Project Experience

Dr. Smith provides consulting services in toxicology, risk assessment, and environmental sciences to a wide variety of clients. Brief descriptions of representative project experiences in these service areas are listed below:

 

Focused/Goal-Oriented Risk Assessment

Massachusetts Contingency Plan Characterization of Human Health Risk.  Over the last 10 years, Dr. Smith has performed more than 100 separate risk characterizations of petroleum release sites in Massachusetts, including Massachusetts Contingency Plan (MCP) Method 1, 2, and 3 risk characterizations in support of Phase I, II, III, IV, and V document submissions and Response Action Outcome (RAO) Statements. 

PAH Source Determination.  The source of polycyclic aromatic hydrocarbon (PAH) compounds in environmental media determines whether such compounds are subject to the provisions of the Massachusetts Contingency Plan (MCP).  The release and/or threat of release of oil and/or hazardous material related to coal, coal ash, or wood ash, but not wood ash resulting from the combustion of lumber or wood products, is exempt from notification under the MCP, and consequently may be excluded from evaluation in risk assessment.  Dr. Smith uses a quantitative analytical tool, methyl aromatic ratio analysis (MARA) as the cornerstone of his approach to determining whether soil PAH compounds derive from a petrogenic (i.e., petroleum) or pyrogenic (i.e., coal or coal ash) source.  In many cases, existing Gas Chromatograph/Mass Spectrum (GC/MS) data can be used in MARA.

Characterization of Human Health Risk Under the TSCA PCB Mega Rule. Dr. Smith performed a risk assessment of PCB-impacted soils for the Arsynco, Inc. facility in Carlstadt, New Jersey in order to comply with the requirements of the amended Toxic Substances Control Act (TSCA), 40 Code of Federal Regulations (CFR) 761 – Disposal of Polychlorinated Biphenyls (PCBs).  The proposed remedial plan included excavation and offsite disposal of all material with PCB concentrations ≥500 ppm and the consolidation, capping, and containment (including berms for flood control) of remaining material with concentrations of PCBs ≥50 ppm.  Dr. Smith conducted the “baseline” risk assessment required by U.S. EPA and also evaluated risks associated with an “alternative remedy” involving only the removal of material with PCB concentrations ≥500 ppm while leaving all remaining PCB contaminated materials in place (i.e. - no consolidation, capping or containment).  Dr. Smith demonstrated that there is no significant health risk to potential human receptors under the U.S. EPA baseline remedy condition and no significant health risk associated with the less conservative alternative remedy condition.

Characterization of Human Health Risk at a Charter School. A private charter school was constructed within a former manufacturing facility contaminated by petroleum products, metals, bird excrement, and polychlorinated biphenyl (PCB) compounds.  After construction, the City refused to provide a Certificate of Occupancy (C of O) to the owner of the school without assurance children, teachers, and maintenance personnel would be without significant health risk.  The issues of concern included PCB compounds detected in air within a storage area adjacent to the school, PCB and petroleum compounds in offsite soils, pigeon droppings from roosts near the school, and mold.  The Licensed Site Professional (L.S.P.) of record engaged Dr. Smith to address human health risks at the school, including identification of additional data necessary for risk characterization, air sampling requirements, and correct identification of PCBs in soil and air.  The risk characterization demonstrated that materials at the school posed "No significant Risk" to students, teachers, and maintenance workers. Dr. Smith presented credible evidence regarding the health risk posed by site-related compounds in a civil court hearing.  The court found Dr. Smith’s testimony to be credible and reliable.

Evaluation of Cyanide Availability and Mobility in Groundwater.  Pennsylvania Department of Environmental Protection (PADEP) identified groundwater at a former industrial site as exceeding allowable cyanide concentrations.  The presence of cyanide in groundwater at the site is associated with the historical use of soluble potassium cyanide in metal plating operations, which ceased more than 45 years ago.  Dr. Smith used multiple year quarterly ground water monitoring results and existing ground water analytical data obtained from selected wells using a unique pump and sampling protocol to derive an estimate of the free (i.e., dissolved) cyanide concentration in groundwater of less than 10 percent the total cyanide concentration measured in groundwater.  Dr. Smith demonstrated groundwater cyanide concentrations were in compliance and did not require further monitoring or remediation.

