Daily Archives: March 27, 2012

Press Spin: Rep. Schiff (CA) grandstanding for Chromium 6

The Safe Drinking Water Act (SDWA) requires the use of the best available peer-reviewed science when establishing drinking water regulations. A peer-review panel recommended inclusion of an inhalation study which is taking additional time. So Rep. Schiff (CA) has introduced a bill to force earlier action……and perhaps reap some political hay.

Click here for news article….

USEPA sole sources agricultural non-CO2 (NO2) greenhouse gas modeling contract

B–DAYCENT Modeling & Analysis of N2O Emission Mitigation Options

Solicitation Number: SOL-DC-12-FS001

The U.S. Environmental Protection Agency (EPA) Office of Air and Radiation (OAR), Office of Atmospheric Programs (OAP), Climate Change Division (CCD) intends to award a sole source, fixed price purchase order under the authority of Federal Acquisition Regulation (FAR) Part 13: Simplified Acquisition Procedures to Colorado State University for DAYCENT modeling results and analysis of non-CO2 agricultural emissions and mitigation scenarios. DAYCENT is a process-based, biogeochemical model that has the ability to investigate the mitigation potential, as well as the effects on crop yields for both irrigated and non-irrigated crops, of different land management scenarios at the global and regional level. EPA plans to utilize the global non-CO2 soils data and marginal abatement cost information from the DAYCENT modeling results to update EPA?s 2012 non-CO2 Greenhouse Gas Mitigation Report.

The Statement of Work (SOW) outlines 6 major tasks: 1) the acquisition and formatting of activity data required to run DAYCENT at the global scale; 2) conducting global simulations of business-as-usual cropping and related non-CO2 and soil carbon emissions levels; 3) validating simulated business-as-usual N2O emissions; 4) conducting national and regional N2O mitigation simulations; 5) compiling and explaining of model results to contribute to EPA?s report on non-CO2 emissions; and, 6) conducting model output analysis, report writing and responding to comments.  

 

https://www.fbo.gov/index?s=opportunity&mode=form&id=de862395f1fd90e84d4dc11c3f3f6239&tab=core&_cview=0 

 

Fluoride passes the placenta at low concentrations

Gupta, S., Seth, A.K., Gupta, A., and A.G. Gavane. Transplacental passage of fluorides. J Pediatr. 1993 Jul;123(1):139-41.

Transplacental passage of fluorides was studied in 25 randomly selected neonates. Blood samples collected simultaneously from the mother and the umbilical cord showed that average fluoride concentration in the cord blood was 60% of that in mother’s blood. When concentration in the mother’s blood exceeded 0.4 ppm, the placenta acted as a selective barrier.

Danish drinking water fluoride study results are misleading…

These types of studies are used to show the potential benefits of fluoridation of drinking water. However, they are based entirely on an ecologic study design, and do not consider total fluoride exposure, and other factors that confound the results. Such studies are considered hypothesis generating, and not indicative of a causal relationship. In addition, other adverse effects (e.g., fluorosis) were not measured or reported. 

Kirkeskov, L., Kristiansen, E., Boggild, H., von Platen-Hallermund, F., Sckerl, H., Carlsen, A., Larsen, M.J., and S. Poulsen. The association between fluoride in drinking water and dental caries in Danish children. Linking data from health registers, environmental registers and administrative registers. Community Dent Oral Epidemiol. 2010 Feb 10.

Abstract – Objectives: To study the association between fluoride concentration in drinking water and dental caries in Danish children.

Methods: The study linked registry data on fluoride concentration in drinking water over a 10-year period with data on dental caries from the Danish National Board of Health database on child dental health for 5-year-old children born in 1989 and 1999, and for 15-year-old children born in 1979 and 1989. The number of children included in the cohorts varied between 41.000 and 48.000. Logistic regression was used to assess the correlations, adjusting for gender and taxable family income as a proxy variable for socioeconomic status.

