Study Shows Pollution Increases Alzheimer’s Risk

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Three Arizona State University health economic researchers have found that living in areas with high levels of small particulates for a decade increases the risk of Alzheimer’s disease and also impairs financial decision making. We hear from one of the researchers, Jonathan Ketcham, the Earl G. and Gladys C. Davis Distinguished Research Professor in Business at ASU’S W.P. Carey School of Business.

TED: THREE ASU RESEARCHERS HAVE FOUND THAT RESIDENTS LIVING IN AREAS THAT RECORD HIGH LEVELS OF SMALL PARTICULATES HAVE AN INCREASED RISK OF DEMENTIA. JOINING US NOW IS ONE OF THOSE RESEARCHERS, JONATHAN KETCHAM, HE'S THE EARL G. AND GLADYS C. DAVIS DISTINGUISHED RESEARCH PROFESSOR AT ASU'S W.P. CAREY SCHOOL OF BUSINESS. GOOD TO SEE YOU, THANKS FOR BEING HERE.

JONATHAN: THANKS FOR HAVING ME.

TED: WHAT DID THIS STUDY EXACTLY LOOK AT?

JONATHAN: WHAT WE DID WAS WE FOLLOWED THE MEDICARE POPULATION, AGE 65 AND ABOVE, ACROSS 15 YEARS, FROM 1999 UNTIL 2013. WHAT WE COULD SEE IS WHERE PEOPLE LIVED AND WHEN THEY MOVED DIFFERENT PLACES AND WE LINKED THAT UP WITH DATA FROM THE ENVIRONMENTAL PROTECTION AGENCY THAT TOLD US THE AMOUNT OF POLLUTION AT SOMEBODY'S HOUSE. AND SO WE COULD TRACK THE AMOUNT OF POLLUTION THAT PEOPLE WERE BREATHING BASED ON WHERE THEY LIVED OVER A LONG TIME PERIOD. WE COULD ALSO SEE THEIR HEALTH CONDITIONS, WHEN THEY GOT DEMENTIA, IF THEY GOT DEMENTIA, AS WELL AS WHETHER THEY HAD HIGH BLOOD PRESSURE, IF THEY HAD DIABETES, IF THEY HAD STROKES. AND WHAT WE DID THEN WAS TO LOOK AT HOW THE LEVEL OF AIR POLLUTION AND SMALL PARTICULATES ESPECIALLY LEAD TO THE INCREASE IN RATES OF DEMENTIA.

TED: SMALL PARTICULATES. IS THAT THE KIND OF STUFF WE SEE HERE IN THE PHOENIX AREA. IN THE DESERT?

JONATHAN: WE HAVE LARGE PARTICLES, PM 10 IT’S CALLED AND THIS IS WHAT MAKES OUR BEAUTIFUL RED SUNSETS AND OCCURS VERY NATURALLY IN THE DESERT. THERE ARE SMALLER PARTICLES, KNOWN AS PM 2.5 AND THESE ARE THINGS THAT ARE LESS THAN 1/40TH OF THE DIAMETER OF A HUMAN HAIR, AND WHAT IS PARTICULARLY TROUBLING ABOUT THESE IS THEY ARE ABLE TO GET AROUND OUR BODY'S NATURAL DEFENSE SYSTEM. SO WE ARE PRETTY GOOD AT FILTERING OUT MUCH OF PM 10. OUR BUILDING ALSO FILTERS OUT PM 10. PM 2.5 BECAUSE IT’S SO SMALL AS WE INHALE IT IT CAN GO THROUGH OUR LUNGS INTO OUR BLOODSTREAM AND EVEN END UP IN OUR BRAINS.

TED: DO WE KNOW—I WAS JUST GOING TO ASK. DO WE KNOW WHY THIS WOULD BE A RISK FACTOR FOR DEMENTIA. HANGING AROUND IN YOUR BRAIN I WOULD IMAGINE IS ONE OF THEM.

