JOHN: TONIGHT ON PBS NEWS WEEKEND, TURMOIL AT THE CDC AFTER THE DIRECTOR IS ABRUPTLY FIRED, AS HEALTH SECRETARY ROBERT F. KENNEDY JR.

EYES SWEEPING VACCINE POLICY CHANGES.

THEN, HOW AI CHATBOTS MAY BE TRIGGERING DISTORTED THOUGHTS IN USERS AND HARMING THEIR MENTAL HEALTH.

AND NEARLY A YEAR AFTER HURRICANE HELENE, WE MEET VOLUNTEERS FROM AROUND THE WORLD STILL AT WORK RESTORING THE FAMED APPALACHIAN TRAIL.

>> THE OVERRIDING THING I THINK THEY LEAVE WITH IS THE FEELING THAT THEY'RE PART OF SOMETHING THAT'S BIGGER THAN THEM.

THEY KNOW THEY'RE CONNECTED TO OTHER PEOPLE WHO CARE ABOUT THE SAME THINGS AND THAT MIGHT BE THE HIGHEST VALUE.

♪ JOHN: GOOD EVENING.

I'M JOHN YANG.

ON THIS LABOR DAY WEEKEND, THERE'S BEEN NO HOLIDAY FROM THE TURMOIL AND CONTROVERSY AT THE AGENCY IN CHARGE OF PROTECTING THE AMERICAN PUBLIC'S HEALTH.

SEVERAL CDC LEADERS HAVE RESIGNED AFTER THE WHITE HOUSE OUSTED THE AGENCY'S NEW DIRECTOR, DR. SUSAN MONAREZ, AFTER LESS THAN A MONTH IN THE POSITION.

HER LAWYERS SAY IT'S BECAUSE SHE REFUSED TO "RUBBER STAMP UNSCIENTIFIC" DIRECTIVES AND "FIRE DEDICATED HEALTH EXPERTS."

IN JUST SIX MONTHS, THE AGENCY HAS LOST NEARLY HALF ITS BUDGET, THOUSANDS OF EMPLOYEES, AND IS CAUGHT IN A POLITICAL STRUGGLE AS HEALTH SECRETARY ROBERT F. KENNEDY JR. MOVES TO RESHAPE THE NATION'S VACCINE POLICIES.

IN AN ESSAY IN THE NEW YORK TIMES THIS WEEKEND, DEMOCRATIC SENATOR BERNIE SANDERS OF VERMONT CALLED FOR KENNEDY'S RESIGNATION.

ALI ROGIN SAT DOWN WITH DR. RICHARD BESSER, WHO WAS ACTING CDC DIRECTOR IN THE OBAMA ADMINISTRATION.

HE'S NOW CEO OF THE ROBERT WOOD JOHNSON FOUNDATION WHICH, WE SHOULD NOTE, IS A FUNDER OF PBS NEWS.

ALI: DR. RICHARD BESSER, THANK YOU SO MUCH FOR JOINING US.

YOU'VE BEEN IN COMMUNICATION WITH DR. MONAREZ.

WHAT IS YOUR UNDERSTANDING OF WHAT SECRETARY KENNEDY ASKED HER TO DO THAT WAS REALLY A RED LINE FOR HER?

DR. BESSER: YEAH, IT WAS REALLY COINCIDENTAL.

SHE AND I HAD A MEETING SCHEDULED FOR WEDNESDAY.

I REACH OUT TO ALL DIRECTORS OF THE CDC TO OFFER MY SUPPORT AND SHE THANKED ME AND SAID THAT SHE DIDN'T EXPECT TO BE IN THE POSITION LONG, THAT SHE HAD TWO LINES THAT SHE WOULD NOT CROSS WHEN SHE TOOK THE JOB.

ONE WAS SHE WOULD NEVER DO ANYTHING THAT WAS ILLEGAL.

AND SHE WAS ASKED TO FIRE HER LEADERSHIP TEAM WHICH SHE FELT WAS ILLEGAL GIVEN THAT THEY WERE OUTSTANDING PUBLIC SERVANTS AND THEN THE OTHER WAS SHE WOULD NOT PROMOTE ANYTHING THAT WASN'T SUPPORTED BY THE BEST SCIENCE.

AND SHE WAS ASKED BY THE SECRETARY TO AGREE TO APPROVE ANY RECOMMENDATIONS THAT CAME OUT OF THE IMMUNIZATION ADVISORY COMMITTEE TO THE CDC.

SHE REFUSED AND EXPECTED THAT SHORTLY AFTER OUR CALL SHE WOULD BE DISMISSED.

ALI: THE OTHER CDC LEADERS WHO RESIGNED AT THE SAME TIME SHE WAS FIRED HAVE SAID THAT, SIMILARLY, THEY SIMPLY COULD NOT SERVE AT THE CDC ANY LONGER.

HOW DO YOU THINK THESE DEPARTURES ARE GOING TO AFFECT THE MISSION OF THE CDC?

DR. BESSER: IT'S GONNA HAVE A MAJOR IMPACT ON THE AGENCY.

