goal was to quantify the contribution of components of maternal diet to prenatal blood mercury level. Methods: Whole blood samples and information on diet and sociodemographic factors were collected from pregnant women (n = 4,484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The blood samples were assayed for total mercury using inductively coupled plasma dynamic reaction cell mass spectrometry. Linear regression was used to estimate the relative contributions of 103 dietary variables and 6 sociodemographic characteristics to whole blood total mercury levels (TBM; untransformed and log-transformed) based on R2 values. Results: We estimated that maternal diet accounted for 19.8% of the total variation in ln-TBM, with 44% of diet-associated variability (8.75% of the total variation) associated with seafood consumption (white fish, oily fish, and shellfish). Other dietary components positively associated with TBM included wine and herbal teas, and components with significant negative associations included white bread, meat pies or pasties, and french fries. Conclusions: Although seafood is a source of dietary mercury, seafood appeared to explain a relatively small proportion of the variation in TBM in our UK study population. Our findings require confirmation, but suggest that limiting seafood intake during pregnancy may have a limited impact on prenatal blood mercury levels. Citation: Golding J, Steer CD, Hibbeln JR, Emmett PM, Lowery T, Jones R. 2013. Dietary predictors of maternal prenatal blood mercury levels in the ALSPAC birth cohort study. Environ Health Perspect 121:1214–1218; http://dx.doi.org/10.1289/ehp.1206115

We improved our inductively coupled plasma mass spectrometry (ICP-MS) whole blood method [1] for determination of lead (Pb), cadmium (Cd), and mercury (Hg) by including manganese (Mn) and selenium (Se), and expanding the calibration range of all analytes. The method is validated on a PerkinElmer (PE) ELAN® DRC II ICP-MS (ICP-DRC-MS) and uses the Dynamic Reaction Cell (DRC) technology to attenuate interfering background ion signals via ion-molecule reactions. Methane gas (CH4) eliminates background signal from 40Ar2+ to permit determination of 80Se+, and oxygen gas (O2) eliminates several polyatomic interferences (e.g. 40Ar15N+, 54Fe1H+) on 55Mn+. Hg sensitivity in DRC mode is a factor of two higher than vented mode when measured under the same DRC conditions as Mn due to collisional focusing of the ion beam. To compensate for the expanded method’s longer analysis time (due to DRC mode pause delays), we implemented an SC4-FAST autosampler (ESI Scientific, Omaha, NE), which vacuum loads the sample onto a loop, to keep the sample-to-sample measurement time to less than 5 min, allowing for preparation and analysis of 60 samples in an 8-h work shift. The longer analysis time also resulted in faster breakdown of the hydrocarbon oil in the interface roughing pump. The replacement of the standard roughing pump with a pump using a fluorinated lubricant, Fomblin®, extended the time between pump maintenance. We optimized the diluent and rinse solution components to reduce carryover from high concentration samples and prevent the formation of precipitates. We performed a robust calculation to determine the following limits of detection (LOD) in whole blood: 0.07 μg dL−1 for Pb, 0.10 μg L−1 for Cd, 0.28 μg L−1 for Hg, 0.99 μg L−1 for Mn, and 24.5 μg L−1 for Se.

Quantification of 241Am in urine at low levels is important for assessment of individuals’ or populations’ accidental, environmental, or terrorism-related internal contamination, but no convenient, precise method has been established to rapidly determine these low levels. Here we report a new analytical method to measure 241Am as developed and validated at the Centers for Disease Control and Prevention (CDC) by means of the selective retention of Am from urine directly on DGA resin, followed by SF-ICP-MS detection. The method provides rapid results with a limit of detection (LOD) of 0.22 pg/L (0.028 Bq/L), which is lower than 1/3 of the C/P CDG for 241Am at 5 days post-exposure. The results obtained by this method closely agree with CDC values as measured by liquid scintillation counting, and with National Institute of Standards Technology (NIST) Certified Reference Materials (CRM) target values.

In this study, we evaluated the effect of temperature on the long-term stability of three mercury species in bovine blood. We used inductively coupled plasma mass spectrometry (ICP-MS) analysis to determine the concentrations of inorganic (iHg), methyl (MeHg) and ethyl (EtHg) mercury species in two blood pools stored at temperatures of -70, -20, 4, 23°C (room temperature) and 37°C. Over the course of a year, we analyzed aliquots of pooled specimens at time intervals of 1, 2, 4 and 6 weeks and 2, 4, 6, 8, 10 and 12 months. We applied a fixed-effects linear model, step-down pairwise comparison and coefficient of variation statistical analysis to examine the temperature and time effects on changes in mercury species concentrations. We observed several instances of statistically significant differences in mercury species concentrations between different temperatures and time points; however, with considerations of experimental factors (such as instrumental drift and sample preparation procedures), not all differences were scientifically important. We concluded that iHg, MeHg and EtHg species in bovine whole blood were stable at -70, -20, 4 and 23°C for 1 year, but blood samples stored at 37°C were stable for no more than 2 weeks.