JONATHAN: YEAH, THE PRECISE MECHANISMS AREN'T KNOWN, BUT THE STORY STARTS BACK IN MEXICO CITY WITH DOGS. ABOUT 15 YEARS AGO, A RESEARCHER NOTICED THAT DOGS IN MEXICO CITY WERE EXHIBITING SIGNS OF DEMENTIA SUCH AS NOT RECOGNIZING THEIR OWNERS. AND AS THESE DOGS DIED THEY DID AUTOPSIES ON THE DOGS BRAINS AND THEY FOUND THE SMALL PARTICULATES FROM THE AIR OF MEXICO CITY IN THESE DOGS BRAIN TISSUE. AND THIS RESEARCH HAS BEEN REPLICATED WITH MICE AND EXPERIENCE AND ALSO DONE ON ABOUT 70 HUMAN CADAVERS WHERE WE’VE SEEN THAT THE AIR WE BREATHE ENDS UP LODGED IN OUR BRAINS. SCIENTISTS DON’T YET KNOW WHAT EXACTLY THAT DOES OR HOW THAT WORKS BUT IT LOOKS LIKE THE SAME SYMPTOMS THAT WE SEE FOR ALZHEIMER’S.

TED: DOES THIS COINCIDE, DOES IT COUNTER AT ALL WITH THE MEDICAL LITERATURE?

JONATHAN: I THINK WHAT WE HAVE DONE IS REALLY THE FIRST LARGE-SCALE STUDY ACROSS THE WHOLE COUNTRY AT A VERY REPRESENTATIVE POPULATION ACROSS A LONG PERIOD OF TIME THAT TRIES TO GET AT WHETHER THIS IS MORE THAN JUST AN ASSOCIATION. SO WHEN WE LINKED UP OUR DATA FROM THE EPA AND FROM MEDICARE, WE COULD QUICKLY TELL THERE WAS AN ASSOCIATION OR THIS CORRELATION BETWEEN HOW MUCH AIR POLLUTION THERE WAS, AND HOW MUCH ALZHEIMER'S THERE WAS IN THOSE AREAS. NOW THE PROBLEM IS PEOPLE AREN’T CHOOSING WHERE TO LIVE OR ARE CHOOSING WHERE TO LIVE, RATHER, SO WE KNOW PEOPLE LIVE IN MORE POLLUTED AREAS MAYBE THAT HAVE PERHAPS LESS EDUCATION, LESS WEALTH AND LESS HEALTH OR POOR HEALTH FOR A VARIETY OF REASONS. SO THE CHALLENGE TO US AS RESEARCHERS IS WE'RE TRYING TO DISENTANGLE ALL OF THESE COMPETING EXPLANATIONS THAT THE MEDICAL LITERATURE IS ALREADY POINTING TO BUT HADN’T BEEN ABLE TO STUDY AT A LARGE SCALE.

TED: AND CORRECT ME IF I’M WRONG, IN READING THE LITERATURE IT SOUNDS LIKE THE RISK INCREASED BY 1.3%.

JONATHAN: YEAH, SO TO PUT THIS IN CONTEXT, WE FIND THAT A 10% INCREASE IN AIR POLLUTION IS ABOUT THE SAME AS THE ELEVATED RISK FROM HAVING HIGH BLOOD PRESSURE. TO GIVE US A SENSE OF 10%, THAT'S ABOUT THE SAME AS MOVING FROM PHOENIX TO SALT LAKE CITY WHERE SALT LAKE IS A LITTLE MORE POLLUTED THAN WE ARE. THIS IS MUCH SMALLER OF AN EFFECT THAN HAVING, SAY, DIABETES IS ABOUT THREE TIMES AS LARGE, HAVING A STROKE IS ABOUT TEN TIMES AS LARGE. SO LUNG DISEASE AND HEART DISEASE IS STILL A MUCH BIGGER RISK FACTOR THAN THESE SORT OF BETWEEN CITY DIFFERENCES IN AIR POLLUTION.

