duaptioning sponsored by newshour proions, llc >> woodruff: good evening. i'm judy woodrufew on theour tonight: vote 2018. the major primary elections are over. progressive and pro-trump candidates win, setting up big isallenges in november. then, venezula in . as citizens flee the country's dire economics, refugees arriving in neighboring countries are adding to regional tensions. and, on "the leading edge of science," regulatingcides known to cause brain damage in young people. >> we knew we had a chemical that was worthy of taking a loot , if we're concerned about its potential adverse effects. >> woodruff: all that and more, on tonight's pbs newshour.

>> major funding for the pbs newshour has been provided : >> babbel. a language program that teaches real-life convsations in a new language, like spanish, french, german, italian, and more. babbel's teno 15 minute lessons are available as an app, or online. more information on babbel.com. >> consumer cellular. >> financial services firm raymond james. >> supporting social entrepreneurs and their solutions to the world's most pressing problems--nd skollfion.org. >> the lemelson foundation. committed to improving lives through invention, in the u.s. and developing countries. on the web at lemelson.org.

>> supported by the john d. and catherine t. macarthur foundation. committed to building a more just, verdant and peaceful world. more information at macfound.org >> and with the ongoing support of these institutions: >> this program was made possible by the corporation for public broadcasting. and by contributionsur pbs station from viewers like you. thank you. >> woodruff: from president trump today, word that white house counsel don mcgahn is leaving his post. he will step down this fall, after an expected senate vote to confirm supreme court nominee brett kavanaugh. investigators with special counsel robert mueller have interviewed mcgahn at length. the presidentoday dismissed talk that he might have a problem with what mcgahn told them. >> any concern about what he's said to the mueller team? >> no. i knew h was going.

also, as you know, i had to approve it. we didn't claim executive-- ( crosstalk ) >> are you aware of what he said? >> no. i don't have to be aware. we do everything straight, we do evonything by the book, and, is an excellent guy. >> woodruff: the chair of the senate judiciary committee, republican chuck grassley, voiced concern about mcgahn leaving. in a tweet aimed at the president, he said, "you can't let at happen." the president today hailed tuesday's republican primary winners. in florida, g.o.p. congressman ron desantis will face democrat andrew gillum for governor. would beahassee mayo the state's first black chief executive. and in arizona, republican congresswoman martha mcsally will run against democratic congresswoman kyrsten sinema to replace retiring u.s. senator jeff flake. we will have a full report, after the news summary. the arizona candidates held off campaigning today as final tributes ban for the late

senator john mccain. a military honor guard greeted e e hearse that carried mccain's casket to the stpitol in phoenix. governor doug cey was among those who spoke at a brief ceremony. >> john mcca was about more than politics. he brought us abovpolitics. john is probably the only politician who could gets to set aside politics and come together as a state and nation, as we have. >> woodruff: afterward, mccain's widow, cindy, and their childre spent privments by the casket, before the public was admitted to pay their respects. the senator died saturday of brain cancer. he would have been 82, today. a white former polexe officer in could get 99 years in prison in the death of jordan edwards, a 15-year-old black youth.

roy oliver was found guilty of murder yesterday by a mostly white jury in dallas county. he claimed he fired into a car of black teens to protect his partner, but the partner testified he had not feared for his life. oliver was fired within days of the shooting in 2017. the united nations human rights office accused nicaragua's government today of a sweeping campaign againstes political pr. it described arrests, torture and other efforts to silence dissidents. more than 300 have died in the violence since april. in geneva, the u.n. human rights chief id it's time to intervene. >> repressioand retaliation against demonstrators continue in nicaragua, as the world looks aw. the violence and impunity of these past four months hav exposed the fragility of the countries, institutions,nd the rule of law, and created a climate of fear and mistrust, and just the numbers of those leaving nicaragua is testimony

to that. >> woodruff: the nicaraguan epgovernment dismissed thet and denied the accusations of excessive force. more than two dozen human rights groups are urging google not to censor its internet searches in china. therhave been reports that the tech giant plans to build a search eine compliant with chinese government restrictions. in a joint letter, the human rights groups say that would be "an alarming capitulation on human rights." google denies it is close to launching any such product. on wall street today, the dow jones industrial average gained 60 points to close at 26,124. r the nasde 79 points, and the s&p 500 added 16. and, this was the second and final day of the late aretha franklin's public viewing in deoit. thousands have filed past the casket at the charles h. wririt museum of n american history.

