The Village of DePue: Put a Fence Around It - Part 15

This is Gabby Garcia.  The CleanUp DePue web site tells me she is standing "in front of the 750,000 ton zinc slag pile."

There is a chain link fence that separates Gabby from the pile of slag left there from 80 years of zinc smelting, fertilizer production and other industrial operations. If I had to guess, I am pretty sure that Gabby perceives this slag pile just as the CleanUp DePue August 15, 2012 press release describes it:

The fence refers to chain link that cordons off 950 waste-tainted acres on the former site of a smelter and other operations that include a 750,000-ton slag pile the locals call “the pile of black death.” 

Why would Gabby think anything different?  Her town's advocate, Nancy Loeb, director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic and pro-bono counsel for the Village of DePue, tells her and others that the pile behind the fence is doing harm:

The reality is that children are growing up here, eating from home gardens, playing in parks and ball fields, boating in the lake, and later working and living as adults in DePue. Any realistic assessment of health risks has to take these multiple, constant and long-term exposures into account.

Northwestern University built a web site to help Gabby understand the danger posed by that pile behind the fence.  They tell Gabby:

The [CleanUpDePue.org] map shows contamination levels for nearly 2,000 samples, as well as the health risks for residents with prolonged exposure to these contaminants. (1)

She is then told by Northwestern that:

heavy-metal contamination in general leads to increased incidence of neurological issues and cancer.

Hmmm...you can see why Gabby might be concerned   So let's say that Gabby wants to know what will happen to her if she plays in White City Park.  She goes to the interactive map and clicks the little icon and this is what she sees:

Source

Gabby is told that she will be exposed to "Contaminants above Illinois EPA soil background level" for which seven chemicals are listed: Barium, Cadmium, Copper, Iron, Lead, Manganese, Zinc.

Gabby then clicks on that little red question mark "?" and she is told:

The Illinois EPA considers these background standards an appropriate measure by which to compare soil samples.

Underneath that statement she reads that the first chemical, Barium:

According to the US EPA, people who ingest excessive Barium in drinking water over a prolonged period of time may experience an increase in their blood pressure.

She then looks at the next chemical, Cadmium and is told:

According to the US EPA, people who ingest excessive Cadmium in drinking water over a prolonged period of time may could develop kidney damage.

Copper...:

According to the US EPA, "Some people who drink water containing copper in excess of the action level may, with short term exposure, experience gastrointestinal distress, and with long-term exposure may experience liver or kidney damage.

Iron...

It is not associated with health risks but an abundance of iron in drinking water may cause "may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color).

Lead

According to the US EPA, "Infants and children who drink water containing lead in excess of the action level could experience delays in their physical or mental development. Children could show slight deficits in attention span and learning abilities. Adults who drink this water over many years could develop kidney problems or high blood pressure."

Manganese

The US EPA does not have any standards regarding the amount of magnesium healthy to ingest in drinking water

Zinc

It is not associated with health risks but an abundance of zinc may cause "cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water" according to the US EPA.

Here is what Gabby sees when she turns around:



Here is what Gabby has been told about what she sees:

• "pile of black death” 
• "heavy-metal contamination in general leads to increased incidence of neurological issues and cancer"
• "may experience an increase in their blood pressure"
• "could develop kidney damage"
• "may experience liver or kidney damage"
• "skin or tooth discoloration"
• "could develop kidney problems or high blood pressure"

Is it any wonder that Gabby and her fellow DePueians would want to sign a petition to:

Support the cleanup of DePue, including full restoration of Lake DePue, removal of the slag pile and other hazardous substances from the plant operation’s site and the entire DePue community.

In the eyes of Gabby and her cohorts, removal of the pile equals cleanup.

That option would take care of the problem, but that's not the best remedy, nor is it necessary to protect Gabby.

If the data that I have access to is a true and accurate representation of the contaminant levels in OU-4, then the risk of adverse health affects will be removed once the remedy proposed for OU-4 is accomplished:

Source: Illinois EPA to the Illinois General Assembly House and Senate August 10, 2012

The problem with that remedy is that it does not meet with the only remedy Gabby has been told is acceptable; removal.

Removal of these piles is not going to happen because there is no reason to remove it other than the perception that leaving it in place harms, or has the potential to harm, the folks who live in DePue.  Leaving the piles where they are is the only viable remedy when all the risks are considered.  That is a bitter pill to make these folks swallow but that's what the need to accept.

As I brought up in my previous posts, removal of the contamination places it in somebody else's backyard.  Not only that, it increases the real risk of harm to other humans when each truck leaves DePue and travels to the new backyard.  The further it travels the greater the risk of an accident  For guys like me, I look at their situation and ask if the probability of death or injury from a head-on collision of a dirt truck more or less than leaving the contamination in place where it is?

I also look at the fact that disturbing that pile will bring up dust and possible contamination when it is worked on.  Is that probability of this exposure more or less than that from leaving the waste in place?

I cannot ignore those risks in my decision process.  They must be weighed along with what the impacted citizens in DePue want  Those are real risks, whereas the pile behind the fence may - or may not-  be a greater risk.

That's what needs to be conveyed to the folks in DePue by Nancy Loeb and Northwestern University.  What Gabby sees and has been told does not accurately reflect the risk to her based on the evidence that has been provided by CleanUp DePue.

If Gabby is being harmed by this pile of slag or from the contaminated areas that were the result of past activities, then there is a real concern.  The sample data does not support that.  The levels of contamination that Gabby has the potential to be exposed to our very low in OU-4.  Once they are cleaned up, as has been proposed, she will be at the exact same risk than if the pile were picked up and moved far away.

I can say this based on what I have been told has been done to the contamination that is there, what is being proposed for the site, what the sample results show, and from what Mr. Garcia's science class found.

So let's bring this all to an end and ask this final question.  Is Gabby's health being compromised as she stands on the other side of the fence?

If yes, remove the pile.  If not, make sure that pile stays where it is, behind a fence, secured.  The genie still in the bottle, the sleeping giant asleep, the lion it its cage.  No exposure, no health effect.

Next post: The Village of DePue: Wants and Needs - Part 16

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The Village of DePue: A totally unrealistic methods for looking at risk - Part 14

In the end, I want the folks in DePue to not be exposed to chemicals that were the result of past operations from a former zinc plant.  Nancy Loeb, director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic and pro-bono counsel for the Village of DePue, wants that too.

We are on the same side.  So why am I so hypercritical of her advocacy?  Because, like all my past posts on evaluating risk, she is not looking at it correctly.

I don't really expect a lawyer to understand the complexity of a risk assessment.  That's not a dis on lawyers, that's a reality.  It is complex.  So when Ms. Loeb states:

"The reality is that children are working and living as adults in DePue. Any realistic assessment of health risks has to take these multiple, constant and long-term exposures into account.” (1)

She is indicating to me that she understands how environmental risk is calculated.  She apparently takes issue with the way CBS and ExxonMobil have calculated that risk.  This indicates to me that she knows another way that it should be done; a way that is different than how we do it as wll as how the Illinois EPA and US EPA require it be performed.