Risk Characterization of PCBs at a Former Industrial Site.  Pending sale of a former industrial site located in Massachusetts, the sellers due diligence site investigation identified several areas of environmental concern, which included the discovery of soils contaminated with fuel oil, polycyclic aromatic hydrocarbon (PAH), volatile organic compound (VOC), and polychlorinated biphenyl (PCB) compounds.  Dr. Smith conducted a Massachusetts Contingency Plan (MCP) Method-3 risk characterization of the site for the purpose of minimizing the removal of PCB contaminated soils while obtaining a condition of no significant risk of harm to human health.  The property subsequently sold at fair market value.

Modified Baseline Risk Characterization.  A developer, negotiating purchase and development of a former wood treatment/manufactured gas plant facility in Massachusetts, was concerned that the cost of site remediation would make the venture unprofitable.  Dr. Smith used a narrowly focused Massachusetts Contingency Plan (MCP) Method 3 “modified” baseline risk characterization to provide the developer with site-specific information concerning the potential cost of site remediation and development.  Dr. Smith focused the risk characterization to evaluate only exposure of construction workers to on site inorganic and organic contaminants in soil, surface water, and air.  As a result, the developer modified plans for site development to minimize potential health risks posed by contaminants.  Following site development, the “modified” baseline risk characterization was submitted to regulatory authorities to demonstrate a finding of “no significant risk of harm to health, safety, public welfare, and the environment.” No further remediation was required under the MCP.

Dose Reconstruction, Remedial Design, Derive Indoor Air Level.  A gas utility employee accidentally released elemental mercury into a residential home in Rhode Island during routine replacement of a gas regulator.  The release went unnoticed for nearly a year before discovery by the occupant’s son, who collected it and subsequently spread it throughout the home.  A Prior attempt to remediate the residence by an unqualified contractor led to further widespread contamination of the dwelling.  In anticipation of litigation, attorneys engaged Dr. Smith as an expert witness.  Dr. Smith reconstructed resident exposure to mercury vapor in indoor air and evaluated the potential for adverse health effects in exposed residents.  Although the residence would typically have been demolished and the hazardous waste appropriately disposed of at little cost, the gas utility was concerned that these actions would unduly alarm its customers and the public. Dr. Smith identified an appropriate, low profile cleanup strategy to obtain an appropriate health protective level of mercury in indoor air.  Dr. Smith evaluated remediation of the residence with respect to a site-specific health risk-based allowable mercury concentration in indoor air.  Through these actions, Dr. Smith obtained a letter from the Rhode Island Department of Health declaring the residence safe for immediate occupancy.

Support of a No Action Alternative.  Potable ground water at a former electronics manufacturing plant in Connecticut contained chlorinated volatile organic compound (cVOC). Analytical differentiation of degradation products identified an anaerobic transport pathway augmented with organic compounds (sewer line).  This information allowed for a more focused evaluation of environmental transport of cVOC contaminants.  Dr. Smith alerted the client to problems with existing analytical cVOC data collected using an inappropriate sampling method and the use of a technical infeasibility argument for limiting further groundwater treatment at the site.  Dr. Smith supported a no action alternative with the development of a Public Health and Environmental Risk Evaluation (PHERE) demonstrating that there are no human receptors impacted by groundwater contaminates. 

Product Evaluation; Human Health Risk. The state of Pennsylvania expressed concern that concentrations of polychlorinated dibenzo-p-dioxins (dioxins or PCDDs) and dibenzofurans (furans or PCDFs) in composted pulp and paper mill sludge might pose a human health risk when used as either a soil amendment or as a retail mulch.  Dr. Smith assisted in a conservative assessment of human health risk posed by these compounds. The risk assessment included evaluation of residential exposure through incidental ingestion of amended soil and vegetables grown in amended soil, as well as potential occupational exposure from direct contact with both sludge and mulch.  The evaluation found no increase in carcinogenic or non-carcinogenic risk to human health from the use of these products.

