Nanotechnology in Water Treatment

Gehrke I, Geiser A, Somborn-Schulz A. Innovations in nanotechnology for water treatment. Nanotechnology, Science and Applications. 2015 Jan 6;8:1-17. doi: 10.2147/NSA.S43773.

Important challenges in the global water situation, mainly resulting from worldwide population growth and climate change, require novel innovative water technologies in order to ensure a supply of drinking water and reduce global water pollution. Against this background, the adaptation of highly advanced nanotechnology to traditional process engineering offers new opportunities in technological developments for advanced water and wastewater technology processes. Here, an overview of recent advances in nanotechnologies for water and wastewater treatment processes is provided, including nanobased materials, such as nanoadsorbents, nanometals, nanomembranes, and photocatalysts. The beneficial properties of these materials as well as technical barriers when compared with conventional processes are reported. The state of commercialization is presented and an outlook on further research opportunities is given for each type of nanobased material and process. In addition to the promising technological enhancements, the limitations of nanotechnology for water applications, such as laws and regulations as well as potential health risks, are summarized. The legal framework according to nanoengineered materials and processes that are used for water and wastewater treatment is considered for European countries and for the USA.

Click here for paper (Open Access).

 

MMP-9 as an Indicator of Dietary Inorganic Arsenic Exposure

A biomarker is useful in exposure assessment but inadequate for assessing health effects.

Kurzius-Spencer M, Harris RB, Hartz V, Roberge J, Hsu CH, O’Rourke MK, Burgess JL. Relation of dietary inorganic arsenic to serum matrix metalloproteinase-9 (MMP-9) at different threshold concentrations of tap water arsenic. Journal of Exposure Science and Environmental Epidemiology. 2015 Jan 21. doi: 10.1038/jes.2014.92.

Arsenic (As) exposure is associated with cancer, lung and cardiovascular disease, yet the mechanisms involved are not clearly understood. Elevated matrix metalloproteinase-9 (MMP-9) levels are also associated with these diseases, as well as with exposure to water As. Our objective was to evaluate the effects of dietary components of inorganic As (iAs) intake on serum MMP-9 concentration at differing levels of tap water As. In a cross-sectional study of 214 adults, dietary iAs intake was estimated from 24-h dietary recall interviews using published iAs residue data; drinking and cooking water As intake from water samples and consumption data. Aggregate iAs intake (food plus water) was associated with elevated serum MMP-9 in mixed model regression, with and without adjustment for covariates. In models stratified by tap water As, aggregate intake was a significant positive predictor of serum MMP-9 in subjects exposed to water As≤10 μg/l. Inorganic As from food alone was associated with serum MMP-9 in subjects exposed to tap water As≤3 μg/l. Exposure to iAs from food and water combined, in areas where tap water As concentration is ≤10 μg/l, may contribute to As-induced changes in a biomarker associated with toxicity.

Click here for paper (fee).

Lawrence Berkeley Climate Model Projections are not Reality

I like computer models. They are very useful. A lot of time and money in the sciences and engineering are devoted to them. Some might even seem to “work” under specified conditions. But there is a serious problem with the underlying assumptions of each and every model. Computer models (electrons flying about) are not the reality. Going further the computer output is dependent on the input. Garbage in, garbage out. And if many assumptions are made pigs can fly.

Oh, you can believe in them as if they were reality. And that is just the problem. Political advocates can use them as a club to beat over the heads of others that do not agree with them. But the conscientious decision-maker will put them in their proper context.

