Comparison of Predicted and Observed Dioxin Levels in Fish: Implications for Risk Assessment

After comparing sampled and modelled dioxin levels in the tissue of fish near pulp and paper mill discharges, the authors argue that, until an improved bioaccumulation model is incorporated into EPA\u27s Risk assessment process, determination of human health Risks associated with consuming dioxin-contaminated fish should be based on sampling

Lessons learned from the application of BEES-C: Systematic assessment of study quality of epidemiologic research on BPA, neurodevelopment, and respiratory health

AbstractEpidemiologic studies evaluating associations between biomarkers of exposure to short-lived chemicals and health endpoints in humans face special challenges. Perhaps the most critical challenges are the need to determine the type and optimal number of samples, and the proper timing of specimen collection. Further, as many short-lived chemicals are ubiquitous in the environment, utmost care is required to avoid sample contamination. A separate set of challenges is associated with appropriate interpretation and reporting of results from multiple simultaneous analyses, which are becoming increasingly feasible. The Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals (BEES-C) instrument is specifically designed to evaluate the quality of epidemiologic studies that measure biomarkers of chemicals with short physiologic half-lives. The instrument provides systematic guidance for evaluating 14 different aspects of study quality divided into three broad categories: 1) biomarker selection and measurement, 2) strategy and execution of exposure assessment, and 3) general considerations of study design and reporting. We evaluated the utility of the BEES-C instrument using epidemiologic studies of exposure to bisphenol A and its association with neurodevelopmental and respiratory health indicators. Each BEES-C element was assessed with respect to needed modifications and concordance among reviewers using professional, scientific judgment. Based on this first use of the BEES-C instrument, we found that most of its elements were effective in comparing the quality of available studies, with reviews generally concordant and justifications consistent. However, we note that certain elements would be improved with slight adjustments and that one of the elements appeared redundant and should be removed

Sketching out the programmatic features of Making Justice: A library program dedicated to court-involved youth

This article sketches out programmatic features that contribute to the success of Making Justice, a public library community program for court-involved youth. This article features images from a collaboration with Lauren Lauter, an educational scholar and artist, alongside text to highlight three programmatic features: aesthetic expression, embracing the present, and reaching out and stepping back. In contrast to traditional forms of education, in particular carceral education, Making Justice offers much needed space for teens to express themselves through the arts and have access to resources allocated for their current enjoyment and wellbeing. This program is predicated on trust that learning can come in multiple forms, matter for multiple reasons, and be determined by the learners themselves

A revised scheme for the reactivity of iron (oxyhydr)oxide minerals towards dissolved sulfide

The reaction between dissolved sulfide and synthetic iron (oxyhydr)oxide minerals was studied in artificial seawater and 0.1 M NaCl at pH 7.5 and 25°C. Electron transfer between surface-complexed sulfide and solid phase Fe(III) results in the oxidation of dissolved sulfide to elemental sulfur, and the subsequent dissolution of the surface-reduced Fe. Sulfide oxidation and Fe(II) dissolution kinetics were evaluated for freshly precipitated hydrous ferric oxide (HFO), lepidocrocite, goethite, magnetite, hematite, and Al-substituted lepidocrocite. Reaction kinetics were expressed in terms of an empirical rate equation of the form: R-i = k(i)(H2S)(t=0)(0.5)A where Ri is the rate of Fe(II) dissolution (RFe) or the rate of sulfide oxidation (RS), ki is the appropriate rate constant (kFe or kS), (H2S)t=0 is the initial dissolved sulfide concentration, and A is the initial mineral surface area. The rate constants derived from the above equation suggest that the reactivity of Fe (oxyhydr)oxide minerals varies over two orders of magnitude, with increasing reactivity in the order, goethite < hematite < magnetite << lepidocrocite ≈ HFO. Competitive adsorption of major seawater solutes has little effect on reaction kinetics for the most reactive minerals, but results in rates which are reduced by 65-80% for goethite, magnetite, and hematite. This decrease in reaction rates likely arises from the blocking of surface sites for sulfide complexation by the adsorption of seawater solutes during the later, slower stages of adsorption (possibly attributable to diffusion into micropores or aggregates). The derivation of half lives for the sulfide-promoted reductive dissolution of Fe (oxyhydr)oxides in seawater, suggests that mineral reactivity can broadly be considered in terms of two mineral groups. Minerals with a lower degree of crystal order (hydrous ferric oxides and lepidocrocite) are reactive on a time-scale of minutes to hours. The more ordered minerals (goethite, magnetite, and hematite) are reactive on a time-scale of tens of days. Substitution of impurities within the mineral structure (as is likely in nature) has an effect on mineral reactivity. However, these effects are unlikely to have a significant impact on the relative reactivities of the two mineral groups

Dietary exposure to PCBs and dioxins.

comments on S. Patandin et al. : Dietary exposure to polychlorinated biphenyls and dioxins from infancy until adulthood: a comparison between breast-feeding, toddler, and long-term exposure. Environ Health Perspect 107:45-51 (1999)

Daily intake of bisphenol A and potential sources of exposure: 2005–2006 National Health and Nutrition Examination Survey

Nationally representative data on urinary levels of bisphenol A (BPA) and its metabolites in the United States from the 2005–2006 National Health and Nutrition Examination Survey (NHANES) were used to estimate daily BPA intakes. In addition, NHANES data on potential sources of BPA exposure and personal characteristics were explored for their association with urinary BPA levels. On the basis of 2005–2006 NHANES urinary BPA data and assumptions described in this paper, median daily intake for the overall population is approximately 34 ng/kg-day. Median daily BPA intakes for men are statistically significantly higher than for women; there is a significant decrease in daily BPA intake with increasing age. Gender- and age-specific median intakes differ from the overall population by less than a factor of 2. Although estimates of daily BPA intake have decreased compared with those from the 2003–2004 NHANES, it is premature to draw conclusions regarding trends at this time, as there is no indication that BPA use declined from 2003 to 2006. On the basis of an assessment of urinary BPA and questionnaire data from the 2005–2006 NHANES, consumption of soda, school lunches, and meals prepared outside the home — but not bottled water or canned tuna — was statistically significantly associated with higher urinary BPA