A multi-agency workshop was held from 25 to 27 August 2009, at the National Institute of Standards and Technology (NIST), to identify and prioritize the development of radioanalytical Certified Reference Materials (CRMs, generally provided by National Metrology Institutes; Standard Reference Materials, a CRM issued by NIST) for field and laboratory nuclear measurement methods to be used to assess the consequences of a domestic or international nuclear event. Without these CRMs, policy makers concerned with detecting proliferation and trafficking of nuclear materials, attribution and retribution following a nuclear event, and public health consequences of a nuclear event would have difficulty making decisions based on analytical data that would stand up to scientific, public, and judicial scrutiny. The workshop concentrated on three areas: post-incident Improvised Nuclear Device (IND) nuclear forensics, safeguard materials characterization, and consequence management for an IND or a Radiological Dispersion Device detonation scenario. The workshop identified specific CRM requirements to fulfill the needs for these three measurement communities. Of highest priority are: (1) isotope dilution mass spectrometry standards, specifically 233U, 236gNp, 244Pu, and 243Am, used for quantitative analysis of the respective elements that are in critically short supply and in urgent need of replenishment and certification; (2) CRMs that are urgently needed for post-detonation debris analysis of actinides and fission fragments, and (3) CRMs used for destructive and nondestructive analyses for safeguards measurements, and radioisotopes of interest in environmental matrices.

This survey of the literature on the value of active management shows that the average active manager does not outperform but that a significant minority of active managers do add value. Further, studies suggest that investors may be able to identify superior active managers (SAMs) in advance by using public information. Investors who can identify SAMs should be able to improve their overall Sharpe ratio by including a meaningful exposure to active strategies.

Bovine tuberculosis (bTB) is endemic in white-tailed deer (Odocoileus virginianus )i n northeastern Michigan, USA, and research suggests transmission to cattle. Prevalence of the disease in deer is estimated at 1.8%, but as prevalence decreases the difficulty of detection increases. Research suggests coyotes (Canis latrans) have a higher prevalence of bTB in Michigan than deer and sampling coyotes may be a more efficient surveillance tool to detect presence or spread of the disease. Coyotes possess suitable ecological characteristics to serve as a sentinel species, assuming transmission between coyotes is not significant. The question of whether free-ranging coyotes shed Mycobacterium bovis, the causative agent of bTB, has not been previously addressed. We actively used coyotes as a sentinel to detect bTB in infected and uninfected counties in Michigan's Northeastern Lower Peninsula. We determined whether bTB infection was present through bacteriologic culture of lymph nodes and tissues containing lesions and cultured oral/ nasal swabs and feces to establish shedding. Seventeen of 171 coyotes were M. bovis culture positive, one of which was from a previously uninfected county. All oral, nasal secretions and feces were culture negative suggesting minimal, if any, shedding of M. bovis. Thus, infection of coyotes is likely to occur through ingestion of infected deer carcasses and not from interaction with conspecifics. These findings support previous research suggesting that coyotes are useful sentinels for bTB. The use of coyotes as a sentinel, may allow wildlife managers to detect the spread of bTB into naive counties. With earlier detection managers may be able to take proactive surveillance measures to detect the disease in deer and reduce the potential risk to domestic livestock and captive deer herds. Published by Elsevier B.V.

Background Lead exposure is associated with elevated blood pressure during pregnancy; however, the magnitude of this relationship at low exposure levels is unclear. Objectives Our goal was to determine the association between low-level lead exposure and blood pressure during late pregnancy. Methods We collected admission and maximum (based on systolic) blood pressures during labor and delivery among 285 women in Baltimore, Maryland. We measured umbilical cord blood lead using inductively coupled plasma mass spectrometry. Multivariable models were adjusted for age, race, median household income, parity, smoking during pregnancy, prepregnancy body mass index, and anemia. These models were used to calculate benchmark dose values. Results Geometric mean cord blood lead was 0.66 μg/dL (95% confidence interval, 0.61–0.70). Comparing blood pressure measurements between those in the highest and those in the lowest quartile of lead exposure, we observed a 6.87-mmHg (1.51–12.21 mmHg) increase in admission systolic blood pressure and a 4.40-mmHg (0.21–8.59 mmHg) increase in admission diastolic blood pressure after adjustment for confounders. Corresponding values for maximum blood pressure increase were 7.72 (1.83–13.60) and 8.33 (1.14–15.53) mmHg. Benchmark dose lower limit values for a 1-SD increase in blood pressure were < 2 μg/dL blood lead for all blood pressure end points. Conclusions A significant association between low-level lead exposures and elevations in maternal blood pressure during labor and delivery can be observed at umbilical blood lead levels < 2 μg/dL.