the funeral for the legendary singer takes place tomorrow.l st come on the newshour: takeaways from the primaries in arizona and florida, and looking ahead to the general election. waves of refugee flee venezuela as the economic crisis worsens. remembering senator john mccain. and, much more. ni >> woodruff: last was the final time this year we will have primary election results from more than one state. wlisa desjardins reports t the winners in arizona anda florll us about the 2018 midterms. >> reporter: he entered election day behind in funding and behind in the polls, but last night, democrat andrew gillum pulled off an historic upset in florida. democrats narrowly picked the progressive tallahassee mayorn over better-knd more

moderate opponents, like gwenah gram, a former congresswoman and daughter of former governor bob graham. i gillthe state's first black nominee for governor, onec of three a american gubernatorial candidates this year, along with fellow democrats ben jealous in maryland and stacey abrams in georgia. s>> just a few people whod this moment would not be possible. ( cheers ) a few. and then there were, and then there were, and then there were a few more, who believed this thing was possible. ( cheers ) >> reporter: this sets up a battle between polar forces in u.s. politics, as gillum, backed by bernie sanders, will face g.o.p. nominee and congressman ron desantis, who was embraced by president trump. >> and i was able to talk to the president. i want to thank him for his support.

i wa to thank him for entrusting me with, viewing me as somebody who could be a great leader for florida. so thank you, mr. president. >> reporter: the state also faces a fierce senate race as republicans overwhelmingly picked outgoingovernor, rick scott, to take on democratic senator bill nelson. meanwhile, as floridians picked firebrands, in arizona, wins by the more moderate. in the race to replace retiring g.o.p. senator jeff flake, republican congresswoman marthyp mcsally conservative firebrands kelli ward and former maricopa county sheriff joe arpaio. the retired air force fighter pilot turned to the november battle.hi >>is how i see this campaign-- it's a choice between a doer and a talker; between a patriot and a protester. >> reporter: by protester, she meant her now-opponent, democratic congresswoman kyrsten sinema, who has appet anti-war rallies. but she has also ved with republicans in congress.

>> arizonans don't care whether you have an "r." or a "d." a the end of your name. what they care about is whether you're able deliver real sults for every-day arizonans. >> reporter: whichever candidate wins will become the firstle feenator from arizona. >> woodruff: and lisa joins me o w with more reporting, along with kyle kondik, alyzes elections at the university of virginia's center for cs. hello to both of you. so, kyle, let's start with you and with where lsa's reort left off, arizona, the jeff flake senate seat. how do you explain this republican primary result where you have two people fiercely pportive of president trump running against martha mcsally who had to walk a delicate line there and all this happening the me week of john mccain's passing? there. >> 's kind of two fringe candidates who basically split at share of the arizona vote and allowed martha mcsally to win but she only got over 50%,

pretty reminiscen't of john mccain's last primarin 2016 where he beat kelly ward but only got a little over 50% himself. i wouldn't necessarily say mcsay or mccain are "moderates" but are more mainstream conservatives and maybe not inhe case of this election president trump enough for the electorate but mcsallyup endewinning comfortably. >> woodruff: lisa, what do we know about martha mcsally? >> she's fascinating because this is an issue of the tone and rhetoric she used. she voted for the president 98% of the time in congress. when she ran in 14, she talked about things like working across party lines, campaigned on protecting social security. in 27, she said she s not in favor of one large contiguous border wall, flipped to this race this year in the primary,an now she's campaigning on

protecting the border and saying she willwauild a border. so it's really her words have changed because she's trying to embrace the president's policies more and looked like that helped her get througthe primary. >> woodruff: kyle, what does that mean for the race we look to between her and sinema the demo iat? >> arizoone of the few places where they can pick up a senate. if the democrat has a shot to n the u.s. senate and it's a small chance, they have to win arizona. so sinema and mcsally are both the choices of quarterip leaderin both parties. this should be a competitive open seat race for a senate seat that republicans have held for a long time but documents are hoping arizona is trending f:uer. >> woodr clear choice between the two. >> truly. >> woodruff: what would yo add about arzona? >> fascinating to look how it voted in presidential elections. it d vote for prident trump, but arizonans voted more for mitt romney. so this is a plce that doesn't

like this sort of extreme rhetoric, doesn't like these sharp candidates as much as they like establishment when it comes to statewide voting. >> woodruff: turning to florida, fascinating results there, kyle. the surprise upset, the mayor o tallahassee s running third or fourth in the polls, turns out to defeat his democratic colleagues, challengas. how much ourprise was it? how did he do this? >> it was a big surprise. i think hsoe benefited inme instances from the structure of the racrebecause tere several of the candidates ahead of him who were beatingeach other up on the air waves and that sort of dynamic in a multi-candidate primary can alw, you know, a different person to emerge than the person you would think would win in this primary, what would you would consir establishment democrats would have preferred gwen graham, the former congresswoman, to win this way women have done so well in

