Monthly Archives: May 2013

China Medieval Warming Period temperatures comparable to today.

Reconstruction of temperature changes over the past 2000 years in China and found the Medieval Warming Period temperatures during AD 981–AD 1100 and AD 1201–AD 1270 comparable to the Present Warm Period.

Q. Ge, Z. Hao, J. Zheng, and X. Shao. Temperature changes over the past 2000 yr in China and comparison with the Northern Hemisphere. Clim. Past, 9, 1153-1160, 2013.

We use principal component regression and partial least squares regression to separately reconstruct a composite series of temperature variations in China, and associated uncertainties, at a decadal resolution over the past 2000 yr. The reconstruction is developed using proxy temperature data with relatively high confidence levels from five regions across China, and using a temperature series from observations by the Chinese Meteorological Administration, covering the period from 1871 to 2000. Relative to the 1851–1950 climatology, our two reconstructions show four warm intervals during AD 1–AD 200, AD 551–AD 760, AD 951–AD 1320, and after AD 1921, and four cold intervals during AD 201–AD 350, AD 441–AD 530, AD 781–AD 950, and AD 1321–AD 1920. The temperatures during AD 981–AD 1100 and AD 1201–AD 1270 are comparable to those of the Present Warm Period, but have an uncertainty of ±0.28 °C to ±0.42 °C at the 95% confidence interval. Temperature variations over China are typically in phase with those of the Northern Hemisphere (NH) after 1000, a period which covers the Medieval Climate Anomaly, the Little Ice Age, and the Present Warm Period. In contrast, a warm period in China during AD 541–AD 740 is not obviously seen in the NH.

Click here for full paper (Open Source).

Fluoride-elicited developmental testicular toxicity in rats

Zhang S, Jiang C, Liu H, Guan Z, Zeng Q, Zhang C, Lei R, Xia T, Gao H, Yang L, Chen Y, Wu X, Zhang X, Cui Y, Yu L, Wang A. Fluoride-Elicited Developmental Testicular Toxicity in Rats: Roles of Endoplasmic Reticulum Stress and Inflammatory Response. Toxicol Appl Pharmacol. 2013 May 22. pii: S0041-008X(13)00217-2. doi: 10.1016/j.taap.2013.04.033.

Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague-Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of Glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by genes up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress.

Click here for full paper (fee).

Top British Scientist: $$Billions wasted on global warming

Professor Myles Allen:

“So the time has come to focus on something just as important: that 90 per cent of the measures adopted in Britain and elsewhere since the 1997 Kyoto agreement to cut global emissions are a waste of time and money – including windfarms in Scotland, carbon taxes and Byzantine carbon trading systems.”

Click here for full article….

Dental fluorosis is an adverse effect

Fluoride adovcates say dental fluorosis is no big deal (as long as it is not their kid?) But it is a big deal and is an adverse effect. Someone has to pay to have it corrected. And why should the patient or insurance company pay the cost of restoration when some government official somewhere has decided to add it to their drinking water?

Khandelwal V, Nayak UA, Nayak PA, Ninawe N. Aesthetic management of dental fluorosis. BMJ Case Rep. 2013 May 22;2013(may22_1). pii: bcr2013010029. doi: 10.1136/bcr-2013-010029.

Significant numbers of patients visiting the paediatric dental clinics have aesthetically objectionable brown stains and desire treatment for them. Intrinsic tooth discolouration can be a significant aesthetic, and in some instances, functional, problem. Dental fluorosis, tetracycline staining, localised and chronological hypoplasia, and both amelogenesis and dentinogenesis imperfecta can all produce a cosmetically unsatisfactory dentition. The aetiology of intrinsic discolouration of enamel may sometimes be deduced from the patient’s history, and one factor long associated with the problem has been a high level of fluoride intake. Optimal use of topical fluorides leads to a decrease in the caries prevalence but may show an increase in the prevalence of fluorosis staining because of metabolic alterations in the ameloblasts, causing a defective matrix formation and improper calcification. A 12-year-old male patient was screened at the dental clinic for routine dental care. He wanted us to remove and/or minimise the noticeable brown/yellow staining of his teeth. He requested the least invasive and most cost-effective treatment to change his smile. Various treatment modalities are present for the treatment of fluorosis stains. This report discusses the microabrasion technique in the patient having dental fluorosis.

Portland (OR) citizen’s get it. There is no need to add fluoride to drinking water.

“On Wednesday, the city of Portland, Ore., overwhelmingly voted down a proposal to add fluoride to the city’s drinking water – making it the largest city in the United States without fluoride in its water supply or any plans to add it.”

It’s time to end fluoride addition to drinking water everywhere….click here for news article.

Just do a search using the search box on the right, or the tag cloud in lower right to see the latest research on fluoride adverse health effects.

Dr. Murray Salby: man-made CO2 does not control atmospheric CO2

At a conference presentation last November in Toronto, I referred to the latest edition of Dr. Salby’s textbook, Physics of the Atmosphere and Climate. In it, he explains why man-made CO2 does not control atmospheric CO2. It is a good reference….Several others are picking up on this now (click here).

For more on this book, click here or image below.

9780521767187_p0_v1_s260x420 Salby

Low iodine intake, perchlorate, thiocyanate effect on thyroid function

I believe this study shows the importance of having sufficient nutritional iodine levels rather than the impact of multiple contaminants. This study shows that an abnormality (low iodine) can be made worse by adding other stressors (perchlorate, thiocyanate)….not particularly informative.

Craig Steinmaus, Mark D. Miller, Lara Cushing, Benjamin C. Blount, Allan H. Smith. Combined effects of perchlorate, thiocyanate, and iodine on thyroid function in the National Health and Nutrition Examination Survey 2007–08. Environmental Research, Volume 123, May 2013, Pages 17–24.

Perchlorate, thiocyanate, and low iodine intake can all decrease iodide intake into the thyroid gland. This can reduce thyroid hormone production since iodide is a key component of thyroid hormone. Previous research has suggested that each of these factors alone may decrease thyroid hormone levels, but effect sizes are small. We hypothesized that people who have all three factors at the same time have substantially lower thyroid hormone levels than people who do not, and the effect of this combined exposure is substantially larger than the effects seen in analyses focused on only one factor at a time. Using data from the 2007–2008 National Health and Nutrition Examination Survey, subjects were categorized into exposure groups based on their urinary perchlorate, iodine, and thiocyanate concentrations, and mean serum thyroxine concentrations were compared between groups. Subjects with high perchlorate (n=1939) had thyroxine concentrations that were 5.0% lower (mean difference=0.40 μg/dl, 95% confidence interval=0.14–0.65) than subjects with low perchlorate (n=2084). The individual effects of iodine and thiocyanate were even smaller. Subjects with high perchlorate, high thiocyanate, and low iodine combined (n=62) had thyroxine concentrations 12.9% lower (mean difference=1.07 μg/dl, 95% confidence interval=0.55–1.59) than subjects with low perchlorate, low thiocyanate, and adequate iodine (n=376). Potential confounders had little impact on results. Overall, these results suggest that concomitant exposure to perchlorate, thiocyanate, and low iodine markedly reduces thyroxine production. This highlights the potential importance of examining the combined effects of multiple agents when evaluating the toxicity of thyroid-disrupting agents.

Click here for full paper (fee)