Background: Metals can interfere with hormonal functioning by binding at the receptor site and through indirect mechanisms; thus, they may be associated with hormonal changes in premenopausal women. Objectives: We examined the associations between cadmium, lead, and mercury, and anovulation and patterns of reproductive hormones [estradiol, progesterone, follicle-stimulating hormone (FSH), luteinizing hormone] among 252 premenopausal women 18–44 years of age who were enrolled in the BioCycle Study in Buffalo, New York. Methods: Women were followed for up to two menstrual cycles, with serum samples collected up to eight times per cycle. Metal concentrations were determined at baseline in whole blood by inductively coupled mass spectroscopy. Marginal structural models with stabilized inverse probability weights and nonlinear mixed models with harmonic terms were used to estimate the effects of cadmium, lead, and mercury on reproductive hormone levels during the menstrual cycle and anovulation. Results: Geometric mean (interquartile range) cadmium, lead, and mercury levels were 0.29 (0.19–0.43) μg/L, 0.93 (0.68–1.20) μg/dL, and 1.03 (0.58–2.10) μg/L, respectively. We observed decreases in mean FSH with increasing cadmium [second vs. first tertile: –10.0%; 95% confidence interval (CI), –17.3% to –2.5%; third vs. first tertile: –8.3%; 95% CI, –16.0% to 0.1%] and increases in mean progesterone with increasing lead level (second vs. first tertile: 7.5%; 95% CI, 0.1–15.4%; third vs. first tertile: 6.8%; 95% CI, –0.8% to 14.9%). Metals were not significantly associated with anovulation. Conclusions: Our findings support the hypothesis that environmentally relevant levels of metals are associated with modest changes in reproductive hormone levels in healthy, premenopausal women.

Classic inorganic and more recent organometallic compounds capable of polymerizing ethylene to ultra high molecular are compared. Activated catalysts showed varying degrees of productivity when challenged with co-monomers. The general activity trend followed TiCl 3 3 N -(3,5-diiodosalicylidene)cycloheptylamine titanium dichloride was useful in making UHMWPE and compared to previously reported phenoxyimine catalyst structures capable of living polyolefin polymerizations.

Staphylococcal enterotoxin B (SEB) is an extracellular pyrotoxin produced by Staphylococcus aureus, a known etiologic agent of food poisoning in humans. Lateral flow immunochromatographic devices (LFDs) designed for the environmental detection of SEB were adapted for use in this study to detect SEB in milk containing 2 fat, chocolate-flavored milk, and milk-derived products such as yogurt, infant formula, and ice cream. The advantage of using LFDs in these particular food products was its ease and speed of use with no additional extraction methods needed. No false positives were observed with any of the products used in this study. Dilution of the samples overcame the Hook effect and permitted capillary flow into the membrane. Thus, semisolid products such as ice cream and some yogurts, and products containing thickeners needed to be diluted using a phosphate-buffered saline-based buffer, pH 7.2. SEB was easily detected at concentrations of 5 g/mL and 500 ng/mL when the LFDs were used. SEB was also reliably detected at concentrations below 5 and 0.25 ng/mL, which may induce serious disease.

Because the toxicological effects of mercury (Hg) are more serious in the developing central nervous system of children than adults, there are growing concerns about prenatal and early childhood Hg exposure. This study examined postnatal methylmercury (MeHg) exposure and cognition and behavior in 780 children enrolled in the Treatment of Lead (Pb)-exposed Children clinical trial (TLC) with 396 children allocated to the succimer and 384 to the placebo groups. Mercury exposure was determined from analyses of blood drawn 1 week before randomization and 1 week after treatment began when succimer had its maximal effect on blood Pb (PbB). The baseline MeHg concentrations were 0.54 microg/L and 0.52 microg/L and post-treatment concentrations were 0.51 microg/L and 0.48 microg/L for placebo and succimer groups, respectively. Because the baseline characteristics in the two groups were balanced and because succimer had little effect on MeHg concentration and no effect on the cognitive or behavioral test scores, the groups were combined in the analysis of MeHg and neurodevelopment. The children's IQ and neurobehavioral performance were tested at age 2, 5 and 7 years. We saw weak, non-significant but consistently positive associations between blood MeHg and IQ test scores in stratified, spline regression and generalized linear model data analyses. The behavioral problem scores were constant or decreased slightly with increasing MeHg concentration. Additional adjustment for PbB levels in multivariable models did not alter the conclusion for MeHg and IQ scores, but did confirm that concurrent PbB was strongly associated with IQ and behavior in TLC children. The effects of MeHg on neurodevelopmental indices did not substantially differ by PbB strata. We conclude that at the present background postnatal MeHg exposure levels of US children, adverse effects on children's IQ and behavior are not detectable.

