Rolf Halden: Hello every­body, and wel­come. What hap­pens to the germ-killing chem­i­cals that are added by the mil­lions of pounds to antimi­cro­bial and antibac­te­r­i­al con­sumer prod­ucts? The worst-case sce­nario in the spir­it of Murphy’s Law, where we have a chem­i­cal, we design it and we think it’s awe­some. We make mil­lions of pounds of it. And then we add it to thou­sands of con­sumer prod­ucts, only to find out after the fact that the chem­i­cal did not serve the pur­pose it was added for, and it turned out to be per­sis­tent and con­t­a­m­i­nat­ing our envi­ron­ment, our wildlife, and our­selves, caus­ing tox­ic effects.

My team stud­ied and found not only one such chem­i­cal, but two such chem­i­cals. The chem­i­cals are called tri­closan and tri­clo­car­ban. I see a bland look so you prob­a­bly don’t know what that means. But even if you have not heard the names of these chem­i­cals, they are the chem­i­cals that make our con­sumer prod­ucts antimi­cro­bial and antibac­te­r­i­al. So if you have ever picked up a prod­uct that said it’s antimi­cro­bial, whether it is a tent, a sock, a shoe, a deter­gent, a deodor­ant, then you are guilty as charged.

So when we wash our hands, if we wash them at all, it takes about six sec­onds, okay. And that amount of time on aver­age is just too short in order to give us a ben­e­fit if antimi­cro­bials are present in our soap. So the chem­i­cals are ren­dered use­less and are flushed down the drains in our kitchens and in our bath­rooms. And there they go on their mer­ry way toward the waste­water treat­ment plant.

But sad­ly in the envi­ron­ment, once the chem­i­cals were out there, ani­mals were exposed for very long peri­ods of time. Even life­long, and for gen­er­a­tions, we found. And this we found out by look­ing at sur­face water sed­i­ments. And so by going down into the sed­i­ment core, we were able to do some time trav­el. And we found that organ­isms had been bathing in antimi­cro­bials ever since we start­ed pro­duc­ing them in the late 1950s and the 1960s. Antimicrobials don’t real­ly like water, and they like to seek shel­ter. And they seek shel­ter in liv­ing organ­isms.

So, looks like we have con­t­a­m­i­nat­ed every­thing. What about out­er space? We had an oppor­tu­ni­ty to ana­lyze water from the International Space Station. And guess what we found in the water loop: antimi­cro­bial chem­i­cals.

So you see we have an omnipres­ence of antimi­cro­bial chem­i­cals. We can­not escape them any­more. They are in our water, in our air, in our soil, in our food. They are in the wildlife and they are in us. But iron­i­cal­ly, they are much more effec­tive in killing things oth­er than microor­gan­isms. We should call them antial­gal agents, or antiplank­ton­ic agents, or fish-killers. All of these names would be bet­ter than the name that we use today.

So if we want to under­stand the life cycle of the chem­i­cals, and the tox­i­c­i­ty, we have to look at the begin­ning. When we syn­the­size them, we already make super tox­ic, car­cino­genic diox­ins. They are part of the antimi­cro­bials. And then at the end of the life cycle of the chem­i­cal, when they fall apart, one sin­gle mol­e­cule can make two car­cino­gens if it falls apart.

But the chem­i­cals also are tox­ic by them­selves in their own right. And among the many effects that antimi­cro­bials can have, the one thing that we are real­ly con­cerned about is endocrine dis­rup­tion. This is a scram­bling of the mes­sag­ing sys­tem in liv­ing organ­isms. Animal stud­ies have shown that small con­cen­tra­tions of antimi­cro­bials can lead to mal­for­ma­tion of repro­duc­tive organs, low­ered sperm count, spon­ta­neous abor­tion, an increase in aller­gies, and changes in metab­o­lism that can lead to obe­si­ty.

And when microor­gan­isms are exposed to antimi­cro­bials and sur­vive it, they can become tough, they can become superbugs. And so some stud­ies have shown that if a pathogen is exposed to tri­closan, the organ­ism gets resis­tant not only to the antimi­cro­bial but also to antibi­otics. And not just one but six; half a dozen antibi­otics that are used in clin­ics and hos­pi­tals around the world to pre­vent peo­ple from los­ing their limbs and lives from micro­bial infec­tions.

Why did­n’t we ban the chem­i­cals in the first place? It turns out in the 1950s and 60s we did­n’t have the right tools to ful­ly under­stand the impact of these chem­i­cals on our phys­i­ol­o­gy and on the envi­ron­ment. And things like genome sequenc­ing, or epi­ge­net­ics, or even endocrine dis­rup­tion weren’t under­stood or dis­cov­ered at the time. It’s also true that in America we do a lim­it­ed amount of test­ing of chem­i­cals before they reach the mar­ket. Oftentimes the assump­tion is that the chem­i­cal is safe until proven harm­ful. In Europe peo­ple typ­i­cal­ly do more safe­ty test­ing, and they have some­thing that’s called the pre­cau­tion­ary prin­ci­ple, which says that if some­thing could be poten­tial­ly real­ly bad but we don’t have enough infor­ma­tion, we’d much rather not use it.

But on both sides of the Atlantic, there is a leg­isla­tive back­door that allowed tri­closan and tri­clo­car­ban to slip into con­sumer prod­ucts and ulti­mate­ly into our bod­ies. And that door is the grand­fa­ther­ing” process. Once we make chem­i­cals for a long time, we don’t have to test them again when new reg­u­la­tions come out. So they are grand­fa­thered in and they cir­cum­vent the test­ing that might have revealed some of their effects.

How long does it take to ban a chem­i­cal? On September 2nd of 2016, the United States Food and Drug Administration announced a ban of tri­closan, tri­clo­car­ban, and many oth­er antimi­cro­bial chem­i­cals. It has tak­en four­teen years between our dis­cov­ery of tri­clo­car­ban in urban streams in Baltimore to the ban of antimi­cro­bials that will take effect in 2017. Today tri­closan and tri­clo­car­ban are the top ten pol­lu­tants of our drink­ing water resources.

So soon, the dark cloud of antimi­cro­bial pol­lu­tion should lift from the United States. But what about oth­er coun­tries? Over 200 sci­en­tists have signed our call to action, The Florence state­ment on Triclosan and Triclocarban, and it calls for removal of these chem­i­cals from all con­sumer prod­ucts where they don’t have a ben­e­fit, around the world.

Unfortunately my stu­dents and I, by help­ing to get these chem­i­cals banned, worked our­selves out of our job. That is actu­al­ly not entire­ly true because there are a lot of chem­i­cals in com­mer­cial use, actu­al­ly 70,000 or so in America alone, and every year we intro­duce 2,000 chem­i­cals more. So there’s plen­ty of work to be done to scan the ever-expanding chem­i­cal hori­zons to look for, among this very use­ful and life-saving and con­ve­nient chem­istry, the few bad play­ers that might do us in. So this is our job and we try to keep you safe and healthy. And so with this, I hope I did­n’t scare you too much but I give you a lit­tle bit of appre­ci­a­tion for chem­istry. So remem­ber, next time when you enjoy a deli­cious meal, great com­pa­ny, and maybe even love, it’s all about good chem­istry. Thanks for lis­ten­ing.

Help Support Open Transcripts

If you found this useful or interesting, please consider supporting the project monthly at Patreon or once via Cash App, or even just sharing the link. Thanks.