                Case: 17-10894       Date Filed: 05/14/2018       Page: 1 of 22


                                                                                   [PUBLISH]

                  IN THE UNITED STATES COURT OF APPEALS

                            FOR THE ELEVENTH CIRCUIT
                              ________________________

                                     No. 17-10894
                               ________________________

                      D.C. Docket No. 8:14-cv-01748-MSS-TGW


RHONDA WILLIAMS,

                                                           Plaintiff-Appellant,

versus

MOSAIC FERTILIZER, LLC,

                                                  Defendant-Appellee.
                               ________________________

                      Appeal from the United States District Court
                          for the Middle District of Florida
                            ________________________

                                       (May 14, 2018)

Before TJOFLAT and ROSENBAUM, Circuit Judges, and UNGARO, * District
Judge.

TJOFLAT, Circuit Judge:

         In this toxic tort suit, Rhonda Williams appeals the District Court’s grant of

summary judgment against her and in favor of Mosaic Fertilizer, LLC (“Mosaic”).
         *
          Honorable Ursula Ungaro, United States District Judge for the Southern District of
Florida, sitting by designation.
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Ms. Williams alleged that toxic substances emitted from a factory operated by

Mosaic caused or exacerbated various medical conditions from which she suffers,

including pulmonary hypertension, obstructive pulmonary disease, and other lung

and non-lung-related conditions. The District Court, acting pursuant to Federal

Rule of Evidence 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509

U.S. 579, 113 S. Ct. 2786 (1993), excluded the opinions of her proffered expert

witness, Dr. Franklin Mink. Dr. Mink’s opinions were Ms. Williams’ only

evidence as to general and specific causation. Therefore, upon excluding Dr.

Mink’s opinions, the Court granted Mosaic’s motion for summary judgment with

respect to all causes of action requiring a showing of causation. The District Court

also excluded Ms. Williams’ testimony about the value and salability of her home,

and, in the absence of other evidence showing that the value of her home was

diminished by Mosaic’s alleged contamination of it, granted summary judgment in

favor of Mosaic as to the remaining cause of action.

      After careful review of the record, and with the benefit of oral argument, we

affirm.

                                         I.

      Ms. Williams was born in 1967 and has lived her entire life at the same

residence in Tampa, Florida. The home, located in the Progress Village

neighborhood, is approximately three miles from Mosaic’s Riverview plant. She

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alleged that she suffers from G6PD associated pulmonary hypertension, asthma-

related restrictive pulmonary function, obstructive pulmonary disease, airway

remodeling, lower lung scarring, allergic reactions, side effects from therapeutic

treatments for her lung disorders, extreme fatigue, intense abdominal pain, and

diabetes. She alleged that chemicals emitted from Mosaic’s facility caused,

contributed to, or exacerbated these conditions.

      According to Ms. Williams, Mosaic’s operations in and around the

Riverview plant involve the production and handling of a number of chemicals,

including sulfuric acid, phosphoric acid, fluoride, and ammoniate phosphates. She

averred that Mosaic’s production of these substances produces emissions, in the

form of dust and particulates, of toxic substances that permeate the ambient air in

and around her home and community. Some of these include various types of

particulate matter, arsenic, cadmium, chromium, lead, manganese, nickel,

phosphorous, and zinc.

      In the past, the U.S. Environmental Protection Agency (“EPA”) and the

Hillsborough County Environmental Protection Commission have promulgated

data taken from monitoring stations at or near the Riverview plant showing that

sulfur dioxide levels in the ambient air at those stations exceeded the National

Ambient Air Quality Standard (“NAAQS”) of 75 parts per billion. Additionally,

Hillsborough County at large has been found in violation of the NAAQS standard,

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and the ambient air at a monitoring station at the Riverview plant has on multiple

occasions been found in violation of Florida’s more lenient standard of 100 parts

per billion. In addition to these sulfur dioxide emissions, monitoring data at a

testing site located near the Riverview facility and Ms. Williams’ neighborhood

showed, on at least one occasion, that the concentration of PM10 respirable

particulates, a respiratory irritant, exceeded the national standard of 150

micrograms based on a one-hour average.

