Antibiotics, "Night Soil," and *The Martian* [SPOILERS]

[LitaAlto]

There have been a number of excellent critiques of Andy Weir's novel, The Martian, from a scientific POV.

But one that I haven't seen mentioned has to do with Watney taking antibiotics, then using his feces as fertilizer when creating arable Martian soil.

Since the novel specifically uses the word "take," I presume these are oral antibiotics, as opposed to injections, salves, or other delivery mechanisms.

First, there's the concern that antibiotics aren't as effective in space as on earth, presumably due to microgravity effects. NASA is currently studying this issue, and the results of their first AES-1 experiment haven't been made public yet.

Let's presume that by the time we're ready for Mars, we've resolved that issue.

How can we be sure that there won't be antibiotics in Watney's stool? And, furthermore, how can we be sure they wouldn't negatively impact the Earth soil, used to culture beneficial bacteria in the sterile Martian soil?

If Watney waited until he was done with his antibiotic regimen, that would not be an issue--but there's no indication in the novel that he waits two weeks. Indeed, Watney wanted to make sure he had plenty of feces to use, so he started collecting his stool immediately.

This isn't an abstract concern. There are studies which show that antibiotic usage can have adversarial effects on soil.

At any rate, this is one aspect of The Martian which kind of bugs me....

[Kerbart]

Given that the movie has to take place in 2035 we can argue that medication has evolved much further and the microgravity issues with antibiotics have been fixed.

Further, the movie suggests that he uses everyone else's stools as well. So perhaps for the first two weeks he relied on the fertilizer made by his crew mates, before he utilized his own?

[LitaAlto]

Given that the movie has to take place in 2035 we can argue that medication has evolved much further and the microgravity issues with antibiotics have been fixed.

Further, the movie suggests that he uses everyone else's stools as well. So perhaps for the first two weeks he relied on the fertilizer made by his crew mates, before he utilized his own?

As I mentioned above, "Let's presume that by the time we're ready for Mars, we've resolved that issue." That's a heck of a presumption, but I'm willing to gloss over that.

I didn't see anything in the novel (which is my focus here--I have yet to see the movie) to suggest he was using anyone's stool but his own. It's entirely possible that everyone's waste was available, and wasn't processed beyond extracting water, but again, that wasn't mentioned in the novel as far as I can recall. I'll check when I'm home.

[KSK]

It was definitely mentioned in the film - there was a line about one of his crewmates being particularly malodorous.

It's at least hinted at in the book at the beginning of the entry for Sol 14.

Edited October 13, 2015 by KSK

[LitaAlto]

It's at least hinted at in the book at the beginning of the entry for Sol 14.

It was definitely mentioned in the film - there was a line about one of his crewmates being particularly malodorous.

Thanks, I'll re-read the Sol 14 entry tonight. I might've glossed over that bit.

Presuming they had five days' worth of stool from the rest of the crew, that's a 30-day supply, and might help offset antibiotics in Watney's own stool. But still, presuming he was on antibiotics for 14 days, that's about a third of the supply. That's still pretty significant.

[Kerbart]

Thanks, I'll re-read the Sol 14 entry tonight. I might've glossed over that bit.

Presuming they had five days' worth of stool from the rest of the crew, that's a 30-day supply, and might help offset antibiotics in Watney's own stool. But still, presuming he was on antibiotics for 14 days, that's about a third of the supply. That's still pretty significant.

The movie addresses that issue.

Ridley Scott made the storm hit on sol 12, or maybe even 18 (I forgot), to quash complaints that there wouldn't be enough fertilizer available. In the movie, excrement is automatically placed in sealed bags (I guess to prevent bio contamination) and stored in a "bio hazard" container right outside the living quarters

[LitaAlto]

The movie addresses that issue.

Ridley Scott made the storm hit on sol 12, or maybe even 18 (I forgot), to quash complaints that there wouldn't be enough fertilizer available. In the movie, excrement is automatically placed in sealed bags (I guess to prevent bio contamination) and stored in a "bio hazard" container right outside the living quarters

Glad the movie does that. Although it doesn't entirely remove the risk of contamination with antibiotics from Watney's stool, it would soften the effect. It might lead to antibiotic-resistant Martian soil rather than sterile soil. I'm not sure if I like that idea better.

And if Ridley Scott made this change, I guess I'm not the first to go "huh wha?" at Watney's fertilizer strategy--but I don't know of anyone who raised the antibiotics issue before.

[KSK]

I think the film also had Watney planting each tuber (or tuber part) in its own little patch of fertilizer to begin with, rather than mixing up a Hab covering amount before planting.

[monstah]

Yeah, I missed all the dirt-making sessions. Instead, he merely fertilizes the hole he plats the taters into.

A good concession to make for the screen, tho. In fact, I find the movie full of concession concessions with regards to translating the book to the screen, but the flip side is that things seem so much easier on the film version.

[PB666]

Given that the movie has to take place in 2035 we can argue that medication has evolved much further and the microgravity issues with antibiotics have been fixed.

Further, the movie suggests that he uses everyone else's stools as well. So perhaps for the first two weeks he relied on the fertilizer made by his crew mates, before he utilized his own?

By 2035 antibiotics wont work anywhere, problem solved; the bugs in the compost will use it as growth substrate.

[p1t1o]

Did anyone else read "Night Soil" and think of Game of Thrones?