IT HAS BEEN A VERY CHALLENGING FIVE YEARS FOR PEOPLE IN PUBLIC HEALTH.

WITH THE COVID PANDEMIC, WE SAW POLITICIZATION OF PUBLIC HEALTH LIKE WE'VE NEVER SEEN BEFORE.

AND SO THOSE WHO WERE STILL THERE FOR THIS ADMINISTRATION WERE ALREADY UNDER INCREDIBLE STRESS.

SO TO HAVE A SECRETARY COME IN AND IMMEDIATELY FIRE THOUSANDS OF FEDERAL HEALTH WORKERS, CUT FUNDING TO THE NIH, AND REALLY CONDEMN CDC AS AN INSTITUTION NOT WORTH FOLLOWING.

IT'S BEEN EXTREMELY HARD AND THESE LEADERS HAVE DONE A LOT TO HOLD MORALE TOGETHER, TO HOLD PEOPLE TOGETHER.

SO WITHOUT THEM, THE AGENCY IS DEFINITELY GOING TO BE STRUGGLING EVEN MORE.

ALI: THE FDA EARLIER THIS WEEK APPROVED COVID BOOSTERS FOR A MUCH SMALLER POPULATION OF INDIVIDUALS.

WHAT DO YOU THINK THE FUTURE OF VACCINE ACCESS IS GOING TO LOOK LIKE IN THE NEAR FUTURE, ESPECIALLY AS WE'RE ENTERING THIS NEW SCHOOL YEAR?

DR. BESSER: MANY PEOPLE'S ACCESS TO VACCINES IS DEPENDENT ON A RECOMMENDATION FROM THE CDC.

IF THE CDC DOESN'T RECOMMEND THE VACCINE, MANY INSURANCE COMPANIES ARE NOT GOING TO PAY FOR IT.

THERE'S AN INCREDIBLE PROGRAM IN AMERICA CALLED THE VACCINE FOR CHILDREN PROGRAM, AND IT ENSURES THAT EVERY CHILD HAS ACCESS TO RECOMMENDED VACCINES.

IT'S WONDERFUL AND IT ELIMINATED ANY KIND OF DISPARITIES FOR VACCINES BY INCOME.

WITHOUT A CDC RECOMMENDATION FOR VACCINATION FOR ALL CHILDREN, MANY CHILDREN ARE NOT GONNA BE ABLE TO GET THE VACCINE AND YOUR ABILITY TO GET IT WILL DEPEND ON YOUR INCOME.

THAT'S ABSOLUTELY WRONG.

WE'RE GONNA NEED THE STATES TO STEP UP AND FILL SOME OF THOSE GAPS.

AND THERE'S ABSOLUTELY NO WAY THAT THE STATES CAN REPLACE THE MASSIVE FEDERAL FUNDING THAT WENT INTO OUR VACCINE SYSTEM.

ALI: WHAT DOES THIS SAY TO YOU ABOUT THE ABILITY OF THE UNITED STATES TO WHETHER ANOTHER PUBLIC HEALTH EMERGENCY, SUCH AS ANOTHER PANDEMIC?

DR. BESSER: YOU KNOW, WE ARE AT RISK FOR SO MANY DIFFERENT REASONS.

MOST OF THE MONEY THAT COMES TO CDC GOES THROUGH TO STATE AND LOCAL PUBLIC HEALTH DEPARTMENTS, AND THERE HAVE BEEN BIG CUTS THERE.

THE AGENCY IS GOING TO BE LED BY AN INDIVIDUAL WITH NO PUBLIC HEALTH EXPERIENCE.

YOU KNOW, I SERVED AS THE ACTING DIRECTOR AT THE CDC FOR AN IMPORTANT REASON.

I HAD SPENT FOUR YEARS RUNNING EMERGENCY PREPAREDNESS AND RESPONSE FOR THE AGENCY.

YOU NEVER CAN PREDICT WHEN THERE'S GOING TO BE A PUBLIC HEALTH EMERGENCY.

AND DURING MY TENURE, THAT'S WHEN THE H1N1 SWINE FLU PANDEMIC STARTED.

WE NOW HAVE IN MR. O'NEILL, AN INDIVIDUAL WHO DOESN'T KNOW THE AGENCY AND DOESN'T KNOW PUBLIC HEALTH RESPONSE.

SO IF THERE IS A PANDEMIC, IF THERE IS A NEW THREAT TO PEOPLE'S HEALTH, I HAVE ABSOLUTELY NO CONFIDENCE THAT HE'S GOING TO BE ABLE TO MANAGE THAT APPROPRIATELY.

ALI: AND TO THAT END, JIM O'NEILL, AS YOU SAID, HAS NO MEDICAL BACKGROUND.

HE HAS SERVED AT HHS BEFORE.

DURING HIS HEARING, HE SAID THAT HE WAS PRO-VACCINE, BUT ANTI-MANDATES.

WHAT DO YOU THINK OF HIS ABILITY TO STEWARD THIS AGENCY AT THIS TIME IN GENERAL?