       Ms. Williams alleged six causes of action under Florida law in separate

counts: negligence, gross negligence, strict liability, strict liability failure to warn,

strict liability for “prohibited discharge” of pollutants, and medical monitoring and

environmental testing. 1 To establish general and specific causation, she turned to

Dr. Mink. Dr. Mink, an experienced toxicologist, prepared and furnished a

summary of his “preliminary expert opinions.”

       The report contained sixteen pages of analysis, including a description of

Ms. Williams’ medical background, information on G6PD deficiency, and a set of

“preliminary expert opinions” reached “with a reasonable degree of scientific

certainty.” Those opinions were:

       1) Rhonda Williams has been exposed to significant quantities of
       regulated pollutants and hazardous materials from both direct and

       1
         The District Court had diversity jurisdiction under 28 U.S.C. § 1332. Mosaic removed
the action from Florida state court to the Middle District of Florida in accordance with 28 U.S.C.
§§ 1332, 1441, and 1446.
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      fugitive sources as a result of Mosaic’s operations including
      phosphogypsum mining, processing, storage, transportation and waste
      handling operations over her lifetime residence in Prospect Village,
      Florida primarily through inhalation and dermal exposures.

      2) Rhonda Williams has developed significant adverse health effects
      as a result of these hazardous exposures including G6PD associated
      pulmonary hypertension and obstructive pulmonary disease resulting
      in a diminished quality of life and potentially reduced life span.

      3) Rhonda Williams has developed significant adverse health effects
      as a result of secondary effects from therapeutic agents used to treat
      her diseases/symptoms resulting from these exposures further
      diminishing her quality of life and threatening her long-term physical
      and mental wellbeing.

At the end of the analysis section of the report, Dr. Mink listed fifty-eight

references. These consisted of various empirical studies, website references, and

regulatory documents. Within the body of the analysis, he cited another eighteen

sources. None were pin-cited or otherwise annotated to show which portions

supported each conclusion.

      After Dr. Mink submitted his preliminary report, Mosaic deposed him.

After the deposition, Mosaic moved to exclude Dr. Mink’s testimony under

Federal Rule of Evidence 702 and Daubert. Mosaic also moved for summary

judgment as to all of Ms. Williams’ claims. Ms. Williams filed responses in

opposition. Without conducting a Daubert hearing, the District Court granted

Mosaic’s motion to exclude Dr. Mink’s opinion testimony. The Court explained

its decision thusly:

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      [T]he Court concludes that Dr. Mink’s expert report and proposed
      testimony cannot survive a Daubert challenge. Critically, Dr. Mink
      has neglected the hallmark of the science of toxic torts—the dose
      response relationship. In and of itself, this is a sufficient basis for
      excluding his testimony. He also unjustifiably relies on regulatory
      standards to determine dose, infers facts from studies that contradict
      his conclusions, fails to consider the background risk for Plaintiff’s
      illnesses, fails to rule out alternative potential causes of Plaintiff’s
      illnesses, and renders speculative and conclusory opinions about
      Plaintiff’s exposure to Mosaic’s emissions. All in all, it is clear that
      Dr. Mink has failed to adhere to the methodology expected of
      toxicologists in toxic tort cases, and he has not demonstrated a reliable
      basis for his opinions.

      In its order granting the motion, the Court comprehensively analyzed Dr.

Mink’s report and methodology, identifying and explaining its primary concerns

and others. Because Dr. Mink was Ms. Williams’ sole source of causation

evidence, the Court, in the same order, granted Mosaic’s motion for summary

judgment as to all claims requiring a showing of causation.

