captioningponsored by wshour productions, llc >> woodruff: good evening. i'm judy woodruff. on the newshour tonight: vote 2018. the major primary elections are over. progressive and pro-trump candidates n, setting up big challenges in november.ne then, la in crisis. as citizens flee the country's dire economics, refugees arriving in neighboring countries are adding to regional tensions. and, on "the leading edge gu science," reting pesticides known to cause brain damage in young people. >> we knew we had a chemical that was worthy of taking a look at, if we're concerned about its potential adverse effects. >> woodruff: all tt and more, on tonight's pbs newshour.

>> major funding for the pbs newshour has been provided by: >> babbel. a language program that teaches real-life conversations in a new language, like spanish, french, german, italian, and more. babbel's ten to 15 minute lessons are available as an app, or online. more information on babbel.com. >> consumer llular. >> financial services firm raymond james. >> supporting social entrepreneurs and thei solutions to the world's most pressing problems-- skollfoundation.org. l >> telson foundation. committed to improving lives through invention, in the u.s. and developing countri 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 rld. more information at macfound.org >> and with the ongoing support of these institutions: >> this program was made possible by the corporation for public broadcasting.tr and by cutions to your 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 president today dismissed m talk that ht have a problem with what mcgahn told them. r any concern about what he's said to the muelam? >> no. i knew he 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. bo do everything straight, we do everything by th, and, donex is allent guy. >> woodruff: the chair of the senate judiciary committee, republican chuck grassley,rn voiced conbout mcgahn leaving. in a tweet aimed at theid prt, he said, "you can't let that 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. the tallassee mayor would be the state's first black chief executive. and in arizona, republican congresswoman martha mcsallywi 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

etributes began for the l senator john mccain. a military honor guard greeted the hearse that carried mccain's casket to the state capitol in phoenix. goveor doug ducey was among those who spoke at a brief ceremony. >> john mccain was about more than politics. he broht us above politics. john is probably the only politician w could get us to set aside politics and come together as a state and nation, as we have. >> woodruff: afterward, mccain's widow, cdy, and their children spent private moments by the casket, before the public was admitted to pay their respec. the senator died saturday of brain cancer. he would have been 82, today. a whit in texas could get 99 years in prison in the death of jordan edwards, a 15-year-old black

youth. roy oliveras 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 partne 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 against political protests. 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 said it's time intervene. n repression and retaliat against demonstrators continue in nicaragua, as the world looks away. the violencend impunity of these past four months have exposed the fragility of the countries, institutions, and the rule of law, and created a climate of fear and mistrust, and just the numbers of those

leaving nicaragua is testimonyto hat. mi woodruff: the nicaraguan government ded the report and denied the accusations of excessive force. more than two dozen human rights t oups are urging google not to censor its interarches in china. there have been reports that the tech giant plans to build a search engine 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 pduct. on wall street today, the dow jones industrial average gained 60 points to close at ,124. e nasdaq rose 79 points, and the s&p 500 hided 16. and,was the second and final day of the late aretha franklin's public viewing in detroit. thousands have filed past the casket at the chmules h. wright um of african american

history. the funeral for the legendary singer takes place tomorrow. still to come on the newshour: tanaways from the primaries arizona and florida, and looking ahead to the general election. waveof refugees flee venezue as the economic crisis worsens. remembering senator john mccain. and, much more. dr >> wf: last night was the final time this year we will have primary election results from more than one state. lisa desjardins reports on what the winners in arizona and florida tell us about the 2018 midterms. >> reporter: he entered election day behi 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 mayor b

ovter-known and more moderate opponents, like gwen graham, a former congresswoman and daughter of former governor bob graham. gillum is the state's first black nominee for governor, onef hree african american gubernatorial candidates this year, along with fello democrats ben jealous in maryland and stacey abrams in georgia. >> just a few people who said 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 fors in u.s. politics, as gillum, backed by bernie sanders, will face g.o.p. nominee and congressman ron desantis, who was embraced by presidentrump. >> and i was able to talk to the president. i want to thank him for his

