Grey Water on Veggies and Illness Transmission

January 6, 2009 2:05 PM

My husband used old grey water (daughter's bath water, a few days old) to water potted capsicum/pepper plants (with fruit) and tomato plants (not yet fruiting) and then came down with vomitting that night. I hope it is only a gastro-intestinal virus. It is clear that the grey water was old, and he should not have used it. That's not the question. My question is this: Do we have to cook all the fruit that are currently on the plants, even if they need a few more weeks to ripen? Say I pick all the fruit off now, then what about subsequent fruit? I was hoping to keep these pepper plants for a few years and we do like to eat the tomatoes and peppers raw in salads.
posted by Tsisqua47 to Home & Garden (26 answers total)

Be sure to wash them, and you should be fine. Plants grown on farms are commonly raised in the presence of any number of nasty bacteria, especially the ones fertilized with manure. These are seldom passed on to consumers except on the surface of vegetables, and a good washing will get rid of that.

I believe that plants can absorb heavy metals from soil, but that's not what we're talking about here. A good washing should be entirely sufficient to remove any nasties that may have been in that water.
posted by valkyryn at 2:19 PM on January 6, 2009

IANAF (I am not a farmer), but it would seem to me that there is a high chance that there was fecal material in the bathwater. This could mean that there was fecal material poured onto your plants. Of course, there is also fecal matter on plants grown outdoors, that's one ofthe reasons its a good idea to rinse your fruits and veggies. You might also want to try a fruit/veggie cleanser like this. If you clean your fruits/veggies there shouldn't be any reason that you would have to cook them.


By the way, just curious, what was the reasoning behind using the bath water? Are you trying to conserve water or is there some other reason?
posted by anansi at 2:21 PM on January 6, 2009

Don't shell out for a veggie cleaner soap/spay. Use vinegar.
posted by Science! at 2:28 PM on January 6, 2009

I'm reminded of the notion that correlation does not imply causation.

Honestly, it seems unlikely to me that pouring out some old bath water could transmit a GI virus to your husband. IANA: doctor, scientist or farmer, and I know nothing about grey water usage.
posted by gnutron at 2:30 PM on January 6, 2009 [2 favorites]

Yeah, I don't think the fact that the grey water had "aged" would have made it more dangerous. It certainly would have had fecal matter in it to start with and any outdoor plant is going to be shat on by something at some point. Just wash it good and cook as normal. (I have no training, experience or expertise with which to back up the foregoing opinion)
posted by bonobothegreat at 2:38 PM on January 6, 2009

He watered the plant and vomited the same day? Pretty unlikely the two are related.
posted by O9scar at 2:44 PM on January 6, 2009

Was your daughter sick? The way that people get sick from contaminated water is when it's been contaminated by other people or animals that are already sick. Plain old water isn't a good growth medium for bacteria anyway, there's not much food in it for the bacteria to eat. Also keep in mind that a number of different types of food poisoning don't show up for a few days to a week after you ingest the bacteria so there's no particular reason to assume that his vomiting was caused by eating from those plants.
posted by TungstenChef at 2:46 PM on January 6, 2009

IANAF (I am not a farmer), but it would seem to me that there is a high chance that there was fecal material in the bathwater. This could mean that there was fecal material poured onto your plants. Of course, there is also fecal matter on plants grown outdoors, that's one ofthe reasons its a good idea to rinse your fruits and veggies. You might also want to try a fruit/veggie cleanser like this. If you clean your fruits/veggies there shouldn't be any reason that you would have to cook them.



Have you ever heard of manure? almost everything you eat has been grown in shit. I think this is just a coincidence
posted by kanemano at 2:50 PM on January 6, 2009

Grey water and health
Storage of grey water
Grey water on veggies

With that background in mind: if those were my plants, I would (a) not put any more grey water on them (b) give the sun a couple of weeks to disinfect anything that did get splashed on them and (c) enjoy my peppers and tomatoes without a worry in the world.
posted by flabdablet at 3:00 PM on January 6, 2009

Just to clarify -- since a couple of other people seem to have the same confusion I do -- your husband didn't ingest any of the water, or any of the peppers or tomatoes? He just poured old water onto plants? And you think this is related to his vomiting?
posted by creasy boy at 3:19 PM on January 6, 2009

While people are saying it's no big deal, because there's manure on most plants, the difference here is that the organisms in this bathwater are from humans, and so much more likely to be infectious to other humans.