      When the dust settled, Ms. Williams had one remaining claim: her

“prohibited discharge” claim. This claim was brought under Section 376.313 of

the Florida Statutes, which confers a private right of action on citizens who suffer

damage from a discharge of materials in violation of Florida’s environmental

standards. For this claim, Ms. Williams alleged that the pollutants and dust from

the Riverview plant diminished the value of her home to the point where it was

unsellable. Ms. Williams planned to testify on her own behalf as to the value of

her home. According to her responses to Mosaic’s interrogatories, Ms. Williams

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believed and planned to testify that “the property has no present value as any sale

would require the disclosure of the toxins found in and around the home and

neighborhood, . . . which came directly from Mosaic Fertilizer.”

      As the case proceeded towards trial, Mosaic moved to exclude Ms.

Williams’ valuation testimony, arguing that such testimony was beyond her

expertise as a lay witness, irrelevant, and substantially more prejudicial than

probative because it called for heavy speculation and conjecture. The District

Court granted Mosaic’s motion. Upon consideration of her discovery responses

and prior testimony, it found that Ms. Williams’ testimony “lack[ed] foundation

and [wa]s purely speculative.” Then, in the same order, the District Court granted

summary judgment for Mosaic sua sponte as to the remaining claim. The Court

observed that Ms. Williams “was on notice that she was required to come forth

with all her evidence regarding the damages element of the Section 376.313

claim,” yet failed to produce anything more than her own inadmissible testimony.

Thus, the Court found that summary judgment was warranted as to her “prohibited

discharge” claim on account of her failure to prove any damages resulting from the

discharge. The Court therefore entered judgment in favor of Mosaic. Ms.

Williams timely appealed.




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                                          II.

      We review the District Court’s grant of summary judgment de novo. Doe v.

Sch. Bd., 604 F.3d 1248, 1253 (11th Cir. 2010). We begin with the exclusion of

Dr. Mink’s opinion testimony. Federal Rule of Evidence 702 makes expert

opinion testimony admissible only “if (1) the testimony is based upon sufficient

facts or data, (2) the testimony is the product of reliable principles and methods,

and (3) the witness has applied the principles and methods reliably to the facts of

the case.” As interpreted by the Supreme Court in Daubert, this requires the trial

court “to act as a gatekeeper to insure that speculative and unreliable opinions do

not reach the jury.” McClain v. Metabolife Int’l, Inc., 401 F.3d 1233, 1237 (11th

Cir. 2005). To properly serve as a gatekeeper, the trial court must perform “a

preliminary assessment of whether the reasoning or methodology underlying the

testimony is scientifically valid and of whether that reasoning or methodology

properly can be applied to the facts in issue.” Daubert, 509 U.S. at 593–94, 113

S.Ct. at 2796. When doing so, “the court must consider the testimony with the

understanding that the burden of establishing qualification, reliability, and

helpfulness rests on the proponent of the expert opinion.” McClain, 401 F.3d at

1238 (quotations omitted) (alterations omitted) (quoting United States v. Frazier,

387 F.3d 1244, 1260 (11th Cir. 2004)).




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       “The trial judge must have considerable leeway in deciding in a particular

case how to go about determining whether particular expert testimony is reliable”

under Daubert. Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152, 119 S. Ct.

1167, 1176 (1999). Hence, we review a district court’s Daubert rulings for abuse

of discretion. Gen. Elec. Co. v. Joiner, 522 U.S. 136, 143, 118 S. Ct. 512, 517

(1997). We will affirm unless the court “has made a clear error of judgment, or

has applied an incorrect legal standard.” Piamba Cortes v. Am. Airlines, Inc., 177

F.3d 1272, 1306 (11th Cir. 1999) (quotations omitted).

