Portland School Board Votes to Open Tubman Next August Pending Environmental Questions


Amidst well-founded demands from pedagogically under-served North and Northeast Portland communities whose children currently attend under-enrolled K-8 schools, the Portland Public Schools Board of Education has voted to re-open the Harriet Tubman School as a much needed middle school come next August. The vote is contingent on what both board members and PPS declare will be a robust and potentially disqualifying environmental review.

Spend the money on a super HVAC system, some $2-million according to PPS’s budget projections, and the district can make the indoor air safe to large degree. (See the discussion on indoor-air filtration in Part 2 of this report.) And though there are indeed mitigation strategies to pursue to lessen the risk of outdoor air fouled by pollutants from the busy, bottlenecked highway down below, specifically the barriers afforded by a wall and/or trees, their efficacy is both incomplete – cutting pollutants by up to a half or less – and for Tubman’s location, also perhaps uncertain.

These barrier methods offer partial amelioration only: again, half the pollutants or more may well make it through. There’s no off-the-shelf set of measures that solves the issue of staff and students exposed daily to the emissions off stop-and-go Interstate 5 a bit north of the Moda Center. Up to 17,800 trucks a day pass through, according to the Oregon Department of Transportation, the most of any road in Portland, grinding to a halt and lurching forward, spewing diesel exhaust from within 20 feet of the Tubman campus.

Twenty feet is the few steps from the corner of your kitchen to the far corner of your living room. The roadway emissions, including the tiny ultrafineparticles (UFPs) small enough to get into your blood, brain and heart, waft on the wind a football field and more, certainly far enough to impact the entire Tubman campus as well as the Portland Park & Recreation soccer and baseball fields just north of the school.

Similar to the fifteen-foot or higher noise walls seen alongside many highways, barrier walls are tricky. Build one wrong, and you well might project pollutants up and over the school to where kids may linger on the far side of the building away from I-5. And it’s quite clear that if a wall isn’t long enough – Portland Parks & Rec – it’ll increase the health-adverse load on soccer and baseball players, heavily breathing children being particularlyvulnerable.

As to trees, having to be transplanted a half-dozen or so feet apart to allow the immature trees room for growth, a stand of Douglas firs (a likely species) is several years away from full effect. At best, trees alone cut pollutants by a little more than half or less. And when transplanted, the gaps between immature trees – unless they’re planted in conjunction with and behind a wall, as the U.S. Environmental Protection Agency advocates – might serve to shoot pollutants further downwind from I-5 than with no trees at all.

Still, research at locations different than Tubman’s indicates that a wall and/or trees provide a real measure of relief – something along the order, roughly speaking, of cutting the pollution in half. One skeptic of PPS’s ability to make the air acceptable for student outdoor activities is State Senator Lew Frederick (D-Portland), who boasts long ties to the community as well as a long tenure as PPS’s chief spokesperson from 1993 to 2005.

And Frederick, whose district includes Tubman Middle School and its four potential grades K-5 feeder schools, recognizes the conundrum at hand. He emphasizes the community’s need for a middle school, and that Tubman “needs to open for educational purposes.” Referring to the closing of a prior Tubman Middle School in 2007, when the district embraced a K-8 pedagogy – an apparently mistaken policy PPS is now moving to reverse – Frederick said it never should have closed in the first place.

But, as to the issue of roadway emissions, he said, “I don’t see a technical fix for that.” Asked about kids running around outside the school, he paused before saying, “I don’t have an answer for that.” He added that, if nothing else, Oregon needs to ban the old, ‘dirty-diesel’ trucks foisted on the state by the sale of outmoded spewers from Washington and California, which have banned them. Something must be done to try to curb the high asthma rates that afflict, he says, residents all up and down the 1-5 corridor. While Tubman’s site may be most egregious, Frederick counts nine PPS schools as too close to I-5 in his view.

Interviewed at a School Board meeting November 28, PPS Chief Operating Officer Jerry Vincent, discussed the likelihood of a wall on the top lip of the narrow little hill that runs down to I-5. He also said there might be trees on both sides of these wall: on the school side for pollution mitigation and on the road side to deter graffiti. (Whether trees before a wall lessen the overall mitigation remains to be seen. I encountered no research on that configuration.)

