Illustration by Eddie Man
MICHAEL SNYDER, PH.D., is carrying 4 sensible watches.
Inside his lab, the largest on Stanford’s perennially sunny campus, the director of the Middle for Genomics and Customized Drugs pulls up a seat and walks me by way of his very particular on a regular basis carry.
For almost a decade, Snyder has been attempting to quantify human well being. And though he has lots of of volunteers in six totally different trials, he’s his personal greatest topic. His 4 totally different smartwatches spill out 9 years’ value of heart-rate and skin-temperature knowledge; a steady glucose monitor graphs the consequences that weight loss plan and train have on his blood sugar; an Oura ring tracks his sleep high quality; and a black walkie-talkie-sized field he calls an exposometer “breathes” the identical air as him and identifies all of the airborne particles and chemical compounds he’s uncovered to in a day. (Not within the workplace at present are his radiation monitor, a pulse oximeter, a digicam that mechanically takes pictures of his surroundings each 5 minutes, and his sensible biking shorts, which had been a little bit of a bust.) Add all this to his semiannual MRIs, the microbiome and genome sequencing, and the hormone measurements and Snyder has greater than 2 million gigabytes of his personal well being knowledge saved. It’s distinctly attainable that Michael Snyder has extra knowledge on Michael Snyder than anybody has had on any human who has ever lived.
Snyder is a geneticist, famend for serving to to create revolutionary methods to research the genetic blueprint that makes up a life. For so long as people have lived and died, we’ve been attempting to clarify why folks get sick. Hippocrates blamed an imbalance of the biles, blood, and phlegm; medieval medical doctors chalked sickness as much as man’s sinful methods. And for a technology now, since scientists first started to unravel our DNA, we’ve been primed to suppose that illness is written into our genes.
However lately, Snyder is taking a extra holistic view of well being. The smartwatches and the exposometer and the blood work and the MRIs—at present, Snyder is a strolling, respiration experiment, a one-man case examine of how every thing in addition to your genes can have an effect on your well being. “For the very first time, we’re discerning how your exterior surroundings, as you breathe it, influences your insides.”
How, in different phrases, your surroundings is making you sick.
Genetics is a crucial a part of human well being. For years now, it has been the 800-pound gorilla within the analysis world and in our minds. And but there’s a motive, 20 years after the Human Genome Undertaking was famously accomplished, you don’t have your genes sequenced at your annual wellness checkup. That’s as a result of heart problems, cancers, diabetes, neurodegenerative illness—none of those are primarily pushed by your genes. In actual fact, your genes account for under about 10 p.c of illness improvement and development.
Most of our maladies seem, as an alternative, to be introduced on by issues humankind has inflicted upon itself, like life-style components (weight loss plan and train) and what scientists name environmental components: publicity to air and water air pollution, poisonous waste, and chemical compounds similar to pesticides. “Take into consideration a plant,” says Konstantinos Lazaridis, M.D., the manager director of the Middle for Individualized Drugs on the Mayo Clinic. A plant’s progress and well being don’t rely solely on the DNA in its seed. The place you plant it, the soil and its contaminants, the fertilizer you unfold, the pesticides and chemical compounds and air pollution your plant is uncovered to—all these components have an effect on your plant’s life. “I actually imagine people aren’t totally different: We’re natural and we’re uncovered to tens of millions of issues,” Dr. Lazaridis says.
But when we’re crops, then our backyard is fairly tousled. A 2021 examine on the College of California, San Francisco discovered 109 totally different industrial and client chemical compounds in its topics’ blood. They ranged from plasticizers used for packaging to per- and polyfluoroalkyl sub-stances (PFAS) utilized in nonstick prepare dinner ware to pesticides and flame retardants. Greater than 50 of the chemical compounds had by no means been seen in folks earlier than; 42 had been “thriller chemical compounds,” compounds of unknown origin. The examine underscores an unsettling actuality: Over the span of a technology or two, human beings have grow to be petri dishes, our our bodies unplanned experiments by which chemical compounds and substances that by no means existed in nature can work together in methods we’re solely starting to understand. “I as soon as had a health care provider inform me, ‘Once I began my follow, all my sufferers had been regular,’ ” a coauthor of the UCSF examine, professor Tracey Woodruff, Ph.D., says.“ ‘But it surely’s slowly shifted to all irregular instances. Now it’s bizarre to have a traditional case.’ “
The whole lot from ballooning most cancers charges for folks underneath 50 to a disaster in sperm high quality and fertility has been tied to our environmental exposures. Untangling the fallout will take years. And within the interim, greater than 12 million folks will die every year—1 / 4 of all world deaths—because of our poisonous exposures.