       Here, the District Court did not abuse its discretion in excluding Dr. Mink’s

opinions. The Court comprehensively analyzed Dr. Mink’s report and deposition

testimony, carefully reviewed the literature upon which he relied in forming his

causation opinions, and determined that his methodology was undermined by

multiple defects. 2 We find no error in the Court’s analysis and no need to discuss


       2
          Ms. Williams argues that the District Court abused its discretion in requiring Dr. Mink
to demonstrate both general and specific causation, as opposed to just specific causation. This
Court has delineated two categories of toxic tort cases: “those cases in which the medical
community generally recognizes the toxicity of the drug or chemical at issue,” and “those cases
in which the medical community does not generally recognize the agent as both toxic and
causing the injury the plaintiff alleges.” McClain, 401 F.3d at 1239. In the former cases, “[t]he
court need not undertake an extensive Daubert analysis on the general toxicity question.” Id. In
the latter, “the Daubert analysis covers not only the expert’s methodology for the plaintiff-
specific questions about individual causation but also the general question of whether the drug or
chemical can cause the harm plaintiff alleges.” Id. (emphasis in original).
        In Ms. Williams’ view, the scientific sources she and Dr. Mink cite demonstrate that it is
generally accepted in the scientific community that the toxins emitted by Mosaic’s facility
“cause the exact type of harm alleged by Ms. Williams.” The District Court treated the toxicity
of the substances as not generally accepted because it found that “Plaintiff has failed to offer any
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every aspect of its comprehensive assessment anew. However, three of the most

significant problems with Dr. Mink’s methodology are illustrative: first, his failure

to properly assess dose-response with regard to Ms. Williams; second, his failure

to meaningfully rule out other potential causes of Ms. Williams’ medical

conditions; and third, his failure to account for the background risk of her

conditions.

       With respect to dose-response, we have explained the importance of the

dose-response assessment in these sorts of cases before. “When analyzing an

expert’s methodology in toxic tort cases, the court should pay careful attention to

the expert’s testimony about the dose-response relationship.” McClain, 401 F.3d

at 1241. This attention is due because dose-response is “the hallmark of basic

toxicology.” Id. at 1242. Stripped to its bare essentials, a dose-response

assessment estimates scientifically “the dose or level of exposure at which [the

substance at issue] causes harm.” Id. at 1241.




evidence of general acceptance within the medical community that sulfur dioxide and the other
constituents from the Mosaic emissions cause the illnesses from which she claims she suffers.”
We need not and do not decide this question. Setting general causation aside, to establish
specific causation, Dr. Mink would still have to reliably calculate whether Ms. Williams was
“exposed to enough of the toxin to cause the alleged injury,” McClain, 401 F.3d at 1239, which
he could have done only after reliably calculating how much exposure would have adversely
affected her. In other words, under either category, he still needed to perform or rely upon a
methodologically sound dose-response assessment specifically relevant to Ms. Williams. As
discussed, his dose-response analysis was deeply flawed. See infra. Thus, no matter whether the
case was treated as a category one case or a category two case, the District Court’s exclusion of
his opinion testimony was not an abuse of discretion.
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      Here, Dr. Mink conceded he never conducted an independent dose

calculation specific to Ms. Williams. Instead, he relied on two academic studies

measuring the ambient air concentration of pollutants in the area in which Ms.

Williams lived to estimate the dose she received and on the EPA’s NAAQS

regulatory standards to establish the dose threshold above which Ms. Williams’

conditions would likely result from her exposure. As the District Court correctly

observed, his reliance on these sources was methodologically problematic in

multiple respects. Among the most glaring problems was the fact that both

academic studies he relied upon directly contradicted his causation opinions. For

example, one study concluded that “phosphate fertilizer plants make minor

contribution to the ambient levels of HAP metals compared to other sources for the

general population in the Tampa Bay area,” and that the air concentration of the

various pollutants studied fell hundreds of times below levels that would present

health risks to the public. Hsing-Wang Li, et al., Impacts of Hazardous Air

Pollutants Emitted from Phosphate Fertilizer Production Plants on Their Ambient

Concentration Levels in the Tampa Bay Area, 8 Air Qual. Atmos. Health 453, 453,

464 (2015).

      This cuts directly against his opinion that Mosaic’s emissions adversely

affected Ms. Williams. And although Ms. Williams argues that Dr. Mink relied on

the studies’ underlying data while disagreeing with their ultimate conclusions, Dr.

