Monthly Archives: December 2012

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Group regulation of VOCs in drinking water

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group voc reg

Osteosarcoma and fluoride exposure in Northern Ireland

 Osteosarcoma is a relatively rare cancer, and the relative risk estimate confidence intervals are wide……such that this study cannot rule out an association between fluoride exposure and osteosarcoma.

Harry Comber, Sandra Deady, Erin Montgomery, Anna Gavin. Drinking water fluoridation and osteosarcoma incidence on the island of Ireland. Cancer Causes & Control, June 2011, Volume 22, Issue 6, pp 919-924.

The incidence of osteosarcoma in Northern Ireland was compared with that in the Republic of Ireland to establish if differences in incidence between the two regions could be related to their different drinking water fluoridation policies. Data from the Northern Ireland Cancer Registry (NICR) and the National Cancer Registry of Ireland (NCRI) on osteosarcoma incidence in the respective populations were used to estimate the age-standardised and age-specific incidence rates in areas with and without drinking water fluoridation. One hundred and eighty-three osteosarcoma cases were recorded on the island of Ireland between 1994 and 2006. No significant differences were observed between fluoridated and non-fluoridated areas in either age-specific or age-standardised incidence rates of osteosarcoma. The results of this study do not support the hypothesis that osteosarcoma incidence in the island of Ireland is significantly related to public water fluoridation. However, this conclusion must be qualified, in view of the relative rarity of the cancer and the correspondingly wide confidence intervals of the relative risk estimates.

Climate alarmism from California on polar melting nothing new…

From Saturday, May 31, 1947….

Climate Alarm

h/t: Real Science

Drought of 2012 not a new record….

Palmer Index_365-dec-28-22-48

http://www.ncdc.noaa.gov/temp-and-precip/time-series/index.php?parameter=pmdi&month=11&year=2012&filter=12&state=110&div=0

Memory impairment induced by sodium fluoride

Marcela Pereira, Patrícia A. Dombrowski, Estela M. Losso, Lea R. Chioca, Cláudio Da Cunha, Roberto Andreatini. Memory Impairment Induced by Sodium Fluoride is Associated with Changes in Brain Monoamine Levels. Neurotoxicity Research, January 2011, Volume 19, Issue 1, pp 55-62.

Previous studies suggest that sodium fluoride (NaF) can impair performance in some memory tasks, such as open-field habituation and two-way active avoidance. In the present study, we evaluated the effect of NaF intake (100 ppm in drinking water for 30 days) and its short-term (15 days) withdrawal on open-field habituation and brain monoamine level. Adult male rats were allocated to three groups: tap water (NaF 1.54 ppm) for 45 days (control group); 15 days of tap water followed by NaF for 30 days; and NaF for 30 days followed by 15 days of tap water. The results showed that NaF impairs open-field habituation and increases noradrenaline (NA) and serotonin (5-HT) in the striatum, hippocampus and neocortex. Dopamine (DA) increase was restricted to the striatum. Short-term NaF withdrawal did not reverse these NaF-induced changes, and both NaF treatments led to a mild fluorosis in rat incisors. No treatment effect was seen in body weight or fluid/water consumption. These results indicate that sodium fluoride induces memory impairment that outlasts short-term NaF withdrawal (2 weeks) and may be associated with NA and 5-HT increases in discrete brain regions.

Natural factors dominate climatic variations in arctic ocean

These researchers reconstruct sea ice coverage in the Beaufort Sea of the Canadian Arctic over the past 150 years and find modern sea ice coverage [9.4 months per year] significantly greater than during the period from ~ 1887-1945 [8.3 months per year]. Sea ice coverage was dominated by natural variation from the Pacific Decadal Oscillation [PDO] and Arctic Oscillation [AO]……

L. Durantou, A. Rochon, D. Ledu, G. Mass´e, S. Schmidt, and M. Babin. Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns. Biogeosciences, 9, 5391–5406, 2012.

Dinoflagellate cyst (dinocyst) assemblages have been widely used over the Arctic Ocean to reconstruct sea-surface parameters on a quantitative basis. Such reconstructions provide insights into the role of anthropogenic vs natural forcings in the actual climatic trend. Here, we present the palynological analysis of a dated 36 cm-long core collected from the Mackenzie Trough in the Canadian Beaufort Sea. Dinocyst assemblages were used to quantitatively reconstruct the evolution of sea-surface conditions (temperature, salinity, sea ice) and freshwater palynomorphs fluxes were used as local paleo-river discharge indicators over the last ~ 150 yr. Dinocyst assemblages are dominated by autotrophic taxa (68 to 96%). Cyst of Pentapharsodinium dalei is the dominant species throughout most of the core, except at the top where the assemblages are dominated by Operculodinium centrocarpum. Quantitative reconstructions of sea-surface parameters display a series of relatively warm, lower sea ice and saline episodes in surface waters, alternately with relatively cool and low salinity episodes. Variations of dinocyst fluxes and reconstructed sea-surface conditions may be closely linked to large scale atmospheric circulation patterns such as the Pacific Decadal Oscillation (PDO) and to a lesser degree, the Arctic Oscillation (AO). Positive phases of the PDO correspond to increases of dinocyst fluxes, warmer and saltier surface waters, which we associate with upwelling events of warm and relatively saline water from Pacific origin. Freshwater palynomorph fluxes increased in three phases from AD 1857 until reaching maximum values in AD 1991, suggesting that the Mackenzie River discharge followed the same trend when its discharge peaked between AD 1989 and AD 1992. The PDO mode seems to dominate the climatic variations at multi-annual to decadal timescales in the western Canadian Arctic and Beaufort Sea areas.

Click here for full paper (Open Source).

Climate models exaggerate projected warming…

Global climate models have temperature-dependent biases resulting in overestimation of projections of regional temperatures. These researchers estimate that 10-20% of projected warming is due to model deficiencies.

Jens H. Christensen, Fredrik Boberg. Temperature dependent climate projection deficiencies in CMIP5 models.  GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L24705, 5 PP., 2012. doi:10.1029/2012GL053650

Monthly mean temperatures for 34 GCMs available from the CMIP5 project are compared with observations from CRU for 26 different land regions covering all major land areas in the world for the period 1961–2000 by means of quantile-quantile (q-q) diagrams. A warm period positive temperature dependent bias is identified for many of the models within many of the chosen climate regions. However, the exact temperature dependence varies considerably between the models. We analyse the role of this difference as a contributing factor for some models to project stronger regional warming than others by looking at the entire ensemble rather than individual models. RCP4.5 temperature projections from all GCMs for two time periods (2021–2050 and 2071–2100) are compared against a linear fit to the 50% warmest months from the respective q-q plot for each model and region. Taken together, we find that in general models with a positive temperature dependent bias tend to have a large projected temperature change, and these tendencies increase with increasing global warming level. We argue that this appears to be linked with the ability of models to capture complex feedbacks accurately. In particular land-surface atmosphere interactions are treated differently and with different degree of realism between models.

Click here for the full paper (fee).