DR. BESSER: WHEN SOMEONE SAYS THEY'RE ANTI-MANDATES, I WANT TO EXPLORE THAT FURTHER.

AS A PEDIATRICIAN, I KNOW THAT ONE OF THE WONDERFUL THINGS FOR A NEW PARENT WHEN THEY'RE SENDING THEIR CHILD TO SCHOOL IS THAT THEY KNOW THAT THE OTHER CHILDREN IN THE CLASSROOM WILL BE VACCINATED.

THAT'S A VACCINE MANDATE.

I WORRY THAT THIS IS A SECRETARY WHO'S GOING TO BRING THOSE THOSE REQUIREMENTS INTO QUESTION, HE'S GOING TO CHALLENGE MORE AND MORE OF THE CHILDHOOD VACCINES THAT HAVE ELIMINATED IN OUR COUNTRY SO MANY DISEASES THAT CAUSE HAVOC AROUND THE WORLD.

ALI: SOME OF THE DEPARTING LEADERS HAVE SAID THAT THEY FEAR THAT THE CDC IS NOW BROKEN BEYOND REPAIR.

WHAT DO YOU MAKE OF THAT?

DR. BESSER: WELL, IT IS BROKEN.

I DON'T AGREE WITH THE BEYOND REPAIR, BUT IT WILL TAKE CONGRESS STEPPING UP AND SAYING THAT THIS IS NOT A GOOD THING FOR OUR NATION.

IT IS A DANGEROUS SITUATION THAT WILL AFFECT EVERY PART OF OUR COUNTRY.

RURAL COMMUNITIES ACROSS AMERICA WILL BE HIT VERY HARD BY THIS DECIMATION OF OUR PUBLIC HEALTH SYSTEM.

AND WE NEED OUR ELECTED OFFICIALS TO SAY, THIS IS NOT WHAT WE WANT TO SEE FOR AMERICA.

THIS IS ABSOLUTELY UNACCEPTABLE.

ALI: RICHARD BESSER, THANK YOU SO MUCH FOR JOINING US.

DR. BESSER: THANK YOU VERY MUCH, I APPRECIATE IT.

JOHN: AND IN TODAY'S OTHER NEWS, ISRAELI FORCES POUNDED THE AREA AROUND GAZA CITY OVERNIGHT, DESTROYING HOMES AND SENDING MORE PEOPLE LOOKING FOR A SAFE - - MORE PEOPLE FLEEING.

THE AREA'S LARGEST HOSPITAL SAID 29 BODIES WERE BROUGHT TO ITS MORGUE, INCLUDING TEN PEOPLE WHO WERE SEEKING AID.

THE ISRAELI MILITARY HAS STOPPED PAUSING FIGHTING TO ALLOW FOOD DELIVERIES AS THEY RAMP UP THEIR OFFENSIVE AGAINST HAMAS.

ISRAEL ALSO SAID THAT A TARGETED OPERATION HAD KILLED A LONGTIME SPOKESMAN FOR HAMAS'S MILITARY WING.

IN UKRAINE, 60,000 PEOPLE ARE WITHOUT ELECTRICITY AFTER RUSSIA STRUCK POWER FACILITIES ACROSS THE COUNTRY.

IN RECENT WEEKS, BOTH SIDES HAVE INCREASINGLY TARGETED ENERGY AND FUEL INFRASTRUCTURE AS THEY INTENSIFY THEIR AIR STRIKES.

UKRAINIAN PRESIDENT VOLODYMYR ZELENSKYY VOWED TO RETALITE WITH STRIKES DEEP INSIDE RUSSIA.

AND EUROPEAN LEADERS ARE WORKING ON PLANS TO SEND THOUSANDS OF TROOPS TO UKRAINE AS PART OF POST-CONFLICT SECURITY GUARANTEES.

EUROPEAN COMMISSSION PRESIDENT URSULA VAN DER LEYEN TOLD THE FINANCIAL TIMES IT WOULD BE A MULTINATIONAL FORCE.

SHE SAID PRESIDENT TRUMP HAS AGREED TO PROVIDE TECHNOLOGICAL AND INTELLIGENCE SUPPORT.

EU AND U.S. SECURITY GUARANTEES ARE ONE OF THE CONDITIONS ZELENSKYY HAS SET FOR ANY PEACE AGREEMENT.

FORMER NEW YORK MAYOR RUDY GIULIANI IS RECOVERING IN A NEW HAMPSHIRE HOSPITAL FROM SERIOUS INJURIES HE SUFFERED IN A CAR CRASH LATE SATURDAY EVENING.

A SPOKESMAN SAID GIULIANI FRACTURED A VERTEBRAE AND HAD MULTIPLE CUTS AND BRUISES.

THE SPOKESMAN SAID GIULIANI'S RENTAL CAR WAS HIT FROM BEHIND AT HIGH-SPEED.

TODAY WAS THE FIRST SUNDAY MASS OF THE ANNUNCIATION CATHOLIC CHURCH IN MINNEAPOLIS SINCE AN ATTACK KILLED TWO CHILDREN AND WOUNDED 20 OTHERS.