primaries this year and she was thonly female cdidate and wasn't able to win. >> woodruff: two of the other candidate putting a lof money in and going after her with what they were saying. lisa, no sooner thwe saw the results than there is already controversy in this chntest. >> that is rigt. for congressman desantis, this is a huge win, a much coveted prize for him this primary win in florida. this morning, he goes on x news talking about now the race against mr. gillem, and he says something that's gotten a lot of attenttn. let's play >> he is an articule spokesman for those far left views and he's aat chari candidate. the last thing we need to do is monkey this up by trying to embrace a socialist agenda with huge tax increases and bankrupting the state. >> n minutes later but sconds later, of course, many people on twitter pointing out tho are words, monk i didn't think around ," that are offensive toa african-americans and long been used as race baiting terms

and a term artaticto describe a minority as something that is seen as not being as post-racial." talked to the desantis campaign. they sent a statement saying ron desantis was obviously thinking about floridians not making the wrong decision on policies, and the policies gillem espouses. but, judy, i think this is orsonating today, and republicans to have race be an ssue right out of the gate is not just a problerall in eerms of republicans messaging, but, in florida, sident trump won in florida, of course, we know, in 2016, but we also though that that was a year that saw large, sharp decreases in minority turnout in. flori president obama won in florida twice, so if you see an african-american at the tp of the ballot, especially when there is concern about minoritym issues, it's thing democrats think could drive out their ufters. >> woo meantime, on the other side, kyle, the president has endorsed desantis. he didt some time ago. today he's weighing in, already

criticizing gillem with a tweet. i'm quoting, he said, not only did congressman ron desantis easily win in the republicany primt his opponent in november is his biggest dream, a failed socialist mayor gamed andrew gillum who's allowed ime and other problems to flourish in his ci, this is not what florida wants or needs. >> i think you may see tump sort of echoing sort of a racially chaened stat talking about crime in relation to an african-american candidate. there is sort of an x ftor in this race in that there is an f.b.i. investigation of tag hasy city government where gillem is the mayor. it's not clear as to whether gillem would be involved ih that, butat's a cloud hanging over his campaign and the reason why some democrats were hesitant to support him. >> woodruff: to be fa says he's not under investigation, not a target. >> that's right. >> woodruff: sa, what more should we know about florida and there were a couple of other things. >> there were.

one last thing about florida, we can get caught up in the personalities and controverswi but ther be a real test of issues here. we have the most conservative ainst the most liberal democratic party in a state wrestling with things like gun policy. there are bibe differences een the candidates and it will be fascinating to see how that plays out. oklahoma, what do you know, oklahoma selected a republican primary runoff, a new county, mortgage company owner and democrats think they might haveo a t at the oklahoma governorship, who knows. >> woodruff: a fier cen of president trump. >> that's exactly right. >> woodruff: kyle kondik, lisa desjardins, thank you oth. >> thanku. >> oodruff: next, we turn to the crisis in venezuela, and beyond.

venezuelans are now the largest group by nationality seeking asylum in the u.s. last year, more than 28,000 applied for that status, five times the number in 2015. they are fleeing political turmoil and a country in economic freefall that is threatening its neighbors. today, the brazilian military is deploying to a region along its border with venezuela that has suffered a spike in violence since venezuelan refugees arrived. millions of veneelans have fled for the surrounding countries in south and central america. as nick schifrin reports, itsfu a regee crisis that the united nations warns could soon equal that caused by the war in syria. >> schifrin: for millions of t venezuelans, line between starvation and survival is the border with peru. refugees bring only what they can carry, along with their entire families, fleeing from their homeland.

on the ecuadoran border, refugees take over a highway. they have been walking for hundreds of miles, and hope to escape a life that has become unbearable. and on the brazilian border, little girls carry what's most valuable. families at the border wait for their turn, wait for what they hope is a better life. >> ( translated ): i've come to i came here to work and help my family. because you can't, back there. >> schifrin: venezuela president nicolás maduro has overseen an economic catastrophe. inflation is predicted to be one million percent, pulverizing incomes, spreading hunger, and crumbling health services. sktv recently filmed in a hospital in an area held by the opposition. patients sleep behind ftaircases, in dark corridors. most doctors have ue to lack of salaries. those still here, work for nearly free. margaret gamboa's a medical student.