A paper by six EPA researchers, “Near-road air quality monitoring” by Baldauf et. al. (2009) (see here) serves as something of a primer on issues of roadway emissions. (The link provides its full text for motivated readers.) It states that various “studies indicate that populations living, working orgoing to school near major roads may be subjected to an increased risk for a number of adverse health effects….” [Emphasis added.]

Noting that California prohibits the siting of new schools within 500 feet of a busy highway, some experts declared Tubman’s location as untenable, the campus located from 20 to 80 feet off I-5. Dr. Thomas Cahill is a physicist and professor of atmospheric sciences emeritus at the University of California, Davis whose recent research has focused on the copper and iron Particulate Matter (PM) scraped from car and truck brakes. He said, “That is about the last place in Oregon I would want my child to go to school.” Pointing out that the school is downwind, generally speaking, from I-5 for good portions of the year (see the Wind Rose in Part Two), he added, “That building should be used for storing unused school furniture.”

Dr. Linda George, a prominent professor of environmental science at Portland State University who’s served on numerous official advisory bodies, said, “I sent PPS several published studies that documented the impact of freeways on health, especially of children. There is nothing about Tubman that would suggest that this site would miraculously escape from impact.”

And quite a dramatic site it is. Stand a few steps from the building’s southwest corner, you look down a mere 20 feet – like peering down from your second-floor bedroom window – onto the roadway. Just beyond lies a hard-scrabble industrial district, former home to now shuttered Uroboros Glass. Adding to the toxic stew, a busy Union Pacific rail yard lies a half-mile off, the closest tracks half that distance. The Fremont Bridge looms to the northwest with its elevated tangle of feeder roads.

It’s a narrow, little hill.

The school’s elevation such, there’s open sky to Tubman’s south, west and northwest. Then moving west to east, comes I-5, the West Coast’s vehicular zipper, a bottleneck choked with those up to 17,800 trucks a day ODOT says, and well more than 100,000 cars. Next comes a narrow little hill that ranges from 20 to 80 feet wide and from 20 to 50 feet above the roadway. Good portions of the hill crest at 20 feet above the road. North of the building, it barely deserves to be called a hill at all, topping out at well less than 20 feet alongside the whole length of the athletic field where kidsplaying soccer and baseball on Parks & Rec property suck UFPs deep into their lungs – there and on Tubman’s outdoor basketball court.

Elevation and distance measurements come from a contour map from the Conservation Biology Institute (see here). Plain old Google Maps is also useful.

Where the hill is steepest – an approximately 25-degree angle – there’s an ODOT retaining wall some dozen feet high that’s in distress from the lateral movement of a hill formed 65 years ago partly with poorly engineered fill. Then the top lip of the hill, the 5-foot fence visible in the photo below, a 20-foot or so strip of asphalt and then the school building. Standing by that little fence, you could toss a tennis ball into the exhaust pipe of a truck stuck down below.


Whether to open the school or not comes down to a judgement call on the part of the PPS Board of Education. North and Northeast Portland parents have been plagued for years by meager educational offerings provided to their 6th to 8th graders in under-enrolled classes at Martin Luther King, Jr. School, Boise-Eliot/Humboldt, Sabin and Irvington – Tubman’s four feeder schools. (2016 preliminary enrollment figures in grades 6 to 8 were 61 students total for MLK Jr. School; 94 total for Sabin; 134 total for Irvington; and 144 total for Boise-Eliot/Humboldt.)

Many of these distressed parents are African-Americans who have seen their community decimated by gentrification. Their well-being shunted aside in so many ways for so many years, they view the new middle school, currently slated to open in August, as something they both need and deserve. Bad feelings still linger from the 2007 closing of the original Tubman Middle School, which dated from the 1980s.

(A soccer coach needing to speak to one of his players, I had occasion recently to visit a 6th-grade class in one of the beige-in-all-respects portable classrooms behind Sabin. While Sabin has a crackerjack principal who’s doing fine work, the tepid atmosphere out in that portable did not encourage.)

But now, the hundreds of parents who’ve yearned for years for a proper middle school for their kids run the risk of more disappointment should the PPS board bow to an environmental assessment that may deem the Tubman site too hazardous. This after years of setbacks for one reason or another, including the decision in 2016 that the district had too many staff vacancies and too much on a crowded plate otherwise to cope with also opening two middle schools.

A few short steps from the building to the campus boundary. 

