Michael D. Klein, P.E., CHMM06/26/2012

Topics that will be covered includeSpecialty experts.Experts and the science of exposure to chemical

hazardous materials.What steps an expert takes to evaluate a chemical

exposureSample case study

2

You have located, screened, and selected an expert whose credentials are:above reproachhas the education, training, and experiencewho can withstand a Daubert challengewhose particular skills are what are needed for the

casewho has communication skills

3

Before signing that engagement letter, you the litigator should think through what will be required for the case.

Does the case require aworkhorse?a show horse? or a racehorse?

Is the case dependent largely on the quality and sophistication of calculations and analysis?

Does counsel need a polished courtroom appearance?

4

Does the expert need to be capable of translating arcane formulae and calculations into opinions that will not put a jury panel of mere mortals to sleep?

Does the case demand someone with expertise in a highly specialized area?

Does the expert need to be capable of hitting top speed when emergencies arise or timelines are tight?

5

The litigator and the expert must define the facts and assumptions — the “givens” — on which the expert will base the evaluation of a chemical exposure.

These facts and assumptions represent the foundation of the expert’s opinion.

An expert who undertakes an evaluation of a chemical exposure without having facts and assumptions clearly defined and articulated is on a very slippery slope.

6

Litigation involving the chemicals said to pose excessive risks to health requires litigants to present evidence regarding exposure.Exceeding regulatory standards

Understanding the exposure is essential to understanding whether the toxic properties of chemicals have been or will be expressed in humans or the animal population.Exceeding levels that lead to adverse health effects

7

Claims of toxic tort or product liability generally require expert testimony in MedicineThe sciences of epidemiology and toxicologyThe nature and magnitude of the exposures incurred

by those alleging harm

8

Litigation involving the chemicals said to pose excessive risks to health requires litigants to present evidence regarding exposure.

Where the magnitude of exposure is an important component of the needed evidence, and if that magnitude is not a simple question of fact, then expert testimony will be important.

9

Exposure science is not yet a distinct academic discipline.

Initially, exposure assessment was typically practiced by toxicologists and epidemiologists.

As the breadth and complexity of the subject began to be recognized scientists and engineers are now necessary to provide scientifically defensible assessments.

10

The engineer and scientist is a grouping of experts who can provide expertise as to the properties of chemicalsHow they behave and undergo change in different

environmentsThe methods available to identify and measure

chemicals in products and in the environmentTheir training, education and experience.The necessary foundation of an expert to provide

scientifically defensible assessments.

11

The expert’s job goes beyond merely stating conclusions.

He or she must be comfortable articulating the basis for calculations and conclusions.

This will require the ability to “deconstruct and reconstruct” the big picture into all its component parts and computations.

The expert will not simply be called on to opine based on a static set of facts. He or she must be able to master the event chronology in the case.

12

Exposure science is the study of how people can come into contact with (are exposed to) chemicals that may be present in various environmental mediaAirWaterFoodSoilConsumer products of all types

They evaluate the amounts of those chemicals that enter the body as a result of these contacts.

13

Human beings are exposed to natural and industrial chemicals from conception to death.

Almost all chemicals can become harmful if exposures exceed certain levels.

The exposure expert brings understanding as to the magnitude and duration of exposures to chemicals This is critical to understanding their health impacts.

14

Exposure scientists also study whether and how those amounts change over time.The goal of exposure science is to quantify those

amounts and time periods.The quantitative expression of those amounts is

referred to as a dose.Ultimately the dose incurred by individuals or

populations is the measure needed by health experts to quantify risk of toxicity.

Exposure science does not typically deal with the health consequences of those exposures.

15

Exposure assessments can be directed at past, present, or even future exposure

They can be narrowly focusedOne chemicalOne environmental mediumOne population group

They can also be very broad in scopeMany chemicalsSeveral environmental mediaSeveral different population groups

16

Oil and gas recovery operations utilize the process of Hydraulic Fracturing.Perform a chemical exposure evaluation of the

operations.Information that is required to perform it.Results obtained from a chemical exposure evaluation.How the results are used.