>> everything here is so sad. i cannot help them, because they need help, there is nobody here. >> schifrin: one of the few remaining doctors shows off cabinets supposed to be full of medicine-- today, all empty. 'tis boy needs antibiotics the hospital doeave. and in a nearby room, a mother shows cell phone video of her daughter, once a dancer in the orange dress-- now, near immobilized by a brain tumor. but there's no cancer medicine in venezuela, so her mother, emyuri fuentes, will try and make t difficult journey to colombia. >> ( translated ): because she's my daughter, i have to support her. we've been here for two months. >> schifrin: the conditions have used an exodus of 2.3 million, and a regional migration crisis, says colombia's migration director, christian kruger. >> ( translated ): we cannot lie to ourselves. we are talking about a nation of nearly 30 million residents that clearly will continue leaving their country. regional nations must unite. >> schifrin: to try and fix the economy, the government

recently raised salaries by 3,500 percent, and introduced a new currency-- with five fewer zeroes. but in a country full of long gas lines, a.t.m. lines, and groceries th can cost two weeks of salary, that may be too little, too late, says venezuelan business organization president carlosarrazabal. >> ( translated ): without controlling the hyper-inflation, the impact of these incremental changes withtally counter- productive. >> schifrin: the maduro government says it's preventing chaos and fighting internal and external enemies. maduro himself urges venezuelans to stay home. even if life isn't perfect, he said, leaving is worse. >> ( translated ): some venezuelans who left the countr- to clean toile'm saying this even if it hurts-- have left to be economic slaves abroad. >> schifrin: for more, i'm joined now by javier corrales, professor of political science at amherst college. javier corrales, do the

countrie refugees are arriving in, do they have the capacity to accept so many refugees? >>eshey don't. are countries that are not necessarilimpoverished, bu they do not have the capacity to have a refugee crisis of ths magnitude and happening at this speed. there's no queson that these governments are going to have to respond. these are large number of people in dire need, suddenly arriving. some of them are incredibly honest people, but there's also a lot of contraband and illicit trade and criminal activity happening at the same time, and all of this is arriving at a fast speed. so it is a real emergency situation in many communities. ezuela,rter: inside ven we saw last year a lot ofan resi to the government. we've seen less resistance recently. >> yes. why is that? ell, you have to understand it is very difficult, num

one, to resist in the midst of such economic devastation. the avage salary is one dollar a month, and there is complete scarcity. also, and this is the second heason, last year, t government inflicted quite a bit of repression, and it has continued to do so, but last year's repression was pretty brutal, signaling to the rest of the population that it's very costly to engage in polical activism. so most venezuelans are either gieng up or sping time trying to survive or just opting to leave. >> has the repressio worked? in some way has the ma duren government won. >> in some ways. venezuelans fe very watched and not safe from the government and it is taking a toll.on this silenche part of the opposition together with this

exodus is a sign that that the government is prevailing. >> as the government is prevailing, to use your words, do they feel any pressure to make some of the reforms that are required? >> this is what's so interesting, under any normals, circumstanny government facing this type of economic calamity would try to do something to stop it, but what i believe is happening in venezuela is that the governmen alized that this economic crisis works to its advantage because it cometely decimates the private economy and it als decimates civil society and leaves only one actor standing, and that is the state. so the administration, the ma madura administration has concluded strangely that this economic crisis is politically convenient for them and so, th have no incentive necessarily to put an immedte end to the

economic crisis. >> but we have seep somge sin there are some cracks within the rank and file of the elates and perhaps even within the military, so does that mean that the government real feels no pressure to try and make life better for everyone in the country? >> the one incentive to try to t x the situation is that the economic environmis unbearable for almost everyone, so the government is responding with the classic combination of cooping some groups -- co-opting some groups and repressing those that are a bit more uppity. to the repression ist no just seemed at opposition forces but sectors of the ruling party that are beginning to show discontent. there are reports of about 200 military personnel havi been arrested, for example, and that attells us thhe government is trying this combination of

coopting some groups but also applying some force inside the movement itself including thery miliand the government feels that this is a battle that it can win, that this is a game where they can be good a >> if they're not feeling secure, can ey maintain the status quo and perhaps buy time till, for example, oil prices increase again? i> that is essentially wha think they are hoping for, that all they need to do is to wait it out for a few more months and that, at some point, the price of oilill go and this will give them some more room r maneuvering. so it's a matter of just holding steady for a little longer, make sure that they don't introduce drastic change, and wait forthe price of oil to go up.