Ms. Loeb is telling DePue that how the risk has been calculated is wrong.

As part of a university, Northwestern, I expect her, a lawyer, to get the necessary expertise to comment on the plan.  She appears to have done that according to the Campus Life newspaper at Northwestern:

Loeb quickly called on her Northwestern colleagues to help assess the situation. When she needed expertise to analyze reports on the human and ecological health risks in Lake DePue, she called on environmental engineering professor Kimberly Gray. (2):

Okay, cool, she has an environmental engineer assisting her.  So then it must have been Ms. Gray that told her "any realistic assessment of health risks has to take these multiple, constant and long-term exposures into account.”  I am assuming that Ms. Gray is familiar with EPA's soil screening levels and how that same methodology is used by the Illinois EPA to establish a cleanup objective.

Let's look at what Ms. Loeb contends is an unrealistic method for long term - chronic - risk.

“In determining whether a person is exposed to potentially harmful levels of toxic pollutants, CBS and ExxonMobil are counting each exposure as if it were an isolated incident, and pretending that residents are exposed only to a single contaminant and only in one area of the town."

Whatever contaminant levels the Illinois EPA agrees to in DePue must be calculated in a scientifically sound way.  At the present time, the way we look at chronic exposure for a non-carcinogen is based on this philosophy:

"Based on our understanding of homeostatic and adaptive mechanisms, systemic toxicity is treated as if there is an identifiable exposure threshold (both for the individual and for populations) below which there are no observable adverse effects." (EPA)

This leads us to accept the assumption that there is:

"a range of exposures from zero to some finite value can be tolerated by the organism with essentially no chance of expression of the toxic effect.” (EPA)

When we calculate a cleanup level for contaminated soil, we do it based on estimating what the level could be that can be tolerated by the organism.  In the case of DePue, we are looking at humans as our organism of concern.

What we want to know is for any given amount of soil that my human comes in contact with, what concentration of that toxic material can be tolerated.  This is based on the concept of a reference dose.

Whatever clean up objectives the Illinois EPA is agreeing to will be based on that assumption and concept.

We do not count each exposure "as if it were an isolated incident."  We look at exposure at a set amount over a lifetime of 70 years.  If a sample of soil is above that acceptable dose we assume it needs to be remediated.

I must assume, based on the statement from the Illinois EPA to the Illinois House and Senate, that the soil in OU-4, the area where people live, work, and play, will be remediated to a sound risk-based concentration.

Source

I don't know what those levels are, but for the Illinois EPA to "concur with this approach," they must be based on a sound risk based calculation such as the EPA's soil screening level models.  Ms. Loeb is indicating that there is a better model to use, one that takes "these multiple, constant and long-term exposures into account.”

Okay...show me how this is done and why it is more sound than the method we use now.

Is the concern one that believes the contaminants are not being addressed as additive?  Let's look at Illinois EPA's TACO's for an explanation on this concept:

TACOs Fact Sheet

I have discussed how we look at carcinogens in my previous posts.  Carcinogens will be cleaned to background, the chronic non-carcinogens that may be additive are cleaned so that the calculated HI is less than 1.

I am a bit confused here.  Since the Press Release was issued after the Illinois EPA letter to the Illinois House and Senate, does Ms. Loeb contend that the Illinois EPA is not following TACOs?

Because the Illinois EPA tells the House and Senate that CBS and ExxonMobil "proposes to excavate contaminated soil from residential lots and other areas of the Village" I am assuming that TACOs has been met.  If it has not, then Ms. Loeb has a beef and she should be advocating that TACOs be followed.

Ms. Loeb contends that this plan "leaves backyards, playgrounds and Lake DePue without real remediation.”  If that is true, show me.  Show me how her data calculates a risk differently than the one the Illinois EPA is agreeing to.

If TACOs is not being followed, show me.  Show me where the Illinois EPA has agreed to leave "backyards, playgrounds and Lake DePue without real remediation.”

Show me what a "realistic assessment of health risks" looks like that takes "these multiple, constant and long-term exposures into account.”  Show me where the plan is unrealistic in terms of risk.  I am not seeing it from the evidence provided in the CleanUp DePue website.

What Ms. Loeb is advocating for is one remedy and one remedy only.  Clean up.

They want the waste removed.  Picked up and taken away.

The reason for this is perception.  Behind that fence is “the pile of black death.”  The folks in DePue have been waiting for something to happen to cleanup this pile, and "after 17 years of waiting, the companies presented a plan that basically proposes to dig up a handful of the polluted areas and throw the toxic waste over the fence.”

This is how they see their situation and Ms. Loeb is doing little to bring them to understand the real risk.  Look at what they are being told by Northwestern's campus paper:

While no longitudinal health studies have been conducted on the residents of DePue, heavy-metal contamination in general leads to increased incidence of neurological issues and cancer. 

See it from the perspective of a citizen in DePue that lives in OU-4.  Pile of "black death,"  heavy metal contamination, and "increased incidence of neurological issues and cancer."

Now counter that with my 14 posts.  Yeah, they are all asleep and bored out of their minds.

She wins because she tells them "ExxonMobil and CBS are continuing to minimize the risks to human health and the environment and to set the groundwork for leaving the contaminated waste where it is.”

That's what they want to hear because that's what they think is going on in their town.  Pile of "black death,"  heavy metal contamination, and "increased incidence of neurological issues and cancer."


Next post: The Village of DePue: Put a Fence Around It - Part 15

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The Village of DePue: Put it in someone else's backyard - Part 13

NIMBY (an acronym for the phrase "Not In My Back Yard"), or Nimby, is a pejorative characterization of opposition by residents to a proposal for a new development because it is close to them, often with the connotation that such residents believe that the developments are needed in society but should be further away. Opposing residents themselves are sometimes called Nimbies. (1)

With that in mind, let's begin:

In a nut shell, here is how the public looks at a situation similar to the one in DePue.

Source

It does not matter what the chemical of concern is, if there is any type of risk involved, the public reacts in a very predictable way.  In the case of DePue we are not talking about siting a facility there, but keeping the waste in place.  Revers siting so-to-speak, same thing though, the folks in DePue do not want it in their back yard.

In my last post I asked the question "what's the beef?"  I found out that the contamination in OU-4, the area of public health concern because that's where actual exposure can take place, is going to be cleaned up.

"[Exxon Mobil and CBS/Viacom] proposes to excavate [OU-4] contaminated soil from residential lots and other areas of the village and deposit the soil in the corrective action management unit..." (2)

So if that contaminated soil is going to be removed, what's the issue that requires the involvement of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic?

According to the Chicago Tribune article that started me on these posts:

[T]he involvement of Northwestern University's Environmental Advocacy Center — which is providing DePue with free legal representation — has given them some much-needed clout and could help the town finally realize its goal of eliminating or containing the contamination.