OUTSIDE, WELL-WISHERS LEFT FLOWERS AND MESSAGES.

THE REVEREND DENNIS ZEHREN WAS AT THE CHURCH DURING THE WEDNESDAY ATTACK.

>> IT'S BEEN A TREMENDOUS OUTPOURING OF LOVE.

IT'S KIND OF A FUNNY MYSTERY, WHEN THE DARKNESS IS ITS MOST INTENSE, THAT'S WHEN THE LIGHT OF GOD SHINES ALL THE MORE BRIGHTLY.

AND WE'VE BEEN SEEING THAT IN SO MANY WAYS.

I'VE NEVER SEEN SUCH AN OUTPOURING OF LOVE.

JOHN: AT THE VATICAN, POPE LEO PRAYED FOR THE VICTIMS AND CALLED FOR AN END TO WHAT HE TERMED "THE PANDEMIC OF ARMS, LARGE AND SMALL, WHICH INFECTS OUR WORLD."

AND CROWDS HAVE FLOCKED TO A MUSEUM IN NORTHERN FRANCE THIS WEEKEND TO SEE THE FAMED BAYEUX TAPESTRY BEFORE IT GOES ON LOAN TO THE BRITISH MUSEUM IN LONDON.

THE 76-YARD LONG MASTERPIECE TELLS THE STORY OF WILLIAM THE CONQUEROR'S INVASION OF ENGLAND IN 1066.

CRITICS IN FRANCE FEAR THE TAPESTRY, WHICH IS ACTUALLY EMBROIDERED, IS TOO FRAGILE TO BE SAFELY MOVED SUCH A LONG DISTANCE.

IT WILL BE THE FIRST TIME THE TAPESTRY HAS RETURNED TO ENGLAND IN NEARLY 1,000 YEARS.

STILL TO COME ON PBS NEWS WEEKEND, HOW AI CHATBOTS MAY BE AFFECTING MENTAL HEALTH.

AND THE HEAD OF THE WORLD FOOD PROGRAMME ON THE DEVASTATING HUMANITARIAN CRISIS IN SUDAN.

OHN: FIRST, WE SHOULD WARN YOU THAT THIS STORY DISCUSSES SUICIDE.

THIS PAST WEEK, THE PARENTS OF A 16-YEAR-OLD WHO TOOK HIS OWN LIFE FILED A WRONGFUL DEATH SUIT AGAINST OPEN AI, WHICH OWNS CHATGPT.

THEY SAY THAT AFTER THEIR SON EXPRESSED SUICIDAL THOUGHTS, CHATGPT BEGAN DISCUSSING WAYS HE COULD END HIS LIFE.

THE LAWSUIT IS ONE OF THE FIRST OF ITS KIND BUT THERE HAVE BEEN A NUMBER OF REPORTS ABOUT PEOPLE DEVELOPING DISTORTED THOUGHTS OR DELUSIONAL BELIEFS TRIGGERED BY INTERACTIONS WITH AI CHATBOTS.

THE REPERCUSSIONS CAN BE SEVERE, CAUSING SOME USERS TO EXPERIENCE HEIGHTENED ANXIETY, AND IN EXTREME CASES, TO HARM THEMSELVES OR OTHERS.

IT'S BEEN DUBBED AI PSYCHOSIS.

DR. JOSEPH PIERRE IS A CLINICAL PROFESSOR IN PSYCHIATRY AT THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO.

DR. PIERRE, THIS IS NOT AN OFFICIAL DIAGNOSIS YET.

IT'S NOT IN ANY DIAGNOSTIC MANUALS.

HOW DO YOU DEFINE AI PSYCHOSES?

DR. PIERRE: WELL, PSYCHOSIS IS A TERM THAT ROUGHLY MEANS THAT SOMEONE HAS LOST TOUCH WITH REALITY.

AND THE USUAL EXAMPLES THAT WE ENCOUNTER IN PSYCHIATRIC DISORDERS ARE EITHER HALLUCINATIONS WHERE WE'RE SEEING OR HEARING THINGS THAT AREN'T REALLY THERE, OR DELUSIONS, WHICH ARE FIXED FALSE BELIEFS, LIKE FOR EXAMPLE, THINKING THE CIA IS AFTER ME.

AND MOSTLY WHAT WE'VE SEEN IN THE CONTEXT OF AI INTERACTIONS IS REALLY DELUSIONAL THINGS.

SO THESE ARE DELUSIONS THAT ARE OCCURRING IN THIS SETTING OF INTERACTING WITH AI CHATBOTS.

JOHN: ARE SOME PEOPLE MORE SUSCEPTIBLE TO THIS THAN OTHERS?

DR. PIERRE: WELL, THAT'S REALLY THE MILLION DOLLAR QUESTION.

I DISTINGUISH BETWEEN AI ASSOCIATED PSYCHOSIS, WHICH JUST MEANS THAT WE'RE SEEING PSYCHOTIC SYMPTOMS IN THE CONTEXT OF AI USE.

BUT I ALSO TALK ABOUT AI EXACERBATED PSYCHOSIS OR AI INDUCED PSYCHOSIS.