Preliminary Characterization of Inhalation Air Risk. At a former frop forge site in Massachusetts, Dr. Smith assessed the potential health risk to residents at a nearby apartment building.  Air contaminants of potential health concern included several polycyclic aromatic hydrocarbon (PAH) compounds, benzene, and chlorinated and non-chlorinated volatile organic compounds (cVOC and VOC, respectively).  The result identified additional sampling and risk assessment alternatives under the Massachusetts Contingency Plan (MCP) to reduce potential receptor health risks.

 

Derivation of Alternative Remedial Goals

Derivation of Risk-Based Remedial Groundwater Concentrations.  Groundwater containing Methyl tertiary Butyl Ether (MtBE) and benzene migrated from its release point, a service station, beneath a residential neighborhood into a storm water pipe whose outfall entered a 300-foot long swale discharging to a small stream.  Dr. Smith derived risk-based concentrations of MtBE and benzene allowable in groundwater underneath the residential neighborhood based on their potential to infiltrate indoor air.  Dr. Smith also derived a risk-based surface water concentration in the swale considering contaminant volatilization to air and adsorption to sediment.  Dr. Smith evaluated receptor exposure through the inhalation of outdoor air, dermal contact with surface water and sediments, and ingestion of surface water and sediments by nearby residential receptors.  The client used these risk-based allowable media concentrations to back calculate allowable groundwater concentrations at a point of onsite compliance.  Dr. Smith presented the findings of his analysis in a report and during court ordered arbitration that resulted in Pennsylvania Department of Environmental Protection (PADEP) agreement that the current release to surface water and current onsite and offsite groundwater MtBE and benzene concentrations do not pose significant health risk to residential receptors.

Derivation of Alternative Remedial Goal for Mercury.  Using the State default remedial goal for mercury in soil, a confidential client faced removal and treatment of more than 200,000 cubic yards of soil at a former pesticide manufacturing and battery disposal facility .  Dr. Smith managed the development and application of an innovative technique for estimating the bioavailability of inorganic mercury from soil using soil speciation and an in vitro bioaccessibility test.  Dr. Smith used this information to derive an alternate risk-based soil cleanup level for inorganic mercury that was more than 12-fold greater than the State default cleanup goal.  This resulted in a significant reduction in the amount of soil requiring removal and treatment, a projected remedial cost savings of $20–$30 million.

Negotiated Increased Remedial Goals for Selenium, Chromium, and Arsenic.  Concentrations of selenium, arsenic, and chromium in soil at a former forge site in Endicott, New York exceeded acceptable state action levels.  Remedial efforts to reduce the concentration of these metals in soils would have required the removal and/or treatment of approximately 16,000 cubic yards of soil.  Negotiation with the New York State Departments of Environmental Conservation (NYDEC) and Health (NYDOH) resulted in significant increases in the concentration of these metals allowed in site soils without restriction, resulting in an 80 percent reduction in the volume of soil requiring removal and/or treatment, a substantial savings in remedial costs.

Derivation of Alternative Remedial Goal for Mercury.  Dr. Smith assisted a competitor in the development of an alternative cleanup level for inorganic mercury in soils at a former thermometer and barometer manufacturing facility in Rochester, New York. Dr. Smith managed derivation of an alternative industrial site risk-based cleanup level for inorganic mercury in soil using site-specific bioaccessibility data. The alternative cleanup goal is estimated to save $5 million dollars in remedial costs.

Derivation of Alternative Remedial Goals for Boron and Lithium.  A confidential client had purchased a Superfund site for its stockpile of relatively pure Lithium.  Soils and ground water at the former mineral mining operation were determined to contain significant concentrations of boron and lithium.  The Pennsylvania Department of Environmental Protection (PADEP) assumed site soils were contributing to ground water contamination.  Dr. Smith was engaged to critically review information on boron and lithium mobility and toxicology to develop an argument for the derivation of alternative risk-based remedial goals for these metals in site soils.  Chemical-specific properties and site soil characteristics were used to develop an argument that soil boron and lithium were not mobile in site soils and therefore, were not a continuing source of contamination to ground water.  The result was a several fold increase in the allowable levels of lithium and boron which could remain in soil.