Isn't that the goal of the Illinois EPA?  Isn't that what is being proposed in the plan?  I have read all that I can find about this situation in DePue.  Unless the Illinois EPA is lying to the Illinois House and Senate, the issue in OU-4, the area where exposure could take place, is being rectified.  No where in the CleanupDePue.org website or press release does it specifically tell me what they - DePue - want done differently.

But I think I know.  NIMBY.  An not just regular good ol' NIMBY, but NIMBY made acceptable by educated folks who are associated with a prestigious university.

When Nancy Loeb, the director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic states in the Press Release...:

"The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks, and they delivered a superficial plan that barely touches many of the contaminated areas, leaves the slag pile and other waste in place, does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.”

...she is helping the NIMBY phenomenon by perpetuating all five of the factors that lead to a strong opposition.  The burden to educate and advocate soundly falls squarely on her shoulders.  She is the educated one here, and she - through Northwestern University - has the ability to bring in the expertise needed to confirm protection of public health for the citizens of DePue and provide analysis and clarification of the data and risk for the remediation proposed.  This, in my opinion, has not been done. If it had, I would not be writing 13 posts explaining what the risks are.

Let's look at these five factors giving way to the NIMBY phenomenon using CleanUp DePue's Press Release:

Distrust of government and other project components:

 "The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks..."

"Illinois EPA has had the responsibility for oversight, and for most of that time, the Illinois EPA did little to force ExxonMobil and CBS to fulfill this order."

 “People here are tired of ExxonMobil and CBS earning record profits while jeopardizing the health and well-being of the children, families and wildlife in DePue,”

“We are raising awareness, and raising funds so we can hire experts to reply to ExxonMobil and CBS’s faulty science,”

 Limited information about the problem and risks:

"Visit www.CleanUpDePue.org to see an interactive map that details the way-above-normal concentrations of pollutants at hundreds of contaminated sites."

“The consent order required the responsible parties to come up with the plan, supervised by the Illinois EPA. I don’t know how to respond to that plan. It’s not even close to what’s needed.” 

Parochial and localized view of problem, risks, and costs:

"and their “solution” would turn the central Illinois River town into a permanent toxic waste dump."

"the companies presented a plan that basically proposes to dig up a handful of the polluted areas and throw the toxic waste over the fence.”

"ExxonMobil and CBS are continuing to minimize the risks to human health and the environment and to set the groundwork for leaving the contaminated waste where it is,”

"Keith Garcia, a science teacher at DePue High School who had his class sample soil and water to document unsafe concentrations of pollutants."

Emotional assessment to siting proposals

The reality is that children are growing up here, eating from home gardens, playing in parks and ball fields, boating in the lake, and later working and living as adults in DePue."

 “Industry took their profits, and left their toxic contamination here,” 

“I feel like the victim again,”

Generalized and particular risk aversion

"Contaminated debris blows onto public and private property throughout the village and surrounding natural areas, exposing residents -- more than a quarter of whom are children under the age of 16 -- and local wildlife to arsenic and heavy metals such as lead, mercury and cadmium."

That press release, that quotes Nancy Loeb, is dated August 15, 2012.  It came out after the August 10, 2012 letter from the Illinois EPA to the Illinois House and Senate detailing the plan of action proposed.

What is being proposed and considered by Illinois EPA does not support CleanUp DePue's press release rhetoric which basically contends the plan is "not even close to what’s needed."

What exactly is the opposition to this plan?  The Illinois EPA tells us in their letter:

Source

It's that last sentence that is the crux of what all of this is about.  The plan is to remove the [OU-4] soil and place it in a corrective action management unit, on the existing slag pile, or to temporarily store the soil elsewhere on the plant site.  This, with Nancy Loeb's apparent blessing, is construed to mean "dig up a handful of the polluted areas and throw the toxic waste over the fence.”

Northwestern University, through Nancy Loeb, should be assisting the town in moving away from this "parochial and localized view of problem, risks, and costs" into one of understanding what the best remedy for this situation is.  Instead, Ms. Loeb tells them:

"ExxonMobil and CBS are continuing to minimize the risks to human health and the environment and to set the groundwork for leaving the contaminated waste where it is,”

Because Ms. Loeb has a "parochial and localized view of problem, risks, and costs" those that are listening to her will also have said view.  What Ms. Loeb is advocating for is to have the contaminated soil removed from DePue.  Dig it up and move it out of there appears to be the only acceptable method of remediation that Ms. Loeb will consider for DePue. What she is not addressing is the fact that if you removed it from DePue, who's backyard will you send it to?

She should be advocating to make sure that the levels of contamination where people are exposed, OU-4, are brought to a legal and/or risk-based level.  That appears to be the remedy for OU-4.  So why is she alowing the town to take exception to the deposition of Village soils on the plant site?

Why, because of NIMBY.  Only in this case, NIMBY would result in taking this slag pile and putting it somewhere else, you know, in somebody else's backyard.

Who's backyard?  A hazardous waste landfill?  Sure, those guys would love to receive 750,000 tons of soil.  But there is more risk of digging it up and transporting it then any exposure to that soil if it is left in place.  Right now that slag pile and corrective action management unit does not appear to be exposing anyone.  If it is, then something needs to be done about that.  Since none of the data on their website supports that (I checked - see previous posts), then the slag pile and corrective action unit are not presenting a health issue.  And once the elevated soils are removed from OU-4, exposure ceases for the folks in DePue.

But, Ms. Loeb claims the plan "does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.”  Show me why.

That's not what the Illinois EPA is telling the Illinois House and Senate.  That's not what they tell the folks in DePue.  You can read about what has been done here.  Show me what "real remediation" means.  Right now what I know has been done, and what has been proposed, makes sense to me.  If I am missing something here, then put that on the CleanUp DePue website.

If the only acceptable remedy is to "remove the materials and clean the site of all contaminants to the satisfaction of the Village" and to "clean the site and have it removed from the NPL [Superfund List]" then nothing is going to make these folks happy short of that. (3)

Ms. Loeb needs to help them understand all of the risks involved.  The contamination is already there.  It sucks that it is, but that's the reality.  There is no practical way to dig up and remove all of that soil without filling up somebody else's backyard.  If you claim it is unsafe to leave it there, why would you want to place it somewhere else?  And if you think a hazardous waste landfill is the way to go, you need to think about capacity and the distance to drive a truck to that location. What needs to be advocated for is minimizing real exposure, not removing the contaminant.

To remove 750,000 tons of the slag pile would take about 28,000 trips on the road.  Is the risk of a truck hauling dirt on a public highway less than the risk of leaving that slag pile in place?  Is the risk of occupational accidents as we excavate that soil less than the risk of leaving that slag pile there?  Would the risk of air dispersion of contaminants when the soil is excavated and loaded onto trucks be less than leaving the slag pile untouched?