Comparing United States and Canadian population exposures from National Biomonitoring Surveys: Bisphenol A intake as a case study

The Centers for Disease Control and Prevention provides biomonitoring data in the United States as part of the National Health and Nutrition Examination Survey (NHANES). Recently, Statistics Canada initiated a similar survey — the Canadian Health Measures Survey (CHMS). Comparison of US and Canadian biomonitoring data can generate hypotheses regarding human exposures from environmental media and consumer products. To ensure that such comparisons are scientifically meaningful, it is essential to first evaluate aspects of the surveys' methods that can impact comparability of data. We examined CHMS and NHANES methodologies, using bisphenol A (BPA) as a case study, to evaluate whether survey differences exist that would hinder our ability to compare chemical concentrations between countries. We explored methods associated with participant selection, urine sampling, and analytical methods. BPA intakes were also estimated to address body weight differences between countries. Differences in survey methods were identified but are unlikely to have substantial impacts on inter-survey comparisons of BPA intakes. BPA intakes for both countries are below health-based guidance values set by the US, Canada and the European Food Safety Authority. We recommend that before comparing biomonitoring data between surveys, a thorough review of methodologic aspects that might impact biomonitoring results be conducted

Necessity of overvoltage protection studies for gas-insulated switchgear

Kaasueristeisten kytkinlaitosten määrä kantaverkossa lisääntyy tulevaisuudessa merkittävästi erityisesti korvausrakentamisen myötä. Kaasueristeinen kojeisto on herkkä ylijännitteille ja aiheuttaa vikaantuessaan pitkän keskeytyksen sähkönsiirtoon sekä suuret korjauskustannukset. Tämän vuoksi sen ylijännitesuojaukseen on kiinnitettävä erityistä huomiota. Suomen kantaverkkoyhtiö Fingrid Oyj on aikaisemmissa kytkinlaitoshankkeissaan tilannut kojeistovalmistajilta erillisen ylijännitesuojausselvityksen, jossa tarkastellaan tarvetta tehostaa kytkinlaitosten ylijännitesuojauksia kaasueristeisillä ylijännitesuojilla. Selvityksissä annetaan kuitenkin usein liikaa painoarvoa epätodennäköisille kytkinlaitoksen käyttötilanteille, mikä voi lopulta johtaa erittäin kalliiden kaasueristeisten ylijännitesuojien hankkimiseen ilman todellista tarvetta. Tämän diplomityön ensisijaisena tavoitteena oli selvittää, onko kaasueristeisille ylijännitesuojille tarvetta ilmaeristeisten ylijännitesuojien lisäksi kantaverkon 110 kV:n kaasueristeisten kytkinlaitosten ylijännitesuojauksessa. Toisena tavoitteena oli määritellä kytkinlaitoksen todelliset käyttötilanteet, joihin on perustelua jatkossa vaatia kojeistojen valmistajilta ylijännitesuojausselvitykset. Työssä laadittiin simulointimalli, jolla simuloitiin salamaniskun aiheuttamia ylijännitteitä eri käyttötilanteissa. Työn lopussa määritettiin suojausriskitaso, jonka perusteella tehtiin päätelmät kaasueristeisten ylijännitesuojien tarpeesta. Johtopäätöksenä voidaan todeta, ettei kaasueristeisiä ylijännitesuojia tarvita ilmaeristeisten suojien lisäksi 110~kV:n kaasueristeisten kytkinlaitosten yhteydessä. Ylijännitesuojausselvityksistä voidaan siten luopua tällä jännitetasolla. Lisäksi suositellaan, että jatkossa 220 ja 400 kV:n ylijännitesuojausselvityksissä vaaditaan selvityksen laatijaa ottamaan huomioon kytkinlaitoksen käyttötilanteiden todennäköisyydet.The number of substations with gas-insulted switchgear in the Finnish main grid will increase significantly in the future in particular due to renewal construction. Gas-insulated switchgear is sensitive to overvoltages and damages in it cause a long interruption in power transmission as well as large repair costs. Therefore, its overvoltage protection requires special attention. The Finnish transmission system operator Fingrid Oyj has ordered a separate overvoltage protection study from the switchgear manufacturers in earlier gas-insulated switchgear projects to examine the need to enhance the overvoltage protection of the switchgear with gas-insulated surge arresters. However, these studies often give too much weight to unlikely switchgear operation situations, which may eventually lead to the purchase of highly expensive gas-insulated surge arresters without actual need. The primary purpose of this thesis was to find out whether a need for overvoltage protection of 110 kV gas-insulated switchgear by gas-insulated surge arresters in addition to air-insulated surge arresters exists. Another objective was to define realistic switchgear operating situations, in which overvoltage protection studies should be required from the manufacturer in the future. A model was developed to simulate overvoltages caused by lightning surges in different operating situations. At the end of the thesis, a protection risk level was established and based on that, conclusions on the need for gas-insulated surge arresters were made. In conclusion, it is stated that no gas-insulated surge arresters are needed in addition to air-insulated surge arresters for 110~kV gas-insulated switchgear. Overvoltage protection studies can thus be given up at this voltage level. Moreover, it is recommended that taking probabilities of switching situations into account should be required from the manufacturer in the future overvoltage protection studies at voltage levels of 220 and 400 kV