support. i want to thank him for entrusting me with, viewing me as somebody who could be a greao leader forda. so thank you, mr. president. >> reporter: the ste also faces a fierce senate race as republicans overwhelmingly ed outgoing governor, ri scott, to take on democratic senator bill nelson. meanwhile, as floridians picked rebrands, in arizona, wins by the more moderate. in the race to replace retiring g.o.p. senator jeff flake, republican congresswoman marthy mcsally topped conservative firebrands kelli ward and former maricopa county sheriff joe arpaio. the retired air force fighter pilot turned to the novemberle ba >> this is how i see this i campaigns a choice between a doer and a talker; between aot patriot and a ter. >> reporter: by protester, she meant her now-opponent, democratic congresswoman kyrste sinema, who haappeared at anti-war rallies. but she has also voted with

repuicans in congress. >> arizonans don't care whether you have an "r." or a "d." at the d of your name. what they care about is whether you're able to deliver real results for every-day arizonans. >> reporter: whicheverandidate wins will become the first female senator from arizona. >> woodruff: and lisa joins mewi no more reporting, along with kyle kondik, who analyzes elections at the university of virginia's center for politics. hello to both of you. so, kyle, let's rt with you and with where lisa's report left off, arizona the jeff flake senate seat. how do you explain this oepublican primary result where you have two le fiercely supportive of president trump running againsttha mcsally who had to walk a delate line there and all this happening the same week of john mccain's passing? there. >> 's kind of two fringe candidates who basically split that share of the arizona vote and allowed martha mcsally to

win but she only got over 50%,in pretty rcen't of john mccain's last primary in 2016 where he bet kelly ward bu only got a little over 50% himself. i wouldn't necessarily say mcsally or mccain are "moderates" but are morein ream conservatives and maybe not in the case of this election for the electorate but mcsally ended up winning comfortably. >> woodruff: lisa, t do we know about martha mcsally? >> she's fascinating because this is an issue of the tone ant ic she used. she voted for the president 98% of the time in coress. when she ran in 2014, she talked about things like worki across party lines, campaigned on protecting social security. in 2017, she said she is not in vor of one large contiguous border wall, flipped to tis race this year in the primary,

and now she's campaigning on protecting the border and saying she will build a border wall. so it's really her wor have changed because she's trying to embrace the president's policiea mo looked like that helped her get through the primary. >> woodruff: kyle, what does that mean for therace we ok to between her and sinema the democrat? >> arizona is one of the few k up a where they can pic senate. if the democrat has a shot to win the u.s. senate and it's ath small chance have to win arizona. so sinema and mcsally are both the choices of quarter leadership in both parties. this should be a competitive open seat e ce for a senat that republicans have held for a long time but documents are hoping arizona is trending bluer. >> woodruff: a clear choice between e two. >> truly. >> woodruff: what would you add about arizona? >> fascinatingvoo look how it d in presidential elections. it did vote for president trump, but arizonans ved more for

mitt romney. so this is a place 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 resu ks therle. the surprise upset, the mayor oh tasee who was running third or fourth in the polls, turns out to defeat his democratic colleagues, w challengers. ch of a surprise was it? how did he do this? >> it was a big surprise. i think hite ben in some instances from the structure of the race because there were several of theda cans ahead of him who were beating each other up on the air waves and that sort of dynamic in a multi-candidate primary can allow, you know, a different person to emrge thathe person you would think would win. in this primary, what would you would consider establishment democrats would have preferred gwen graham, the former

