Critics of the Nishi project have pointed toward air quality concerns as a reason to potentially oppose student housing on the site. They cite the EIR as evidence of the potentially significant impact.
Here the EIR notes:
The level of health risk exposure from TACs [toxic air contaminants] generated by nearby stationary sources and diesel PM [particulate matter] generated by trains passing on the Union Pacific Rail Road line would not be substantial. However, the level of health risk exposure from pollutants generated on I-80 would be substantial. Based on measurements collected near the project site it is estimated that the level of cancer risk on the project site is approximately 235-in-a-million, which exceeds the 100-in-a-million cancer risk level specified by BAAQMD [Bay Area Air Quality Management District]. Substantially high UFP [ultrafine particle] concentrations were also measured near the project site and subsequent elemental analysis indicates that the UFPs contain transitional metals associated with severe adverse health effects. For these reasons, exposure to diesel PM and UFPs on the project site is considered to be a significant impact.
However, simply citing this passage is tantamount to cherry-picking from the EIR, which proceeds to go through a series of mitigation measures.
For example, the EIR suggests, “All residential buildings shall be located as far as feasible from I-80, and no residential buildings shall be located on the southwest portion of the project site along the elevated segment of I-80. Residential buildings shall be sited more distant from I-80 than non-residential buildings…”
It goes on to state that “housing where individuals typically reside for a longer period of time, such as for-sale residential units, shall be located more distant from I-80 than other residential units.”
The current version of the project does not have any for-sale units, which will clearly make a huge difference.
Alan Pryor, who opposed the original Nishi project, downplayed the issue of air quality this week.
“I was very clear in the No on Nishi campaign that I didn’t share that concern, particularly if we restricted it to students who are only going to be there for a few years and we have the highest quality air filtration there,” he said.
“By having it only be student housing there, that takes half the equation off the table,” he said. “And installing hepa-filtration, I’m comfortable that’s not going to be a significant quality (issue).”
The site will also utilize vegetative filtration, and the air filtration systems on “all residential buildings and buildings in which people work shall achieve a minimal removal efficiency of 95 percent for UFP.” These measures including pressurizing buildings, double-door entrances, and a high-volume, low-pressure drop air exchange system.
Some have asked whether the residents would be expected to keep their windows shut constantly. One of the claims has been that the prevailing wind from the southwest direction would simply funnel particulate matter toward the project and the matter would be trapped by the Union Pacific Railroad (UPRR) berm.
However, studies of the prevailing winds indicate otherwise (see here and here). The delta breeze comes more from the south than the southwest, and north winds are predominant at other times, which would actually act to keep the particulate matter away from Nishi.
Charles Salocks, an environmental toxicologist working with the California Environmental Protection Agency, in an op-ed from the spring of 2016, wrote that he reviewed Dr. Cahill’s rationale for supporting the New Harmony housing project, which is even closer to I-80 than the proposed Nishi property housing.
Professor Salocks notes, “(Thomas Cahill) supported New Harmony in part because it was upwind of the freeway, while Nishi is downwind.” However, the professor believes “this perspective is simplistic and misrepresents the complexity of climatic conditions in Davis.”
He explains, “Wind roses – which are a clever way of graphically presenting wind speed and direction – clearly show that wind speed and direction vary from month to month, and also depend on whether it’s day or night.”
He writes, “This is important, because in order for Cahill’s ‘ultra-fine particulates generated by braking on an elevated portion of the freeway’ exposure scenario to be relevant, a southwest wind and the traffic backups have to occur at the same time. The monthly wind rose graphs suggest to me that, for much of the year, these two factors are not likely to occur at the same time.”
Others note that the five-foot tall berm that the railroad tracks sit on above the ground level is not going to “trap” pollutants on the site. They argue that if there is no breeze, the tracks are not a barrier and, if the winds are as indicated on the graphs linked above, “the UPRR would not be an obstacle or trap pollutants.”
The EIR concludes that these mitigation measures “would reduce health risk exposure to residential areas.” The EIR was most concerned with the for-sale units, “where individuals typically reside for a longer period of time.”
Still, the report concludes, “While Mitigation Measures 4.3-5a, 4.3-5b, and 4.3-5c are expected to result in substantial reductions to exposure levels of UFPs and diesel PM, the level of effectiveness cannot be quantified. For this reason, and because ‘safe’ levels of UFP exposure and diesel PM exposure have not been identified by any applicable agency, or by a consensus of scientific literature, this analysis assumes that resultant levels UFP exposure and diesel PM on the project site could potentially be associated with a substantial increase in health risks. Therefore, this impact would be significant and unavoidable.”
But what are the actual risk factors here? One of the big questions that arises is not whether exposure to these particulate matters is harmful to the health of residents, but how to place that within an overall risk assessment.