>> javier corrales of amherstco ege, thank you very much. >> my pleasure. >> woodruff: stay with us. coming up on the newshour: the push to regulate a chemical that is known to caurain damage in children. and, police departments trainint to reduce implias within the forces. earlier, we reported on mourners gaering in phoenix today t pay their final respects to arizona senator john mccain, lyinin state in the capitol building. his death on saturday-- nine years to the day after his friend, senatoted kennedy, died from the same type of brain cancer-- has drawn parallels between the two men, known for their occasional bipartisan efforts and their shared sentiment that "a fight not joined was a fight not enjoyed." a short while ago, i spoke with senator kennedy's widow, vicki

kennedy, about their friendship. and i started by asking her what senator john mccain meant to her. it was a real privilege to know john mccain, and i know my u- ted felt the same way. john was a very, very special friend. he was a loyal friend, he wa a kind friend, he was a wonderful senator, and i'm going to miss him. >> woodruff: i want to ask you about their relationship, but first i want to show ou audience just a little bit of what senator mccain had to say at the memorial service for ur husband, the lenator kennedy in 2009. here's just a part that. >> he took the long view. he never gave up, and though, on most issues, i verysuch wihed he would give up, he taught me to be a betterenator. >> woodruff: vicki kennedy, they had an interesting relationship, didn't they? >> they most certainly did. they most certainly did.

i think, at the very beginning, they didn't like each other very much. they both were very fond of saying that. they loved saying thatfa, inct. and john said, before you like someone you had to respect themn and i that's very true, and they came to respect each other and then to bece very, very good friends. i recall one very interesting time in the very early 1990s where john and ted were ats on an issue on the floor of the united states senateand they had, let's say, heated words right off the floor out of earshot, but as thy walked off and they patted ea other on the back and they said, that's pretty good, isn't it? and bey startedter which they did both did so well. they both had a terrific sense of humor, and it was the beginning of sowing seeds of a very special friendship. >> woodruff: but we should say their politics were very different. csmean, your husband was a -- >> oh, their policould not

be more different. john was a cash mat conservative and republican. teddy was a past,sionate democ he was a passionate progressive but they wele to look for the areas where they could agree. they looked for the areas where they could find cod.on gro one of those areas was inio immigr they both knew we had a broken ymmigration system and they wanted to find a to resolve the problem, so they would meet every morning with a group of other senators. they would meet at 7:30 or k 00 in the morning and they would start to td listen and try to see where they could come together. i mean, i thought that was an extraordinary thing whhey were looking for a way to move the issue forward, to fndthat resolution, and neither of them got what they wanted completely, but they got out of their comfort zone a little bit on the compromise legislation that they put forward, but they also knew that they were advancing the ball, that they were helping to

resolve a problem. i know from ted's point of view and in talking to john as well, on ofhe great disappointments of both their careers was that iney were unable to ly get that legislation pass bid both houses and signed. >> woodruff: right. i think i asked you this because i think maybe it's a lesson for today. why do you think they were able to work together on an issue like immigration? and there were others. >> i think because they listened to each ther, i think beause they did have respect. they both side that we love this country, we just have a different way, maybe, of getting there to resolve an issue, but if u listen to each other, you might just find that nugget of common ground. ngdy, i think there are so many reasons we're heathis outpouring of love and affection for john mccain this week he so deserves it. he was such ariot, he's a man who served his country with distinction, but it's also

because he was a person who wasn't afraid to reach out and talk to people on the other side of the aisle. i was struck, even in this last year of his life, howhe stood on the floor of the united states senate and said that the greatest moments of his public life were when he worked with his colleagues on the other side of the aisle to advance an isree. i think th a real lesson for all of us here. and he did that first and foremost, i think, by sitting down and listening. >> woodruff: that's what i wanted to ask you because people look at that and, i mean, some people would say why is that so hard for other senators, other political figures to do? what was it about john mccain, do you think? >> i think he lived life, he had seen a lot, he believein country first. he had sved our country honorably, and he was alwaysth

thinking about. he just had a big-picture view, and getting a problem res was the paramount thing. it wasn't party first, it was untry first, and he was able to just try to reachcompromi in that way, not to compromise his values but to find a way to find common ground, and those are two very different thing woodruff: i was just going to say that i think torture, an issue that came up after the invasion of i that came up as an issue, and your hus and senator mccain, who, unlike most other republicans, said this is something we can't stand for. >> well, john knew really painfully and from firsthand experience what torture was, and felt that it was a violation of our american values to hae torture as a tool of war, and

teddy was vehemently opposed to torture, and that was a place where they found common ground. so in armed services committee hearings, ty would botbe on the same side of that issue, even to the point of exchanging notes with each other from their briefing sheets and passing them back and forth, because there was no prideof authorship, it was about how to we resolve this fundamental issue we're facing how do we solve this problem and ay true to our american values. >> woodruff: vicki kennedy, you stay close tohi waston. do you see other senators today working across the aisle the wan your huand john mccain did? >> i actually do, judy. i actually do, and i think it may not make the front pages all the time, but i see a lot of outreach. i'm really pleased that there are those seeds of partisanship, republicans and democrats looking for ways to work together. i remain optimistic.