Results: Fluoride concentration in drinking water varied considerably within the country from very low (<0.10 mg/l) to more than 1.5 mg/l. Only little variation was found over the 10-year study period. Dental caries in both 5-year-olds and 15-year-olds decreased over the study period. An inverse relation between the risk of dental caries and fluoride concentration in drinking water was found in both primary and permanent teeth. The risk was reduced by approximately 20% already at the lowest level of fluoride exposure (0.125-0.25 mg/l). At the highest level of fluoride exposure (>1 mg/l), a reduction of approximately 50% was found. Similar findings were found if analysis was limited to children residing in the same place during the entire study period.

Conclusions: The study confirmed previous findings of an inverse relation between fluoride concentration in the drinking water and dental caries in children. This correlation was found in spite of the extensive use of fluoridated toothpaste and caries-preventive programs implemented by the municipal dental services in Denmark. Linking Danish health registers with environmental and administrative registers offers an opportunity for obtaining sample sizes large enough to identify health effect, which otherwise could not be identified.

Fluoride in low concentrations found to affect enzyme activity

Research on fluoride toxicology has progressed substantially since the 1940s and 1950s.

Gutowska, I, Baranowska-Bosiacka, I., Safranow, K., Jakubowska, K., Olszewska, M., Telesinski, A., Siennicka, A., Drozdzik, M., Chlubek, D., and E. Stachowska. Fluoride in low concentration modifies expression and activity of 15 lipoxygenase in human PBMC differentiated monocyte/macrophage. Toxicology. 2012 Mar 7.

Abstract: Epidemiological and experimental evidences demonstrate positive correlation between environmental and occupational fluoride exposure and risk to various cardio-respiratory disorders. That fore we decided to examine the effect of fluorides on activity and expression of 15LOX enzyme which is implicated in biosynthesis of inflammatory mediators. Expression of 15LOX-1 and -2 enzymes mRNA and protein was analyzed using RT PCT and immunoblotting methods respectively whereas HPLC method was used to measure the levels of 15 lipoxygenases end products. Additionally AA and LA concentration in cells was measured using GC method. We observed that fluoride in small concentration may significantly decrease activity of 15LOX-1 and -2 in human PBMC macrophages and then concentration of its end products: 15-HETE, 12-HETE and 9+13-HODE, what may cause development of inflammation through the cholesterol arrest into the macrophages and its differentiation to foam cell. Noted by our team overexpression of the 15LOX-1 enzyme in macrophages after addition of lowest fluoride concentrations (1 and 3μM) may be aimed at fighting inflammation development and excessive intracellular lipid accumulation. But highest fluoride concentrations (6 and 10μM) added to cell culture slowly declined expression of this enzyme probably because of developing inflammation. Additional 15LOX-2 expression in macrophages after fluoride addition was low in 1 and 3μM concentrations, but increased significantly after 10μM fluoride addition what may suggest developing acute inflammation, because 15LOX-2 is associated to increased local hypoxia. This study indicated that even in small concentrations fluorides changes the amounts and activity of 15 LOX-1 and -2 enzymes taking part in the development of inflammatory process.

Click here for the full paper (fee).

 

Galactic cosmic rays have a greatest influence on O3

Galactic cosmic rays have a greatest influence on O3.  Mechanism for ozone influence on climate is described in this paper.

N.A. Kilifarska Climate sensitivity to the lower stratospheric ozone variations.  Journal of Atmospheric and Solar-Terrestrial Physics.  http://dx.doi.org/10.1016/j.jastp.2012.03.002

Abstract: The strong sensitivity of the Earth’s radiation balance to variations in the lower stratospheric ozone – reported previously – is analyzed here by the use of non-linear statistical methods. Our non-linear model of the land air temperature (T) – driven by the measured Arosa total ozone (TOZ) – explains 75% of total variability of Earth’s T variations during the period 1926–2011. We have analyzed also the factors which could influence the TOZ variability and found that the strongest impact belongs to the multi-decadal variations of galactic cosmic rays. Constructing a statistical model of the ozone variability, we have been able to predict the tendency in the land air T evolution till the end of the current decade. Results show that Earth is facing a weak cooling of the surface T by 0.05–0.25 K (depending on the ozone model) until the end of the current solar cycle. A new mechanism for O3 influence on climate is proposed.

Click here for full paper (fee).

Water use to be restricted in Mangalore, India

Lower water infow to Thumbay dam, higher water use is necessitating water use restrictions…..click here for more….