Derivation of an Alternative Remedial Goal for Arsenic.  State regulators in Minnesota required remediation of arsenic in site soils to a specified level at a former arsenic pesticide manufacturing facility.  Dr. Smith negotiated a higher remedial objective for arsenic in soil using information on soil arsenic bioavailability, planned future land use, and site- and receptor-specific exposure parameters.  Regulators agreed that an appropriate remedial goal for arsenic in site soils is twofold higher than initially proposed, resulting in significant cost savings in site remediation. 

Derivation of Groundwater Remedial Objectives.. Potable ground water beneath a former electronics manufacturing facility in Rhode Island contained several chlorinated volatile organic compounds (cVOC).  An engineering consulting firm hired to remediate the property was planning to remove and treat contaminated soils and ground water beneath the building slab.  Dr. Smith developed alternative groundwater remedial objectives based on estimates of human health risk posed by cVOC infiltrating indoor air, eliminating the need to remediate site soils underneath the building slab.

 

Exposure Assessment

Proposed Evaluation of Ambient Air Quality in Two Southern Maine Communities. Dr. Smith teamed with another consulting firm to propose a multiyear study of ambient air quality and health effects in two adjoining communities in southern Maine. Survey data for the two communities suggested higher incidences of certain adverse health effects and early mortality.  Both communities suspect sir contaminants from area industry play a causative role in these outcomes.  The proposed work plan included broad-based community health surveys to identify the type and incidence of adverse health effects and a real-time sampling of ambient air quality from more than 6 locations within the community. Ambient air samples are to be analyzed fro particulate mater (i.e., PM10 and PM2.5), volatile organic compounds (VOC), and selected semi-volatile organic compounds (SVOC). Analysis of the resulting information is to include an evaluation of potential associations between identified adverse health effects and identified ambient air quality indicators. The results will be used by area health professionals and leaders to improve the quality of peoples health in these communities.

Evaluation of Human Exposure. At the clients request, Dr. Smith evaluated New York State concerns regarding human health risk posed by mercury in offsite soils, air, and fish, near an operational mercury retort facility.  Dr. Smith used an evaluation of potential exposure routes and pathways to convince State regulators that there was no need to characterize human health risks at offsite areas of concern.

Critical Review of Exposure Parameters Used in Risk Assessment.  At the request of a national environmental consulting firm, Dr. Smith critically evaluated a draft report characterizing human health risks associated with ingestion of fish containing mercury and PCBs from Onondaga Lake in New York.  Dr. Smith’s evaluation identified changes in several exposure assumptions to more accurately reflect human exposure at the site.  Dr. Smith assisted in the revision of the exposure assessment to include this information, including more appropriate default exposure assumptions and a federally defined estimate of PCB loss through fish preparation and cooking.  The changes resulted in a several-fold reduction in the human health risk posed by mercury and PCBs in fish.

 

Methodology Development and Evaluation

Develop Methodology for Determining an Alternative Remedial Goal for Chromium.  Dr. Smith developed a site-specific approach for deriving an alternative remedial goal for chromium in soil.  The approach determines the relative solubility of chromium species in site soils using newly developed techniques differentiating between relatively non-toxic chromium species (CrIII) and more toxic ones (CrVI).  Speciation techniques and a modified in vitro bioavailability test assessing chromium solubility in the gastrointestinal track can provide information useful in the derivation of an alternative risk-based cleanup levels for chromium in soil.  The approach promises to offer substantial remedial cost savings over generically applied cleanup criteria.

Evaluation of Estrogenic Compounds in Sediment.  A confidential client was under regulatory scrutiny as a potentially responsible party responsible for remediation of sediments containing persistent chlorinated organic compounds with estrogenic activity.  Regulatory authorities focused on eliminating contaminated sediments with a potential to cause reproductive effects in wildlife through dredging of sediments in New York harbor.  New Jersey determined that estrogenic compounds, historically associated with the client’s site, were primarily responsible for sediment reproductive toxicity.  Dr. Smith critically reviewed the available assays of estrogenic activity, characterizing assays by their ability to differentiate between anti-estrogenic and estrogenic contaminants, sensitivity, selectivity, and cost.  Dr. Smith developed an integrated approach for the phased analysis of the sediment estrogenic activity using a unique in vitro bioassay.  Client responsibility for sediment estrogenic activity is still being assessed.

