It's a staggering amount. Again, the greatest source (by far) is agriculture, as most animal feeds (whether intended for cows, pigs, chickens, you name it) are injected with prophylactic levels of antibiotics at production. The agricultural benefits of the use of such treated feeds are unquestionable: animal morality rates from infections of all sorts are much lower, and the average weight of animals significantly higher, in animals fed with antibiotic-laced feeds as compared to those fed feeds without antibiotics. (This is going back, again, probably 15 years ago to the last time I researched this, so perhaps things have changed today though honestly I doubt it.) The problem is, no one really ever asked the environmental question before. I mean, if these are chemicals that are safe for us to take into our own bodies, how could they possibly be bad for the environment? That was the prevailing attitude until very recently, when studies started popping up demonstrating that bacteria in the soil, or in groundwater/rivers near large farms, had significantly higher resistance to a whole variety of antibiotics than these bacteria normally have. This started raising all sorts of red flags about the impact of this.kerokero wrote: I never really thought about antibiotic pollution but I guess few people realize how much is actually getting tossed into our rivers.
It's also worth noting that the reason environmental levels can get so high has to do with the animal (and, for us, human) waste. For many common antibiotics, less than 50% of the dose taken into our bodies (or the animals' bodies) is actually metabolized. With some antibiotics, it can be as low as 10 or 15%. All the rest is excreted, unchanged, right into wherever the waste is going.
Yes, exposure (especially long-term exposure) to sub-lethal levels of antibiotics are probably the greatest cause of the development of antibiotic resistant strains. Some bacteria actually have an active mechanism by which they can adapt to certain toxic chemicals and "learn" to neutralize them. (Similar, though in a way less sophisticated way, to our own immune systems becoming immune to certain diseases after we have been exposed to them and fallen ill with them once.) In these cases, if the first exposure doesn't kill the bacteria (and a first exposure via the environment is far from likely to be a lethal dose), you basically help create a strain of superbug. Plus you have a Darwinian sort of mechanism operating as well; if you had 10 million bacteria in a certain water aquifer and that aquifer gets exposed to a low-level of an antibiotic, maybe 9.5 million of those bacteria die, but the strongest half million survive. Well, what happens next? Now with all of their competition gone, that half million--which already showed the highest resistance to the antibiotic--starts multiplying at a highly accelerated rate. Give them a few weeks (or however long it takes), you now once again have 10 million bacteria there...only now all 10 million come from an original set of "parents" who proved themselves resistant to this particular antibiotic. Now, you have a problem...It's shocking especially since (to my understanding) low doses of antibiotics would just help bacteria build resistance where low doses of bleach or alcohol would likely just be metabolised into the system like other simple chemicals. Very scary thought (and one of the reasons I like "organic" - less antibiotics).
Alcohol is actually even better than bleach because you wouldn't even have to rinse it. Let it sit for a few hours and it will completely evaporate away. As long as it's pure alcohol & water, there won't be any residue of any sort left.I'd be more interested in seeing what the alcohol would also take care of, but at least - like bleach - it could be easily applied to all nooks and crannies, as well as any decor and what not you wanted to keep. It's something that could be an easy "preventative" that wouldn't be a harmful overkill, at least in theory. It's much like the bleach useage.