Background Adverse health effects of cadmium in adults are well documented, but little is known about the neuropsychological effects of cadmium in children, and no studies of cadmium and blood pressure in children have been conducted. Objective We examined the potential effects of low-level cadmium exposure on intelligence quotient, neuropsychological functions, behavior, and blood pressure among children, using blood cadmium as a measure of exposure. Methods We used the data from a multicenter randomized clinical trial of lead-exposed children and analyzed blood cadmium concentrations using the whole blood samples collected when children were 2 years of age. We compared neuropsychological and behavioral scores at 2, 5, and 7 years of age by cadmium level and analyzed the relationship between blood cadmium levels at 2 years of age and systolic and diastolic blood pressure at 2, 5, and 7 years of age. Results The average cadmium concentration of these children was 0.21 μg/L, lower than for adults in the National Health and Nutrition Examination Survey (NHANES), but comparable to concentrations in children < 3 years of age in NHANES. Except for the California Verbal Learning Test for Children, there were no differences in test scores among children in different cadmium categories. For children with detectable pretreatment blood cadmium, after adjusting for a variety of covariates, general linear model analyses showed that at none of the three age points was the coefficient of cadmium on Mental Development Index or IQ statistically significant. Spline regression analysis suggested that behavioral problem scores at 5 and 7 years of age tended to increase with increasing blood cadmium, but the trend was not significant. We found no significant associations between blood cadmium levels and blood pressure. Conclusion We found no significant associations between background blood cadmium levels at 2 years of age and neurodevelopmental end points and blood pressure at 2, 5, and 7 years of age. The neuropsychological or hypertensive effects from longer background exposures to cadmium need further study.

Polyolefin coordination catalysts useful for prducing UHMWPE are surveyed, including classic Ziegler-Natta (ZN), current commercial generation ZN, metallocene single site, and non-metallocene. Catalysts were prepared and compared for productivity and selected polymer properties under a variety of conditions. Classic catalysts used were long lived TiCl 3 crystalline metal clusters made by reducing TiCl 4 by co-crystallizing with aluminum alkyls. Data presented from the synthesis and polymerization with these catalysts shows temperature and molecular weight response that were expected for these systems. Commercially available titanium on silica/ magnesium chloride was activated with aluminum alkyls and had higher activity than those of the previous generation. Conditions for polymerizing supported metallocenes for producing polymers in the UHMWPE range were described. Long range "non-metallocenes" of the phenoxy-imine class were activated with MAO was tested and reported.

A critical issue in the organisation of Proficiency Testing/External Quality Assessment Schemes is the definition of the criteria against which the performance of individual laboratories should be evaluated. Organisers of EQAS in Occupational and Environmental Laboratory Medicine ( http://www.occupational-environmental-laboratory.com ) collaborate to define common acceptable levels of performance. The aim of this study was to compare the Horwitz function to the Fraser’s approach. Sets of results obtained from the distribution of test materials in the Network schemes (for the measurands: copper, selenium or zinc in serum) were used to calculate Z-scores according to both approaches. Quality specifications derived from both approaches were also compared to the standard deviations obtained. Except for selenium, Horwitz criteria suggests a more stringent evaluation than Fraser criteria, the latter being very stringent as regard the participant analytical variability.

Since 1971, the general U.S. population has been monitored for dietary iodine sufficiency by urinary iodine (UI) measurements through the National Health and Nutrition Examination Survey (NHANES). This report presents the UI levels for the population participating in NHANES 2003-2004. It is the third assessment of the U.S. population since NHANES III (1988-1994), when the median UI level was observed to decrease from NHANES I (1971-1974).In 2003-2004, a stratified, multistage, probability sample of approximately 5000 participants per year were selected to participate in NHANES Household interviews, and specimen collection were performed. UI level was measured by inductively coupled plasma mass spectrometry on a random subsample of 2526 participants aged 6 years and older.The median UI level for the general U.S. population in 2003-2004 was 160 microg/L (95% confidence interval [CI] 146-172), and 11.3 +/- 1.8% of the population had a UI level below 50 microg/L. Children had a higher UI level than adolescents and adults. Among all (pregnant and nonpregnant) women of reproductive age, the median UI level was 139 microg/L (95% CI 117-156), 15.1 +/- 3.2% women had a UI level50 microg/L, and Non-Hispanic blacks in this group had a lower UI level than other racial/ethnic groups.These findings affirm the stabilization of the UI level and the adequate iodine nutrition in the general U.S. population since 2000. Future surveys designed to achieve UI levels representative of pregnant women can improve the estimate of iodine sufficiency in this population subgroup. Continued monitoring of the population for iodine sufficiency is warranted because of groups at risk for iodine deficiency disorders.