congresswoman, to win this ways. women have done so well in primaries this year and she was the only female candidate and sn't able to win. >> woodruff: two of the other candidate putting a lot of money in and going after hera with wht they were saying. lisa, no sooner than we saw the results than there is already controversy in this chntest. >> that isight. for congressman desantis, this is a huge win, a much coveted prize for him this prinmary in florida. this morning, he goes on fox news talking about now the race against mr. gillem, and he says something that's gotten a lot of attention. let's play it. >> he is an articulate spoan for those far left views and he's a charismatic candidate. the last thing we need to do is monkey this up by trying to embrace a sociaitst agenda h huge tax increases and bankrupting the state. >> not minutes later but seconds later, of course, many people on twitter pointing out those are words, monk i didn't think around ,t are offensive to many african-americans and long

been used as ce baiting terms and a term articulate to describe a minoty as something that is seen as not being as post-racial." we talked to the desantis campaign. they sent a statement saying ron desantis was obviously inking about floridians not making the wrong decision on policies, and the policies gillem espouses. but, judy, i think this is resonating today, and for republicans to have race be an o issue right o the gate is not just a problem overall in terms of republicans messaging, but, in florida, president trump woin florida, of course, we know, in 2016, but we also though that that was a year that we saw large, sharp decreas in minority turnout in florida. president obama won in florida twice, so if yousee an african-american at the top of the ballot, especially when c there isoncern about minority issues, it's something democrats think could drive out eir voters. >> woodruff: meantime, on the nther side, kyle, the presi has endorsed desantis.

he did it some time ago. today he's weighing in, already criticizing gillem with a tweet. i'm quoting, he said, not only did congressman ron desan is easily withe republican primary but his opponent in novemb is his biggest dream, a failed socialist mayor gamedew anillum who's allowed crime and other problems to flourish in his city, this is not what florida wants or needs. >> i think you may see trp sort of echoing sort of a racially crged statement talking about crime in relation to an african-american candidate. there is sorof an x factor 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 clr as twhether gillem would be involved in that, but that's a cloud hanging over his campaign and the reason why some democrats were hesitant to support him. >> woodruff: to be fair, says he's not under investigation, not a target. >> that's righ >> woodruff:so, lisa, what utmore should we know ab florida and there were a couple

of other things.>> here were. one last thing about florida, we can get caught up in the personalities and controversy, but there will be a real test of issues her we have the most conservative against the mostal lib democratic party in a state wrestling th things like gun policy. there are big differences between the candidates and it will be fasc inating e how that plays out. oklahoma, what do you know,ma oklaelected a republican primary runoff, a new county, mortgage company owner and democrats think they might have a shot at the oklahoma governorship, who knows. >> woodruff: a fierce fan o president trump. >> that's exactly right. >> woodruff: kyle kondik, lisa desjardins, >>ank you both. hank you. >> woodruff: next, we turn to

the crisisn venezuela, and beyond. venezuelans are now the largest group by nationali seeking asylum in the u.s. last year, more than 28,000 applied for that stas, 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 regiog its border with venezuela that has suffered a spike in violence since venezuelan refugees arrived. millio of venezuelans have fled for the surrounding countries in south andal america. as nick schifrin rorts, it is a refugee crisis that the united nations warns could soonqual that caused by the war in syria. >> schifrin: for millions ofve zuelans, the line between starvation and survival is the border with peru. refugees bring only what they a can carrng with their entire families, fleeing from their homeland. b

on the ecuadorder, 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. sky tv recently film in a hospital in an area held by the opposition. patients sleep behind staircases, in dark corridors most doctors have left due 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 fe remaining doctors shows off cabinets supposed to be full of medicine-- today, alempty. this boy needs antibiotics the hospital doesn't have. and in a nearby room, a mother shows cell phone video of her daughter, once a dancer in the orange dress--nearly immobilized by a brain tumor. but there's no cancer medicine in venezuela, so her mother, emyuri fuentes, will try and make the difficult j to colombia. >> ( translated ): because she's my daughter, i have to support her. we've been here for two months. >> schifrin: the conditions have caused 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 inclearly will continue le their country. e.regional nations must un >> schifrin: to try and fix