The Lawrence Berkeley study claiming regarding California GHG targets is a good example (click here). Claims are being made by the study authors (they are free to do so) which are now trumpeted in the media to support California’s GHG rules. Not having examined the study I would ask several questions. (1) What assumptions have been made in the model? Are they arbitrary? (2) Has the model code itself (not just the output) been examined and tested by other independent researchers? Is the code available in a usable form? (In some cases model code is been made available only in a very elaborate line-by-line specific coding or partial code. In this form it is essentially unusable by anyone else but the researchers.) (3) What distinctions can be made between the “opinion” of the scientists in their interpretation of the model output and the model output itself. Model code and outputs are not neutral. They require an interpreter. And the interpreter will have presuppositions that drive the interpretation. Are the presuppositions here valid or arbitrary? (4) Has the model been validated? Almost anyone can build a computer model. Building a “valid” model is much more difficult. (5) Have the unintended consequences been addressed fairly? (6) Has the model properly considered the “negative feedback” from the consequences (intended or unintended) of the model projections? In other words, does the model shoot itself in the foot in ways not recognized by the study authors?

The above are just a few questions I would pose. But there is an even more significant problem with this modeling effort. Let’s assume that the model is accurate or accurate enough. So what?

Will there be any benefit at all to meeting arbitrary GHG reduction goals? Based on the best available science (not just model projections) the effort in California to legislate and regulate GHGs using cap and trade will have no practical effect, if any effect at all, on climate changes in California or anywhere else. No, I am not “against” renewable energy. I am arguing for honest answers to simple questions that should be asked of any study in order make sound policy decisions resulting in a sustainable outcome. (This seems to be missing.)

Advocates argue that California should “lead the way”. Well, I would agree. But not in the wrong direction. To paraphrase an often cited quote from Richard Feynman, in science the easiest person to fool is yourself. The California legislature, CARB, and climate advocates have done just that.  

 

Unsustainable Water System Infrastructure Increases Risk of AGI

These findings are to be expected especially if water pressure is lost or becomes negative in a water distribution system. I must say it always strikes me as very strange when government agents go in to investigate a situation with blinders on, come to a conclusion and then make pronouncements without consideration of all factors.  Financial stresses in the community, the cost of other government rules, increasing costs of energy, the poor condition of the national economy, increasing costs of materials, and barriers imposed at the state level all play a role in creating the poor condition of infrastructure in a community. It is easy to say blame the infrastructure and say “fix it”.

In reality it is difficult if not impossible to fix or replace aging infrastructure when key factors are completely ignored by government. Indeed, the fact that infrastructure has deteriorated so much is all the evidence needed to conclude that such infrastructure is unsustainable. Rather than just beg for more free government money (from the printing press) let’s place the root cause of deteriorating infrastructure in its proper perspective. As the old saying goes, “It’s the economy, stupid.”

Gargano JW, Freeland AL, Morrison MA, Stevens K, Zajac L, Wolkon A, Hightower A, Miller MD, Brunkard JM. Acute gastrointestinal illness following a prolonged community-wide water emergency. Epidemiology and Infection. 2015 Jan 22:1-11.

The drinking water infrastructure in the United States is ageing; extreme weather events place additional stress on water systems that can lead to interruptions in the delivery of safe drinking water. We investigated the association between household exposures to water service problems and acute gastrointestinal illness (AGI) and acute respiratory illness (ARI) in Alabama communities that experienced a freeze-related community-wide water emergency. Following the water emergency, investigators conducted a household survey. Logistic regression models were used to estimate adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for self-reported AGI and ARI by water exposures. AGI was higher in households that lost water service for ≥7 days (aPR 2·4, 95% CI 1·1-5·2) and experienced low water pressure for ≥7 days (aPR 3·6, 95% CI 1·4-9·0) compared to households that experienced normal service and pressure; prevalence of AGI increased with increasing duration of water service interruptions. Investments in the ageing drinking water infrastructure are needed to prevent future low-pressure events and to maintain uninterrupted access to the fundamental public health protection provided by safe water supplies. Households and communities need to increase their awareness of and preparedness for water emergencies to mitigate adverse health impacts.

Click here for paper (fee).

USEPA, Obama Administration Adopt a “Warfare” Model of Climate Science?

