Research Tidbits

Some more quick topics of interest while I labor to generate some real content:

The National Cancer Institute just published a occupational epidemiology study of formaldehyde exposure based on a based on a cohort that’s been followed for over the past 30 years. The study suggests a possible relationship between formaldehyde exposure and leukemia, and possibly Hodgkin lymphoma and multiple myeloma. This sounds like a prospective cohort study which would make it some of the strongest epidemiological evidence available. Still, the authors are recommending more follow up and exploration of molecular mechanisms of toxicity. More of the story is forthcoming, once I get a copy of the paper from the Journal of the National Cancer Institute which behind a payment firewall.

Researchers at Michigan University’s School of Public Health have shown that antibiotics in waste water treatment plants are providing an optimal environment for breeding antibiotic-resistant superbugs, which are then discharged to surface water in the effluent. Treatment plants aren’t designed to fully degrade small organic molecules such as antibiotics. I’ve been hearing similar news about effluents from feedlots for cattle operations, where antibiotics are also used. Beyond becoming more thoughtful about using antibiotics (didja hear that livestock industry?), we may start having to land-dispose of them, rather than following the conventional advice of flushing them down the toilet.

Speaking of unintended consequences, silver nanoparticles, which are becoming more common in consumer products to make socks that inhibit odor-causing bacteria, and washing machines that disinfect clothes (where would we be without these technological marvels, I wonder), get discharged in wastewater streams and kill bacteria used for secondary treatment in wastewater treatment plants.

Back to the paper that’s overdue.

Evolution-Proof Insecticides

The title of this article in PLOS-Biology was at first a little scary. Insect resistance to insecticides is the bane of malaria control programs, but I jumped to the conclusion this was talking about making the Anophales mosquito extinct. Wouldn't there be unintended consequences?

Turns out that was an error on my part. The authors put forward an intriguing idea that shows the problem-solving abilities of evolutionary theory (could ID ever come up with something like this? I wonder). Insecticides used in malaria control kill lots of mosquitos, which imposes intense selection pressure for resistance. The females bite and feed on blood, make eggs and lay them in water, every few days. They go through this cycle only a few times before they die. The development cycle of the malaria parasites is longer, so that there will be some biting/feeding/egg laying cycles where the female mosquito is not yet capable of infecting someone with malaria. The authors draw the conclusion from this:

These facts together lead to one of the great ironies of malaria: most mosquitos do not live long enough to transmit the disease.

The strategy then is to only kill mosquitos after they've reproduced, but before the malaria parasites become infective. The goal is to find insecticides that minimize selection pressures by killing only older mosquitos who have had some opportunity to breed. While noone is actually doing this yet, the authors discuss the modes of action of "late-life acting" (or LLA) insecticides and identify the kinds of research needed to test this concept.

Let's hope someone gives it a try.

Quick Links

Some topics of interest I’ve run across, while I try to generate some real content:

Ok, so hexavalent chromium is carcinogenic when you ingest it in drinking water. Just what we need, another chemical we’ll find difficult to make decisions about. That needs a little bit of context, but it’s taking awhile to create.

Climate modeling goes local. This has a lot of promise – increasing the usability of climate modeling for decision-making; building more acceptance of the need for action to mitigate climate change. More details can be found here. The EPA grant seems to have run out, and hopefully these folks can find some more funding.

Huffington Post is exasperating because it’s 95 percent a waste of my time, but will produce gems like this the remaining 5 percent of the time, so it’s just marginally useful enough for me to keep checking into it. We’re going to need initiatives such as the Pileus Project because, according to Joe Romm, the mainstream media sure seem to be agents of disinformation when it comes to climate change issues.

Matt Nisbet must think that Monsanto needs help framing itself as a sustainability company.

DDT is really bad for human health and should be used sparingly. I was taught that was true for all pesticides, but I guess the lesson hasn’t sunk in yet. What’s surprising is how active health effects research is with DDT.

Have to run. The paper I’m overdue on isn’t going to write itself.

Culture War, Obesity and the New Puritans

I almost forgot I’m a blogger. Nah, not really, but it’s been difficult to keep up lately. I write longer posts, and want to take care to do the homework, so that I’m not producing something that’s misleading. For example, take this recent post by Paul Campos over at Lawyers, Guns and Money. Paul objects to the idea that public health measures involving promoting changes in lifestyle, specifically with what we eat or drink, might help reduce health care costs, or as he says it:

[i]n any case the notion we can cut health care costs significantly by getting people to drink less soda and eat fewer Doritos is unsupported by any evidence.

Riffing off of a post by Matthew Yglesias, Campos also makes lifestyle intervention – public health matters an outpost in the culture war, putting those of us who are interested in the social benefits of exercise and healthy eating into the bin of “cultural Puritanism. We’ll put aside for a moment the point that equating “puritan” with someone who disapproves of pleasure is a bit of historical misdirection. You can even find some evidence for his point that long-term health care costs are driven by old age and not lifestyle choices.

Last year, RIVM published a study modeling lifetime health care costs for cohorts of obese people, smokers and “healthy living” folks, defined as non-smokers with BMIs between 18.5 and 25. The results were that annual health care costs were highest for obese people earlier in life, until age 56, and were highest for smokers in later years. However, the overall highest lifetime health care costs were for the healthy-living folks. Life expectancy from age 20 is reduced by 5 years in obese people and 7 years in smokers. Healthy-living people live on to incur greater medical expenses, more than compensating for the expenditures related to smoking or obesity.

So, I should start smoking again and eat like this to do my part to control health care costs. However, before you shout “gotcha”, take a look at the commentary traveling along with this article. Compare a lean and obese population with the same age and sex distribution, and the latter will have greater health-care costs throughout life. So during the productive adult years of your life, when you should be spending money on other things, such as books, vacations and family, your're spending it on health care. There are other costs associated with obesity such as absences from work and lost productivity, in addition to health care costs. In the UK, these extra costs are estimated to be about four times as great in obese than in lean people.

The problem in the health care debate that no-one seems to want to talk about is that people want to live forever, and it in those years at the end where the health care costs are highest. However, living longer shouldn’t be the goal, rather maximizing the number of years free of disease burden. For me at least, I’d rather not be clomping around on knee or hip replacements, being treated for diabetes or putting up with erectile dysfunction.

Holding ED at bay. . . ok, now we’re getting to why I really pay attention to exercise and what I eat. I’m so transparent. See you in the gym.