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Mink and Ms. Williams never clearly explained why Dr. Mink reached a different

conclusion with regard to Mosaic’s contribution to pollution in Ms. Williams’

community or why his conclusion was correct and the authors’ incorrect until after

the District Court ruled on the admissibility of his testimony. Thus, he failed to

squarely present the basis for his disagreements to the District Court until after the

fact. See Kilpatrick v. Breg, Inc., 613 F.3d 1329, 1341 (11th Cir. 2010) (holding

the district court did not abuse its discretion in excluding expert testimony, when

the expert “had ample opportunity to identify all of the bases for his conclusions

and to explain his methodology in reaching those conclusions” yet failed to do so).

      Moreover, assuming for the sake of argument that Dr. Mink’s dose estimates

were methodologically sound, he failed to demonstrate a scientific basis for

concluding that those exposure levels would likely produce, contribute to, or

exacerbate Ms. Williams’ conditions. For example, he estimated that Ms.

Williams was exposed to sulfur dioxide at a long-term concentration rate

exceeding 75 parts per billion (though he never reached a more specific number

than this), and, based on her purported heightened sensitivity to exposure and the

NAAQS standard’s calculation to protect sensitive members of the population,

assumed that exposure at or above this level was likely to cause her conditions. He

based this sweeping assumption on the fact that the 75 parts per billion number is

the primary emissions standard set by the EPA for sulfur dioxide in its NAAQS

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standard. However, this Court has previously explained the potential

methodological perils of relying, at face value, on regulatory emissions levels to

establish causation. See McClain, 401 F.3d at 1249 (observing that face-value

reliance on regulatory dose standards raises a “subtle methodological issue”).

      The biggest problem stems from the potential difference in purpose between

regulatory standards and toxicological dose-response calculations: regulatory

standards often build in considerable cushion in order to account for the most

sensitive members of the population and prophylactically protect the public (in

other words, they are protective), while dose-response calculations aim to identify

the exposure levels that actually cause harm (in other words, they are predictive).

See id. at 1249–50 (explaining the different calculations and burdens of proof

employed by regulatory agencies in setting exposure standards for the general

public, as compared to those employed by toxicologists in calculating dose-

response).

      But Ms. Williams argues that Dr. Mink’s facial reliance on NAAQS

standards in this case is different, because those standards are predictive. She

contends that the EPA’s assessments reveal that “exposure to 75 ppb of [sulfur

dioxide] causes (not may cause or can cause, but actually does cause) respiratory

morbidity,” and that the standards result from “dose-response assessments based

on human studies.” (Emphasis in original). In other words, relevant dose-response

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assessments are built into the standard. However, the EPA’s own regulations

require the agency to establish NAAQS levels ensuring “protection of public health

with an adequate margin of safety,” even if this means setting emissions thresholds

at a level at which “the risk is not precisely identified as to nature or degree.” 75

Fed. Reg. 35520–01 at *35521 (June 22, 2010). Further, Dr. Mink stated that he

relied upon dose-response calculations included in the EPA’s Integration Risk

Information System (“IRIS”), which the EPA relies upon in setting NAAQS

standards. But the EPA has expressly stated that the dose-response assessments in

IRIS are not suited to predicting the incidence of exposure-caused disease in

humans:

      In general, risk values, such as those on IRIS, cannot be used to
      predict the actual incidence of human disease or the type of effects
      chemical exposures may have on humans. This is due to the
      numerous uncertainties involved in risk assessment, including those
      associated with extrapolations from animal data to humans and from
      high experimental doses to lower environmental exposures. The
      organs affected and the types of adverse effects resulting from
      chemical exposure may differ between study animals and humans. In
      addition, many factors besides exposure to a chemical influence the
      occurrence and extent of human disease.