SO THE REAL QUESTION IS, IS THIS HAPPENING IN PEOPLE WITH SOME SORT OF PREEXISTING MENTAL DISORDER OR MENTAL HEALTH ISSUE AND THE AI INTERACTION IS JUST FUELING THAT OR MAKING IT WORSE?

OR IS IT REALLY CREATING PSYCHOSIS IN PEOPLE WITHOUT ANY SIGNIFICANT HISTORY?

AND I THINK THERE'S EVIDENCE TO SUPPORT THAT BOTH ARE HAPPENING.

PROBABLY IT'S MUCH MORE COMMON THAT IT'S A WORSENING OR EXACERBATING EFFECT.

JOHN: TELL US A LITTLE BIT ABOUT WHAT YOU SEE IN YOUR PRACTICE.

ARE YOU SEEING PEOPLE COMING IN TO TALK ABOUT THIS?

DR. PIERRE: I HAVE SEEN A HANDFUL OF CASES.

I PRIMARILY WORK IN A HOSPITAL, SO THE PATIENTS THAT I'VE SEEN ARE PATIENTS WHO HAVE BEEN ADMITTED.

AND AS I SUGGESTED BEFORE, SOME OF THEM ARE PEOPLE WHO HAVE OBVIOUS AND LONG-STANDING MENTAL ILLNESS WHO NOW HAVE DEVELOPED A WORSENING OF SYMPTOMS IN THE CONTEXT OF AI USE.

I HAVE A FEW CASES OF PEOPLE WITHOUT ANY SUBSTANTIAL MENTAL HEALTH ISSUES PRIOR TO BEING HOSPITALIZED ALSO.

JOHN: I WANNA TALK ABOUT THAT SECOND CATEGORY.

HOW COMMON IT IS AMONG PEOPLE WHO DON'T HAVE AN EXISTING PSYCHOLOGICAL OR MENTAL PROBLEM GETTING CAUGHT IN WITH CHATBOTS?

DR. PIERRE: I HAVE TO THINK THAT IT'S ACTUALLY FAIRLY RARE.

I MEAN, IF YOU THINK ABOUT HOW MANY PEOPLE USE CHATBOTS, THAT, OF COURSE, IS A LARGE, LARGE NUMBER OF PEOPLE.

AND WE'VE ONLY SEEN REALLY A FAIRLY SMALL HANDFUL OF CASES REPORTED IN MEDIA.

THOSE OF US IN CLINICAL PRACTICE ARE STARTING TO NOTICE THIS MORE AND MORE.

SO I DON'T THINK IT'S A HUGE RISK IN TERMS OF THE NUMBER OF THE PEOPLE.

TYPICALLY, THIS OCCURS IN PEOPLE WHO ARE USING CHAT BOTS FOR HOURS AND HOURS ON END, OFTEN TO THE EXCLUSION OF HUMAN INTERACTION, OFTEN TO EXCLUSION OF SLEEP OR EVEN EATING.

AND SO IT REALLY, I THINK, IS A KIND OF DOSE EFFECT THAT WE'RE SEEING.

JOHN: WE REACHED OUT TO CHAT GPT, AND HERE'S PART OF WHAT THEY TOLD US.

THEY SAID CHATGPT INCLUDES SAFEGUARDS, SUCH AS DIRECTING PEOPLE TO CRISIS HELPLINES AND REFERRING THEM TO REAL-WORLD RESOURCES.

WHILE THESE SAFEGUARDS WORK BEST IN COMMON SHORT EXCHANGES, WE'VE LEARNED OVER TIME THAT THEY CAN SOMETIMES BECOME LESS RELIABLE IN LONG INTERACTIONS WHERE PARTS OF THE MODEL'S SAFETY TRAINING MAY DEGRADE.

HOW MUCH OF THIS IS THE RESPONSIBILITY, DO YOU THINK, OF THE AI COMPANIES, AND ARE THEY DOING ENOUGH?

DR. PIERRE: WELL, I THINK OF IT AS A SORT OF SHARED RESPONSIBILITY, JUST LIKE FOR ANY CONSUMER PRODUCT.

I THINK THERE'S A RESPONSIBILITY ON THE MAKER AND THERE'S RESPONSIBILITY FOR US AS CONSUMERS ON HOW WE UTILIZE THESE PRODUCTS.

SO I CERTAINLY THINK THAT THIS IS A NEW PHENOMENON THAT DESERVES ATTENTION AND THAT THE COMPANIES OUGHT TO BE THINKING ABOUT HOW TO MAKE A SAFER PRODUCT OR PERHAPS HAVE WARNING LABELS OR WARNINGS ABOUT WHAT INAPPROPRIATE USE MIGHT LOOK LIKE.

UNFORTUNATELY, WE DID SEE SOME EVIDENCE OF OPENAI DOING THAT, TRYING TO MAKE A NEW VERSION OF THEIR CHATBOT THAT MIGHT CARRY LESS OF THIS RISK.

AND WHAT WE SAW WAS THAT CONSUMERS, THERE WAS A BACKLASH.