The point I have been making from the start here is that the levels are clearly high enough to trigger significant and unavoidable impacts, but they don’t appear to rise to the level of a health alarm – particularly since most of the impacts are gauged based on long-term exposure not the expected two- to three-year maximum exposure that a student living at Nishi would most likely face.
Gary Jakobs, the EIR consultant, told the Vanguard that “a health risk, as presented in the Nishi EIR, is most easily and readily defined as the possibility or estimated probability of adverse health effects (e.g., illness, injury, or disease) from a person’s exposure to toxic air pollutants. The numbers presented in the EIR are a quantitative measure of the probability of such a risk.”
He noted, “A health risk is not a guarantee that a specific number will contract a particular adverse health effect, but rather an assessment of a particular condition (e.g. proximity to elevated freeway) and the probability that individuals subject to that condition could experience an adverse health effect.
“It is true that the conditions at the Nishi site do not make it the worst place to live in the state,” Mr. Jakobs stated, adding that “the relative health risks within many of the urban areas in the state are likely much greater.”
He also stated, “It is important to note that ultra-fine particulates (UFP) is not generally assessed as part of current health risk assessments, and there are no established ambient air quality standards (national or state) for UFP, as of yet.”
Back in January, Mayor Pro Tem Robb Davis, himself a public health professional, argued that the risk assessment at Nishi was actually quite low.
Section 4.3 of the Draft EIR for example, notes, “One common metric of health risk is the number of additional cancer cases that may occur in the population exposed to a particular TAC, or located in an area exposed to TACs in general. This is typically reported as additional cancer risk per million people.”
Here the EIR notes that, according to the American Cancer Society, “the lifetime probability of contracting/dying from cancer in the United States is 43.3%/22.8% among males and 37.8%/19.3% among females. In other words there is a lifetime probability that over 430,000 per 1 million males and over 370,000 per 1 million females will develop cancer over their lifetime.”
In his comments to council, Robb Davis noted that the lifetime risk of respiratory cancer was about 10 percent or 100,000 in 1 million.
The numbers shown here are 235 per 1 million.
The EIR notes, “Long-term exposure to this concentration of diesel PM corresponds to an incremental cancer risk level of 235 in one million above the background level of cancer risk from TACs in the region for residential receptors.” They add, “The estimated level of increased cancer risk based on SMAQMD’s [Sacramento Metropolitan Air Quality Management District’s] Roadway Protocol (SMAQMD 2011) is approximately 197 in one million.”
Again the key is “long-term exposure” which, as student rental units, the residents would not be receiving. But also the risk factor itself, while significant, is still very low. You are adding 0.0002 percent risk for long-term exposure.
Robb Davis last year said that in a real sense the risk of additional cancer and overall health impacts are quite low. They claim that one problem with the analysis is that they do not address the issue of additional mortality associated with the risks over what time period.
Tim Ruff made a similar comment: “The EIR consultants came to the conclusion it is significant and unavoidable because there is no ‘proof’ so to speak. There are no levels set regarding safe levels and only studies that show how promising urban forests are and other mitigating factors. Given this uncertainty the consultants made that determination.”
However, this isn’t enough to satisfy Thomas Cahill. He argues that this is an emerging area of science and he would use the term “dangerous” to describe what he believes is a significant added risk of death from exposure to the particulate matter at Nishi.
Instead, he suggested that there is the need to err on the side of caution, or what he would call the “precautionary principle.”
He said, “After getting all the scientific information possible I would have to make my judgment with the ‘Precautionary Principle.’ This requires that in the face of uncertainty, I would have to choose on the basis of the most conservative estimate of the impact, which is almost always lower than the scientist’s bottom number. In Davis, this means that (if) there is any reasonable chance that I and my colleagues are right, I would have to reject residential use and maximize protection of workers in commercial or research facilities. The best way to solve this is to have better data, covering at last a year and including all the most toxic components. This is what I recommended in Jan 2015.”
However, Dr. Salocks has a different view, concluding, “Although I respect Dr. Cahill, acknowledge that he has done excellent research, many of his claims concerning the health risks Nishi residents will face are overstated.”
From my perspective, the EIR is very thorough in laying out the risks at Nishi, and, based on a several pieces of information, I believe the risk is manageable.
First, the impacts we are talking about are based on “long term exposure.” I take that to mean at least 20 years and am told that it could be much more than that. The change from having some for-sale units to having all rental units is a huge mitigation against long-term exposure.
Second, the wind patterns suggest that this is not a “perfect storm” scenario where the pollutants are simply blowing into the project and sitting there indefinitely. The graphs show that, for much of the year, the winds would actually blow the particulate matter away from and not toward the project.
Third, the filtration, trees, and building design would mitigate some of these effects.
Fourth, all available research indicates that the risk level itself is extremely low.
Adding mitigation makes sense, but going further than that ignores just how low a risk this actually appears to be.
—David M. Greenwald reporting