Thursday, July 25, 2019

On Carbon Footprints and Cognitive Decline

We didn't always spend most of our time indoors. Some of us still don't. From a global perspective, most of us still don't. But for most of those living in the developed world, more time is spent indoors than out. Human-body-pollution is not a problem outside, where it is maximally distributed. Indoors, anything that is generated will accumulate, and unless it is exhausted abundantly, it can have adverse health effects. Even our own breath can fill the air until it reaches concentrations that actually have effects on cognition (according to this pretty good study, at least.)

I never thought of myself as a smokestack, as an incinerator burning garbage and belching toxins. But then I read a book called The Metabolism of the Anthroposphere, where I learned that half of all the matter we ingest will then leave our bodies not as solid waste and not as liquid waste. Half of everything we eat, by weight, is exhaled as carbon dioxide, and as the by-product of energy production. We burn food for energy, and emit the by-products like a tailpipe.

Cows release carbon dioxide when they breathe too, because they are also burning food to fuel their bodies. And just like coal power plants, except that their bodies are the infrastructure of our anthroposphere.

These emissions may be bad for the planet, but when humans do it, it's only a problem indoors. This hasn't been known as a problem until recently. Coincidentally, it's also a problem that has been getting worse. Then again, some of us might argue that the effect, reduced executive decision-making proficiency, is not a problem at all(!).

The history of fresh air vs human offgas may traverse a few threads. Sure, to this day people live in overcrowded and underventilated conditions. Sure squared, too many of us are exposed to pollutants that are magnitudes more harmful than CO2, and not just to our cognitive function but to organs and critical systems.

This is a first world problem. And that the very few of us on the planet of a swelling 7 billion can worry about lowering their high-level executive decision-making abilities, means there are a few less of us worrying about dying at 30 years old due to excessive inhalation of machine-generated combustion by-products indoors, for example.

That being said, we have made progress in limiting harmful exposures in the workplace and in the home. But we have neglected ourselves as a point source of pollution. And baked into our building practices from 1970 to 1990 (roughly) are energy efficient strategies that are really good at making sure we stay cooped up in a pool of our own breath.

So to recap, once we get rid of all the really harmful pollutants in the workplace – respirable particles, inert mineral fibers, toxic chemical vapors, biologically-active dust – we then start to consider the relatively invisible threat of carbon dioxide.

And why should we care; is it really a threat to human health? Maybe not. But it is a threat to our mental health. Being in a room that is poorly ventilated so that it contains double the amount of CO2 found outdoors (and generated by the exhaling human occupants) makes you a bit less sharp (actually a lot less sharp, see more details below). Double that even more, and people get even less sharp.

Trying to prove that anybody was ever killed by being less sharp is like trying to implicate climate change in a single heat wave. But there are some people who care about this – those whose job it is to provide facilities designed for people to think. Not to build cars or computer parts or to make perfumes, but to think. Classrooms are thought chambers. What is the most important thing people are doing in that space? Thinking.

Executive conference rooms are thought chambers. The small amount of people in that one room could be making decisions worth a lot of money. What if they could think 30% better, whatever the heck that means.

How about we should all want to think better. We should all want as much fresh air as possible indoors at all times. That doesn't come without a cost. You have to heat that outside air, or cool it, or take the water out of it, or put it back in, and filter and circulate. That all costs money, especially the heating and cooling.

How much is it worth to do one thing that would get every student to think a little bit better? How much does it cost to condition their fresh air during a cold snap or a heat wave? How much is it worth for a group of six entrepreneurs to craft a plan that's a little bit better?

It may take a while for us to reach the point where we can begin to care about these things, but this is the logical next step.

Progress will march on, and as more and more of the world spends their time indoors, (and cleans up their act so they are no longer worried about physically harmful pollutants), then more and more will be looking for the next improvement in their environment. And this is final frontier, removing our own carbon dioxide from the equation.

*Body odor is not known to be a health hazard, although the WELL Certification regimen, for assessing the health and wellness of the insides of a building, includes criteria for "Olfactory Comfort;" Designers can obtain credits for providing abundant exhaust/fresh air, or for controlling and limiting the migration of odors, problems that occur to the human occupancy of interior spaces.

**It should be noted that this study, and those like it, do not tell us how carbon dioxide negatively affects our cognition, just that it does, or at least it did on the tests they administered.

Post Script
Jun 2019,

Squalene, which is the greasy, grimous protective substance that once accumulated on your skin, interacts with ozone to produce secondary pollutants.

infographic image source

By Veronique Greenwood, The New York Times, May 6, 2019

Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance. Usha Satish, Mark J. Mendell, Krishnamurthy Shekhar, Toshifumi Hotchi, Douglas Sullivan, Siegfried Streufert, and William J. Fisk. Environmental Health PerspectivesVol. 120, No. 12. 1 December 2012.

Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers - A Controlled Exposure Study of Green and Conventional Office Environments. Allen, Joseph G., Piers MacNaughton, Usha Satish, Suresh Santanam, Jose Vallarino, and John D. Spengler. 2015. “Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments.” Environmental Health Perspectives 124 (6): 805-812. doi:10.1289/ehp.1510037.

We simulated indoor environmental quality (IEQ) conditions in “Green” and “Conventional” buildings and evaluated the impacts on an objective measure of human performance: higher-order cognitive function.

On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001).

Cognitive function scores were significantly better under Green+ building conditions than in the Conventional building conditions for all nine functional domains.

W. J. Fisk. Indoor Air - International Journal of Indoor Environment and Health. 06 July 2017.

There is compelling evidence, from both cross‐sectional and intervention studies, of an association of increased student performance with increased ventilation rates.