Said one parent at a recent MLK Jr. School PTA meeting regarding Tubman, the goal is “to be seen, to be heard, and to continue to pester” the board. They certainly were seen the night of the vote to re-open Tubman, November 14, when a score and and more MLK parents and students lined the walls of the meeting room at PPS headquarters, silently holding banners featuring a portrait of Dr. King that quoted his wisdom on various topics.

Not that either the board or PPS’s leadership, including new superintendent Guadalupe Guerrero, are looking for a reason to kibosh Tubman. In fact, the board resolution (# 5534) to open Tubman in August 2018 noted that the “Initial staff assessment at this time indicates that there are no insurmountable health and safety impediments to opening Harriet Tubman.” (See discussion of the timing of this statement in Part Two.)

Speaking at a board committee meeting, member Mike Rosen said, “We expect the situation is not bad, and we’re going to confirm that.” Hearing affirmation of that expectation from Dr. John Burnham, PPS Interim Senior Director of Environmental Health and Safety, Rosen said of the air-quality hazards, “It looks like it’s manageable, but more data will help.”

Yet that same board resolution to open Tubman also stated, “If the ongoing comprehensive environmental assessments shows significant, irremediable health or safety risks for students and staff, the Superintendent will conduct contingency planning for an alternative location.” That location has not been identified, but many MLK Jr. School parents fear their building might get tapped; indeed, a board member mentioned that in passing.

As with many environmental assessments, it’ll come down to a judgement call, a call ground between the wheels of politics on the one hand and an assessment of risk on the other. It’s a call that’ll depend to a large degree on the crucial air-quality tests on tap, as well as an understanding of the still emerging science and techniques, some still subject to debate, of outdoor-air mitigation. That body of knowledge may be particularly debatable given that Tubman is perched on a hill, open sky for most of the horizon the other side of the road where the winds mostly come. Bottom line, it rests on how a voting majority of the board weighs these issues.

And board members say they’re looking to be honest brokers of the science that’s ultimately presented to them. That, despite heaps of community pressure, it really could go either way. In a joint interview, both Scott Bailey and Rita Moore, the latter the board’s designated point-person on Tubman, stated that the board will rescind the decision to open the school next August should the environmental risks be deemed too steep to overcome.

“If something unanticipated arises, there are two options: If it’s remedial, we could post-pone moving in for a year until it’s remediated,” Moore told me.

“But if it’s so severe and hazardous to health and safety that it can’t be remediated,” Moore added, “in extremis, we will go elsewhere. We have not yet identified an alternative.”

Asked about the political heat of rescinding Tubman’s approval, board member Paul Anthony said that after PPS “knowingly” put students into schools with lead hazards, he was not going to be a party to putting any more kids at risk.

Interviewed after a Tubman planning session with some three dozen parents from the four Tubman feeder-schools, Superintendent Guerrero said simply that he’d trust to the experts. Articulate, forceful and quite deliberately vague, he deftly fended off a reporter.

Referring to the November 14 board meeting, PPS spokesperson Dave Northfield said, “As you heard from staff and the board, the district is committed to doing whatever it takes to properly prepare the building, but would not ignore serious health concerns if they should arise.”

Though one board member has spoken in public about MLK, Jr. School being a PPS “contingency plan” for a potential new middle school should Tubman not open in August, Moore said that MLK, Jr. School has not yet been identified as such. And Northfield echoed that when he said, “There has been no decision by the board on a ‘plan B’.”


There’s been some sketchy talk of basically restricting Tubman students’ outdoor activities, of keeping them inside a sealed up building as much as possible. Under normal circumstances, when you add up before-school, after-school, lunch, recess, any outdoor gym classes – restless adolescents simply escaping adult oversight for a spell – students at Tubman might venture outdoors for something approaching an hour a day. Some more, some less.

Said board member Anthony, “What kind of experience do we want children to have, boxed up in buses, shipped into school, warehoused for seven hours a day, put back on buses and taken away. It doesn’t sound like the kind of school I’d want my kids to go to.”

Nor does it necessarily sound appealing to Tubman Planning Principal, Natasha Butler. Addressing the board at its meeting on December 5, Butler said that in her discussions with prospective Tubman students and their parents, she fielded requests for both a full athletic program and – on someone’s wish-list – the instillation of a turf field. She didn’t reply to an emailed request for her further thoughts on outdoor activities.