53 Fed. Reg. 20162–02 at *20163 (June 2, 1988). It is for precisely these reasons

that we have cautioned against facial reliance on regulatory standards as a

substitute for scientifically rigorous dose-response assessments. And while it is

true that the EPA’s studies “led to the conclusion that there is a causal relationship

between respiratory morbidity and short-term exposure to SO2,” the existence of a
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generalized “causal relationship” was not the operative issue. What mattered was

whether the EPA’s data provided a reasonably specific calculation as to the

exposure amounts required to cause Ms. Williams’ conditions upon which Dr.

Mink could reasonably rely in forming his opinions.

      Though Ms. Williams alleged that, on account of her G6PD, she is more

sensitive to exposure than the average member of the general public, Dr. Mink

never attempted to quantify how much more sensitive she is. As the District Court

observed, at the time it made its ruling, he did “not cite with specificity which

studies and peer-reviewed literature demonstrate the increased sensitivity of

individuals with G6PD. Consequently, the Court [could] not evaluate those

sources and determine whether they are based on reliable methodologies or

otherwise support his opinions.” Without this, he could not rely on NAAQS

standards, because he never adequately established whether her sensitivity to

exposure placed her within the class of persons who would likely suffer from

exposure at the ranges he estimated, let alone whether the standards were

predictive or protective with regard to her.

      To be clear, we have never required an expert to “give precise numbers

about a dose-response relationship,” McClain, 401 F.3d at 1241 n.6, and we do not

do so here. But we do require an expert to lay a “reliable groundwork for

determining the dose-response relationship.” Id. at 1241. Here, Ms. Williams bore

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the burden of demonstrating to the District Court that Dr. Mink’s facial reliance on

NAAQS standards was methodologically sound. In light of their protective nature

and the EPA’s express warnings that those standards—and the IRIS assessments

upon which they were formulated—are unreliable predictors of conditions in

humans, we are not persuaded that the District Court erred in determining that Ms.

Williams failed to meet that burden. 3

       Further, the District Court correctly observed that Dr. Mink’s report suffered

from methodological errors related to the cause of Ms. Williams’ conditions. Dr.

Mink failed to meaningfully rule out other potential causes of Ms. Williams’

       3
          We further note that both in the District Court and before this Court, when put to the
task of identifying the bases of Dr. Mink’s dose-response conclusions with specificity, Dr. Mink
and Ms. Williams obfuscated. We granted leave for counsel to file a one-page letter brief with
citations in the record to authorities relied upon by Dr. Mink which employed predictive, rather
than protective, analyses. In response, we received an eleven-page, shotgun-style brief with
citations to dozens of regulatory documents comprising hundreds of pages. Most had nothing to
do with studies—predictive or protective—at all, many included only estimated “fatal” doses of
the various substances discussed (and nothing about doses that could lead to Ms. Williams’
conditions), many of the studies were concerned solely with the carcinogenic effects of those
substances (Ms. Williams does not have cancer and the carcinogenicity of the substances is not
otherwise at issue in this case), many were not in the record below, and none were pin-cited.
         Dr. Mink’s expert report submitted in the District Court fared no better. At the end of the
analysis section of his report, Dr. Mink listed 58 references. These consisted of various
empirical studies, website references, and regulatory documents. Within the body of the
analysis, he cited another 18 sources. Included with none of those 76 sources were endnotes, pin
cites, or any other explanations as to what information Dr. Mink gained from those references or
what sources supported what conclusions. And certainly nothing pointed the District Court to
the underlying dose-response assessments Dr. Mink purportedly relied upon. It was only after
the District Court excluded his testimony that Dr. Mink filed a more concise statement
concerning the bases of his conclusions. Thus, to the extent the District Court was limited in its
assessment of Dr. Mink’s methodology by his and Ms. Williams’ obfuscation in explaining the
bases of his conclusions, it did not err in considering only that which was squarely before it. See
Kilpatrick, 613 F.3d at 1341 (holding the district court did not abuse its discretion in excluding
expert testimony, when the expert “had ample opportunity to identify all of the bases for his
conclusions and to explain his methodology in reaching those conclusions” yet failed to do so).
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conditions and symptoms. Indeed, one of the studies heavily relied upon by Dr.