we're in difficult times, buti really believe that things will cool. i they have to, and that 'll go back to a time when we go back to regular order, whenub we have rcans and democrats working together more. but we're starting to see it, all right. >> wdruff: vicki kennedy, widow of senator edward kennedy, remembering him, remembering john mccain. thank you very much. thank you, judy. >> woodruff: it is not well known to the general public yet, but the environmenenl protection under president trump wants to change which scientific studies can be used by the federal government to regulate industry. the administration-- and business voices-- say studies

should only be used iff the data is publicly available and transpart. but, many scientists and researchers say doing so would violate privacy protections for patients in studies. this issue is now playing out in long-running battle over whether to ban pesticidesthat harm babies and chilen. miles o'brien looks at the science and debate behind it all, part of our weekly seriesle on the "ing edge" of science, medicine and technology. >> o'brien: when fidelia morales moved into her dream home nestled among orange grovess in californintral valley 12 years ago, she didn't know much about agriculture. >> we didn't know that they were fumigating with these huge machines, that they were spraying these extremely strong chemicals. >> o'brien: it happens on the calm margins of the day. when the wind ys down, growers gear up, to spray their crops

with pesticides. >> ( translated ): look at the distance between the machine and our yard. it's impossible to keep the pesticides off my property. sometimes at night we have the air conditioning on, and we can still smell the pesticides they're spraying throughout the entire house. >> o'brien: she wonders what the y emicals may be doing to her children-- especiar youngest son, the only one born here. >> ( translated ): he can't sit in one place. we have received many complaints about him from his teachers, who say he nee to focus. >> o'brien: while it is hard to make a direct link, those are textbook symptoms exposure to chemicals known as organophosphates. the most widely used variety is called chlorpyrifos,nu ctured by dowdupont. after decades of research, review and debate, theen ronmental protection agency

was on the cusp of banning all use of chlorpyrifos in november of 2016. but in march of 2017, then- e.p.a. administrator pruitt delayed a decision on the ban by five years, sayingan amerarms that rely on the insecticide needed "regulatory certainty." dowdupont called it "the right decision for farmers." and yet, on august 9, a panel of federal judges ruled the e.p.a. had "no justification" t continued use of chlorpyrifos "in the face of scientific evidence that its residue on food causes neuro-developmental damage to children." chlorpyrifos and otheros organophates are neurotoxins, a poison that attacks the nervous system. >> it causes a huge excitatory burst in the nervous sysm. >> o'brien: robert sapolsky is a professor of neuroscience at stanford university.

the burst of nerve firing can be so severe it works the neurons to death. the body's response:ervous system tries to repair itself, by growing new connections to patch the damaged circui >> one of the things that sometimes happens is, the wirinh goes sort wire and a neuron will wind up coming backt anulating itself. so that every time it fires, it stimulates itself and it fires, and it fires-- and what you've now set up with a positive feedback loop, like this is a chronic seizure disorder. >> o'brien: first introduced as an insecticide in 1965, chlorpyrifos was sold to consumers for home andarden use under various brand names, including "raid." >> hello. good-bye. it really kills them dead. >> o'brien: it was widely used even though scientists had published evidence that exposure to organophosphates causes permanent brain damageron

nts. so what were the consequences for humans exposed to this neurotoxin? t we knew we had a chemical that was worthy ing a look at it if we're concerned about its potential adverse effects. >> o'brien: virginia rauh is an epidemiologist at the columbia university mailman school of public health. for 20 years now, she has followed50 mothers and their children in the washington heights section of manhattan. pregnant mothers in her study wore backpack with a pump designed to gather air samples as they went about their daily routine. uh's team found organophosphates in 99% of the air samples she gathered, and 70% of the blood samples of the children. rauh concludes that higher levels of organophosphates found in the blood of her subjects lead to lower birth weight, reduced i.q., a.d.h.d. symptoms, and tremors.

m.r.i.s of the brains of exposed subjects reveal enlargement in son areas, and abnormally t cortices-- the outermost layer of nerve cls in the brain-- crucial for cognitive functions such as percepti, language, .emory and consciousne >> i think in reality, there is no safe level. it depends upon the level of risk that we tolerate as a society. but to damage even to the extent of several i.q. points or someio very tiny attel issues, in imy mind, is not acceptabwe know that it is associated with an exposure. >> o'brien: the food quality protection act says exposure to a pesticide must be safe for infants and children if it going to be used on food. with evidence mounting that chlorpyrifos posed a human