It’s a very good factor, then, that after ignoring these environmental components for many years, scientists now have a reputation for the totality of such exposures, to your personal private accumulation: the exposome. “The exposome is the idea that almost all exposures, even from the time in utero, will have an effect on us,” says Dr. Lazaridis. The examine of your exposome— exposomics—is a complete new manner to consider taking care of our well being. It’s an invite for us to cease and take inventory of all of the crap that goes into our our bodies. And it’s an opportunity for scientists like Michael Snyder to reevaluate the causes of illness. There’s only one downside: In a world of endlessly chemical compounds and refineries and artificial flavors and smells, the place do you even start teasing out what impacts us and the way?
SEEING INSIDE YOUR BODY
In Snyder’s workplace, he digs into the info from his assortment of sensible gadgets. He exhibits me blood-oxygen knowledge from 2015, which allowed him to detect and deal with a Lyme-disease an infection earlier than signs appeared, then heart-rate knowledge from one in all his smartwatches, which helped detect the Lyme in addition to predict a Covid an infection earlier than he examined constructive. Snyder is each broad and trim, with the thick, darkish beard that always comes with a bald head. He was a runner, however when knowledge from his frequent blood checks revealed he was pre-diabetic, he switched to weightlifting, based mostly on the speculation that “muscle mass is healthier for glucose regulation—maybe.” He’s been lifting for six years, and at present the cephalic vein that snakes down his surprisingly yoked 67-year-old biceps pops beneath his polo.
I ask him to point out me his exposometer, the small wearable—across the identical measurement as a smartphone—that his crew developed and constructed in-house to trace the entire chemical compounds and airborne particles its wearer is uncovered to and that has introduced his data-collection obsession to exposomics. “What’s particular about our exposometer is it’s private publicity,” he says. “It’s yours.”
Toxicologists have lengthy recognized that many man-made chemical compounds and environmental toxins like lead trigger illness and different antagonistic well being results. Anybody who watches the information has doubtless heard tales of commercial toxins like benzene inflicting leukemia or seen class-action lawsuit commercials for sufferers who developed mesothelioma after asbestos publicity.
In contrast to these substances, nevertheless, nearly not one of the 80,000 different probably poisonous chemical compounds which can be at the moment in use within the U. S. are carefully monitored by the EPA. And most of the people do not know what they’ve been uncovered to in a day. That’s the place Snyder’s exposometer is available in. Chemical compounds, micro organism, pollution, and fungi are all sucked up by the machine after which introduced again to his lab for DNA sequencing and chemical profiling. To date, he’s captured traces of round 3,000 chemical compounds he’s are available contact with. Of that bunch, his crew has been capable of determine 158, together with 67 which can be almost certainly harmful to our well being.A couple of third are pesticides, 21 p.c come from prescribed drugs and personal-care merchandise, 11 p.c come from plastic, and a further 10 p.c or so are in all probability carcinogens. It’s going to be awhile till there’s a transparent catalog of which exposures, and the way a lot of every one, trigger which well being issues, however there are issues you are able to do to guard your self within the meantime.
And in a wild “n of 1” trial—a examine of 1 topic, on this case Snyder himself (after all)—the crew discovered real-time correlations between these exterior exposures and Snyder’s internal workings. Sure chemical compounds from plastics had been related to inflammatory markers and adjustments within the inhabitants of his intestine microbiome; different pesticides correlated with inflammatory results involving his kidney and liver features.
It’s a tantalizing, thrilling step towards a future by which a Star Trek–like tricorder may inform us what ails you. However proper now Snyder’s exposometer can solely present present exposures, those his machine breathes, too. To construct “a library of your exposures”—the lead in your childhood house’s water provide, the air pollution from the refinery you used to stay close to—and tease out your full historical past, one thing exposomics researchers dream of, we have to know your previous exposures.
And for that, we’d like one thing you’ve in all probability misplaced or discarded: your child enamel.
YOUR EXPOSURE TIME CAPSULE
People have discovered or created greater than 150 million chemical compounds. (The periodic desk of components you memorized 20 years in the past? Yeah, there are actually 118 entrants.) And should you suppose there’s some regulator or security board between you and Large Chemical’s brand-new brainchild, suppose once more: Though the federal government has the ability to dam chemical compounds earlier than they attain the market, in follow it not often does. (The EPA has banned solely 13 chemical compounds—ever.)
We’ve already unlocked proof that chemical compounds not meant to be within the physique can hurt it. Dr. Lazaridis, the MayoClinic honcho and an skilled on persistent liver illness, spent years on the lookout for the genetic mutation that was thought to trigger major sclerosing cholangitis, a uncommon liver dysfunction. Then, 5 years in the past, he determined to look at his sufferers’ blood for exposures. Inside months, he discovered a correlation between the illness and a pesticide banned within the U. S. however nonetheless discovered on imported fruits. Exposomics researchers suppose we’re getting ready to discovering new correlations. The power to see what you’re uncovered to proper now’s growing; we simply don’t know methods to learn all of your knowledge but. The query is whether or not we are able to determine all of it out in time to avoid wasting ourselves.