I think not.

If Nancy Loeb thinks those new risks are necessary to take in order to protect the folks in DePue, then let her advocate for them by showing why those new risks can be ignored.  But if she does, then she will also have to explain why putting the contaminant in someone else's backyard makes sense as well.



Next post: The Village of DePue:  A totally unrealistic methods for looking at risk - Part 14

The Village of DePue: What's in store for OU-4 - Part 12

I began writing this series of posts because I was skeptical of the claims made in the Chicago Tribune in an an article titled "Pace of hazardous waste cleanup frustrates DePue residents."

My skepticism was elevated when I read in the DePue Press Release that:

Contaminated debris blows onto public and private property throughout the village and surrounding natural areas, exposing residents -- more than a quarter of whom are children under the age of 16 -- and local wildlife to arsenic and heavy metals such as lead, mercury and cadmium.

I had no idea where these posts would lead me.  But one thing I knew, is that there was a claim of contamination and numbers to back that claim up with:

Visit www.CleanUpDePue.org to see an interactive map that details the way-above-normal concentrations of pollutants at hundreds of contaminated sites.

So a bit skeptical, and curious, I went in pursuit of an answer to the claim that the people in DePue are exposed to "way-above-normal concentrations of pollutants at hundreds of contaminated sites."

Now this trip down the blogosphere can be a bit onerous if one is grasping at straws for information that will support, substantiate, or refute a statement of "way-above-normal concentrations of pollutants at hundreds of contaminated sites."  So when I saw that the folks in DePue had Northwestern University on their side, my skepticism started to wane a bit.  Maybe there was something going on to substantiate a website called CleanupDePue.org demanding that "responsible parties, Exxon Mobil and CBS/Viacom return to DePue and clean up their mess."

Instead of saying - as I usually do - show me the numbers, which is tantamount to stating "show me the beef!"  I instead asked myself "what is the beef?"

The Cleanup DePue Press Release quotes Nancy Loeb, the director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic, as claiming:

“The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks, and they delivered a superficial plan that barely touches many of the contaminated areas, leaves the slag pile and other waste in place, does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.”

So there I was, Mr skeptical, looking at two claims telling me and anyone who visits their web page that there are "Way-above-normal concentrations of pollutants at hundreds of contaminated sites" and the clean up plan "leaves backyards, playgrounds and Lake DePue without real remediation.”

What I know about the site - and I am privy to just what a citizen living in DePue has access to - is that there are five areas - called "operable units (OU)" - designated as contaminated.

Source

When dealing with contaminated property, we normally look to see who or what is going to be adversely - or negatively - affected.  What I write about - and have set this series of posts on - is an impact to public health.  I am only concerned about exposure to a chemical contaminant whereby the contaminant can enter into the human receptor.  Basically, what we need are two conditions to have the possibility of a health effect;  exposure and dose.

My primary concern is where exposure can take place day in and day out.  That limits my research to OU-4 which is where the people of DePue live, work, and play.  Here is what I am told about Operable Unit 4: Off-site Soils:

• Includes plant area residue used as fill throughout the Village of DePue, including in residential yards, public parks and other public areas, alleys, etc.
• Additional metal contamination is present as a result of air deposition of contamination from the plant area.

 From a public health standpoint, that's the area that will present the two components - exposure & dose - necessary to perform a risk calculation.

What's nice about this, and I had no idea of this when I started writing these posts, is that I have access to all the sample data.  It's not perfect, but it does paint a picture of what the potential exposure is.

When I looked at the data for OU-4 (see previous post) I found that there were 125 samples of soil that had been collected from this area.  Although they tested for a number of metals and salts, my concern is to look at the ones that present the greatest potential for a health effect based on toxicity and concentration found.

These Chemicals of Concern (CoCs) are what we focus on.  So for OU-4, there are four heavy metals that I need to address; Arsenic, Barium, Cadmium, and Lead.  The other metals, including zinc, are all under soil screening levels in the 125 soil samples collected.

For the 125 soil samples 102 samples have one or more of the four CoCs above a soil screening level or cleanup objectives.  Of these 102, the data shows:

• 97 of 102 samples have arsenic above the background 11.3 mg/kg
• 6 of 102 samples have barium above the Illinois objective 5500 mg/kg
• 19 of 102 samples have cadmium above the Illinois objective 78 mg/kg
• 36 of 102 samples have lead above the Illinois objective 400 mg/kg

Now there are a ton of ways to spin this statistical data.  I'm not going to play that game.

• The highest concentration of arsenic is 4.2 times higher than background.
• The highest concentration of barium is 1.6 times higher than the Illinois cleanup objective.
• The highest concentration of cadmium is 1.9 times higher than the Illinois cleanup objective.
• The highest concentration of lead is 2.0 times higher than the Illinois cleanup objective.

For 102 samples, those are the highest possible exposure a person living in living, working or playing OU-4 could have.

With that in mind, let's look at what an average exposure would be for the 102 samples.  If you are paying attention, I am not going to include the 23 samples below a level of concern.  In this way, I can get a pretty good feel for what an high sided average exposure would be in OU-4:

• The average concentration of arsenic is 1.7 times higher than background.
• The average concentration of barium is 1.2 times higher than the Illinois cleanup objective.
• The average concentration of cadmium is 1.2 times higher than the Illinois cleanup objective.
• The average concentration of lead is 1.3 times higher than the Illinois cleanup objective.

Because I know that the cleanup objectives and screening levels are very health protective, these average exceedances are nothing that would cause me a concern.  That's not to say I would recommend nothing being done about them, what it does indicate is that this statement:

Visit www.CleanUpDePue.org to see an interactive map that details the way-above-normal concentrations of pollutants at hundreds of contaminated sites.

...is not supported.  I did go to the website.  I did look at the interactive map.  I did crunch the numbers from the Excel sheets they provided.  What I found does not come close to how I view "way-above-normal."

Additionally, the claim that "contaminated debris blows onto public and private property throughout the village and surrounding natural areas, exposing residents" is not supported by the analytical data from the samples collected by Mr. Garcia's, the local high school science teacher.

Nancy Loeb, the director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic, asserts that the cleanup plan that has been submitted:

"...does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.”

My read on that leads me to conclude that apparently the potentially responsible parties (PRPs) - Exxon and CBS - have said that OU-4, the off-site soil area where the good people of DePue live, work and play, "poses no significant risks."

I kind of concur.  However, and there's that nasty little bit of ethics I spoke about in my last post, I believe that these PRPs have a moral obligation to reduce the risk to an acceptable level.  Are they really telling the folks that live in DePue that they are going to nothing about the soil that exceeds the Illinois cleanup objectives?

Ms. Loeb tells us:

"and they delivered a superficial plan that barely touches many of the contaminated areas...and leaves backyards, playgrounds and Lake DePue without real remediation.”

How can this be?  What is supposed to happen in DePue regarding the soil in OU-4?