lealth hazard, the chemi industry struck a deal with the e.p.a. in 2000 to stop selling the pesticide for home use. raid and other consumer products were reformulated and some agricultural uses were curtailed.da but chlorpyrifos remains a favorite among farme bob blakely is vice president at california citrus mutual, representing about three quarters of the industry. >> the referenced to by a lot of those who are opposed to this chemical have n been replicated, and they have not been substantiated by the rest of the scientific community, n have they been duplicated in another countries. >> o'brien: the e.p.a. says the columbia data "remains inaccessible, and has hindered the agcy's ongoing process to fully evaluate the pesticide." dow says it "remains confident that authorized uses of chlorpyrifos products, as directed, offer wide margins of protection for human health and

safety." the company has funded several studies that support that conclusion. robert sapolsky and a team of neuroscientists at stanfordpo d through many of these papers. >> fshman science majors are not supposed to make mistakes like this. the science was basically empty. >> o'brien: d, he says, every time there was a mistake-- and there were dozens of them-- it favored the industry position that organophosphates used properly don't harm humans. >> if the literature as a whole is as lousy as the subset of these papers that i looked at, this really does bring into question lots of things, most basically whether dow has a leg to stand on, saying this stuff has been scientifically shown to be safe. >> o'brien: e.p.a. scientists agree, but in the trump administration, thei conclusions are frequently reerruled by industry pres miriam rotkin-ellman is a senior scientist with the natural

resources defense council, which is suing the e.p.a., hoping to force the agencyo follow its own rules and take its own scientific advice. >> when we have the evidence right in front of us, that exposure that's widespread in the american population could be or is increasing the risk of those arning disabilities, and we are refusing to take action on that, it's terrifying. >> o'brien: especially so for fidelia morales and her family, surrounded by citrus and sticides in california. >> ( translated ): if our children are exped to chlorpyrifos, they are not going to have a future. together as a community, we are f ghting for them to stop and to prohibit the use olorpyrifos here in this county. i think that they don't ca, because if they did care, they would try to stop this without

us asking. >> o'brien: the state of hawaii recently banned chlorpyrifos, and california's e.p.a. has come to the same scientific conclusions as their federal counterparts, and that could lead to a statewide ban there. hanwhile, the federal cou ordered the e.p.a. to enact a ban on corpyrifos nationwide within 60 days. the agency can appeal, but says it is still reviewing the decision. in california's central valley, i'm miles o'brien for the pbs newshour >> woodruff: finally tonight, the latest installment in our "race matters-solutions" series. earlier, we reported on how a riite police officer in texas, convicted of mur an unarmed african american teenager, is still undergoing the sentencing phase of his

trial. it is another case in the t going tensions between law enforcemd the african american community. and around the cntry. police departments are looking for new ways to officers about race and policing. reporting from new york city, special correspondent charlayne dehunter-gault examines onl of training that's gained popularity across the country. >> reporter: here in new york paty, issues between the new york police ment and african americans have long been simmering, with cases like thern death of eric four years ago representing something of a boiling point. the father of six, whoeen selling cigarettes on the street, died after an officer him in a headlock while arresting him. the incident sparked massive protests. ( protesto ) in july, the n.y.p.d. said it would begin preparg disciplinary hearings for the

officer involved in garner's death. the city had reached a $5.9 million settlement withga er's family in 2015. meanwhile, other cases around the country have also resulted in settlements into the millions. against that backdrop, here at its sprawling training academy in queens, the n.y.p.d. has ndintroduced the "fair impartial policing" training-- a relatively new peagram aimed ating officers about so-called "implicit bias." the concept-- which has gained popularity in recent years-- is that subconscioubiases and stereotypes can influence a person's behavior, even if that person is not explicitly biased. >> reporter: each of the department's more than 40,000 members will attend e six- to seven-hour class.

today, 19 of them, mostly lieutenants, were instructed on the science behind implicit bias. >> reporter: the training costs the n.y.p.d. $4.5 millstn. n.y.p.d. feputy commissioner benjamin tucker explns the rationale behind adopting the program. >> they've been prolific in terms of their amount of departments they've trained. the feedback from those departments is that their sficers were able to hear the message, and we'n that to re true here. >> reporter: the is, however, signthicant skepticism from bo social scientists and law enforcement about how much this type of training can aolually changee behavior. i put that and other questions to lorie fridell, who runs the implicit bias training program, and noble wray, a member of the training team and former chief of police for the madison,ce wisconsin poepartment. welcome to you both.