the economy, the government recently raised salaries by 3,500 percent, and introduced a new currency with five fewer roes. but in a country full of long gas lines, a.t.m. lines, and oceries that can cost tw weeks of salary, that may be too little, too late, saysel vene business organization president carlos larrazabal. >> ( translated ): without controlling the hyper-inflation, the impact of these incrementaln s with be totally counter- productive. >> schifrin: the maduro government says 's preventing chaos and fighting internal and external enemies. maduro himself urges venezuelan. to stay ho even if life isn't perfect, he said, leaving is worse. >> ( translated ): some venezuelans who left the countre to toilets-- i'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 countries that these venezuelan refugees are arriving in, do they have the capacity to accept so many refugees? >> they don't. these are countries that are not bunecessarily impoverishedt they do not have the capacity to have a refugee crisis ofis magnitude and happening at this speed. thers no question thaese governments are going to have t. resp these are large number of people in dire need, suddenly arriving. some of them are incredibly honest people, but there's o a lot of contraband and licit 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. >> reporter: inside venezuela, we saw last year a lot of resistance to the government. we've seen less resistance recently. >>aes.

why is ell, you have to understand it is very difficult, number one, to resist in the midst of such economic devastation. the average salary is one dollar a month, and there is complete scarcity. also, and this is the second reason, last year, the government inflicted quite a bit of repression, and it has continued to do , but last year's repression was pretty brutal, signaling to the rest of the population that 's very costly to engage in political activism. soelmost venes are either giving up or spending time trying to survive or just opting to leave. r >> has tression worked? in some way has the ma duren government won. >> in some waysne. veelans feel very watched and not safe from the government and it is taking toll. wiis silence on the part of the opposition togethe this

exodus is a sign that that the government is prevailing. >> as the government is prevailing, to use yr words, do they feel any pressure to make some of theeforms that are required? >> this is what's so interesting, under any norcil umstances, any government facing this type of economic calamity would try to do something to stop it, but what i believe is happening in vezuela is that th government has realized that this economic crisis works to its advantage because it completely decimates the privatdeconomy an it also decimates civ society and leaves only one actor standing, and that is the state. so the administration, the ma madura administration has concluded istrangely that t economic crisis is politically convenient for them and so, they have no incentive necessarily to

put an immediate end to the economic crisis. >> but we have seep some sign there are some cracks within rank and file of the elates and perhaps even within the military, so does mean that the government really feels no pressure to try and make life better for everyone in the country? >> the one incentive to try to fix the situation is that the t onomic environment is unbearable for almeryone, so the government is responding with the classic combination of cooping some groups -- co-opting some groups anred essing those that are a bit morite upp to the repression is not just seemed at opposition forces but ctors of the ruling paty that are beginning to show discontent. ere are reports of about 200 military personnel having been arrested, for example, and that tells us that the government is

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

price of oil to go up. >> javier corrales of amherst college, thank you very much. >> my pleasure. >> woodruff: stay with us. coming up on the newshour: e push to regulate a chemical that is known to cause brain damage in children. and, police departments training to reduce implicit bias within the forces. ixrlier, we reported on mourners gathering in phooday to pay their final respects to e izona senator john mccain, lying in state in pitol building. his death on saturday-- nine years to the day after his friend, senator ted kennedy, f dim the same type of brain cancer-- has drawn parallels between the twmen, known for their occasional bipartisan efforts and their shared sentiment that "a fight not joined was a fight not enjoye" 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 ilr. it was a real pre 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 frend, he was 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 our audience just a little bit of what senator mccain had to say at the memorial service for your husband, the late enator kennedy in 2009. here's just a part of that. >> he took the long view. he never gave up, and though, on most issues, i very much wished he would give up, he taught me to be a better senator. >> woodruff: vicki kennedy, they had an interestingsh relati, didn't they? >> they most certainly did.