Tridentate 2,6-bis[3(5)-pyrazolyl]pyridines and 2,6-bis(4-pyrimidinyl)pyridine were synthesized and characterized spectroscopically and by single-crystal X-ray structure analysis. The derived complexes with FeCl2 and CoCl2 were investigated for their activity in the ethylene polymerization in the presence of methylalumoxane (MAO). Iron and cobalt catalysts bearing the ligand 2,6-bis[5-butyl-1-(4-nitrophenyl)pyrazol-3-yl]pyridine showed moderate catalytic activity and gave PE with high molecular weight, although the aryl substituents are not equipped with additional bulky side chains in the 2,6-positions to shield the metal centre. This can be explained by the geometric parameters of the pyrazole units, which provide efficient shielding of the active site, even with unsubstituted aryl groups. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The purpose of the study was to assess the neurocognitive status of 6-month-old infants whose mothers were exposed to low but varying amounts of lead during pregnancy. Lead levels in the cord blood were used to assess environmental exposure and the Fagan Test of Infant Intelligence (FTII) assessed visual recognition memory (VRM). The cohort consisted of 452 infants of mothers who gave birth to babies at 33-42 weeks of gestation between January 2001 and March 2003. The overall mean lead level in the cord blood was 1.42 microg/dl (95% CI: 1.35-1.48). We found that VRM scores in 6 month olds were inversely related to lead cord blood levels (Spearman correlation coefficient -0.16, p=0.007). The infants scored lower by 1.5 points with an increase by one unit (1 microg/dl) of lead concentration in cord blood. In the lower exposed infants (1.67 microg/dl) the mean Fagan score was 61.0 (95% CI: 60.3-61.7) and that in the higher exposed group (>1.67 microg/dl) was 58.4 (95% CI: 57.3-59.7). The difference of 2.5 points was significant at the p=0.0005 level. The estimated risk of scoring the high-risk group of developmental delay (FTII classification 3) due to higher lead blood levels was two-fold greater (OR=2.33, 95% CI: 1.32-4.11) than for lower lead blood levels after adjusting for potential confounders (gestational age, gender of the child and maternal education). As the risk of the deficit in VRM score (Fagan group 3) in exposed infants attributable to Pb prenatal exposure was about 50%, a large portion of cases with developmental delay could be prevented by reducing maternal blood lead level below 1.67 microg/dl. Although the negative predictive value of the chosen screening criterion (above 1.67 microg/dl) was relatively high (89%) its positive predictive value was too low (22%), so that the screening program based on the chosen cord blood lead criterion was recommended.

This paper examines the leaching patterns of pyruvic acid, and relates this to similar patterns of oxalic, glyoxylic and malonic acids in a further attempt to clarify the mechanism of the corrosion process. It appears that these acids selectively leach boron to a greater extent than other cations, and as boron is part of the E-glass matrix rather than just an interstitial ion, this would explain the means by which these relatively weak acids are able to corrode the glass fibres. It is well known that oxalic acid forms strong complexes with boron, and it is likely that other dicarboxylic acids or carboxylic acids with appropriately placed ligand groups (e.g. glyoxylic acid) will do likewise. This work presents a study of the rate of strength loss and the rate of leaching of cations from E-glass fibres with particular emphasis on boron.

Mercury can be present in the body as inorganic mercury (mostly Hg2+), metallic mercury (elemental, Hg0), and organic mercury (mostly methylmercury). Common inorganic sources include air and water pollution, some skin creams, and herbal medicines. Seafood (including fish) consumption is a major contributor of methylmercury to blood total mercury; metallic mercury typically comes from amalgam dental fillings and industrial exposure. Although inhaled metallic mercury is a less common source of blood mercury, in humans about 80% of inhaled metallic vapor is retained by the body [World Health Organization (WHO) Task Group 1991]. It has a half-life in blood of about 60 days (range, 31–100) (Counter and Buchanan 2004). Like methyl-mercury, after crossing the blood–brain barrier, metallic mercury can be oxidized to inorganic mercury, which does not freely return to the circulation, resulting in accumulation in the brain. Much more mercury ends up in the brain of mice and monkeys after inhalation of the metallic form than after injection of the inorganic form (WHO Task Group 1991). The collapse of the World Trade Center (WTC) towers on 11 September 2001 resulted in the dispersion of many potentially harmful pollutants, including heavy metals (Lioy et al. 2002; McGee et al. 2003; Offenberg et al. 2003). Hundreds of thousands of gallons of airplane fuel, stored diesel fuel, and gasoline in vehicles parked beneath the buildings burned there, releasing some mercury into the air. Metallic mercury was also released with the crushing of tens of thousands of fluorescent light bulbs, major brands of which contain 3.5–15 mg of metallic mercury in a 4-foot bulb (Inform, Inc. 2003). In addition, nearly half of the demolished automobiles would have contained at least one hood or trunk light, or antilock braking system switch bearing metallic mercury (Adsit et al. 2002), each containing about 1,000 mg of metallic mercury [U.S. Environmental Protection Agency (EPA) 2005]. Other possible mercury sources included cathode ray tubes, such as those used for computer screens, and industrial switches and relays, which can contain from 1 to 91,000 g of metallic mercury (U.S. EPA 2002). Maternal exposure to methylmercury has been associated with decrements in cognitive function in the child (Budtz-Jorgensen et al. 2007; Grandjean et al. 1997, 2005; Jedrychowski et al. 2006; Oken et al. 2005). The developmental effects of maternal inhalation of low levels of metallic mercury vapor during pregnancy have been explored primarily in animals [reviewed by Counter and Buchanan (2004)]; however, in a study of women in Tagum, the Philippines, a fish-eating community using metallic mercury in gold mining/processing, cord blood total mercury was associated with developmental and language deficits at 2 years of age (Ramirez et al. 2003). A few studies have shown a relationship between occupational mercury exposure and various adverse reproductive outcomes using work setting or hair levels to define exposure (Seidler et al. 1999; Sikorski et al. 1986). Less is known about the relation to birth outcomes of lower-level, nonoccupational, metallic mercury exposure. A study, using questionnaires to assess exposure, of pregnant women having mercury dental fillings replaced during pregnancy showed no reductions in newborn birth weight (Hujoel et al. 2005). To evaluate the relation of blood total mercury to birth outcomes and child development, we used data collected in a study of the effects of the WTC attack of 11 September 2001 on women delivering several months after the event. We measured total mercury in maternal and cord blood, a measurement that reflects methylmercury from fish consumption, as well as inorganic and metallic mercury. We explored the relation of blood total mercury to proximity to the WTC and hypothesized that higher blood total mercury levels, whatever their source, would be associated with differences in birth outcomes and adversely affect child development, as measured by the Bayley Scales of Infant Development (2nd ed., BSID-II) (Bayley 1993) at 12, 24, and 36 months, and the Wechsler Preschool and Primary Scale of Intelligence, Revised (WPPSI-R) (Wechsler 1989), at 48 months. Although consumption of fish has been shown to be associated with higher maternal and/or cord mercury concentrations (Daniels et al. 2004; Jedrychowski et al. 2006), significantly higher infant scores on the MacArthur Communicative Development Inventory at 15 months and on the Denver Developmental Screening Test at 18 months have been associated with increasing fish intake during pregnancy (Daniels et al. 2004). Therefore, we also evaluated whether maternal fish/seafood consumption would have a protective effect on the child’s cognitive development and whether, by including it in the analyses, we would more clearly detect detrimental effects of prenatal mercury exposure.