>> thank you. >> thank you. >> reporter: dr. fridell, let me start with you. what led you to start this training? >> i started thinkinabout bias in policing when i worked at the police executive research council. i became perplexed during that study period because i came to believe two things that didn't go together in my head. and one was that i came to believe that bias in policing was more than just a few bad apples.i buso came to understand that most police are well- intentioned individuals who want to serve their communies. and i couldn't figure out how both of those things could be true, until i was introduced to the science of bias. >> reporter: but that leads me to the definition. what is implicit bias? >> okay, so explicit bias would be, like, a racist. it's conscious, it's deliberate. the stertypes that a person has is based on animus and hostility. with implicit as, we still have stereotypes about groups, but it's not conscio and deliberate. ofd in fact, implicit biases can impact us outsidonscious awareness, and it impacts even on individuals who at the conscious level reject biases

and stereotypes and prejudice. one of the critical aspects of th training is not just telling them about implicit biases so they recognize them,th bu need to have tools to reduce and manage biases. ur reporter: like? >> if we recognizemplicit omases and we're motivated, we can actually oveour biases and implement bias-free behavior. >> reporter: so the moon has to come from these classes or these sessions. >> it does, but also comes again, most cops are well- meaning individuals. and so, once they understand that their mind is playing tricks on them and it might produce discriminatory behavior, with the large, large number that say "i want to do better." >> reporter: chief wray, how dio get involved in this? i mean, you're a black policeman, and i think that most people, when they think about blas in police, they think about white policemen ank people. how did you get involved? >> you know, throughout my career, i always thought the issues relused to bias, i lly focused on explicit bias.

so i would go into a training, foy, my arms and say, litera this is for the white guys. what iealized is that it wasn't about a specific race, in terms of, you ow, an african american police officer not being impacted by it, or a white police officer are t only ones. what i realized is that i didn't get a pass on that.e i realat this was an issue of human beings, that we all have implicit biases.an so, that's what really got me into it. >> reporter: okay, so now today when you were having a class, you asked the people, the policeman in the room to fill out cards. >> so we ask them to write down the thought that comes to mind when they hear "racial profiling" or "bias policing." r orter: this one says "greatly exaggerated, unfair political tool." edis one says "sensational and another one says "ridiculous." how do you deal with that kind of pushback? >> a lot of officers come in believing that bias and policing is not a big issue. they think it's been exaggerated.

they picture it as expli bias. and they look around the room lld they don't see their gues as having explicit bias, and so they say "we're being unfairly castigathd." an is our first task. we need to reduce that defensiveness. and we come in and we say, "we're going to talk to you about how your mind works." >> reporter: does it always rk? >> not always work.a therw people that, there's always going to be, their minds are made up.ta but i always the class off saying, you know, if you're not t trospective, and if you personally don't wprove, this is, this may not work for you. >> reporter: yet some of the critics i've read say that there's an absence of probing objective research, and that longer study is needed to determine if officers really retain what they're being taught, and if civilians actually benefit. y i'd li both to respond to that. >> so, the curriculum is based

on a body of research. but the implicit bias training, including our own, has not yet been evaluated, and that's what we need. and in fact, in the context of doing our training in n.y.p.d., we are conducting a ed5-year controvaluation. >> reporter: how do you respond to that criticism? >> one of the things that i think is powerful about implicit training is that there are rtain things that you can do in your daily operational as a police officer to help mitigate some of the issues that you're confronting. by keeng lines of communication open, slowing things down, because if you slow things down, you get to know the person more. mentact theory. the more you know e, the more your positive interactions with someone, the better you are able to teract. so we talk about a series of things. and from a policing standpoint, that you can do to mitigate some of those issues.

>> reporter: and over time, how many departments can you think of that you'd gone bk to and found that the training was sustained? i think departments that, where leadership at the top embraces it, it is sustained. you know, you plant the seed. like, most organizational experts will say, this is change, this is, this is difficult chan it's transformation, and that takes time. >> reporter: how much time, do you think? >> i think this is, this issue is generational, meaning we are we're changing the way we think about this issue. we're changing the tools that we're using to address it. and i think we are on the right trajectory and i think we're going to see great changes in policing along rhese lines. orter: well, i certainly hope so. thank you both for joining us. >> thank you. >> thank you. >> woodruff: our "ce matters- solutions" coverage continues poline with more on the guilty verdict in the 201ce fatal shooting of 15-year-old jorda edwards. that's on our websitww pbs.org/newshour. and, a correction before we go:

we stated earlier in the prograh that afranklin's funeral is scheduled for tomorrow. it is actually set for friday in detroit. and that's the newshour for tonight. i'm judy woodruff. join us online, and again here tomoow evening, where we examine the ways israelis and palestinians are trying to move toward peace by building bridges through business partnerships. for all of us at the pbs newshour, thank you, and we'll see you soon. >> major funding for the pbs newsho has been provided by: >> consumer cellular understands that not everyone needs ante unliwireless plan. our u.s.-based customer service reps can help you choose a plan based on how much you use your phone, nothing more, nothing less. to learn more, go to consumercellular.tv >> f raymond james.s firm >> babbel. a language program that teaches real-life conversati a new language, like spanish, french, german, italian, and more.

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