Manish Arora’s response to this downside is to gather child enamel.
Arora, a Ph.D. who’s a professor of environmental medication and public well being on the Icahn College of Drugs at Mount Sinai, has a singular background for a chemist turned epidemiologist: He’s a educated dentist. In the future, Arora noticed a felled tree and it struck him (not actually). Enamel, like timber, have progress rings. No matter is in your bloodstream will get deposited in these rings. Learn the rings, like all outdoorsman reads a tree ring, and also you get a visualization of an individual’s chemical exposures over time.“Like a organic laborious drive,” Arora says,“archived in chronological order.” When he examined child enamel from Flint, Michigan, he instantly discovered the “progress rings” from once they had been uncovered to lead-contaminated water. (It’s lots simpler to get folks to donate child enamel than grownup enamel.) “Pesticides, vitamins—we are able to choose up day by day irritation markers from earlier than you had been born, and we are able to put a time stamp on it.” He received’t name it this, however Arora has constructed himself considerably of an publicity time machine.
Exposures have an effect on the physique in myriad methods, as Snyder has already proven. They’ll change the micro organism in your intestine, upending your microbiome. They’ll alter the way in which your cells speak to 1 one other, throw-ing off organic operate.They’ll impair your nervous system or put your physique right into a state of stress or disrupt your hormones or trigger irritation. They usually can work together along with your genes. In Flint, about99,000 folks had been uncovered to steer, however solely about half of households reported that their youngsters had been unwell.
Those that had been worse off from lead poisoning could have been predisposed to undergo attributable to numerous various factors, their our bodies primed for one thing to come back in and mess up the place. And lead—the publicity—set the ball in movement.“Genetics masses the gun,” as former NIH director Francis Collins, M.D., Ph.D., places it,“and surroundings pulls the set off.” The query, then, for the remainder of us is: How will we maintain the protection on?
THE GREAT CLEANUP
In Utrecht a university city within the Netherlands, a brand new neighborhood underdevelopment is betting that it has some options. The Dutch are huge on exposomics, so when Utrecht wished to show a rail-way yard right into a residential neighborhood, it known as Roel Vermeulen, a professor atUtrecht College and the chief of a nation-wide exposome analysis group. The aim for this new neighborhood was, on its face, absurd—builders mentioned they wished to make each resident stay 5 years longer in good well being.
Vermeulen was recreation. Seven million folks worldwide die from air air pollution every year—the obvious of exposures. And solely about 30 p.c of individuals develop persistent sicknesses based mostly purely on their genetics, he figured, so designing this neighborhood with the exposome in thoughts may certainly lengthen folks’s well being span. In Vermeulen’s neighborhood, altering the surroundings means having a greater transport infrastructure so folks can stroll and bike day by day whereas respiration fewer emissions. It additionally means having an enormous group backyard proper in the midst of a central park that’s designed to extend exercise and increase alternatives to socialize. “Your choices to vary genes are very restricted,” Vermeulen says. “However the surroundings is lots simpler to vary.”
It’s a lesson we may all take to coronary heart.
It doesn’t need to be laborious—or tremendous costly—to restrict the quantity of poisonous chemical compounds you’re uncovered to. “Individuals, once they speak exposures, they consider like an explosion of the nuclear reactor at Chernobyl,” Dr. Lazaridis says. “But it surely’s not the catastrophic expertise—it’s the stuff we’re uncovered to daily that we don’t even learn about.” The little exposures add up—Snyder’s exposometer exhibits that very clearly. And though chemical compounds come at you from many angles, his wearable additionally reveals that subtracting them, even in small methods, issues in relation to cleansing up your physique.
Michael Snyder desires to quickly and dramatically increase the type of fact-finding he’s doing. His exposometer isn’t fairly prepared for mass manufacturing but; an app in your smartwatch received’t warn you to your exposures this yr. However should you grow to be your personal exposometer—cease and consider what you set in or in your physique daily—you could find alternatives to make small adjustments that make a distinction, typically to extra our bodies than yours.Should you forgo spray odor eliminators, you and your toddler received’t inhale probably dangerous artificial scents; should you skip dry cleansing, the one who works on the cleaners could also be uncovered to fewer cancerous solvents; should you choose out of waterproof-ing your boots, your entire group could have fewer PFAS within the water provide.
So most of the main challenges we face, like struggle and local weather change, can appear intractable and out of our arms. However we have now company over what we deliberately put in and round our our bodies. Take what we all know now and begin placing your self accountable for your physique’s future.
This story seems within the March 2023 difficulty of Males’s Well being.

David Ferry is a reporter in Los Angeles who has written for publications together with Outdoors, Wired, and The Atlantic.