You know that advice to travelers from the US about not eating uncooked veggies and fruits in Mexico? That's the deal here.

I recommend cooking the vegetables before eating them.

Moderate derail: if you're interested in recycling grey water, as I am, then there's some health code / plumbing code (at least in my area) that at first seems arbitrary, but is designed to minimize the transmission of nasties from one human to another without imposing too much of a burden.
posted by zippy at 3:25 PM on January 6, 2009 [1 favorite]

And yeah, he totally could have exposed himself to something nasty (fecal coliforms for example) if they were in the water, plus they had a chance to grow for a few days. If he didn't wash his hands well after using the water. I wouldn't sweat eating the veggies though. The bacteria will die, the sun will fry them, and then you'll wash the food.
posted by Science! at 4:07 PM on January 6, 2009

Have you ever heard of manure? almost everything you eat has been grown in shit.

yep, that's why I said this. Of course, there is also fecal matter on plants grown outdoors
posted by anansi at 4:21 PM on January 6, 2009

This is exactly how the recent tomato/pepper outbreak and others before them occur. Using shitty water to irrigate the plants.

Even if the daughter didn't literally poop in the tub, her butt was in it and if she had anything going on down there, its on your vegetables. I wouldn't eat them. YMMV.
posted by gjc at 4:55 PM on January 6, 2009

This is exactly how the recent tomato/pepper outbreak and others before them occur. Using shitty water to irrigate the plants.

But in the case of last year's salmonella outbreak, aren't we talking about bacteria on the *outside* of the peppers and tomatoes? Yes, I think we are. The poster's question is more concerned with long-term effects to the *inside* of the plant and fruit. Which is very much *not* "exactly how the recent tomato/pepper outbreak and others before them occur." My guess is washing the current fruit would be fine. And I seriously doubt the plants and any future fruit are ruined forever. But if you're in the U.S., your best bet isn't AskMe, it's your local agricultural extension office:

Each U.S. state and territory has a state office at its land-grant university and a network of local or regional offices. These offices are staffed by one or more experts who provide useful, practical, and research-based information to agricultural producers, small business owners, youth, consumers, and others in rural areas and communities of all sizes.

They're trained to answer questions like this.
posted by mediareport at 5:59 PM on January 6, 2009

I don't see how the veggies made him sick either, if they were washed.

Also, I don't know where you are, but there's a nasty 24-hr stomach bug going around. The gray water and the veggies and the vomiting may just be a coincidence.
posted by desuetude at 6:06 PM on January 6, 2009

mediareport, thanks for your condescension. Food is not hermetically sealed. What's outside can get inside. And yes, salmonella can exist inside fruits and veggies.
posted by gjc at 8:37 PM on January 6, 2009

Calling your local agricultural extension office is the best idea so far.

I really wouldn't sweat it. Most bugs take at least a few days to develop once inside the host, so if he vomited that same day it's likely not the water's fault. Just wash the veggies before you use them; the bacteria can't survive long when exposed to open air & sunlight anyway, and to my knowledge cannot be absorbed into the plant itself or its fruit.

If you're really that worried, just get rid of the plants. Peppers and tomatoes are annuals anyway, so you wouldn't have been getting much more fruit off them whatever your climate.

Please post what you learn here so we can all learn!
posted by GardenGal at 8:42 PM on January 6, 2009

This is the part I don't understand: daughter's bath water, a few days old

Did you leave the tub undrained as to use the bathwater for watering plants? Is there any disadvantage to doing that, if so? Does it make the home more humid? Attract insects? I've never left standing water, myself.

However, I'd like to use water more responsibly, and I'm just curious about the logistics of it.