Well I went looking for an answer to that question.  Here is what I found in a document dated August 10, 2012 from the Illinois EPA to the Illinois General Assembly House and Senate:

Source

OU-4 is going to be cleaned up so that the levels are below a health risk threshold.  Low exposure equals low risk.  Safe.  Why is Ms. Loeb telling DePue that this "leaves backyards, playgrounds and Lake DePue without real remediation.”  It does not.  So what's the beef here?

Oh...I see...so that's what this is all about.


Next post: The Village of DePue:  Put it in someone else's backyard - Part 13

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The Village of DePue: The ethics of drawing a line - Part 11

Looking at the 125 samples collected in OU-4, I found that a number of them exceed the level of concern.

Arsenic, in particular, creates the most problem for establishing a "safe" level at which to leave the soil in OU-4.  Because OU-4 is the area where exposure can take place.

The problem with arsenic is not the poison part we all associate it with, but instead our knowledge that it may cause cancer at low concentrations.

The problem with contaminants that are suspected to cause cancer is that we are told:

The underlying presumption for carcinogens is that the introduction of even one molecule of the contaminant can cause cancer in an individual even if the probability is very low. This conservative, “non-threshold” concept is used because it is presumed that there is no level of exposure to a carcinogen that does not pose a certain level of risk.

That's from Illinois' TACO's Fact Sheet.  That statement is one of the presumptions we hold as true when we look at risk of exposure to a chemical.

You can see the bind that puts us in.  If we say exposure to "even one molecule of the contaminant can cause cancer in an individual" setting a "safe" concentration is, well, not possible.  Instead we draw a line in the sand and say:

You see how they put us risk calculating types between a rock and a hard place?  For exposure to a contaminant in soil, I have to come up with a concentration that theoretically will show no more than one excess cancer per 1,000,000.  That number, based on what we know today, is calculated to be no more than 0.39 mg of arsenic in a kg of soil (0.39 mg/kg).

Now there is no way on God's green earth that you will ever find soil at less than 0,39 mg/kg of arsenic.  Arsenic is a naturally occurring element.  It is everywhere.  Because it is everywhere, we are constantly exposed to it.  In this case, we cannot reasonably ask that soil be cleaned up to a standard lower than what good ol/ mother nature has exposed us to.  So we settle on a background concentration as our cleanup objective.

According to the regulations in Illinois (742.Appendix A, Table G) the background for arsenic in soil at 11.3 in non-metropolitan areas.  Therefore, we are now going to live with this:

But this creates a sense of foreboding when the levels exceed background.  What is the probability of added risk?

In OU-4 there are 98 samples out of 125 that are at or above the background concentration of 11.3 mg/kg arsenic.  The spreadsheet provided by Cleanup DePue shows the average amount of arsenic in OU-4 to be 19.6 mg/kg of arsenic.

Now anyone can see that 19.6 is higher than 11.3.  Does that constitute a "way-above-normal concentrations?"

As I discussed in my last post, what we need to look at is the amount of exposure above normal.  In this case, on average, the soil in OU-4 is 8.3 mg/kg higher in arsenic than the regulatory background limit.

If, and this is a big if, a citizen of DePue is exposed to that soil for 350 days a year for 70 years, by my estimate, that would bring about a probability of 1.8 excess cancers in 10,000.

Now anyone can see that a probability of 1.8 in 10,000 is much higher than 1.0 in 1,000,000.  But that probability of 1.8 in 10,000 is based on coming in direct contact with the soil and having the arsenic in that soil enter into the body.  You must also have that happen each day for 350 days a year for 70 years.  It is also based on a theoretical slope factor that we guestimate will show cancer at a particular concentration.

So how close is that added probability of 1.8 excess cancers in 10,000 to what might actually happen?  Possible?  Maybe.  Probable?  Not even close.

That puts me between a rock and hard place.  One one hand I accept the "even one molecule of the contaminant can cause cancer" presumption and on the other I can soundly state that ya' got nothin' to worry about in OU-4.

And here is where it get's all ethical on us...or at least for me.

• If I accept the "even one molecule of the contaminant can cause cancer" presumption then exposure to any molecule above zero presents a risk.
• If I accept one in one million as being an acceptable level of risk, then I accept as "safe" a concentration that will not present a risk of no more than one excess cancer in one million as my threshold.
• If I accept the premise that arsenic - like chromium, cadmium, and lead - are naturally occurring in the soil, then I must accept the fact that I will always be exposed to some concentration of those contaminants when I come in contact with soil.
• If I accept that there is a concentration of contaminant in the soil that is low enough to be considered "safe" then my responsibility to cleanup my mess will end when that threshold is met.

That last one is the premise of "how clean is clean?"  Since we are concerned about a risk of acute and chronic health problems because of our exposure to the soil in OU-4, we must draw a line in the sand and say on this side it is clean.

That side is determined by doing a risk assessment.  Apparently, Nancy Loeb, the director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic, has told the folks in DePue that this risk assessment is flawed:

“The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks, and they delivered a superficial plan that barely touches many of the contaminated areas, leaves the slag pile and other waste in place, does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.”

Ms. Loeb claims that the "safe" line is not set low enough.  She offers no calculations or explanation to support that claim, but, nonetheless, that's her contention.

I am going to look for this plan that she speaks of to see what those cleanup levels and remediation methodologies are to see if they are indeed lacking.

Right now, all I have is a bunch of data that shows an average concentration of arsenic in the soil in OU-4 to be 8.3 mg higher than the legal background concentration established by Illinois in  742.Appendix A, Table G.

Regardless of what I think the true risk is.  Regardless of whether or not 8.3 is to be considered "way-above-normal," the one fact that remains is this.  If I am going to draw a line in the sand that says "clean" then I must do something about the soil that has a concentration above that threshold.

I need to see what is proposed for OU-4.  In particular, I need to see how they are addressing arsenic above background.

Ethically, if I use a concentration to make the statement of clean soil, then I have a responsibility to do something about soil that falls above that level designated as "safe."  I have an obligation regardless as to whether or not the soil above that line presents a risk or not.

This is the double-edged sword we live by.  If I draw a line in the sand to say "safe" and therefore my responsibility is ended, then I have an ethical responsibility to rectify those areas that are above that threshold.

Since Illinois has stated that background may be used as a cleanup objective, anything above background must be remediated.  This is the ethical contract we must adhere to if we are to use the benefit it provides in establishing a level of "safe."  If my responsibility can be terminated at a particular concentration, then ethically I need to be responsible for areas above that.  I cannot accept background when it suits me and discount it when it does not.

Ms. Loeb seems to indicate that the bar of what is "safe" has been moved to allow for exposure to higher concentrations then she thinks is "safe."  What I need to see is how the soil screening levels are being calculated and what constitutes a "safe" concentration.

At this point, 98 samples are above background concentrations for arsenic in OU-4.  The Illinois regulators have drawn a line in the sand and said that background is an appropriate cleanup objective.