The air inside the building can be cleansed – mostly. And the building isn’t going to slide off the hill into a truck’s path, according to John Cunningham of Alder Geotechnical Services, a geotechnical engineer I showed reports from PPS’s soil stability consultant, RhinoOne Geotechnical. PPS hired RhinoOne back in late 2013 regarding the slow, steady lateral movement of the land Tubman rests on, such movement being part of the reason Tubman’s roof is declared the worst in the PPS system, slated for replacement to the tune of $3,000,000.

RhinoOne’s Managing Principal, Dr. Rajiv Ali, wouldn’t tell me much beyond his three formal letters to PPS, which the district has made available. But based on his reading of RhinoOne’s work, Cunningham an engineer with decades of sub-soil experience, said the ground beneath Tubman will continue to slide laterally until it’s shorn up, but that presents no danger to students. (PPS is budgeting $2,000,000 to stablize the school as well as the ground it rests on.) Cunninghan declared there’s certainly almost no danger of a “flush-the-toilet” dumping of the hillside down on to I-5 below. Dr. Ali, the RhinoOne boss, will conduct further tests following the cessation of this winter’s rains – water, of course, being a catalyst to soil movement. (See Part Two.)


So if any environmental concern delays Tubman’s opening, it seems it’ll rest on the outdoor air’s potential to induce health-adverse effects.

Consider where Tubman rests. Its original building, Eliot Elementary School, was built in 1952 on a hill over a ravine back when the interstate highway system, including 1,376 mile-long I-5, was just a gleam in Dwight Eisenhower’s eye. That the school came first is a dead letter, but a weighty one.

The Oregon DOT Portland Region 2016 Traffic Performance Report (June 2017) (see here) calls I-5 “a primary north-south interstate freight route … an international link from Canada to Mexico carrying major freight through-traffic to all of the major cities on the West Coast.” With an average of up to 17,800 trucks a day in 2015, it had “the highest truck volume in the Portland region.” And the truck volume has no doubt increased in the past two years as the region’s economy continues to grow.

And there those trucks travel and sit, directly below Tubman – trucks spewing diesel exhaust, along with many thousands of less polluting cars (truck volume accounted for 10 to 17 percent of total traffic, ODOT says), the brakes of all them shedding both coarse particulate matter (PM) of PM10 or less, which includes PM2.5, and ultrafine particles (UFPs) of copper and iron.

PM10 is defined as particles 10 micrometers (µm) or smaller; PM2.5 as particles 2.5 µm or smaller (detectable only with an electron microscope and about 3 percent the diameter of a human hair); and UFPs, which are less than 0.1 µm or 100 nanometers (nm).

All those vehicles halt and lurch forward, grinding and heating their brakes for almost the entire school day, according to the ODOT report, whichstates that the I-5 bottleneck below Tubman heading southbound extends from 7:45 a.m. to 6:15 p.m. (“with a three-mile queue”), with a little more than an hour break at 10:00 a.m.

Going north, ODOT says the bottleneck extends from 6:30 a.m. to 2:15 p.m. But that doesn’t include the afternoon bottleneck heading north to the I-5 bridge; that stall also sits below Tubman and lasts from 1:30 to 7:30 p.m. (Again, traffic has increased since this data was gathered a couple of years ago – as anyone who’s driven a block in Portland knows.)

That the Board of Ed takes the issue of UFPs seriously is demonstrated by the fact that when voting November 14 to conditionally re-open Tubman, it passed an amendment to its resolution directing PPS to investigate the issue of UFPs, including, iron, copper and zinc from brake wear and other roadway emissions. It also mandated testing for cadmium, a legacy from Tubman’s location up the hill about two football fields from Uroboros Glass. Now shuttered by its owner, Uroboros melted all sorts of poisons in its glass furnaces, the emissions released through unfiltered stacks for 40 years.

So, keep the kids sequestered in the building for three long years? Or let them outside, kids needing to be kids? How much damage will some of them suffer in perhaps an hour a day, give or take, from the roadway emissions wafting up that narrow little hill, some of them running around or playing basketball on the court next to the school, many others quiescent, working their phones?

It rains in Portland. As discussed in the Part Two section on indoor and outdoor air-quality testing, the good news is rain markedly cuts particulate matter pollution; it also cuts down on adolescents hanging around outside.