As for re-using water, we have a large container that we put cutlery in to soak for anywhere from 1-5 days before it hits the dishwasher (my husband's idea, as our dishwasher doesn't do a great job on cutlery) and when I load the dishwasher to run it, I tend to grab that rather nasty water and use it on houseplants, thinking it's full of stuff, must be good for the plants. Nutrients, or sumpin'. I'm probably not clear on biology or agriculture. Is this stupid? These are decorative plants, not indoor food plants.
posted by Savannah at 10:29 PM on January 6, 2009

Response by poster: Thanks for your replies. First, a couple quick answers about my situation. We are in Australia, so a) conserving water is a big deal and b) it's just the beginning of summer here and my first bumper crop of exotic hot chillis still need to ripen before we can make some nice salsa and hot sauce out of them. Also, capsicum/pepper plants, especially when grown in pots and protected over the winter can live for several years, or so I am told.

I looked into grey water use and read in several places that bath water is good for plants (whereas dishwater isn't as good becasue of more oils/more soaps, I think) if used within 24 hours, but often not recommended for vegetables (though that part was new to me today). So since we had already made the error, I was indeed asking if anyone knew about whether the nasties get INTO the fruit and stay there (thanks, mediareport).

As for what happened to my husband, we had gone away for a few days. The bath water had been scooped into a bucket before we left, but didn't have time to water, so the buckets sat around. When we got back home in 32 degrees celsius heat, he scooped the water out of the bucket to water the plants, got it on his hands and didn't wash before he ate. (Eww...) Classic case of "food poisoning". Symptoms started about 6 hours after ingestion, were pretty severe for 6 hours, lingered for another 6 (couldn't keep water down) and much better now at 24 hours since exposure.

So, I would conclude from this experience that bacteria actually do a good job of living and breeding in stagnant warm-house temperature water, and greywater should indeed be used within 24 hours. I'm happy that it's not a G-I virus, as many of you pointed out, but "food poisoning" and therefore the kids and I aren't going to get it next! Whew!
posted by Tsisqua47 at 12:23 AM on January 7, 2009

Classic case of "food poisoning".

No, this is a classic case of "last meal bias." It almost certainly isn't related to the water. Check out CFSAN's chart on the onset and duration of foodborne illness. To my (admittedly limited) knowledge, none of the typical bugs that would cause symptoms this rapidly would occur based on water exposure. Staph aureus's rapid onset is due to toxin production. You don't need to ingest much of it, but toxin production is unlikely in water, and the form of B. cereus that causes vomiting likes to grow starchy food, and not so much water, and I believe you need to eat a lot of the organisms to get such a rapid onset.

When you're talking about fecal-oral transmission, there is almost always a growth medium that allows the bacteria to grow a sufficient infectious dose. The big exception is norovirus, which has a mean onset between 24 and 48 hours.

I would conclude from this experience that bacteria actually do a good job of living and breeding in stagnant warm-house temperature water...

Living, yes; breeding enough that so many can cling to his hands after scooping the water, letting it dry (dear god, I hope he didn't eat with dripping hands, just from a general ew perspective), and eating (with silverware?) that they can cause symptom onset in six hours: no.

The poster's question is more concerned with long-term effects to the *inside* of the plant and fruit. Which is very much *not* "exactly how the recent tomato/pepper outbreak and others before them occur.

This is incorrect. Bugs can get into fruits. Tomatoes (and, I believe, apples) do this. A MMWR from the CDC discussing the 2004 tomato outbreak in the US, says: "Salmonella can enter tomato plants through roots or flowers and can enter the tomato fruit through small cracks in the skin, the stem scar, or the plant itself. However, whether Salmonella can travel from roots to the fruit, or if seeds can contaminate subsequent generations of tomato plants, is unknown. . . Eradication of Salmonella from the interior of the tomato is difficult without cooking, even if treated with highly concentrated chlorine solution."

That report does warn that they don't know enough about how contamination occurs to "ensure produce safety," though. Which doesn't mean that you'll get salmonella from your tomatoes. There's no need to be alarmist. If you really are concerned, though, cook your food.

I'm happy that it's not a G-I virus, as many of you pointed out, but "food poisoning" and therefore the kids and I aren't going to get it next!