The net annual costs, ranging from a few dollars to about 10 dollars per person, are less than 0.1% of typical public spending on elementary and secondary education in the United States.

Monday, July 15, 2019

The Chemosensitive Organ

Diving off the deep end, I had an olfactory moment the other night that was a bit amazing, a bit scary. Amazing because I may have unlocked a new dimension of olfactory experience for myself, scary because I might be detecting the first real glimpse of neurological dysfunction that awaits my aged, exasperated mind.

Smells are like that. There are moments when I catch a whiff that is so faint, and so impossible to detect (like the mold that grows on the metal of your umbrella), that I often have to consider the myriad olfactory hallucinations that beset our chemosensitive organ, of which there are many.

It was a hot summer night. The crazy smell experiences always start out like that. Odors love heat, because evaporation is what makes them mobile; heat is the odor motor, if you will.

On this hot, sweaty night, I was eating dinner, hot and sweaty, resting my arms on my high-topped table, when I became fussed over the cleanliness of the surface of my table. My resting forearms sheathed in a thin film of slightly sticky, waxy sebum, and my tabletop layered in a similar compound from previous nights of the same scenario. "I need to clean this damn table. It's gross."

I try to keep my arms off the table. But it's a high top, and it's more comfortable for me to hunch over my bowl of gruel, resting on the underside of my forearms. I keep losing the battle, touching my sticky gross arms to the sticky gross table, then remembering not to, sitting straight up, only to capitulate again moments later.

All the while, I'm sampling my dinner, and very thoughtfully. I tried a new recipe last night, and today are the leftovers. The leftovers always taste different, and for some things, even better. The lemon juice in the marinade, the Maillard on the cast iron; What happened there? I used soy sauce and lime last time. What's the difference now? The acid, more sour; The surface texture, less caramelized. I am thinking, but with my mouth, my nose, lost in gustatory, olfactory thought. Shit! Dirty sticky table! And then it happened. Mid-bite, mid-thought, I could smell the table with my forearm.

That's right, mid-bite, the sensations of my dinner coalesced with the sensations of my forearms, and all of the sudden I could taste the table. Not even sure how to describe the taste, it didn't last long enough. My friend who knows a bit about these things says it's synaesthesia, hallucination. I'm not sure. I don't recall ever reading or hearing about this, but the science of smell is more mystery than science.

Our skin is covered in sensory receptors. Our olfactory cortex is entwined with our immune system. There is a hell of a lot going on here. I'm convinced that the reason I can smell mold in ways nobody else seems to be able to is because I trained (inadvertently through paranoia) my immune system in concert with my olfactory system to recognize it, and after a severe and prolonged exposure event in a basement apartment. The two -- immune and olfactory system -- now work together to alert me to its presence in the most impossibly minute airborne concentrations.

And now, I am suspicious that it goes way deeper. Then again, as I said at the outset, I may be slowly and steadily rolling into cognitive decline, my neural tendrils twisting, knotting, brittle and breaking. At least I'm taking notes.

Pattern recognition receptor (PRR)   
A receptor present on the surface of keratinocytes and other cells of the innate immune system that recognizes microbe-specific molecules that are recognized by a given PRR are called pathogen-associated molecular patterns (PAMPs) and include fungal glucans...They are also called primitive pattern recognition receptors because they evolved before other parts of the immune system, particularly before adaptive immunity...The innate immune system is an older evolutionary defense strategy, relatively speaking, and it is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms. 

Thursday, July 4, 2019

The Olfactocracy

No, you don't have to eat your broccoli.

In an experiment that sounds like something we should have done like 70 years ago, we discover that all noses are not created equal. We all smell things differently, perceiving particular odor-features with varying levels of intensity.

I take it back; we didn't have the ability to do this kind of genetics testing 70 years ago. This new experiment showed that of the ~400 genes that control our ~400 different olfactory receptors, the variability is on high. In other words, let's say broccoli has a bunch of different chemicals that make it smell like "broccoli," and that there's a bunch of different receptor-genes that code for those chemicals -- you and I have slightly different versions of those receptors, which make one of us more sensitive to the bad parts of the smell, and maybe even the other of us more sensitive to the good parts.

What you get is one person who doesn't mind eating broccoli, and one of us who gets less ice cream after dinner everytime broccoli's on the menu.

What you also get is an entire sense which lacks in consensus. At the genetic level, what smells good to you won't necessarily smell good to me. So how do we agree?

As groundbreaking a breakthrough as this is, it doesn't even begin to scratch the surface as to how different each of our olfactory experiences are. Each one of us really does live an olfactory world all to ourselves.

We know then that genetics separates us, but it goes even further. Genetics is the hardwiring, but what about the softwiring? If you, for example, were force-fed broccoli while at the same time you're also forced to watch, with your eyes pried open, footage of people trying to peel the foil off a Nutella jar but it rips halfway through, then you might become traumatized by the smell of hot broccoli, and hence highly sensitive, and highly averse to it.

And the reverse can also happen. Don't like Flowerbomb? Wait until you have a few too many romantic encounters with a woman who wears it, and you'll change, you'll see.  That's softwiring. Humans are special because of our neural plasticity, so you can bet we're susceptible to these kinds of changes.

The final note here needs to be on the way we talk about smells. If we all smell a bit different, then how can we really communicate our experiences to each other with any fidelity? 

C. Trimmer, A. Keller, N. R. Murphy, L. L. Snyder, J. R. Willer, M. H. Nagai, N. Katsanis, L. B. Vosshall, H. Matsunami, and J. D. Mainland
PNAS May 7, 2019 116 (19) 9475-9480; first published April 30, 2019

Heather Murphy for the New York Times, May 2019