TED: LET’S TALK ABOUT SOME OF THESE CITIES. BAKERSFIELD, I TAKE IT IS LIKE GROUND ZERO FOR WHERE YOU DON'T WANT TO BE, HUH?

JONATHAN: BAKERSFIELD AND FRESNO ARE AMONG THE WORST. THERE ARE SOME PLACES THAT MAY SURPRISE LIKE IN ALASKA WHERE THEY HAVE A LOT OF WOOD SMOKE. WHERE THERE'S A LOT COAL BURNING IN THE OHIO RIVER VALLEY AND PARTS OF THE MIDWEST ARE ALSO PRETTY HIGH IN THEIR POLLUTION RATES.

TED: WHAT ABOUT PLACES WHERE THE RATES ARE RELATIVELY LOW FOR THESE PARTICULATES ESPECIALLY?

JONATHAN: YEAH, SAN FRANCISCO AND HONOLULU DO THE PREVAILING WINDS OFF THE OCEAN ARE SOME OF THE BEST BIG CITIES IN THE COUNTRY.

TED: NOW I KNOW THAT YOU ARE OBVIOUSLY FROM THE W.P. SCHOOL OF BUSINESS AND LAST I HEARD THAT IS NOT A MEDICAL SCHOOL. SO THERE’S AN ECONOMIC FACTOR TO THIS STUDY AS WELL IN TERMS OF JUST SIMPLE FINANCIAL DECISIONS.

JONATHAN: YEAH THERE’S A COUPLE OF INTERESTING THINGS THAT WE ARE BUILDING ON HERE SO PEOPLE IN BUSINESS SCHOOLS AND ECONOMIST HAVE STUDIED THE EFFECTS OF SHORT-TERM POLLUTION ON CHILDREN AND THEY FIND THAT THEY DO WORSE AT SCHOOL ON TESTS. THEY’VE DONE STUDIES IN CHINA ON ADULTS AND THEY GIVE THEM THESE POP QUIZZES ON COGNITIVE FUNCTION LIKE COUNTING BACKWARDS BY SEVEN AND FIND THAT PEOPLE DO EVEN WORSE. OTHER ECONOMISTS HAVE FOUND THAT UMPIRES MAKE EVEN WORSE DECISIONS IN BASEBALL ON MORE POLLUTED DAYS. SO THERE’S THIS WIDE-SPREAD KNOWLEDGE THAT IT DOES EFFECT YOUNGER POPULATIONS. WHAT HADN'T BEEN STUDIED IS THE ELDERLY POPULATION AND LONGER-TERM EXPOSURE, AND THAT'S WHAT WE WERE THE FIRST TO DO.

TED: AND THE EPA REGULATION—THE EPA REGULATION, THIS IS FROM THE STUDY HERE, DEMENTIA CASES AVOIDED BECAUSE OF THESE REGULATIONS.

JONATHAN: YEAH.

TED: THE GOOD THINGS -- FOLKS THAT WOULD HAVE HAD TO MENTION BUT DIDN'T, OR HADN’T AT A LATER—EQUATES TO $163 BILLION?