Background: Although the maternal fish consumption is supposed to have beneficial effects on development of infants, it may be harmful for child cognitive development since fish is a common source of methylmercury. Purpose of the study: Purpose of the study was to describe the usual pattern of fish consumption during pregnancy in Poland and explain the variability of prenatal mercury exposure due to fish intake by mothers. The other endpoint of the study was the assessment of the cognitive and psychomotor development of infants related to prenatal mercury exposure over the 3-year follow-up. Material and methods: The study sample consisted of 374 infants born at 33–42 weeks of gestation between January 2001 and March 2003 to mothers attending ambulatory prenatal clinics in the first and second trimesters of pregnancy. Total mercury level in whole cord blood was measured and the Bayley Scales of Infant Development (BSID-II) was used to assess the mental (MDI) and psychomotor developmental index (PDI) in children at 12, 24 and 36 months of age. Results: Self-reported weekly amount of fish consumption during the first two trimesters of pregnancy correlated positively with umbilical cord mercury concentrations (rs=0.22, p

Over the last several decades, mass poisonings of diethylene glycol (DEG), usually ingested as an unintended component of pharmaceutical preparations, have occurred. In order to promptly halt the rise in deaths due to ingestion of these pharmaceuticals, laboratory analysis has often been employed to identify and quantify the etiologic agent after the medications have been tentatively implicated. Over the past 15 years, the Centers for Disease Control and Prevention has been involved in identifying DEG in implicated pharmaceutical products during three poisoning epidemics that occurred in Nigeria (1990), Haiti (1995), and, most recently, in Panama (2006). In each case, the timeliness of the identification was paramount in reducing the mortality involved in these mass poisonings. Using state-of-the-art analytical technology, we were able to provide initial identification of DEG within 24 h of receiving samples for each epidemic, allowing a timely public health response. However, over the past 15 years, the analytical instrumentation available and the laboratory responses undertaken have changed. In addition, the type of information and the degree of confirmation of results requested during each epidemic varied based upon the number of individuals involved and the political tenor involved with the outbreak. We describe our historical approach to identifying and quantifying DEG during each of these outbreaks. Furthermore, the reoccurrence of outbreaks has prompted us to establish standard technology to use in potential future outbreaks to allow an even more timely response. This methodology includes the development of biomarkers of DEG exposure, which would be extremely useful in instances where pharmaceuticals are not clearly implicated.

Background Sixteen children diagnosed with acute leukemia between 1997 and 2002 lived in Churchill County, Nevada, at the time of or before their illness. Considering the county population and statewide cancer rate, fewer than two cases would be expected. Objectives In March 2001, the Centers for Disease Control and Prevention led federal, state, and local agencies in a cross-sectional, case-comparison study to determine if ongoing environmental exposures posed a health risk to residents and to compare levels of contaminants in environmental and biologic samples collected from participating families. Methods Surveys with more than 500 variables were administered to 205 people in 69 families. Blood, urine, and cheek cell samples were collected and analyzed for 139 chemicals, eight viral markers, and several genetic polymorphisms. Air, water, soil, and dust samples were collected from almost 80 homes to measure more than 200 chemicals. Results The scope of this cancer cluster investigation exceeded any previous study of pediatric leukemia. Nonetheless, no exposure consistent with leukemia risk was identified. Overall, tungsten and arsenic levels in urine and water samples were significantly higher than national comparison values; however, levels were similar among case and comparison groups. Conclusions Although the cases in this cancer cluster may in fact have a common etiology, their small number and the length of time between diagnosis and our exposure assessment lessen the ability to find an association between leukemia and environmental exposures. Given the limitations of individual cancer cluster investigations, it may prove more efficient to pool laboratory and questionnaire data from similar leukemia clusters.