That said, there are days when it doesn’t rain – truly. Interviewed after a school board meeting November 28, board members Rita Moore, Mike Rosen and Julia Brim-Edwards all said that kids have to be allowed to go outdoors. That there’d be no keeping them cooped up. So what are the possible adverse health effects of short-term daily exposure? After all, in 2015, the EPA advised schools near major highways to “plan strenuous outdoor activities during those times with lower amounts of traffic.” Good enough, except according to ODOT, scant traffic below Tubman is found at 5:00 in the morning or after 7:30 at night.

How much damage will these students suffer while outdoors from the roadway emissions wafting up that short slope, some of them running around or playing basketball on the court next to the school? The school with several hundred students, some portion of the student body will be exposed. And what about the soccer players? A typical soccer practice lasts more than an hour.

Dr. Maria Costantini, principal scientist at Health Effects Institute, a heavy-duty independent research organization, said, “Children … are considered more susceptible to air pollution than adults because of their developing lungs and proportionally higher respiration rates.” Children’s lungs continue developing until age 18 or so.

Baldauf’s et al.’s 2009 “Near-road air quality” paper cited above notes that, “There is no known threshold for total traffic volume, or the percentage of large trucks, below which near-road populations are protected from adverse health effects or pollutant concentrations are maintained” at safe levels.

Trucks aplenty.

As is now well known, diesel truck exhaust is a known carcinogen that contains quantities of nitrogen oxides and all matter of particulates.

“Once outside for lunch or after-school activities, exercising … can quickly make up for a lot of time just sitting at rest [in an air-filtered classroom]. In other words, a short period of running around can counteract a long period of sitting in clean air,” Edward Lawrence Avol, Professor of Clinical Preventive Medicine at the University of Southern California’s medical school, wrote in an email.

“So while the total inhaled amount might well be slightly lower, the increased [breathing rate] during exercise will change the patterns of deposition, the amount inhaled, and may negate the sitting in the classroom during the day. So overall, I actually do not know if the filtered classroom approach really improves a child’s health status because they don’t spend all the critical time periods in the filtered air environment,” Avol’s email added.

Researchers summarized a 2013 World Health Organization finding thus: “Adverse health effect of inhalable Particulate Matter are due to exposure over both short (hours, days) and long (months, years) terms.” [Emphasis added.]

In a 2001 diesel exhaust fact sheet, California’s Office of Health Hazard Assessment stated, “Because children’s lungs and respiratory systems are still developing, they are also more susceptible than healthy adults to fine particles. Exposure to fine particles is associated with increased frequency of childhood illnesses and can also reduce lung function in children.”

Dr. Scott Fruin, an assistant professor at USC’s medical school, said “it’s not settled science” whether peak exposure over some short time frame mightor might not equal the adverse effects of lesser exposure over a longer time frame. “The short-term damage depends on pollutants’ concentration,” he said.

That means there’s a lot riding on PPS’s pending air-quality tests at Tubman, on their design and execution – to be accomplished, one would hope, with oversight from technical experts at the EPA and Oregon’s Department of Environmental Quality. (Part Two.)

There’s no research yet, Fruin added, as to the effects of “short pulses of high exposure versus long-term but lesser daily exposure if the overall daily average is the same.” Saying that no pollution mitigation efforts afford a “complete fix,” Fruin advocated locating the much-needed middle school elsewhere.

Referring to the heavy-metal particles shed by brakes as they work, Dr. Roby Greenwald, an assistant professor at Georgia State University’s School of Public Health, said they cause “acute oxidative stress. It’s sub-clinical and asymptomatic.” That means it’s happening, but you don’t know it. Regardless, the particles may contribute to the etiology of long-term diseases. “There’s damage at the cellular level that can affect lung function, constrict the epithelial linings of the lungs and cause asthma,” said Greenwald. In some cases, children end up as adults with smaller, stunted lungs than they otherwise would, some with life-long asthma.

According to a paper by Grigoratos and Martini (see here), while “almost 40 percent of brake wear debris is emitted as PM10,” a third, by mass, are UFPs – that is, particles smaller than 100 nanometers – with “the highest number of emitted particles … smaller than 30 nm.” And the EPA, in its 2009, 1,000-page report on PM, noted that UFPs of around 30 nm are absorbed by the lungs more than any other size particle (see here, Figures 4-3 and 4-4). From the lungs, they then travel elsewhere in the body.

