Daily Archives: January 4, 2015

Alaska’s “Rapidly Changing Climate” is a “Signal” of “Climate Change”? Hardly…

Climate is defined as a statistical description in terms of the mean and variability of relevant quantities over a period of time. The World Meteorological Organization has adopted a period of 30 years. It can also be thought of as consistent or repetitive weather patterns over a period of time and space. Changes in weather patterns are just that, changes in weather.

Climates are always in a state of change. They are dynamic systems. There is no “normal” state from which the climate changes. Indeed, the climate is always “off-kilter” as it adjusts. Anomalies from an arbitrary “mean” are being put forth as some indicator or signal of hidden ominous changes. Such anomalies are not particularly useful in the long term because they are arbitrary and do not consider the full history of climate in a particular area or even globally. Anchorage not dipping below zero is not necessarily warming caused by some ominous permanent changes in climate. The climate is changing and it will change again and again regardless of any EPA regulations or politician pronouncements.

“We really don’t understand how these sequences occur, but they appear to be random and part of the chaotic climate system, rather than part of the global warming signal,” said Overland, coauthor of NOAA’s 2014 Arctic Report Card. “We’ve had one warm year here. Is this a sucker punch or not?” click here

Oceanic pH Change Data Uninformative

When data is spread as discussed in the article then the significance of any trend is diminished. The post referenced below illustrates this quite clearly. Though a general downward trend can be extracted from the data it is not particularly informative. 

“Following up on my previous investigations into the oceanic pH dataset, I’ve taken a deeper look at what the 2.5 million pH data points from the oceanographic data can tell us. Let me start with an overview of oceanic pH (the measure of alkalinity/acidity, with neutral being a pH of 7.0). Many people think that the ocean has only one pH  everywhere. Other people think that the oceanic pH is different in different places, but is constant over time. Neither view is correct.” click here

Lead Leaching From New Unplasticized PVC Pipes

Zhang Y, Lin Y. Leaching of lead from new unplasticized polyvinyl chloride (uPVC) pipes into drinking water. Environmental Science and Pollution Research International. 2014 Dec 25.

Unplasticized polyvinyl chloride (uPVC) pipes have been used in the premise plumbing system due to their high strength, long-term durability, and low cost. uPVC pipes, however, may contain lead due to the use of lead compounds as the stabilizer during the manufacturing process. The release of lead from three locally purchased uPVC pipes was investigated in this study. The effects of various water quality parameters including pH value, temperature, and type of disinfectant on the rate of lead release were examined. The elemental mapping obtained using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) confirmed the presence of lead on the inner surfaces of the uPVC pipes and their surface lead weight percentages were determined. The leachable lead concentration for each pipe was determined using high strength acidic EDTA solutions (pH 4, EDTA = 100 mg/L). Lead leaching experiments using tap water and reconstituted tape water under static conditions showed that the rate of lead release increased with the decreasing pH value and increasing temperature. In the presence of monochloramine, lead release was faster than that in the presence of free chlorine.

Click here for paper (fee).

Indirect Wastewater Reuse in the United States: Low Impact

Rice J, Westerhoff P. Spatial and Temporal Variation in De Facto Wastewater Reuse in Drinking Water Systems across the U.S.A. Environmental Science and Technology. 2014 Dec 29.

De facto potable reuse occurs when treated wastewater is discharged into surface waters upstream of potable drinking water treatment plant (DWTP) intakes. Wastewater treatment plant (WWTP) discharges may pose water quality risks at the downstream DWTP, but additional flow aids in providing a reliable water supply source. In this work de facto reuse is analyzed for 2056 surface water intakes serving 1210 DWTPs across the U.S.A. that serve greater than 10 000 people, covering approximately 82% of the nation’s population. An ArcGIS model is developed to assess spatial relationships between DWTPs and WWTPs, with a python script designed to perform a network analysis by hydrologic region. A high frequency of de facto reuse occurrence was observed; 50% of the DWTP intakes are potentially impacted by upstream WWTP discharges. However, the magnitude of de facto reuse was seen to be relatively low, where 50% of the impacted intakes contained less than 1% treated municipal wastewater under average streamflow conditions. De facto reuse increased greatly under low streamflow conditions (modeled by Q95), with 32 of the 80 sites yielding at least 50% treated wastewater, this portion of the analysis is limited to sites where stream gauge data was readily available.

Click here for paper (fee).

Two-Year Cancer Study of Acrylamide in Rats

Maronpot RR, Thoolen RJ, Hansen B. Two-year carcinogenicity study of acrylamide in Wistar Han rats with in utero exposure. Experimental and Toxicologic Pathology. 2014 Dec 29. pii: S0940-2993(14)00179-1. doi: 10.1016/j.etp.2014.11.009.

Acrylamide is an important chemical with widespread industrial and other uses in addition to generalized population exposure from certain cooked foods. Previous rat studies to assess the carcinogenic potential of acrylamide have been carried out exclusively in the Fischer 344 rat with identification of a number of tumors amongst which mesotheliomas of the tunica vaginalis is an important tumor endpoint in the classification of acrylamide as a ‘probably human carcinogen. In a rat carcinogenicity study to determine the human relevance of mesotheliomas Wistar Han rats were exposed to 0, 0.5, 1.5, or 3.0mg acrylamide/kg body weight/day in drinking water starting at gestation day 6. At the end of two years, mammary gland fibroadenomas in females and thyroid follicular cell tumors in both sexes were the only tumors increased in acrylamide treated rats. These tumor endpoints have rat-specific modes of action suggesting less likelihood of human cancer risk than previously estimated. This study demonstrates that tunica vaginalis mesotheliomas are strain specific and not likely of genotoxic origin.