they most certainly did. hethink, atery beginning, they didn't like each other very ch. they both were very fond of saying that. they loved saying that, in fact. and john said, befe you like someone you had to respect them, and i think that's very true, rd they came pect each other and then to become very, very good friends. i recall one very interesting time in the ry early 1990s where john and ted were at odds on an issue on the floor the united states senate, and they had, let's say, heated words right off e floor out of earshot, but as theylk wa off and they patted each other on the back and they said, that's pretty good, isn't it? and they started a banter which they did both did so well. they both had a terrific sense ofumor, and it was e beginning of sowing seeds of a very special friendship. >> woouff: but we should say their politics were very different. i mean, your husband was a --he

>> oh, politics could not be more different. john was a cash mat conservative and republican. teddy was a pasatsidemocrat, he was a passionate progressive ey were able to look for the areas where they could agree. they looked for theas where they could find common ground. one of those areas was in immigration. they both knew we had a broken immigration system ao they wantedind a way to resolve the problem, so they would meet every morning with a group of other senators. they would meet at 7:30 or 8:00 in the morninstand they woult to talk and listen and try to see where they could come together. i mean, i thoughthat was an extraordinary thing where they were looking for a way to move the issue forward, to find that resolution, and neither of them got what they wandte completely, but they got out of their comfort zone a little bit on the compromise legislation that they put forward, but they also ew

that they were advancing the ball, that they were helping to resolve a problem. i know from ted's point of view and in talng to john well, on of the great disappointments of both their careers was that they were unable to finally get that legislation pass bid both houses and signed. >> woodruff: riasht. i think ed 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 imigration? and there were others. >> i think because they listened to tch other,nk because they did have respect. they both side at weve this country, we just have a different way, maybe, of getting there to resolve an issue, but if you listen to each other, you inmight just fd that nugget of common ground. judy, i think there are so manyw reasore hearing this outpouring of love and affection for john mccain this week. he so deserves it. he was such a patriot, he's a

man who served his country with distinction, but it' also because he was a person who wasn't afraid to reach out and talk to peop on the ot side of the aisle. i was struck, even in this last ar of his life, how he stood on the floor of the united states senate and said at the greatest moments of his public life were when he word with his colleagues on the other side i the aisle to advance an issue. ink there's a real lesson for all of us here. and he did that fit and foremost, i think, by sitting down and listening. t' woodruff: thawhat 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 t about john mccain, do you thi? >> i think he lived life, he had seen a lot, he believed in country first. he had served our country

honorably, and he was always thinking about that. he just had a big-picture view, and getting a problem resolved was the paraunt thing. it wasn't party first, it was country first, ande was able to just try to reach compromise in that wa, not to compromise his values but to find a way to find common ground, those are two very different things. >> woodruff: i was just going to say that i think torture, an issue that came up after the invasion of iraq, that came up as an issue, and your husband and senator mccain, who, unlike most other republicans,is said thiomething we can't stand for. >> well, john knew relly painfully and from firsthand experience what torture was, and he felt that it was a violation of our american values to have torture as a tool of war, and

wdy wasehemently opposed to torture, and thaas a place where they found common ground. so in armed services committee hearings, they would both be on the same side of that issue, even to the point of exchanging notes with each other from eir briefing sheets and passing them back and forth, because there was no prid of authorship, it was about how to we resolvethis fundamental issue we're facing, how do we solve this problem and stay true to our luerican . >> woodruff: vicki kennedy, you stay close to washington. do you see other senators today working across the aisle the way your husband and 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 bipartisanship, republicans and democrats lookinfor ways work together.