17

The method used to make hard shale rock more porous. Allows gas shale to flow through the fine grained, organic-rich,

sedimentary rock formations to the wellbore.

18

Shale gas is present across much of North America in basins of both extreme and moderate size. Some of the major shale reserves include:

Marcellus (Pennsylvania, New York, Ohio, West Virginia, Kentucky)

Bakken (North Dakota, Wyoming) Haynesville (Texas, Louisiana) Barnett (Texas) Eagleford (Texas) Fayetteville (Arkansas) Antrim (Michigan, Illinois, Ohio) Woodford (Oklahoma)

19

The Marcellus Shale is known as the Saudi Arabia of Natural Gas.

The US Geological Survey estimates 500 trillion cu ft of natural gas in Marcellus alone.

20

Until recently shale gas could not be cost effectively extracted.

Two factors came together in

recent years to make shale gas production economically viable:• Advances in horizontal drilling• Advances in hydraulic fracturing

21

By drilling and casing a well for the extraction of thenatural gas

producers drill into the earth several thousand feet until they reach the natural gas reservoirsteel casings are inserted to a depth of 1,000 to 3,000 feetthe space between the casing and the drilled hole is filled with cement to stabilize the well and prevent any leakagethe cement setsthis process is repeated, using a series of ssuccessively smaller casings until the reservoir is reacheddepths reach distances of 6,000 to 10,000 feet

22

Once drilling and casing is complete

3 to 5 million gallons of water, mixed with sand andchemical additives, are pumped into the wellhead at high pressure, creating cracks in the rock beds

the hydraulic fracturing mixture is 95% water,4.5% proppant, and 0.5% chemical additives

23

Once drilling and casing is complete

Proppant is a material, such as grains of sand, ceramic, or other particulates, that prevent the fractures from closing when the injection is stopped.

Fracturing fluid formulas vary slightly among production sites in accordance with the unique requirements of each site’s geology.

The fracture width is typically maintained after the injection by introducing a proppant into the injected fluid.

24

Shale gas extraction using the process of hydraulic fracturing environmental and human health concerns possibly may include the

Potential mishandling of solid or liquid toxic wastePotential risks to air qualityPotential contamination of ground waterThe unintended migration of gases and hydraulic

fracturing chemicals to the surface within a given radius of drilling operations

25

Exposure assessment is generally intended to answer the following questions:Who has been or could become exposed to a specific

chemical(s) arising from one or more specific sources?Is it the entire general population, or is it a specific

subpopulation?What specific chemicals comprise the exposures?What are the pathways from the source of the

chemical to the exposed population?

26

Pathways include direct product use.Indirect pathways where the chemical moves

through one or more environmental media to reach the media to which people are exposed.AirWaterFoodSoil and dust

Understanding pathways is necessary to understanding exposure routes and quantifying exposures.

27

By what routes are people exposed? Routes include ingestion, inhalation, and dermal

contact.Identifying exposure routes is important because

those routes affect the magnitude of ultimate exposures and because they often affect health outcomes.

What is the magnitude and duration of exposure incurred by the population of interest?

28

Dose: the amount of chemical entering the body or contacting the surface of the body, usually over some specified period of time (often over 24 hours).

Duration refers to the number of days over which exposure occurs.Exposures can be intermittent or continuous and can

be highly variable, especially for some air contaminants.

29

The ultimate goal of exposure assessment is to identify dose and duration.

After a chemical enters or contacts the body, it can be absorbed (into the bloodstream), distributed to many organs of the body, metabolized (chemically altered by certain enzymes in cells of the liver and other organs), and then excreted.

30

Understanding these processes is important to determining whether and how a chemical may cause adverse health effects.

These processes mark the interface between exposure science and toxicology, epidemiology, and medicine.

Understanding the dose is the necessary first step in understanding these processes.

31

Questions?Thank you for having

me!

32