We must always keep in mind that in general USEPA is not an science-driven organization. It is by design a mandate-driven political agency independent and separate from other agencies. It has an agenda and receives deference from the courts on its judgments in matters of scientific disagreement. (Unless they clearly have made a mistake, which I believe is true in many of its judgments on “climate change” science and regulation.) Though unstated, like many other agencies in Washington and as a practical matter their highest priority is to survive politically, beat back those who disagree, and retain if not increase its budget and appropriations.

I’ve known many a fine professional at USEPA over the years. I do believe there is an important role for regulatory agencies under the laws of the US. But the vitriol expressed by the agency leaders on climate simply poisons the well (and the agency). Something is seriously out of whack when it comes to climate and regulatory policy. 

“Ms. McCarthy’s presentation consisted of not only the typical derision of skeptics of man-made climate change and the distortion of climate reality, but included a rather delusional self-assessment.” – ICECAP

 “There are many experienced atmospheric science practitioners like myself who have a different perspective, represent no corporate interests and are not connected with fossil fuel industries (except to enjoy the comfortable benefits afforded by modern energy sources). In my deliberations with numerous environmental professionals, so many have expressed some doubt (most much doubt) that humans are largely responsible for long-term global climate change.”  – Anthony Sadar

Complete articles quoted above are here.

Global “Cooling” is Much More of a Problem Than Warming

“The cold snap currently gripping Britain has led to a higher number of deaths across the country, leaving hospital morgues overstretched.

Earlier this month, the charity Age UK warned one older person could die every seven minutes from the cold this winter.” click here for article

New South Wales Fluoride Study Repeats Limitations of Past Studies; Inadequate for attributions

Here is classic study that fluoride advocates point to as “proof” that water fluoridation is good for everyone.  The results of the study show that there are indeed differences between these areas. Whether the differences in dental health can be attributed to the fluoride concentration is another question altogether. There are several difficulties with relying on this study and those like it of the past to make the attributions claimed by the authors. “Pro-fluoride” advocates have convinced themselves that fluoridation is good by interpreting and applying study results inappropriately   Here are a few thoughts to consider:

1. The study design itself is hypothesis generating. A causal attribution to fluoride for the differences between these areas is unsupported simply because of the methodology.

2. Children and people are not statistical categories. Application of statistical categories masks negative effects on any particular individual. 

3. Studies such as this that have found contrary results (no significant differences) are typically not publishable. This is a well-known reality — publication bias. Yet negative studies are equally as important as this study. Further, there is a very large literature base of toxicity studies on fluoride that should inform the interpretation of any study.

4. A single metric is applied to characterize “dental health”. Confidence limits for the analysis of the raw observations are not reported. A single number metric masks any underlying variability in raw data. What are the 95% confidence intervals on these observations? A particular statistical test may or may not indicate significance depending upon how the raw data are “cut” or “homogenized.” This is simply a basic question that should be asked of any study.

5. Not withstanding the competence of the professionals involved, quality control of the dental examinations as reported is very limited if not inadequate. An objective measure or test of consistency between observers was need at the time of the study. Even very good professionals will disagree on an observation and/or a diagnosis. This is simply a fact and is not intended to be a criticism of anyone involved in the study. Such inevitable differences are not addressed in the article beyond citing “credentials” and experience. “Credentials” and experience are indeed very important. But even as impressive as they are in this case they do not substitute for objective quality control measures to demonstrate observational consistency between observers.

We’ve simply repeated the cycle of the past. Inappropriate attributions are made to promote the addition of fluoride to drinking water. Those who advocate fluoride are usually mystified that anyone would oppose addition of fluoride to drinking water. Yet the study is inadequate to make the attributions argued by pro-fluoride advocates. In the end, fluoride advocate interpretations and attributions are simply a reflection of what has been assumed from the beginning. The study provides no new objective  evidence nor any new compelling arguments to support intentional addition of fluoride to a person’s drinking water. 

Blinkhorn AS, Byun R, Johnson G, Metha P, Kay M, Lewis P. The Dental Health of primary school children living in fluoridated, pre-fluoridated and non-fluoridated communities in New South Wales, Australia. BMC Oral Health. 2015 Jan 21;15(1):9.