Is that legal background concentration in 742.Appendix A, Table sacrosanct?

If we have an ethical duty to reduce the risk for the people living, working, and playing in OU-4, then establishing what a "safe" level of exposure is becomes critical.  This, if I had to guess, is the main sticking point with Ms Loeb.

Not sure if I can get a hold of that information, but I am going to start looking.


Next post: The Village of DePue:  What's in store for OU-4 - Part 12

The Village of DePue: Theoretical Cancer Risk at Background - Part 10

The theoretical cancer slope factor (CSF) that has been set for Arsenic is 1.5 (mg/kg)/day.

So...theoretically:

• The soil screen level that will achieve a risk of one additional cancer in one million for arsenic is 0.39.
• A person exposed for 350 days a year, for 70 years, to 0.39 mg/kg of arsenic in soil would have a 33.3334 percent chance of getting cancer in their lifetime
• A person not exposed to 0,39 mg/kg of arsenic in soil will have a 33.3333 percent chance of developing cancer in their lifetime.
• The difference is 0.0001 percent or a probability of 0.000001 (1 in a million)

This is how we look at chemicals suspected to cause cancer.  There is no "safe" dose, so we calculate the risk based on a chronic exposure to a set amount.

We feel that one in one million is an acceptable risk and the amount of arsenic in soil that would be expected to produce the chronic daily intake (CDI) necessary to show a one in one million risk is 0.39 mg of arsenic per kg of soil.

All of this is theoretical.  But for purposes of setting a cleanup standard, it is the best we have so we will make the assumption that 0.39 mg/kg is the "safe" limit.

That, as we discussed in a previous post, is a value that is unable to be obtained in nature.  That is, there is a natural amount of arsenic that we are exposed to.  We call that "background" and it is set based on what we "normally" see in places where we live.

Illinois has set the background for arsenic in soil at 11.3 in 742.Appendix A, Table G.

11.3 is quite a bit higher than the theoretical "safe" value we want which is 0.39 mg/kg.

There is nothing we can do about background, so we ignore the theoretical what we want, and accept the background as "safe."

So...11.3 mg/kg is "safe."

In OU-4 we have 102 samples that exceed the background concentration that Illinois has said is acceptable.

What do those exceedances  mean in terms of additional risk?

Let's look at this from EPA's Integrated Risk Information System (IRIS) perspective:

IRIS

IRIS shows that the concentration of 0.02 μg of arsenic per liter of drinking water is the "safe" amount that will increase the risk of cancer from 33.3333 to 33.3334 percent.

If you increased the concentration 100 fold, from 0.02 μg to 2.0 μg per liter of water, the risk would move from 33.3333 to 33.3433 percent.

100 times more arsenic consumed increases the risk from 33.3334 percent to 33.34 percent.

Okay, so what does this mean for the people who live in DePue?  It depends on how one wants to look at it.

First off, the slope factor used to calculate the risk is very conservative which means it most likely over-estimates the risk.  Second, the amount of arsenic that enters into the body from soil fluctuates wildly.  Our calculations of how much are based on a consistent amount of arsenic entering into the body 350 days a year for 70 years.  Third, we are looking at excess cancer above and beyond the one in three chance of getting cancer in a 70 year lifetime.

But let's ignore all of that and focus solely on establishing a threshold where on one side it is "safe" and on the other side there is "risk."

The Illinois background level for arsenic has been set at 11.3 mg/kg.  This level is a cleanup objective that Illinois assumes presents a "safe" environment if the arsenic is at or below that amount.

For all intents and purposes, we will assume 11.3 or less to present no excess cancers above the norm of a 33.3333 percent chance of getting cancer in a 70 year lifetime.

That assumption means, theoretically, that exceeding the value of 11.3 presents an additional risk.  So...how much are we talking about?

The average exceedance of the background threshold of 11.3 mg/kg was 1.7 times the background for an average amount of arsenic in the soil in OU-4 (where the people live) of  19.6 mg/kg.

19.6 mg/kg exceeds the threshold of 11.3 mg/kg by 8.3 mg of arsenic.  So...8.3 mg of additional arsenic exposure is what we will estimate the additional cancer risk on.

Here is where it gets fun.

The EPA's soil screening level (SSL) for arsenic is 0.39 mg/kg.  0.39 mg of arsenic in the soil is assumed to present a risk of no more than one additional cancer in one million cancers for a person exposed 350 days a year for 70 years.

EPA's IRIS has calculated the chronic daily intake (CDI) for arsenic to be 0.02 μg of arsenic per liter of drinking water for a risk of one additional cancer in one million cancers  .

Since the average person is assumed to consume 2 liters of water per day, the amount of arsenic that will theoretically bring about a risk of one additional cancer in one million is 0.04 μg per day for 70 years.

So...we can assume that exposure to 0.39 mg/kg of arsenic in soil, for 350 days a year, for 70 years, will equate to a CDI of 0.04 μg of arsenic.

0.04 μg of arsenic.consumed each day for 70 years will theoretically result in no more than one additional cancer in one million.

0.39 mg/kg exposure = 0.04 μg of arsenic consumed.  That's our line in the sand.

On average, in OU-4, the soil exceeds background by 8.3 mg of arsenic per kg of soil.

Okay...take a break and relax.  Here is a picture of a kitten and a puppy to help...before we do more math and take on more assumptions.

Source

Feeling better?  Okay, let's continue.

8.3 mg is 21 times higher than 0.39.  Therefore, the CDI at 8.3 mg of arsenic exposure would - theoretically - be 21 x 0.04 = 0.84 μg of arsenic consumed.  That's based on the SSL calculations the EPA used.

So what is the risk of consuming 0.84 μg of arsenic per day for 70 years?

In my previous post I showed this calculation:

Source

Here is what we know:

• The NSRL is the uptake - 0.84 μg which is equal to 0.00084 mg
• The the slope factor (qhuman) is 1.5 (mg/kg-day)-1
• The body weight we use is 70 kg.

Basic algebra here with the math.  We need to solve for the risk "R"

(0.00084 x 1.5) / 70 = 0.00018 or 1.8 excess cancers in 10,000.

Here is what the TACO's fact sheet says about that:

The risk of cancer due to exposure to a contaminant is commonly expressed in exponential terms, e.g., 10-6 and 10-4. These terms equate to a risk of 1 in 1,000,000 and 1 in 10,000 respectively. Adding a 10-6 risk would increase the probability of an individual getting cancer to 0.333334. With the addition of a 10-4 risk, the probability of an individual getting cancer would be 0.333433.

On average, in OU-4, the probability of an individual getting cancer would be 0.333453.

What that means is one's normal probability of cancer in a life-time of 0.333333 becomes 0.333453 if exposed to that soil for 350 days a year for 70 years.  This is based on contact with the soil so that the soil enters into the body.