Mink determined that environmental factors and emissions by other facilities

caused the vast majority of pollution in the area in which Ms. Williams lived. Li,

supra, at 453. Yet Dr. Mink never addressed how or even if he ruled out those

other potential contributors in reaching his conclusion that Mosaic’s facility caused

Ms. Williams’ alleged harms. Nor did he, in his report or his deposition, eliminate

or even address factors not related to air quality, such as Ms. Williams’ obesity,

allergies, lifestyle, exposure to secondhand smoke, or possible genetic

predisposition. When asked about how he eliminated other potential causes of Ms.

Williams’ conditions, Dr. Mink stated:

      Oh, I think we eliminated causes based on their probability. I mean,
      they were so low in comparison that—that we can eliminate them.
      Are they totally nonexistent, absolutely not, and I think I testified to
      that earlier.

However, Dr. Mink never provided the District Court or this Court with any

probability studies regarding those potential causes, and his expert report never

referenced those probabilities.

      Thus, although he made passing references to the purported “low”

probability of those other causes, Dr. Mink never provided the District Court with

any scientific basis upon which he relied in concluding that the likelihood that

various other potential factors caused Ms. Williams’ conditions was low enough to

reasonably rule them out. The law does not require the District Court to take him
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at his word. See Joiner, 522 U.S. at 146 (“[N]othing in either Daubert or the

Federal Rules of Evidence requires a district court to admit opinion evidence that is

connected to existing data only by the ipse dixit of the expert.”).4

       Nor does it appear Dr. Mink meaningfully accounted for the background risk

of Ms. Williams’ conditions. The background risk “is the risk a plaintiff and other

members of the general public have of suffering the disease or injury that plaintiff

alleges without exposure to the drug or chemical in question.” McClain, 401 F.3d

at 1243 (emphasis in original). When asked during his deposition, Dr. Mink did

not demonstrate specific knowledge of the general prevalence of Ms. Williams’

various conditions:

       Q: What is the prevalence of pulmonary hypertension in the
       population, the general population?
       A: I don’t recall. It’s not large.
       Q: What is the prevalence of obstructive pulmonary disease in the
       population?
       A: I don’t recall specifically, but it’s significant.

These answers do not indicate serious consideration of the background risk. And

while his deposition alone may not authoritatively indicate that he failed to account


       4
          To the extent Ms. Williams argues that Dr. Mink could have better cited the specific
authorities in support of his opinions at a Daubert hearing, we conclude that the District Court
did not abuse its discretion in ruling on the admissibility of his opinion testimony without
conducting such a hearing. Dr. Mink filed his expert report and testified at a day-long
deposition, and Ms. Williams’ counsel had the opportunity to cite those authorities with greater
specificity in her response to Mosaic’s motion to exclude Dr. Mink’s testimony. Thus, Dr. Mink
and Ms. Williams had sufficient opportunity to present those bases to the Court before it decided
the question. This is true with regard to both his dose-response assessments and his assessments
regarding other potential causes.
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for it, he also failed to address background risk in his report or elsewhere. Thus,

the evidence before the District Court at the time it considered Mosaic’s Daubert

motion does not indicate he meaningfully accounted for background risk.

      In conclusion, Dr. Mink failed to meaningfully address other potential

causes of Ms. Williams’ conditions or even the background risk of those

conditions. This fundamental methodological failure undermined the soundness of

his causation opinions, and the District Court was therefore right to exclude those

opinions as unsound.

                                         III.

      We review the District Court’s exclusion of lay opinion testimony pursuant

to the Federal Rules of Evidence for abuse of discretion. United States v. Jeri, 869

F.3d 1247, 1259 (11th Cir. 2017), cert. denied, 138 S. Ct. 529 (2017). Lay opinion

testimony must be “(a) rationally based on the witness’s perception; (b) helpful to

clearly understanding the witness’s testimony or to determining a fact in issue; and

(c) not based on scientific, technical, or other specialized knowledge within the

scope of Rule 702.” Fed. R. Evid. 701.

