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).
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 being modeled but representations. 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.
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).
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.