i remain optimistic. we're in difficult times, but i realth believe thaings will cool. i think they have to, and that we'll go back to a time when we go back to regular order, when we have republicans and democrats working together more. but we're starting to see it, all right. >> woodruff: 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 t general public yet, but the environmental protection agency under president trump wants to change which scientific studies can be used by the federal government tregulate industry. the administration-- and

business voices-- say studies should only be used if all of the data is publicly available and transparent. but, many scientists and researchers say doinould violate privacy protections for patients in studies. t is issue is now playing a long-running battle over whether to ban pesticidesthat harm babies and children. miles o'brien looks at the science and debateehind it all, part of our weekly series on the "leading edge" of science, medicine and technology. >> o'brien: when fidelia morales moved into her dream home nestled among orange groves c ifornia's central valley 12 years ago, she didn't knowul much about agrre. >> we didn't know that they werh fumigating wite huge machines, that they were spraying these extreme strong chemicals. >> o'brien: it happens on the calm margins of the day. when the wind lays down, growers

gear up, to spray their crops with pesticides. >> ( translat ): look at the distance between the machine and our yard. it's impossible to keep the pesticides off my property. sometimes at night we air conditioning on, and we can still smell the pesticides they're spraying throughout then re house. >> o'brien: she wonders what the chemicals may be doing to her children-- especially her youngest son, the only one born here. >> ( translat): he can't sit in one place. we have received many complaints about him from his teachers, who say he needs to focus. >> o'brien: while it is hard to make a direct link, those are textbook sptoms of exposure to chemicals known as organophosphates. the most widely used varietyis called chlorpyrifos, manufactured by dowdupont. after decades of researc review and debate, the

environmental protection agency was on the cusp of banning all use of chlorpyrifos in november of 201 but in march of 2017, then- e.p.a. administrator scott elayed a decision on the ban by five years, saying american farms that rely on the insecticide needed "regulatory certainty." dowdont 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" to allow continued use of chlorpyrifos t n the face of scientific evidence ts residue on food causes neuro-developmentalh damage to dren." chlorpyrifos and other ganophosphates are neurotoxins, a poison thatth attacknervous system. >> it causes a huge excitatory burst in the nvous system. >> o'brien: robert sapolsky is a professor of neuroscience at stanford university.

g the burst of nerve firinn be so severe it works the neurons to death.es the body'snse: the nervous system tries to repair itself, by growing new connections to patch the damad circuit. >> one of the things that sometimes happens is, the wirins ort of haywire and a neuron will wind up coming back and stimulating itself. so that every time it fires, it stimulates itself and it fires,w and it firest 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 and garden use under various brand names, including "raid." >> hello. good-bye. it really kills them dead. >> o'brien: itas widely used even though scientists had published evidence that exposure to organophosphates causes

ain damage in rodents. so what were the consequences for humans exposed to this neurotoxin? >> we knew we had a chemic that was worthy of taking a look at it if we're concerned about its potential adverse effects. t o'brien: virginia rauh is an epidemiologist columbia university mailman school of public health. for 20 years now, she has followed 750 mothers and their children in the washington heights section of manhattan. pregnant mothers in her study wore a backpack withp designed to gather air samples as they went about the daily routin rauh'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 nobjects reveal enlargement in some areas, and ally thin cortices-- the outermost layer n-of nerve cells in the br crucial for cognitive functions suchs perception, language, memory andonsciousness. >> 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 some t vey attentional issues, int my mind, is ceptable if we 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

health hazar the chemical industry struck a deal with the e.p.a. in 2000 to stop selling the pesticide for home use. raid and other consumer products reeformulated and some agricultural uses were curtailed. mot today, chlorpyrifos remains a favorite a farmers. bob blakely is vice president at california citrus mutual,ng represen about three quarters of the industry. >> the studies that are being referenced to by a lot of those who are opposed to this chemical have not been replicated, and they have not been substantiated by the rest of the scientific nmmunity, nor have they b duplicated in another countries. >> o'brien: the e.p.a. says th"r columbia datains inaccessible, and has hindered the agency's ongoingss 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 hand safety." the company has funded several studies that support that conclusion. robert sapolsky and a team of neuroscientists at stanford pored through many of these mapers. >> freshman sciencrs are not supposed to make mistakes like this. the science was basically empty. >> o'brien: and, he says, every time there was a mistake-- and there were dozens of them-- it favored thindustry 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 l to stand on, saying this stuff has been scientifically shown to be safe. o rien: e.p.a. scientists agree, but in the trump administration, their conclusions are frequently overruled by industry pressure. miriam rotkin-ellman is a senioh