Although it is possible, it is highly improbable that any one in DePue would have an uptake of soil over a lifetime that would equate to a risk of 1.8 excess cancers in 10,000.

Based on how conservative these formulas are, and how theoretical the slope factor is, I do not see any reason to be concerned about the amount of arsenic in the soil in OU-4.

But that raises and ethical question.

Should the citizens of DePue be exposed to any risk above one in one million?

Next Post: The Village of DePue:  The ethics of drawing a line - Part 11

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The Village of DePue: By how much and how many - Part 9

Tis the day after Christmas, and Excel sorting I will go....

Okay, it took me a few more days to get through all this....

In my last post I looked at the Illinois requirement for residential use which told me to meet Appendix B, Table A objectives.

Based on the data in the Excel files I downloaded from the Cleanup DePue website, six contaminants were found in OU-4 - the area where people have access to, that were above the Illinois cleanup objective concentrations in Appendix B, Table A.

I now need to sort the data to see by how many of them are over the objectives.  This, along with how much the exceedance is, will give me a good indication of risk.  I am only concerned with OU-4 because that is where exposure can take place.

Right now, I have a ton of data from soil samples collected in OU-4.  What I don't know is what the plan addresses.  What I do know is that the plan is much more complicated  in evaluating risk than what I am doing here.  What I am trying to do in these posts is make an assessment as to the claim of  "way-above-normal concentrations of pollutants at hundreds of contaminated sites" so don't go telling people "Bowman says you only need to clean it up to this level."

With that in mind, lets do some sorting...

Ahh, but first we need to get some things out of the way first.

1. csv_post_date is 1996 and 2009
2. Thallium is identified as less then "<" a value.  Therefore less than 10 will mean it is below TACO Appendix B, Table A objectives.  I am removing thallium from the CoC list.
3. Other values identified with "<" will be assumed to be the number below it.
4. Only one sample exceeded the mercury objective of 23 mg/kg.  Since the analytical value is only 24.4 I am going to remove it from the CoC list.

Now that I have it sorted, of the 125 soil samples:

• 102 exceed the objective for one of the chemicals, arsenic, barium, cadmium, or lead. 
• Of these 102 OU-4 samples, all but five exceed the objective for arsenic, which is set at background.
• Only two samples show exceedance for all four of the CoCs.

How, then, do I make sense out of this data?  That's what's missing from the Cleanup DePue's web site.  Tons of data and no context.  This is where I need to be careful in how I describe what I see.  I don't have access to the plan so I cannot speak on the validity of the risk calculations.  I also do not know what the remediation plan is for OU-4.  If they are going to leave the soil in place, well maybe these folks in DePue have something to beef about.  If these "hot spots" are going to be removed, then what I say from this point on is moot.

Oh how I wish I knew what Cleanup DePue and Nancy Loeb, director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic and pro-bono counsel for the Village of DePue want.  All I know is they think the plan insufficient to protect them.

The other thing missing from their site is what cleanup levels do they think are health protective and what areas do they want these levels met?  I have been writing these previous posts trying to answer my own curiosity about "way-above-normal concentrations of pollutants at hundreds of contaminated sites"

My problem is that I don't know what they construe as "way-above-normal concentrations."  I am missing some important pieces here.  Since I don't now how the remediation plan is addressing the soil in OU-4, I can only look at what I see from the sample data that I have.

Right now, arsenic is where my focus is because of the number of OU-4 samples where it exceeds the threshold - or cleanup objective in Section 742 Appendix A, Table G.

What I see when I sort the OU-4 soil sample concentrations is that arsenic shows up like this:

• 27 of the samples are more than twice background
• Two samples are three times background (3.0 and 3.3)
• One sample is 4.2 times above back ground
• The average exceedance is 1.7 times background with a median exceedance of 1.6.

Depending on how one looks at it, twice the amount could be seen as "way-above-normal concentrations of pollutants at hundreds of contaminated sites."  Unfortunately, that's not how it works out in this case with arsenic.

Arsenic is set at background because natural background concentrations of arsenic are often well above the health-based, direct-exposure goals in soil.  That's a bit confusing.  On one hand you tell me the "safe" concentration in soil for arsenic is 0.39 mg/kg and then you tell me you only need to clean it up to background.

Yeah...that's what we are telling you.  Our health-based cleanup goals (objectives) are theoretical erring on the conservative side.  Because we suspect arsenic to be a human carcinogen, we set the acceptable risk for an adverse health affect to no more than one additional cancer out of one million cancers.

I'll let TACO's explain that:

For carcinogens, risks are estimated as the probability of an individual developing cancer over a lifetime as a result of exposure to a contaminant.

What we are looking at is a probability of cancer, in the case of soil, we set that probability of a "safe" level at a concentration that we expect to see no more than one additional cancer out of one million cancers over a 70 year lifetime.  We do this with a calculation involving our good friend the slope factor:

This value is known as a slope factor (SF), and it converts daily intakes of a carcinogen averaged over a lifetime directly to the upper bound risk of an individual developing cancer.  That is, risk is equal to chronic daily intake (CDI) averaged over 70 years (lifetime) multiplied by the SF. (page 4 of TACOs)

Figuring out the dose that will give you no more than one additional cancer in one million is quite simple:

Source

Calculating how low a concentration of a contaminant needs to be in soil to bring about that dose is a bit more complicated.  For risk, we are assuming that ingestion, dermal contact, and inhalation of dust for getting the chemical into to human receptor.  We know that as little Suzy grows from a toddler to an adult she will come in contact with that contaminated soil.  We assume that little Suzy will be in contact with that soil for some period of time each year for 70 years (default is 350 days/year).  We know, through a bunch of different studies, that people like little Suzy and adult Suzy will ingest a certain amount of soil in a day.  The question becomes how much contaminant in that ingested soil needs to be there to bring about a probability of one additional cancer in a million.

Remember this bad boy calculation?

Source

That's how it is calculated.  When you see "IFS" it is "age-adjusted soil ingestion factor." DFS is the "age-adjusted soil dermal factor."  These formulas take into account the differences in body weight and uptake as little Suzy goes from a toddler to an adult.  They are very, very conservative and very, very protective.

So for arsenic, the amount in soil that will bring about no more than a one in one million probability of an additional cancer is 0.39 mg of arsenic per one kilogram of soil.  Why show y'all this?  Because that's how we come up with a "safe" threshold for a contaminant we suspect to be a carcinogen.  You need to see that in order to understand the next part of the calculation.

