Showing posts with label fresh air. Show all posts
Showing posts with label fresh air. Show all posts

Thursday, December 19, 2019

Gaia Bots and Plant Pots





It was long before artificial turf and breast implants that humans began losing their connection with nature.

There is a long history of our love affair with Mother Earth, and two variations on this theme for those interested in the subject could be the American Frontier and the English Garden (both circa 1700-1800's). In the former, the West was a force to be feared, explored, and eventually dominated. In the latter, the Garden was a symbol of the picturesque, idyllic and meandering qualities of nature, albeit designed and maintained by human intervention.

The picture-perfect English Garden isn't much different from pretty much anywhere else on Earth – it's all a hybrid. Everything on this planet has in some way been shaped by us. You want evidence? How about the serious debate by geologists trying to demarcate the beginning of the Anthropocene as a geologic epoch. We've been terraforming this place since the dawn of agriculture and have no plans on stopping (carbon dioxide be damned).

This is quite a lofty intro for a post about houseplants. But this is where we start because the myth that "houseplants filter indoor air" is tenacious. It's also a great example of what makes a meme sticky, because it's simple, easy to understand, and common to everyone. It's also wrong.

You can't blame us. We want the outside inside; we're all biophiles! We want it to be true that filling our house with plants will enhance our indoor environment in scientifically-supported, quantifiable ways.

But it's fake news. And in the manner of all news that is fake, the idea that houseplants clean our indoor air is not absolutely wrong. They do clean the air, just not enough to make a difference.

I mean, if you were on a spaceship, where ev-er-y-thing makes a difference, then sure. That's where this all started. Studies done for NASA showed that they could use plants as part of a larger air-cleaning strategy. And there you have it, memetic gold.

(You know what's not mememtically robust? The fact that it's the soil microbes doing all the dirty work, not the plants themselves!)

The bottom line is that the amount of clean, fresh air that can be delivered by a typical mechanical exhaust ventilation system is a few magnitudes more than that coming from our vegetal ancestors. Or, if you really insist on bringing the outside in, open a window.

-image source link

Post Script
We start domesticating plants 10,000 years ago as a part of the Neolithic or Agricultural revolution. The ancients of Egypt, India, China, Greece and Rome all put plants in pots, but most of these were used to decorate outdoor spaces (think Hanging Gardens of Babylon). We can trace the practice of using houseplants back to the 1600's with a book called The Garden of Eden. But Buckminster Fuller's 1967 Biosphere might have a lot more to do with their current ubiquity.

Post Post Script
Our indoor space as urban dwellers is vastly different than that of jungle huts. Obviously. But what you may not have known is that our walls and windows trap so much of our own metabolic excreta that we live in higher concentrations of our own filth than someone in a thatched hut.

You can’t really measure “filth” in this context, so the above statement is more hyperbole than fact. However, this collaboration between the Microbiology and Anthropology Departments at Rutgers University, New Jersey, painted a good comparative picture of our respective indoor environments.

They studied a remote Peruvian jungle village of thatched huts with no walls, a Peruvian rural town with wooden houses sans indoor plumbing, a Peruvian city of 400,000 residents, and the two million-strong metropolis of Manaus, Brazil.

They found that we have a higher diversity of chemicals from medications and cleaning products and of fungi associated with human skin, the mouth and the gut, whereas the rural and jungle homes had a greater variety of outdoor-associated bacteria and fungi typically found in water and soil.

This is because the walls themselves trap all this stuff as it floats in the indoor air. We also have warmer, wetter air than a jungle hut, as well as less sunlight and less fresh-air exchange. This plus the tons of dead skin cells we leave lying around all make a great incubation-chamber for fungi. So despite the fact that urban dwellers clean more frequently, their indoor environment is teeming with micro-organisms that live in and on our bodies.

The end result is that our homes, in the more urban areas, and in more modern times, are more like the human body than the body of Mother Earth.

Home chemical and microbial transitions across urbanization, Nature Microbiology (2019).

Walls talk: Microbial biogeography of homes spanning urbanization, Science Advances

Notes
Nov 2019, phys.org

1988, NASA and BC Wolverton.

RL Orwell, RA Wood, MD Burchett, J Tarran, F Torpy.
Water, Air, and Soil Pollution. 177 (1–4): 59–80. 19 September 2006.
doi:10.1007/s11270-006-9092-3.


**Buy Sir Hugh Platt's original 1675 book Garden of Eden, here for $3,500

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, phys.org

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

infographic image source

Notes
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. https://doi.org/10.1289/ehp.1104789


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. https://doi.org/10.1111/ina.12403

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.