Evaluation of Mercury Vapor Analyzer.  Dr. Smith was retained by a homeowner concerned about the hazard posed by mercury vapor in his families home.  Mercury vapor was detected in the home after a Michigan power company technician accidentally released elemental mercury during routine replacement of the gas regulator. Health authorities immediately moved the family out of the house to protect their health. Dr. Smith worked with legal counsel and the power companies consultant to determine appropriate remediation and post-remediation testing of the home. Post-remediation testing of airborne mercury vapor in the home was performed using the Lumex RA-915+ Mercury Analyzer, which although accepted by U.S. EPA Region V, had not been appropriately validated for this use. Under Dr. Smith’s direction, the home was appropriately cleaned and, using the Lumex Mercury Analyzer and an appropriate Quality Assurance/Quality Control (QA/QC) Program, determined to be safe for the homeowner’s family to return.

 

Comparative Risk and Exposure Analysis

Evaluation of Relative Risk (PCBs vs. Dioxins and Furans).  Dr. Smith prepared a report for submission to the State of California Environmental Protection Agency (CA EPA) documenting the incremental hazard posed by polychlorinated dibenzo-p-dioxins (PCDDs) dibenzofurans (PCDFs), and biphenyls (PCBs) in Aroclor mixtures used in electrical transformer fluids.  The state asked the client to investigate the need for monitoring PCDD and PCDF concentrations associated with PCB soil contamination at a transformer maintenance and repair facility.  Dr. Smith compared the relative hazard of PCDDs and PCDFs to that of PCBs from virgin transformer fluid to indicate that monitoring was not necessary.  Because the relative hazard posed by PCDDs and PCDFs was less than 3 percent of that posed by PCBs the client did not have to monitor of devise a separate remedial strategy for PCDDs and PCDFs in site soils.

Evaluation of Relative Risk to PAH Compounds in Soil.  At the request of counsel and on behalf of a confidential client, Dr. Smith compared the carcinogenic risk posed by polycyclic aromatic hydrocarbon (PAH) compounds in Superfund site soils requiring remediation with that posed by PAH compounds identified in two common over-the-counter shampoos containing coal tar.  The carcinogenic risk posed by PAH compounds in Superfund site soil was determined using information and methodologies contained in a US Environmental Protection Agency (EPA) Record of Decision (ROD) for the site.  Carcinogenic risk posed by site soils was determined using the provisional US EPA Estimated Order of Potency (EOP) approach and an earlier approach that assumed all site PAH compounds have the same potency as benzo[a]pyrene (BaP).  Dr. Smith estimated the carcinogenic risk posed by PAH compounds in two brands of over-the-counter shampoo containing coal tar using U.S. EPA methodologies and default exposure factors.  The result suggested that either: 1) PAH compounds in these shampoos pose 4-orders of magnitude (10,000-times) greater risk than PAH compounds requiring remediation in Superfund site soils; or 2) US EPA methodologies for determining carcinogenic risk of PAH compounds are seriously flawed.

Evaluation of Relative Carcinogenic Risk for Several Threshold Carcinogens.  Dr. Smith evaluated the relative carcinogenic risk posed by three threshold carcinogens: dioxin, arsenic, and benzene and compared these carcinogenic risks to an over-the-counter analgesic, acetaminophen (paracetamol).  Dr. Smith estimated the cancer potency of acetaminophen using a linear low-dose, non-threshold, method for extrapolating carcinogenic risk to low levels of human exposure.  Dr. Smith compared the cancer potency estimate for acetaminophen to that published by the US EPA for dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin), arsenic, and benzene.  Although the relative carcinogenic potency of acetaminophen is lower than any of the other compounds, it poses a greater cancer risk.  Excess lifetime cancer risk (ELCR) associated with a dose of 500 mg acetaminophen per week posed more than 100-times the cancer risk associated with the allowable amount of dioxin, 1 part per billion (ppb), in soil and 4- to 7-orders of magnitude higher cancer risk than that posed by typical exposure to the maximum allowable concentrations of arsenic or benzene in drinking water.