If little Suzy is exposed to 0.39 mg of arsenic in one kilogram of soil for 350 days a year for 70 years, we expect her to have a one in one million chance of developing cancer.  This is a probability based on assumptions which are all worst case.  The biggest assumption is the Slope Factor (SF or CSF):

The SF is derived through the plotting of a curve that compares dose to response. Statistical procedures usually calculate the SF as the upper 95th percent confidence limit of the slope of the dose-response curve (i.e., there is only a 5% chance that the cancer risk could be greater). Because this is the upper bound risk, the actual risk is between that value and zero. The SF is roughly equivalent to the risk per unit dose, expressed as (mg/kg/d)-1. As with the RfD, the SF is provided by the U.S. EPA. (page 4 of TACOs)

And what is the SF provided by the EPA for arsenic?  1.5 as it stands today.  With that, we can calculate the chronic daily intake (CDI) for arsenic to get us a one in one million risk probability.  We can use the method described in the California equation above:

• We know the risk (R) we want is one in one million or 1.0 x 10-6 or 0.000001.
• We know the slope factor (qhuman) is 1.5 (mg/kg-day)-1
• We know the average weight of the human is 70 kg

So, a little math...and we can calculate the intake level (I) or CDI

I = (0.000001 x 70 kg) / 1.5 mg/kg-day = 0.000047 mg/day or 0.05 μg/day.

0.05 μg of arsenic consumed for 365 days a year for 70 years should see no more than one additional cancer per one million cancers.  What does that mean?  Here is how Illinois describes it in the TACO's Fact Sheet:

The risk of cancer due to exposure to a contaminant is commonly expressed in exponential terms, e.g., 10-6 and 10-4. These terms equate to a risk of 1 in 1,000,000 and 1 in 10,000 respectively. In the benzene example, the risk estimate of 1.5 x 10-5 means that 1.5 additional cases of cancer above background might occur among 100,000 exposed persons (or 15 cases in 1,000,000 persons) as a result of benzene exposure. The background cancer rate is 1 in 3, meaning that over a lifetime, an American’s probability of getting cancer is 0.333333. Adding a 10-6 risk would increase the probability of an individual getting cancer to 0.333334. With the addition of a 10-4 risk, the probability of an individual getting cancer would be 0.333433.

Confused?  Focus on the numbers here:

The slope factor is a value that is a very conservative number.  It is very, very protective of public health in and by itself.

• The probability of cancer risk is based on a CDI of that concentration of arsenic each day for 70 years.
• The probability of consuming that amount over 70 years and getting cancer is one in one million.
• The chance of getting cancer in your lifetime is one in three - 33.3333%.
• If we expose you to soil with 0.39 mg/arsenic per kg of soil for 350 days a year for 70 years, the chance of getting cancer increases to 33.3334%

Now if you have stayed with me to this point, you might be asking "what is the risk of cancer at the background concentration of arsenic?"

Good question.

Next post: The Village of DePue:  Theoretical Cancer Risk at Background  - Part 10

The Village of DePue: Mmm....TACOs - Part 8

I'm still trying to support Cleanup DePue's Press Release claim that:

Contaminated debris blows onto public and private property throughout the village and surrounding natural areas, exposing residents -- more than a quarter of whom are children under the age of 16 -- and local wildlife to arsenic and heavy metals such as lead, mercury and cadmium. Visit www.CleanUpDePue.org to see an interactive map that details the way-above-normal concentrations of pollutants at hundreds of contaminated sites.

I did visit their site and I have been looking at the data to see where these "way-above-normal concentrations of pollutants at hundreds of contaminated sites."

I thought possibly that it might be arsenic and chromium leading this charge since every single one of the samples in OU-4 - where the people of DePue live, work, and play, were above the screening levels for these two compounds.

Then I remembered that Chemicals of Concern (CoCs) that are carcinogens are calculated differently and calculate considerably lower levels than background concentrations making them impracticable to use for remediation goals.

On the Cleanup DePue's website they write about background concentrations:

"For each parameter whose sampling results demonstrate concentrations above those , the [responsible party] shall develop appropriate soil remediation objectives in accordance with this Part." The Illinois EPA considers these background standards an appropriate measure by which to compare soil samples.

Yes that is true.  But background levels are not the sole remediation goal, and I believe that may be where the confusion lies and why Nancy Loeb, director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic states in the Press Release:

“The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks, and they delivered a superficial plan that barely touches many of the contaminated areas, leaves the slag pile and other waste in place, does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.” 

The issue, as I think I am now coming to understand, is twofold.

1. They are leaving the contaminated areas in place and moving contaminated media to these areas.
2. They are not remediating the area, specifically OU-4, to background levels in Section 742 Appendix A, Table G of Title 35 of the Illinois Administrative Code or groundwater down to MCL/MCLG levels.

Loeb also criticized CBS and ExxonMobil for their totally unrealistic methods for looking at risk:

“In determining whether a person is exposed to potentially harmful levels of toxic pollutants, CBS and ExxonMobil are counting each exposure as if it were an isolated incident, and pretending that residents are exposed only to a single contaminant and only in one area of the town. The reality is that children are growing up here, eating from home gardens, playing in parks and ball fields, boating in the lake, and later working and living as adults in DePue. Any realistic assessment of health risks has to take these multiple, constant and long-term exposures into account.”

I do not have access to the plan, but I am pretty sure that the Illinois EPA is making CBS and ExxonMobil cleanup to a level consistent with the "Tiered Approach to Corrective Action Objectives":

Source

...or more affectionately called "TACOs"

I know nothin' about this thing called TACOs.  All I know is what any other person reading up on this topic and trying to understand it gets to look at on the interwebs.  What I do know about my industry, including the regulators that oversee it, is that they overkill everything when you attach the words "Superfund" and "Town" together.

I am pretty sure that the remediation plan CBS and ExxonMobil put together meets TACOs.  If Cleanup DePue thinks it does not, I will need to see their reasoning.  All I have is a Press Release stating that the plan is not a "realistic assessment of health risks," and a bunch of analytical data.

So let's get back to the question of are there "way-above-normal concentrations of pollutants at hundreds of contaminated sites?"  And, are the levels found high enough to present a concern?

TACOs tells us this:

The purpose of these procedures is to provide for the adequate protection of human health and the environment based on the risks to human health posed by environmental conditions while incorporating site related information.

With that in mind, we must assume that meeting TACOs meets adequate protection of human health and the environment.  If one wants to make an argument that it does not, let me know why in the comments.  For the most part, TACOs gets you to the same place that EPA's soil screening level calculations do.  They will spit out basically the same remediation goals.

Here is how TACO is designed to work:

Source

You can read more about TACOs by going here.

OU-4 will be samples collected in residential areas so that's the path we will go down.  This requires Appendix B Table A and Table E objectives.  Based on the values in Table A, the new CoC list looks like this:

I still show that some of the OU-4 CoCs exceed the Table A objectives (the one's in purple).  Also note how Illinois goals match closely in some cases with EPA's SSLs.

So, based on the data in the Excel files I downloaded from the Cleanup DePue website, six contaminants were found in OU-4 - the area where people have access to - that were above the Illinois cleanup objective concentrations in Appendix B, Table A.

My next quest will be to see by how much over the objectives as well as how many sample points are elevated.


Next post: he Village of DePue:  By how much and how many  - Part 9


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