CONSUMERS ACTUALLY DIDN'T LIKE THE NEW PRODUCT BECAUSE IT WAS LESS WHAT WE CALL SYCOPHANTIC.

IT WAS LESS AGREEABLE.

IT WASN'T VALIDATING PEOPLE AS MUCH.

BUT THAT SAME QUALITY IS, I THINK, UNFORTUNATELY, WHAT PUTS SOME PEOPLE AT RISK.

JOHN: WHAT ADVICE DO YOU GIVE PEOPLE WHO INTERACT WITH THESE CHAT BOTS TO AVOID THIS?

DR. PIERRE: WELL, WHAT I'VE NOTICED IS THERE'S SORT OF TWO, LET'S CALL THEM RISK FACTORS THAT I'VE SEEN PRETTY CONSISTENTLY ACROSS CASES.

ONE I ALLUDED TO EARLIER, IT'S THE DOSE EFFECT.

IT'S HOW MUCH ONE IS USING.

I CALL THIS IMMERSION.

SO IF YOU'RE USING SOMETHING FOR HOURS AND HOURS ON END, THAT'S PROBABLY NOT A GOOD SIGN.

THE OTHER ONE IS SOMETHING THAT I CALL DEIFICATION, WHICH IS JUST A FANCY TERM THAT MEANS THAT SOME PEOPLE WHO INTERACT WITH THESE CHATBOTS REALLY COME TO SEE THEM AS THESE SUPERHUMAN INTELLIGENCES OR THESE ALMOST GOD-LIKE ENTITIES THAT ARE ULTRA-RELIABLE.

AND THAT'S SIMPLY NOT WHAT CHATBOTS ARE.

THEY'RE DESIGNED TO REPLICATE HUMAN ACTION, BUT THEY'RE NOT ACTUALLY DESIGNED TO BE ACCURATE.

AND I THINK IT'S VERY IMPORTANT FOR CONSUMERS TO UNDERSTAND THAT THAT'S A RISK OF THESE PRODUCTS.

THEY'RE NOT ULTRA RELIABLE SOURCES OF INFORMATION.

THAT'S NOT WHAT THEY'RE BUILT TO BE.

JOHN: DR. JOSEPH PIERRE FROM THE UNIVERSITY OF CALIFORNIA, SAN FRANCISCO, THANK YOU VERY MUCH.

DR. PIERRE: THANK YOU.

♪ OHN: THE INTERNATIONAL RESCUE COMMITTEE ESTIMATES THAT WORLDWIDE, COUNTRIES WITH ABOUT 11% OF THE WORLD'S POPULATION ACCOUNT FOR A STAGGERING 82% OF PEOPLE NEEDING HUMANITARIAN AID.

WILLIAM BRANGHAM SPOKE WITH CINDY MCCAIN, HEAD OF THE UN'S WORLD FOOD PROGRAM, ABOUT THE WORLD'S LARGEST, AND OFTEN OVERLOOKED, HUMANITARIAN CRISIS.

WILLIAM: CINDY MCCAIN, I JUST WANT TO ASK YOU A LITTLE BIT ABOUT WHAT IS HAPPENING IN SUDAN, WHICH, WHILE MANY EYES ARE ON GAZA, SUDAN IS PERHAPS AN EVEN GREATER CIRCUMSTANCE THERE.

WE KNOW THAT 14 MILLION PEOPLE AND MORE HAVE BEEN DISPLACED.

IT IS ONE OF THE WORST CRISES IN THE WORLD TODAY.

CAN YOU TELL US A LITTLE BIT ABOUT WHAT IS GOING ON THERE FROM YOUR POINT OF VIEW?

CINDY: WELL, IT IS, AS YOU JUST SAID, THE LARGEST HUMANITARIAN CRISIS ON THE PLANET.

AND, YOU HAVE PEOPLE BEING PUSHED BACK AND FORTH BY VARIOUS FACTIONS THAT ARE HAPPENING COMBINED WITH WHAT WE CALL THE LEAN SEASON, WHICH BRINGS HUGE AMOUNTS OF RAINS, WHICH ARE ALSO DEVASTATING.

AND YOU'VE GOT THE REBELS ROLLING -- ROAMING AROUND MAKING SURE THAT PEOPLE CAN'T EAT.

THERE IS FAMINE IN SUDAN.

AND, QUITE FRANKLY, THE WORLD ISN'T PAYING ATTENTION TO IT AT ALL.

THE FOCUS IS ON GAZA, AND I WISH PEOPLE WOULD PAY CLOSER ATTENTION ALSO TO SUDAN AND TO SOUTH SUDAN.

WILLIAM: ARE YOU ABLE TO OPERATE THERE IN ANY CAPACITY THAT YOU FEEL IS SUFFICIENT?

CINDY: WELL, WE'RE OPERATING, BUT NOT AS WHAT I FEEL IS SUFFICIENT.

WE ARE OPERATING.