JONATHAN: YEAH, IT'S HARD TO GET OUR HEADS AROUND THIS. WHAT WE FIND IS THAT IN 2005 THE EPA PUT IN PLACE SOME STRICTER REGULATIONS, AND THEY DECIDED THAT SOME AREAS WERE NOT MEETING THESE REGULATIONS, SO THESE STRICTER RULES WERE PUT IN PLACE. THE LOCAL REGULATORS, THE COUNTY’S AND THE STATES WORKED TOGETHER AND WHAT WE SEE IS THAT IT ACTUALLY DID BRING AIR POLLUTION DOWN IN THOSE AREAS BY ABOUT 10% MORE THAN IT CAME DOWN EVERYWHERE ELSE. AND WE WERE ABLE TO USE OUR RESULTS TO QUANTIFY HOW BIG THE BENEFITS OF THAT WERE. AND WHAT WE FIND IS THAT THESE REGULATIONS LEAD TO 140,000 FEWER CASES OF DEMENTIA IN 2013 ALONE. TO PUT THIS IN CONTEXT, ABOUT 6 MILLION PEOPLE HAVE DEMENTIA CURRENTLY IN THE UNITED STATES. AND SO IT IS A BIG NUMBER. IT’S LOTS OF LIVES WHO BENEFITED FROM THESE REGULATIONS. AND IT'S SUCH A TERRIBLE DISEASE, SO IF WE CAN REDUCE THESE RATES, THEN I THINK THAT’S WHERE THAT HUGE DOLLAR AMOUNT COMES FROM. JUST THE QUALITY OF LIFE THAT COMES FROM NOT HAVING DEMENTIA.

TED: AND THIS HAS TO BE THE FIRST OF ITS KIND, THIS STUDY OF A STUDY, CORRECT?

JONATHAN: LIKE I SAID, THE MEDICAL RESEARCH HAS POINTED IN THIS DIRECTION BUT WE WERE THE FIRST ONES TO DO THIS ON A LARGE-NATIONAL SCALE. THE OTHER CRUCIAL PIECE WAS TO TAKE ADVANTAGE OF THIS EPA REGULATION. WHAT THIS DOES IS IT CREATES AN EXPERIMENT THAT HAPPENS ACROSS THE WHOLE COUNTRY. WHERE SOME PLACES FOUND THAT THEIR POLLUTION WAS UNEXPECTEDLY REDUCED MORE THAN OTHERS. SO THAT'S THE KIND OF VARIATION OVER TIME THAT WE'RE ABLE TO LEVERAGE TO KIND OF APPROXIMATE WHAT WE COULD DO IN A LABORATORY WITH ANIMALS, BUT ACTUALLY SEE WHAT ACTUALLY HAPPENS OUT THERE WITH PEOPLE OVER A LONG PERIOD OF TIME.

TED: WE HAVE ABOUT 30 SECONDS, SO RELATIVELY QUICKLY HERE, WHAT FURTHER RESEARCH NEEDS TO BE DONE?

JONATHAN: OH THERE IS SO MUCH MORE THAT WE WOULD LIKE TO KNOW. I THINK-- I WANT TO END ON A NOTE OPTIMISM WHICH IS WE’VE SEEN THAT PEOPLE ARE BREATHING LESS POLLUTED AIR OVER TIME. IN PHOENIX IT HAS COME DOWN BY ABOUT 40% OVER THE LAST 15 TO 20 YEARS. THAT’S TRUE NATION-WIDE. AND I'M HOPEFUL AS WE MOVE TO NATURAL GAS AND SOLAR POWERS AND MOVE TO ELECTRIC CARS THAT THAT TREND WILL CONTINUE. THERE’S HUGE VALUE AND HUGE BENEFITS AND THE BENEFITS DUE TO OUR STUDY ARE BIGGER THAN WE EVEN KNEW.

TED: JONATHAN KETCHAM, ASU. INTERESTING STUDY. THANK YOU FOR BEING HERE.

JONATHAN: APPRECIATE THE CONVERSATION.

TED: AND TUESDAY ON ARIZONA HORIZON, A CLEAN ELECTIONS DEBATE. WE'LL HEAR FROM THE TWO CANDIDATES FOR ARIZONA TREASURER. REPUBLICAN KIMBERLY YEE AND DEMOCRAT MARK MANOIL. THAT IS TUESDAY, RIGHT HERE ON "ARIZONA HORIZON." THAT IS IT FOR NOW. I'M TED SIMONS. THANK YOU SO MUCH FOR JOINING US. YOU HAVE A GREAT EVENING. ♪

Researcher, Jonathan Ketcham, the Earl G. and Gladys C. Davis Distinguished Research Professor in Business at ASU’S W.P. Carey School of Business.

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