scientist he natural resources defense council, which isuing the e.p.a., hoping force the agency to 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 populatiocould be or is increasing the risk of those learning disabs, and we are refusing to take action on that, it's terrifying. >> o'brien: especially so forra fidelia s and her family, surrounded by citrus andli pesticides in rnia. >> ( translated ): if our chilen are exposed to chlorpyrifos, they are not going to have a future. together as a community, we are fighting for them to stop and to prohibit the use of chlorpyrifos here in this county. i think that they don't care, because if they did care, they

would try to stop this without us aing. >> o'brien: the state of hawaii recently banned chlorpyrifos, and california's e.p.a. has come toame scientific conclusions as their federal counterparts, d that could lead to a statewide ban there. meanwhile, the federal court has ordered the e.p.a. to enact a ban on chlorpyrifos nationwide within 60 days. the agency can appeal, but saysi it is still ing the decision. in california's central valley, i'm miles o'brien for the pbs newshour. f: >> woodrinally tonight, the latest installment in our rlace matters-solutions" series. r, we reported on how a white police officer in texas, convicted of murdering an unarmed african american teenager, is still undergoing

the sentencing phase of his trial. it is another case in the ongoing tensions between law enforcement and the african american community. and around the country.ar police dents are looking for new ways to teach their officers about race and policing. reporting from new york city, special correspondent charlayne hunter-gault examines one model of traininpothat's gained larity across the country. >> reporter: here in new york pty, issues between the new yoice department and african americans have long been simmering, with cases like theof deatric garner four years ago representing something of a boiling point.si the father o who had been selling cigarettes on the k reet, died after an officer put him in a headlile arresting him. the incident sparked massive protests. ( protestors ) in july, the n.y.p.d. said it would begin preparing

disciplinary hearings for the officer involved in garner's death. the city had reached a ent withlion settl garner's family in 2015. meanwhile, other cases around the country have also relted in settlements into the millions. against that backdrop, here at its sprawling training academy in queens, the.y.p.d. ha" introduced thefair and impartial policing" training-- a relati at teaching officers about so-called "implicit bias." the concept-- which has gained popularity in recent years-- is ubconscious biases 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 the six- to

seven-hour class. today, 19 of them, mostly lieutenants, were instructed on the science behind implicit bias. >> reporter: the traincosts the n.y.p.d.y.4.5 million. d. first deputy commissioner benjamin tucker explains the rationale behind opting the program. >> they've been prolific in termof their amount of departments they've trained. the feedback from those departments is that their officers were able to hear the a messag we've seen that to be true here. >> reporter: there is, however, significant skepticism from both social scientists and law enforcement about how much this type of training can actually change police behavior. i put that and other questions to lorie fridell, who runs the implicit bias training program, and noble wray, a mef the training team and former chief of police for the madison,

wisconsin police department. welcome to you both. t thank you. nk you. >> reporter: dr. fridell, let me start with you. what l you to start this training? >> i started thinking about bias in policing when i worked at the lice executive research council. i became perplexed during that study period bause i came to believe two things that didn't go together in my head. and believe that bias in policing was more than just a few bad apples. but i also came to understand that most police are well- intentioned individuals who want to serve tir communities. 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 stereotypes that a person has is based on animus and hostility. with implicit bias, we still have stereotypes about groups, but it'sot conscious and deliberate. and in fact, implicit uases can impaoutside of conscious awareness, and it impacts even on individuals who at e