      In general, “an owner of property is competent to testify regarding its

value.” Neff v. Kehoe, 708 F.2d 639, 644 (11th Cir. 1983). However, “where the

owner bases his estimation solely on speculative factors, the owner’s testimony

may be of such minimal probative force to warrant a judge’s refusal even to submit

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the issue to the jury.” Kestenbaum v. Falstaff Brewing Corp., 514 F.2d 690, 699

(5th Cir. 1975), modified on other grounds en banc, 575 F.2d 464 (5th Cir. 1978).5

       The District Court did not abuse its discretion in excluding Ms. Williams’

lay valuation testimony. Opinions by lay witnesses must be derived from personal

knowledge or experience. See Fed. R. Evid. 701 Advisory Committee Notes, 2000

Amendments. Here, Ms. Williams does not allege she tried to sell her home or

spoke with an appraiser or real estate agent to ascertain its value. Indeed, she

concedes she did not. When asked by Mosaic in its interrogatories to provide “any

criteria, rationale, bases, or grounds” for calculating her valuation estimate of zero,

she stated:

       Ms. Williams contends the property has no present value as any sale
       would require the disclosure of the toxins found in and around the
       home and neighborhood, as previously produced in this action, which
       came directly from Mosaic Fertilizer. Ms. Williams does not believe
       that a rational, educated person, who had knowledge of the presence
       of the toxic emissions and/or their long-term health effects would
       want to acquire residential property in her neighborhood; and that her
       property is damaged by the stigma associated with the continual and
       on-going exposure to Sulfur Dioxide, Arsenic, Cadmium, Chromium,
       Barium, Radioactive isotopes and other hazardous air pollutants.
       Under the law, a seller in Florida must disclose any facts to a potential
       buyer that would affect the value of the property. Here, Ms. Williams
       would be required to disclose the presence of Sulfur Dioxide,
       Radioactive isotopes and other hazardous air pollutants found at her
       property and in and around her neighborhood.

       5
         We have adopted as binding “the decisions of the United States Court of Appeals for the
Fifth Circuit, as that court existed on September 30, 1981, handed down by that court prior to
close of business on that date.” Bonner v. City of Prichard., 661 F.2d 1206, 1209 (11th Cir.
1981) (en banc).
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This is pure speculation. That a home is contaminated does not necessarily make it

valueless. In fact, Ms. Williams testified from her own knowledge that homes in

her neighborhood, including one on the same block as hers, had recently been sold.

This directly refuted her contention that the value of her home was zero. Thus,

despite the general rule that homeowners may testify as to the value of their homes,

Ms. Williams’ testimony was inadmissible because it would not have been based

on personal knowledge. The District Court therefore did not err in excluding her

testimony for lack of foundation.

      Ms. Williams argues in the alternative that even if exclusion of her valuation

testimony was proper, she should have been allowed to present evidence of

“contamination damages,” including “destruction and remediation damages.” But

Ms. Williams did not allege any functional damage to her home or cognizable

economic losses resulting from the contamination of her home, such as repair

expenses. Instead, she sought “destruction damages (which is full value for

permanent damage caused by the contamination).” This is just another way of

stating that her home’s value was diminished as a result of pollutants from

Mosaic’s facility. Hence, her testimony would not have been any different under a

theory of “stigma damages” (the diminution in value of her home from having to

disclose the presence of contaminants in her neighborhood) or a theory of

“contamination damages” (the diminution in value of her home as a result of its
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actual contamination with pollutants). Therefore, the District Court committed no

error in excluding her testimony.

                                       IV.

      We accordingly affirm the District Court’s exclusion of Dr. Mink and Ms.

Williams’ opinion testimony and its subsequent grants of summary judgment in

favor of Mosaic.

      AFFIRMED.




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