Our Lawns: The Seeds of Our Destruction

What crop do you think consumes the most water in North America? Is it corn? No. Wheat? No. Rutabaga? No. The crop that actually consumes the most water per year in North America is grass. That's right, keeping our lawns green and our yards pretty uses more water than the food that keeps us alive.

But, do our lawns have other negative effects on the environment? This article from the University of Vermont shows the negative effects of chemical fertilizers on the environment. The highly soluble nitrates used in fertilizers can leach into groundwater and are hazardous to human health and cause blue-baby syndrome. The highly soluble ammonium used in fertilizers gets washed into the water system when it rains and can be harmful to the health of local fish populations. And the phosphates (which are usually seen as compounds with ammonium, such as (NH3)3PO4) used in fertilizer cause algal blooms, and eutrophication, which can lead to a "dead lake." 70% of these phosphates entering the water come from non-point sources, such as lawn and garden fertilizers, and pet wastes.

Personally, I don't really understand why people still have grass lawns; they're time consuming, water consuming, and nutrient consuming. And we readily have access to alternatives like clover lawns which don't need to be cut, don't require nearly as much water, and don't need to be fertilized. Switching to clover lawns could save us a lot of water, decrease the amount of pollution in our water, and decrease the amount of air pollution from cutting our lawns.

So, do you think we should still be using grass lawns, or do you think that there are better alternatives?

Lithium Hydroxide and the International Space Station

Carbon dioxide poisoning can have many adverse effects on a person, from headaches, to an increased heart rate, to death. In space these effects, especially ones that can affect behavior, are augmented due to the close crew contact and highly confined spaces.

This journal article by Dr. John T. James, and Dr. Ariel Macatangay explores the many troubles required to keep the air in the ISS safe for the astronauts to breathe.

The ISS currently uses a CO2 removal system called Vozdukh. The Russian Vozdukh absorbs carbon dioxide into an absorption bed and then vacuum desorbed into space. However, if the crew on the space station requires more oxygen, this can be supplemented using lithium hydroxide canisters. These canisters are the only carbon dioxide removal system used in the Space Shuttles, and rely on a reaction between the lithium hydroxide and carbon dioxide. This reaction can be modeled by the equation 2LiOH + CO₂ → Li₂CO₃ + H₂O. The main downfall of these canisters is that they do not regenerate and need to be replenished. To know how much lithium hydroxide is needed, NASA uses measurements of the amount of carbon dioxide exhaled by its astronauts (about 1kg per day), and uses stoichiometric calculations to determine the amount required to keep carbon dioxide levels below the exposure limits.

I personally just think it's awesome that we can put these white pellets into space and they remove a deadly toxin from the air. And the carbon dioxide removal is so important that when the explosion crippled the Apollo 13 Command/Service Module, the main concern was to be able to create breathable air for the astronauts.

So, do you think these lithium hydroxide canisters are necessary? Or should we take them out of the space stations?