conscious level reject biases and stereotypes and prejudice. one of the critical aspects of this training is not just telling them about implicitas so they recognize them, but they need to have tools to reduce and manage biases. >> reporter: like? >> if we recognize our implicit biases and we're motivated, wetu can ly overcome our biases and implement bias-free behavior. s >> reportethe motivation has to come from these classes or these sessions. >> idoes, but it also comest again, mps are well- meaning individuals. and so, once they understand t thatheir mind is playing tricks on them and it might produce discriminatory behavior, with the large, that say "i want to do better." >> reporter: chief wray, how did you get involved in this? i mean, you'ic a black pan, and i think that most people, when they think about bias in police, they think about white policemen and black people.w d you get involved? >> you know, throughout my career, i always thought the issues related to bias, i usually focused on explicit

bias. so i would go into a training, fold my arms and say, literally, this is for the white guys. what i realized is that it wasn't about a specific race, in terms of, you know, an africane american polficer not being impacted by it, or a white police officer are the only ones. what i realized is that i didn't get a pass on that. i realize that this was an issue of human beings, tt we all have implicit biases. and so, that's what really got me into it. >> reporter: okay, so now today when you were having a cyoss, 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." >> reporter: this one says "greatly exaggerated, unfair salitical tool." this one says "sonalized." and another one says "ridiculous." how do you deal with that kind pushback? >> a lot of officers come in believing that bias and policing is not a big iue. they think it's been

exaggerated. they picture ias explicit bias. and they look around the room and they don't see their colleagues as having explicit bias, and so they say "we're being unfairly castigated." and that 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 work? >> not always work. there a few people that, there's always going to be, their minds are made up.t always start the class off saying, you know, if you're not introspective, and if youly personon't want improve, this is, this may not work for you. >> reporter: yet some of the r critics i'd say that there's an absence of probing objective research, and that s longdy is needed to determine if officers really retain what they're being taught, and if civilians actually benefit. i'd like you 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 1.5-year controlled evaluation. >> reporter: how do you respond to that criticism? >> one of the things that i think is powerful about implicit bias training is that there are certain things that you can do in your daily operational as a police officer to heigate some of the issues that you're nfronting. by keeping lines of communication open, slowinggs thown, because if you slow things down, you get to know the person more. contact theory. y the mo know someone, the more your positive interactions with someone, the better you are able to interact. 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 back 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 diffchange. it's transformation, and that takes time. >> reporter: how much time, do you thin >> 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. nkd i think we are on the right trajectory and i te're going to see great changes in policing along these lines. >> reporter: well, i certainly hope so. thank you both for joining us. >> thank you. >> tha you. >> woodruff: our "race matters- solutions" coverage continues online with more on the guilty verdict in the 2017 police fatal shooting of 15-year-old jorda edwards. our website, www.pbs.org/newshour.

and, a correction before we go: we stated earlier in the progr that aretha franklin's funeral is scheduled for tomorrow. it is actually set for fridadein oit. and that's the newshour for tonight. w i'm judruff., join us onlid again here tomorrow 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 newshour has been proby: >> consumer cellular understands that not everyone needs an unlimited wireless 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 >> financial services firm raymond james. >> babbel. a language program that teaches real-life conversations in a new ge, like spanish, french german, italian, and more.

>> and with the ongoing support of these institutions and individuals. s >> togram was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. ctaptioning sponsored by newshour produns, llc captioned by media access group at wgbh access.wgbh.org >> you're watching

mission contntrol: t minus 10, 9, 8... shannon lucid: it was the question every time, was, "ok, are we actually going to launch?" i mean you're just waiting there and you just want it to go. misson control: 7, 6... eileen collins: at t-minus six seconds, the engines light. the shuttle is moving a little bit. misson control: ignition... eileen collins: when t boosters light, you know you're going. starts shaking. it's like you're in a room that's on fire. rhea sheddon: you think you're prepared until it feels like thexphole world's justded. a lot of noise, vibration, acceleration. and that's probably the first five, ten seconds. kathryn sullivan: ow you've got 70,000 hors pumps pulling fuel through those engines and high-speed ts. so, when you're sitting on eight million pounds of thrust, you're paying very close attention to all those dials. rhea sheddon: luckily, i was on the flight deck