Since they’re so light, if a third, by mass, of brake wear is UFPs, that means the number count is truly enormous. And that’s decidedly health-adverse since the sheer number is worse than the mass. That’s why, PPS should, it seems, test for the number of UFPs impacting Tubman (see Part Two). As a California EPA paper on UFPs (see here) put it: “a given mass of ultrafine PM contains thousands to tens-of-thousands greater number of particles, with a correspondingly larger surface area, than an equivalent mass of larger particles [such as PM10]. This implies that a given mass of ultrafine particles will impact a larger surface area of lung tissue than will an equal mass of larger particles, thus increasing exposure.”

UFP from both exhaust emissions and brake wear can have serious health effects, no doubt. According to a quite useful 2012 report (see here) from the influential California agency, the Los Angeles-area South Coast Air Quality Management District, “Due to their small size, UFPs can penetrate deeply into the human respiratory tract, into the blood stream, and be transported to other critical organs such as the heart and brain….” They potentially deliver toxics to those organs “that may lead to adverse effects to the heart, lung, and other organs.”

AQMD adds, particularly in the case of UFPs, that “many of the adverse health effects may derive from oxidative stress, initiated by the formation of reactive oxygen species (ROS) within affected cells.”

Earl Withycombe, a consultant and board member of Breathe California, said that for kids, in his view, exposure of even an hour a day so close to a major highway can cause reduced lung development and more asthma. That was echoed by Dr. Frederick Lurmann, chairman of prominent consultants, Sonoma Technology. Lurmann said the potentially “life-long disease” of asthma can be prompted by roadway emissions in otherwise non-allergic kids. Speaking generally, not just of asthma, he added that vigorous outdoor exercise can lead to “substantially higher exposure. For lots of kids, that’s a definite risk factor.” As to whether time-frames as short as an hour or less might prove harmful, he said the research was lacking.

Back in late 2015, when I first started investigating Uroboros Glass’s fugitive cadmium emissions (the reporting that led to breaking the story of the U.S. Forest Service moss study in The Portland Mercury), I interviewed Mary Peveto, the co-founder of Neighbors for Clean Air. Referring to the Harriet Tubman Leadership Academy for Young Women, which was housed in the building until the academy’s closure in 2012, Peveto said, “I had two kids treated for asthma by respiratory specialists while at Tubman—solely while at Tubman…. Their health issues have resolved since they left.” Anecdotal and of no epidemiological significance, make of Peveto’s statement what you will.

UC, Davis professor Tom Cahill said, “There is a serious potential for harming children at that school, especially if they exercise outdoors at times that the traffic is heavy stop-and-go.”

As with many environmental issues, California is in the forefront: under a California law that took effect in 2004, new schools can’t be built within 500 feet of a freeway (it was 1,000 feet when the law was first proposed) unless it’s been demonstrated that “neither short-term nor long-term exposure poses significant health risks to pupils.”

Unfortunately for Tubman parents wondering how long is too long for children breathing the outdoor air on campus, the state of California did not define the phrase: “short-term.” Sophia Kwong Kim has worked for the state Assembly Education Committee and is currently Chief of Staff to Assemblymember Patrick O’Donnell, who chairs that committee. She said there’s no definition of the term to be found in the statute, and referred me to Angelo Bellomo, who Kim said was instrumental in crafting the legislation when he was Director of Environmental Health and Safety for the Los Angeles Unified School District.

Now Director of Environmental Health for Los Angeles County Department of Public Health, Bellomo declined an interview on what the term short-term exposure meant back when he helped write the law. Replying in his stead, the county press office said, “There is no time-designation for these terminologies of short-term exposure or long-term exposure.”

California’s influential Office of Environmental Health Hazard Assessment offered a more substantial statement from its Deputy Director, Sam Delson. He noted in an email that any California school district’s determination on “significant health risks” could take “potential mitigation measures” into account. Delson added: “The closest OEHHA gets to a “short-term” exposure impact on health would be our acute Reference Exposure Levels (RELs.) [See here.] They are meant to protect against infrequent 1-hour exposures, and only apply to specific air toxics. It is unlikely that vehicle traffic near a school would produce a concentration of an air toxic that would exceed any acute REL.” [Emphasis added.]