Background. Although mercury is toxic, few studies have measured exposure in children who handled elemental mercury briefly. In 2004, a student spilled approximately 60 milliliters of mercury at a Nevada school. Within 12 hours, all students were removed from the source of exposure. We conducted an exposure assessment at the school. Methods. We administered questionnaires and obtained urine samples from students. Using two-sample t-tests, we compared urine mercury levels from students who self-reported exposure to mercury levels of other students. Results. Two-hundred students participated, including 55/62 (89%) who were decontaminated. The students' geometric mean urine mercury level was 0.36 μg/L (95% confidence interval 0.32–0.40 μg/L). The student who brought the mercury to school was the only one to have an elevated urine mercury level (11.4 μg/L). Conclusion. Despite environmental contamination, mercury exposure may have been minimized because of rapid identification of the elemental mercury spill a...

There is little published literature on the efficacy of strategies to reduce exposure to residential well water arsenic. The objectives of our study were to: 1) determine if water arsenic remained a significant exposure source in households using bottled water or point-of-use treatment systems; and 2) evaluate the major sources and routes of any remaining arsenic exposure. We conducted a cross-sectional study of 167 households in Maine using one of these two strategies to prevent exposure to arsenic. Most households included one adult and at least one child. Untreated well water arsenic concentrations ranged from

This essay summarizes the results of the U.S. News & World Report rankings published in 2015 with respect to the academic reputation scores of law schools. In addition to analyzing the most recent results for the U.S. News rankings, the essay supplements the more extensive longitudinal study published by this author in 2013. The article also includes updated appendices from the prior study that catalog the U.S. News academic reputation scores for every law school between 1998 and 2015.

Reproduction and nesting in the ringed map turtle (Graptemys oculifera) were investigated in the Pearl River of west-central Mississippi in 1995 and 1996. Nesting occurred from mid-May until mid-July but peaked in mid-June. Minimum carapace length of females at sexual maturity was 130 mm, but mean size at maturity was between 130 and 140 mm. Mean and modal CSs were 3.7 and 3. Larger females were gravid earlier than smaller ones and both egg and CS declined as the nesting season progressed. CS was positively correlated with both female carapace length and body mass. Mean egg length, width, and mass were 38.8 mm, 22.7 mm, and 11.8 g, respectively. Hatchlings averaged 35.5 mm carapace length and 8.9 g in mass. Annual clutch frequency may range from 0.96 to 1.42, and a minimum of ca. 60% of females reproduced on an annual basis. Predators destroyed an average of 86% of nests each year. Major vertebrate nest predators were armadillos, raccoons, and fish crows. Invertebrate egg predators destroyed an a...

Fly ash, the particulate matter resulting from high temperature combustion of coal, was historically dispersed into the atmosphere and settled as fly-ash spheres on the surface soil from a variety of boilers, including those of steam locomotives and steam-powered farm machinery. In Central Illinois, fly ash provides a time marker extending back to 1850s, coinciding with the development of railroads and cultivation. Two railroads, the primary sources of fly ash, were constructed just south of the Cahokia study site in 1852 and 1854. The objectives of this study were to determine: (1) the distribution, depth of occurrence and the total amount of fly ash present in soil profiles on stable, cultivated and uncultivated summit sites with little or no soil erosion; (2) the effects of elevation, aspect, slope gradient, landscape position, distance from source, past vegetation and time on the amount and depth of fly ash; (3) the effects of erosion on sloping sideslopes; and (4) the amount of deposition of fly-ash rich sediment on footslopes and toeslopes. Total fly-ash content of soil was similar for stable, cultivated and uncultivated summits. Two mound sideslopes maintained a high amount of fly ash because of a lack of cultivation and erosion for the past 80 or more years. Erosion reduced the depth of occurrence and the amount of fly ash present on cultivated sideslopes. It appeared that fly-ash content was initially deposited uniformly within the local landscape even though there were slight variations in the aspect, elevation, slope gradient, and distance from the source. The erosion phases of the soils on all landscape positions were determined based on the amount of fly ash remaining in soil surface layers. Accelerated erosion of cultivated sideslopes resulted in the deposition of fly-ash rich sediment on the adjacent footslopes or toeslopes. The proposed fly-ash method provides a tool to assess the extent of soil translocation from a cultivated landscape and subsequent deposition.

Synthesis of new ansa-metallocene catalysts incorporating branched alkyl groups alpha to the bridgehead carbon of indenyl and thiapentalenyl ligands is reported. Me2Si(2-Me-4-Ph-Indenyl)2ZrCl2 and Me2Si(2,5-Me2-3-Ph-Thiapentalenyl)2ZrCl2 type metallocenes with one and two isopropyl groups substituted for 2-methyl substitutents were prepared and used as procatalysts in propylene polymerizations and E/P copolymerizations. The 2-isopropyl groups influenced catalyst activity, molecular weight, and the relative amounts of microstructure errors. In contrast to procatalysts with only 2-methyl groups, polymer molecular weights increased in E/P copolymerizations with 2-isopropyl substituted complexes.