IT IS, AS YOU KNOW, IS VERY CHALLENGING THERE, NOT JUST BECAUSE OF THE THE POLITICAL ELEMENTS AND ALL THE ELEMENTS THAT ARE CAUSING SO MUCH OF THIS, BUT ALSO FROM A, FROM A JUST OPERATIONS STANDPOINT, TRYING TO GET TRUCKS IN AND TRYING TO GET THE COMMODITIES IN THAT WE NEED TO DO.

THE DARFUR REGION IS DEVASTATED FROM ALL OF THIS.

IT'S IMPERATIVE THAT WE, PUSH FOR THIS.

THE FUNDING CUTS HAVE REALLY, REALLY HAD A REAL DAMPER ON ALL OF THIS, BECAUSE WE DO NEED MONEY TO BE ABLE TO OPERATE THERE.

AND WE DON'T HAVE IT THE WAY WE USED TO.

BUT WE CANNOT FORGET THIS REGION.

WE CANNOT FORGET THESE PEOPLE EITHER.

AND AS I SAID, THEY ARE THERE.

IT'S DEVASTATING THERE, WHAT'S HAPPENING AND WHAT WHAT COULD HAPPEN IF WE DON'T GET MORE AID IN.

WILLIAM: UNICEF RECENTLY SAID THAT AFTER THESE 500 DAYS OF SIEGE, THAT THE CHILDREN IN AL-BASHIR IN PARTICULAR ARE SUFFERING MASS DISPLACEMENT, DEADLY VIOLENCE STILL GOING ON.

ARE YOU ABLE TO OPERATE IN THAT REGION SPECIFICALLY?

CINDY: YES, WE ARE IN SEVERAL OF THE REGIONS, MORE THAN SEVERAL, ACTUALLY.

BUT I'LL BE HONEST WITH YOU, IT DEPENDS ON THE DAY.

DEPENDS ON, YOU KNOW, WHAT'S HAPPENING FROM A SECURITY STANDPOINT AROUND THERE.

WE DO THE VERY BEST WE CAN.

AS I'VE SAID BEFORE, OUR PEOPLE ARE EXTRAORDINARILY GOOD AT WHAT THEY DO, AND THEY'RE VERY EXPERIENCED IN THESE PARTICULAR REGIONS.

WE CAN DO THE THINGS, YOU KNOW, WE WE DO GET IN.

WE DON'T GET IN ENOUGH.

AS I SAID, IN SOME CASES WE DON'T GET IN AT ALL.

IT JUST DEPENDS ON THE REGION, DEPENDS ON THE DAY.

WILLIAM: I MEAN, APART FROM THE VIOLENCE COMING TO AN END, AND I KNOW THAT'S SOMETHING THAT YOU AND FEW OTHER GOVERNMENTS HAVE ANY CONTROL OVER.

WHAT ELSE DO YOU NEED TO HAVE HAPPEN THERE IN ORDER TO HELP ALL OF THESE DESPERATE PEOPLE?

CINDY: WELL, WE NEED TO BE ABLE TO GET FOOD IN AT SCALE, AS I MENTIONED, AND NOT JUST IN THE REGION, BUT ALL AROUND THE COUNTRY.

PEOPLE JUST DON'T HAVE ACCESS.

AND BECAUSE OF THE INFLUENCE OF CLIMATE CHANGE AND ALL THE OTHER ELEMENTS THAT I MENTIONED EARLIER, THEY DON'T HAVE THE ABILITY TO REALLY BE RESILIENT AND GROW THEIR OWN FOOD IN MANY CASES.

IT'S KIND OF A PERFECT STORM OF DISASTER IN TERMS OF THE INABILITY FOR THESE PEOPLE TO FUNCTION IN A NORMAL WAY WITH REGARDS TO FOOD, AND BE ABLE TO MOVE AROUND IN NORMAL WAYS.

WE NEED TO GET IN AND MAKE SURE WE CAN FEED AT SCALE AND MAKE SURE THAT WE CAN CONTINUE TO FEED AND SCALE.

IT'S DEVASTATING TO WATCH, THE CHILDREN ARE THE MOST VULNERABLE IN ALL OF THIS.

WILLIAM: ALL RIGHT.

THAT IS CINDY MCCAIN, THE HEAD OF THE WORLD FOOD PROGRAM.

THANK YOU SO MUCH FOR BEING HERE.

CINDY: THANK YOU.

MY PLEASURE.

OHN: LAST FALL'S HURRICANE HELENE WAS A STORM OF SUPERLATIVES, NOT ONLY WAS IT THE STRONGEST EVER TO HIT FLORIDA'S BIG BEND REGION, ONCE OVER LAND, IT BROUGHT HISTORIC RAINFALL AND RECORD-BREAKING FLOODING ACROSS THE SOUTHEAST.

IN THE IMMEDIATE AFTERMATH, 430 MILES OF THE FAMED APPALACHIAN TRAIL WERE CLOSED, AS DOWNED TREES BLOCKED FOOTPATHS AND BRIDGES WERE WASHED AWAY.

NOW, MONTHS OF LABOR BY VOLUNTEER WORK CREWS HAS BROUGHT THAT DOWN TO JUST FIVE MILES.

ACROSS THE SOUTHEAST, HURRICANE HELENE'S DEVASTATION LINGERS.