Unlikely, sure, but then Tubman’s is an extremely unlikely location for a school.

Another reason OEHHA’s RELs would not apply to roadway emissions, as Delson noted, is that “vehicle traffic is not ‘infrequent.’ ”

Delson added, “Particulate matter might be another story, but we don’t have an ‘acute’ standard for PM of any size right now.” Aside from that, Mrs. Lincoln, how’d you enjoy the play?

Open Sky Across the Road.



Or as USC’s Edward Avol put it, “Researchers are keenly aware that ultra-fine particles offer many unique challenges, because their [tiny] size alone provides a way to evade many of the body’s typical defenses. But much of air pollution research is supported by funding to clarify regulatory standards, and ultra-fine particles are not regulated at this time.”

Delson also said, “I’m not aware of any school siting situation where OEHHA has been asked to weigh in on health impacts from vehicle traffic.” That’s in keeping with the experience of Kim, the Assembly staffer. She said that – theoretically – even risky real estate can be acquired by a district willing to assert that there’s a “severe shortage of sites” who then “adopt overriding considerations in its environmental impact report.”

However, she noted, “I am not aware of any districts that have pursued this option.” By these lights – Delson’s and Kim’s – there’s no districts in California acting to site new schools within 500 feet of a road like I-5, never mind the distance from Tubman’s western wall to the edge of the road that’s less than a fifth of that.


The study cited above (see here) was a review of the literature written by two European Commission researchers,Theodoros Grigoratos and Giorgio Martini. As mentioned, they cite work indicating that brake wear is 40 percent PM10 and that, by mass, UFPs comprise a third of total brake-wear emissions. The particles are up to 60 percent iron, along with copper and zinc.

One expert panel concluded that copper averaged 5 percent of the content of brake pads and linings in the U.S.; for Europe, the figure was ten percent. Given the fleet make-up here in Portland, one wonders at the percentage for Japanese and Korean vehicles. And a British study “recognized brake wear as the largest single source of atmospheric copper.”

Referring to roads like the stretch of I-5 below Tubman, Grigoratos and Martini write that brake wear is a particularly significant contributor “within areas with high-traffic density and braking frequency.” In fact, on that type of road, brake wear contributes more than one-fifth of all traffic related PM10, including that from diesel exhaust.

(Though I-5 is technically a freeway, I’ve been advised to discuss the road below Tubman in terms of urban street data, such is its intense stop-and-go traffic.)

Baldauf et al.’s “Near-road air quality” paper notes that stop-and-go traffic “may lead to higher combustion emissions from acceleration and long idling times, and more brake and tire wear from acceleration and deceleration.”

And trucks, of course, are worse than cars; trucks cause 10-times the PM10 brake-wear emissions as do cars, according to Grigoratos and Martini.

Iron and copper are referred to as transition metals, which, as Georgia State’s Roby Greenwald said above, have the “potential to produce reactive oxygen species (ROS) and therefore oxidative strees in biological tissues.”

In fact, copper is considered so dangerous that California and Washington are requiring its phase-out. And, according to the EPA, “copper in brake pads” will be reduced nationwide to under 5 percent by weight by 2021 and to less than 0.5 percent by 2025. The agreement will also reduce the lesser amounts of mercury, lead and cadmium brakes contain.

Still, many research papers, including Grigoratos and Martini, estimate that within a year or three, as tailpipe exhaust is somewhat reduced by technological advances, that “Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related” PM. The non-exhaust emissions are primarily brake wear, tire wear and re-suspended roadway particles – the re-suspended PM “due to traffic-induced turbulence.”

It seems there’s a serious issue afoot at Tubman, a real if unspecified – and indeed, perhaps unquantifiable – risk of health consequences for kids active outdoors on campus. That’s why the volunteers who give freely of their uncompensated time to serve on the PPS Board of Education get paid the big bucks to make the tough decisions.

For what might be done to lessen the risk, the potential mitigation techniques that might cut pollutants more or less in half, see Part Two of this article – not the breezy walk in the park of Part One.

Know something I don’t? Reach me at ddanforbes@aol.com. My series in The Portland Tribune on lead flying off demolished houses might repay a read. My novel (see here): Derail this Train Wreck.

Paul Koberstein