GI viruses are a form of food poisoning, and frankly, it probably is a virus. The general consensus is that norovirus causes more than 50% of foodborne outbreaks. It's the common cold of bugs that make you puke. Wash your hands a lot. Vomit can aerosolize and it doesn't take much (as few as 10 viral particles) to get you sick. But it doesn't take much to not get sick. Wash your hands a lot, and try to keep them out of your mouth. You'll be fine.
posted by averyoldworld at 6:48 AM on January 7, 2009 [1 favorite]

So how soon after returning home did he water the plants and eat, and did he eat anything while you were on the road? The worst cases of food poisoning I've ever gotten were from eating at roadside diners. You don't say how old your daughter is, and I know kids can bring things home from school that will make the whole family sick, but generally speaking you should have some resistance to each other's germs, and if neither your daughter nor you got sick, it just seems to point elsewhere.

If we're wrong and he did get sick from your daughter's bathwater, perhaps he's acquired some new antibodies in the process, and at least he can eat the peppers without fear--
posted by Restless Day at 10:51 AM on January 7, 2009

This is exactly how the recent tomato/pepper outbreak and others before them occur. Using shitty water to irrigate the plants.

Actually, most of the contamination events have been traced to packing houses, or field packing operations. While studies have shown that Salmonella can travel through tomato plants, I can't actually find an example of "shitty water" having been the source of contamination in any outbreak, except as it occurs on the outside of the vegetable. If you have a source where internal contamination due to fouled water supplies has been found to be the problem, please cite it, because I can't find one.
posted by oneirodynia at 12:27 PM on January 7, 2009

I'm "The Husband" in question -- we've gone over the timelines pretty carefully; nobody else was sick or got sick, nobody else came into contact with the mentioned greywater, and I'm satisfied that bacterica not only can, but cheerfullly do breed in stagnant bathwater. This last finding comes direct from the Australian Department of the Environment, Climate Change, Energy and Water:

Further - the longer you leave greywater the worse it will get -
degrading in quality as bacteria grow, organic matter degrades,
producing toxins and depleting oxygen. Unless it is highly treated -
greywater should be used as soon as possible, and not stored unless
treated.

The full greywater reuse guidelines can be found here
posted by 5MeoCMP at 3:23 PM on January 7, 2009

5MeoCMP, I think you're taking that somewhat out of context. Of course bacteria can grow in water, but we were talking about things that could cause your specific symptoms. For you to be sick in the way you were sick within six hours of your specific exposure, one of two things would have to happen.

One, bacteria would have to produce a lot of enterotoxin (keep in mind that toxins don't necessarily cause gastrointestinal symptoms - many are neurological) before you scooped the water. A lot, because you didn't drink the water. It'd have to stick to your hands, hang around long enough for you to eat, and there would have to be a sufficient amount on the parts of your hand that came in contact with your food. Presuming you didn't lick your hand. The bacteria that make those toxins don't do it in water, although if there were enough crap in the water to act as a growth medium (chicken salad?), they would happily grow. But staph aureus needs to have a population of 100,000 per gram to start producing toxin - it's just not going to happen in your bathwater.

Or two, the bathwater would would need to have a high enough population of the bacteria that could start producing toxin in your body within 6 hours. That'd be the short incubation form of B. cereus, and you'd need to get 10^6 organisms per gram of food into your body for that to happen. Again, not going to happen on your bathwater, definitely not going to happen on your hands.

There are plenty of waterborne illnesses that could make you sick. None of them are going to make you sick in six hours. I sure as hell wouldn't put grey water on anything I was going to eat raw no matter how quickly it was used, but that's me - I was in food safety for a few years, and I tend to be overly cautious. But it's just not the culprit here.

It was almost certainly norovirus. In the 72 hours before you got sick, did you eat anything your family didn't eat? Did it come on pretty suddenly? Maybe you felt funny for an hour or two, and then it hit you like a hammer and you had to run to make it to the bathroom?
posted by averyoldworld at 7:54 AM on January 8, 2009 [1 favorite]

Gastrointestinal diseases usually take one to five days to induce symptoms. Whatever made him puke was probably already in his system. And as stated further up, but in not such eloquent terms as I'm about to use; if you've eaten food you've eaten shit.
posted by ZaneJ. at 12:36 AM on January 9, 2009