>> I HAVE LIVED IN THE MIDDLE EAST FOR MANY YEARS, AND THIS IS WORSE THAN ANY WAR THAT I'VE BEEN IN.

IT'S HORRENDOUS.

JOHN: ON THE APPALACHIAN TRAIL IN NORTHEASTERN TENNESSEE, FALLEN TREES AND OTHER DEBRIS STILL BLOCK FOOTPATHS.

FOR THE PAST 11 MONTHS, AT LEAST 2,000 VOLUNTEERS HAVE WORKED TO CLEAR THOSE OBSTACLES.

THEY'RE FROM GROUPS THAT MAINTAIN THE TRAIL, INCLUDING THE APPALACHIAN TRAIL CONSERVANCY, WHICH IS RESPONSIBLE FOR ITS DAY-TO-DAY MANAGEMENT.

>> THERE ARE NUMEROUS PLACES WHERE TREES USED TO STAND AND THEIR ROOTS WERE IN THE GROUND AND THE ROOTS GOT PULLED UP AND HAVE LEFT A LARGE HOLE IN THE MIDDLE OF THE APPALACHIAN TRAIL.

JOHN: THE TRAIL WAS PROPOSED IN 1921, BUILT BY PRIVATE CITIZENS, AND COMPLETED IN 1937.

IT STRETCHES NEARLY 2200 MILES, WINDING THROUGH 14 STATES FROM MAINE TO GEORGIA.

IT PASSES THROUGH EIGHT NATIONAL FORESTS, SIX SITES IN THE NATIONAL PARK SYSTEM AND TWO NATIONAL WILDLIFE REFUGES.

EACH YEAR, MORE THAN 3 MILLION VISITORS FROM AROUND THE WORLD WALK AT LEAST PART OF THE TRAIL.

>> THE APPALACHIAN TRAIL IS THIS AMAZING WAY TO CONNECT FOLKS.

IT CAN BE SOMEBODY WHO'S, YEAH, WANTING TO HIKE FROM GEORGIA TO MAINE, AND IS GOING TO DO THAT IN ONE SUMMER OR IT'S SOMEBODY WHO'S NEVER STEPPED FOOT ON A TRAIL.

JOHN: THESE DAYS, USING THE TRAIL REQUIRES A BIT OF PLANNING.

SECTIONS ARE EXPECTED TO BE CLOSED FOR THE FORESEEABLE FUTURE.

MATT PERRENOD OF THE APPALACHIAN TRAIL CONSERVANCY SAYS NOT ALL THE WORK IS BEING DONE BY VOLUNTEERS.

>> THE VAST MAJORITY OF WORK GETS DONE BY THE VOLUNTEERS.

HOWEVER, WE CAN'T IGNORE ALL THE OTHER PARTNERS AROUND LIKE THE FOREST SERVICE PEOPLE THAT HELPED GET OUR GEAR UP WHO PAY ATTENTION TO THIS TRAIL DAY IN AND DAY OUT.

SO THERE IS AN ENTIRE INFRASTRUCTURE BUILT AROUND THAT VOLUNTEER EXPERIENCE AND THEN VOLUNTEERS PROVIDE A LOT OF MUSCLE.

JOHN: THE WORK IS ALL DONE BY HAND.

THERE IS NO HEAVY EQUIPMENT.

IT'S TIME-CONSUMING AND THE PROGRESS IS INCREMENTAL.

AMONG THOSE PITCHING IN IS A GROUP FROM JAPAN.

THEY SAY THEY ARE MOTIVATED BY THE GLOBAL RESPONSE TO THE 2011 FUKASHIMA EARTHQUAKE AND TSUNAMI.

THEY ARE EAGER TO TAKE WHAT THEY LEARN HERE BACK HOME.

>> WE ALL WORK FOR JAPANESE LONG DISTANCE TRAIL.

BUT THE HISTORY IS QUITE NEW IN JAPAN, SO NOW WE ARE TRYING TO LEARN HOW TO MAINTAIN MAINTAIN - - HOW TO MAINTAIN AND HOW TO MAKE IT SUSTAINABLE.

JOHN: THE VOLUNTEERS MAY NOT BE GETTING A PAYCHECK FOR THEIR LABORS, BUT PERRENOD HOPES THEY FEEL THAT THEY ARE BEING COMPENSATED IN ANOTHER WAY.

>> THE OVERRIDING THING I THINK THEY LEAVE WITH IS A FEELING THAT THEY'RE PART OF SOMETHING THAT'S BIGGER THAN THEM.

AND THEY KNOW THEY ARE CONNECTED TO OTHER PEOPLE WHO CARE ABOUT THE SAME THING.

PEOPLE LEAVE WITH THAT AND THAT MIGHT BE THE HIGHEST VALUE.

♪ JOHN: THAT IS PBS NEWS WEEKEND FOR THE I'M JOHN YANG.

SUNDAY.

FOR ALL OF MY COLLEAGUES, THANKS FOR JOINING US.

HAVE A GOOD LABOR DAY AND A GOOD WEEK.