Corrosion of E-glass fibers in aqueous organic acids has been investigated. Oxalic acid is particularly severe and causes almost total strength loss after exposure for only a few days. Of particular importance is that oxalic acid is a degradation product of the plastic matrix of glass reinforced plastic materials. Other organic acids, such as glyoxylic and malonic acids, also corrode the glass fibers, and these too are likely degradation products of plastic. The proposed mechanism of corrosion is an ion exchange reaction in which metal ions on the glass surface are replaced by hydrogen ions from the acid. This is enhanced by complex formation of the leached cation with the anion associated with the acid. Some cations are leached more extensively in some acids compared with others, and boron has been implicated in the corrosion by organic acids.

The objective of this study was to investigate the perceived increase in resistance of Streptococcus equi subsp. zooepidemicus ( S. zooepidemicus) isolated from the lower respiratory tract of horses to trimethoprim–sulfamethoxazole (SXT). The recorded SXT-susceptibility results of 50 S. zooepidemicus isolates from the tracheal wash fluid of equine patients examined at Colorado State University Veterinary Teaching Hospital from each of 2 time periods (1987–1990 and 1997–2001) were compared and statistically analyzed using a cross-sectional study design. There was a statistically significant difference between the documented resistance of S. zooepidemicus isolated in the 1987–1990 time period (8%), using quantitative microbroth dilution, and the resistance reported for isolates from the 1997–2001 time period (42%), using Kirby–Bauer agar disk diffusion. Laboratory investigation revealed inadequate quality control of media and subsequent falsely reported resistance of S. zooepidemicus from 1997 to 2001 time period. This study demonstrates how minor deviations from prescribed laboratory-testing guidelines can have a major effect on antimicrobial susceptibility test results. The study also underscores the need for regular surveillance and monitoring of trends in antimicrobial susceptibility to detect and correct such problems. In addition, epidemiologists and others collecting data from laboratories should be cautioned to interact with the laboratory regarding interpretation of results of various testing methods to ensure accurate analysis and conclusions.

In 2001 the Centers for Disease Control and Prevention (CDC) established a program, Ensuring the Quality of Urinary Iodine Procedures (EQUIP); to assist laboratories around the world and assess the accuracy of their urinary iodine (UI). CDC designed EQUIP to issue unknown specimens to participating laboratories three times per year. Each laboratory was asked to analyze unknown samples in duplicate on three different days. During the first five rounds of EQUIP, 41 laboratories participated, measuring unknown samples and reporting their results to CDC. CDC used these results to prepare a statistical report for the laboratories. Feedback to the laboratories provided external confirmation regarding performance. As a group, laboratory performance improved; several laboratories made considerable improvement. Several laboratories that showed no improvement have ordered new equipment or are arranging for additional training. EQUIP is a key tool used to support laboratory quality assurance in an effort to eliminate iodine deficiency disorders (IDD) in the world.

Silty soil materials were deposited as loess on the surfaces of two sandstone ridgetops during the Wisconsin Glacial period (10,000 to 20,000 years B.P.). Between A.D. 900 and 1450, Mississippian Indians occupied the Millstone Bluff summit site near Dixon Springs, Illinois, and built huts with floor

We have characterized environmental exposures among 187 women who were pregnant, were at or near the World Trade Center (WTC) on or soon after 11 September 2001, and are enrolled in a prospective cohort study of health effects. Exposures were assessed by estimating time spent in five zones around the WTC and by developing an exposure index (EI) based on plume reconstruction modeling. The daily reconstructed dust levels were correlated with levels of particulate matteror = 2.5 microm in aerodynamic diameter (PM2.5; r = 0.68) or PM10 (r = 0.73-0.93) reported from 26 September through 8 October 2001 at four of six sites near the WTC whose data we examined. Biomarkers were measured in a subset. Most (71%) of these women were located within eight blocks of the WTC at 0900 hr on 11 September, and 12 women were in one of the two WTC towers. Daily EIs were determined to be highest immediately after 11 September and became much lower but remained highly variable over the next 4 weeks. The weekly summary EI was associated strongly with women's perception of air quality from week 2 to week 4 after the collapse (p0.0001). The highest levels of polycyclic aromatic hydrocarbon-deoxyribonucleic acid (PAH-DNA) adducts were seen among women whose blood was collected sooner after 11 September, but levels showed no significant associations with EI or other potential WTC exposure sources. Lead and cobalt in urine were weakly correlated with sigmaEI, but not among samples collected closest to 11 September. Plasma OC levels were low. The median polychlorinated biphenyl level (sum of congeners 118, 138, 153, 180) was 84 ng/g lipid and had a nonsignificant positive association with sigmaEI (p0.05). 1,2,3,4,6,7,8-Heptachlorodibenzodioxin levels (median, 30 pg/g lipid) were similar to levels reported in WTC-exposed firefighters but were not associated with EI. This report indicates intense bystander exposure after the WTC collapse and provides information about nonoccupational exposures among a vulnerable population of pregnant women.