BACKGROUND: The Local Government Area of Gosford implemented a water fluoridation scheme in 2008. Therefore the opportunity was taken to record the dental health of primary school children aged 5-7 years prior to the fluoridation and compare the results with other communities in NSW with different access to fluoridated water. The aim was to compare the oral health of New South Wales (Australia)s 5-7 year olds living in fluoridated, and non- fluoridated communities. One of the areas was due to implement water fluoridation and is termed the pre-fluoridation site.

METHODS: Pupils in the first year of Public and Catholic Schools in three areas of NSW were recruited. Class lists were used to draw a sample of approximately 900 per area. This number allowed for a non-response rate of up to 30 per cent and would give a sample sufficient numbers to allow statistical inferences to be drawn. Children whose parents consented received a dental examination and the clinical data was collected on mark sense cards.

RESULTS: In the 3 areas the proportion of children who received a dental examination varied; 77.5% (n = 825) for the fluoridated area, 80.1% (n = 781) for the pre-fluoridated area and 55.3% (n = 523) for the non-fluoridated area. The mean dmft was 1.40 for the fluoridated area, 2.02 for the pre-fluoridated area and 2.09 for the non-fluoridated area. These differences were statistically significant (p < 0.01). Differences were also noted in the proportion of children who were caries free, 62.6% fluoridated area, 50.8% for the pre-fluoride area and 48.6% for the non-fluoride location.

CONCLUSION: The children living in the well-established fluoridated area had less dental caries and a higher proportion free from disease when compared with the other two areas which were not fluoridated. Fluoridation demonstrated a clear benefit in terms of better oral health for young children.

Click here for paper (Open Access).

Does Drinking Water Cause Appendicitis?

Exaggerated claims about drinking water and health are nothing new.

1914 Times-Dispatch Jan 18 - Richmond VA appendicitis

January 18, 1914, Times-Dispatch, Richmond, Virginia

happy-bouncing-smilie

Heavy Metals Exposure After Mineral Exploration, Peru

Astete J, Gastañaga Mdel C, Pérez D. [Levels of heavy metals in the environment and population exposure after five years of mineral exploration in the Las Bambas project, Peru 2010]. Revista peruana de medicina experimental y salud pública. 2014 Dec;31(4):695-701. [Article in Spanish]

Objectives. Determine particulate matter (PM10) and heavy metals concentrations in the environment, as well as in surrounding communities of the Las Bambas project after five years of mineral exploration.

Materials and methods. A comparative cross-sectional study was conducted in three districts in the area of influence of the Las Bambas project in Apurimac, Peru. Samples of water, air and soil were obtained to determine the concentrations of PM10 and heavy metals. Blood and urine samples were taken from 310 villagers to evaluate levels of lead, cadmium, arsenic and mercury. Results were compared with those obtained in 2005.

Results. Environmental concentrations of PM10 and heavy metals did not exceed the established reference values. The quality of drinking water and soil was not altered. Compared to the values found in 2005, the 2010 average levels of cadmium and mercury in urine increased significantly in the population of the districts of Chalhuahuacho (2.4 + 0.8 and 2.6 + 0.4), El Progreso (2.6 + 1.1 and 2.9 + 1.3) and Haquira (3.2 + 1.2 and 2.6 + 0.9). Cadmium values exceeded permissible limits.

Conclusions. After five years of mineral exploration activity, environmental characteristics of the areas of influence of the Las Bambas mining project, have not been affected. However, changes are observed in the levels and percentage of people with cadmium in their urine.

Click here for paper (fee).

Ms. Chatharine Rampell “Dangerously in Denial” on Climate Changes

“Last year, government scientists tell us, was the hottest year on record.” click here

Even just a few hours of competent investigation of the matter would prove her government scientist sources as incorrect and unreliable.

Just who is in “denial”?