Evaluation of Relative Exposure to Estrogenic Compounds in Surface Waters. Dr. Smith compared the concentration and relative estrogenic potency of several synthetic compounds, dicofol, DDT and its metabolites DDD and DDE, methoxychlor, lindane, chlordane, dieldrin, and endosulfan, with levels of natural estrogen in surface waters.  Dr. Smith determined the percent contribution of natural estrogen and synthetic estrogen-like compounds historically detected in the Chesapeake Bay watershed to total estrogenic activity in these surface waters.  The amount of natural estrogen, derived solely from chicken farms within this watershed, contributed the majority of the estrogen-like activity to surface water.  Additional agricultural and human sources, such as municipal sewage treatment facilities, are likely to contribute even more natural estrogen than Dr. Smith estimated comes from area chicken farms.  In contrast, Dr. Smith demonstrated that the total of the highest ever recorded concentrations of synthetic estrogenic compounds account for less than 1 percent of the estrogenic activity of surface waters within the Chesapeake Bay watershed.  This suggests that U.S. EPA efforts focused on regulating synthetic estrogenic compounds is inappropriate.

 

Critical Third Party Review

Technical Assistance to Public Interest Groups: Corinna Superfund Site Maine.  Dr. Smith participated as part of a team of consultants receiving technical assistance grant (TAG) moneys for providing public interest groups with technical assistance and review of U.S. EPA and its consultant’s activities at the Eastern Woolen Mills Superfund site located in Corinna, Maine.  U.S. EPA identified chlorinated benzenes, polychlorinated dioxins and furans, and petroleum hydrocarbons in environmental media.  Dr. Smith provided review of the Phase II Scope of Work (SOW) to ensure that public interests in the region are adequately addressed.  Dr. Smith suggested changes to the SOW to include specific sampling and analysis of fish for environmentally persistent halogenated compounds and the retesting of a site-related bulk-storage facility for petroleum contaminants.  Dr. Smith reviewed soil/sediment sampling protocols and dioxin and furan analyses for the purpose of determining their source and the need for additional remediation of this Superfund site.

Critical Third Party Review of an Ecological Risk Assessment.  A confidential client requested review of a competitors draft ecological risk assessment of PCBs in former municipal landfill in New York State.  Dr. Smith managed a team review and evaluation of the draft report prepared for submission to the New York State Department of Environmental Conservation (NYDEC) and U.S. EPA Region II.  The team evaluation identified critical deficiencies that, if not remedied, would likely have increased client liability and agency involvement at this site.

Review of Release Abatement Measure (RAM).  An environmental engineering firm requested Dr. Smith review a draft Release Abatement Measure (RAM) Status Report for a former textile mill in Fall River, Massachusetts.  Dr. Smith’s review focused on limiting client liability by minimizing the need for additional risk characterization work within the Phase I site assessment.  The review identified several statements, wording, and omissions that could have resulted in increased state scrutiny of site investigation activities and more involved risk characterization work required within the following Phase II Site Investigation.

 

Support of Ecological Risk Assessment

Molecular Biomarkers as Measurement Endpoints.  A former chlor-alkali facility, suspected of having released PCBs, dioxins, and furans into a tidal estuary on the coast of Georgia, was the site of Superfund activities related to the evaluation of harm to ecological receptors.  Regulators requested the use of certain biomarkers of exposure and hazard to assess the ecological health risk at the site.  Dr. Smith evaluated the scientific evidence for using molecular biomarkers as measurement endpoints in assessing ecological risks. Dr. Smith’s evaluation identified problems with the use of specific enzymatic biomarkers of exposure as specific measures of population, community, and individual hazard.  Dr. Smith developed an alternative approach using other measurement endpoints as specific indicators of organism and population toxicity.  Dr. Smith’s evaluation resulted in the adoption of an approach that focused on the specific ecological hazards posed by specific PCB, dioxin, and furan congeners, limiting client liability to assessable hazards posed by these compounds and significantly reducing the scope of proposed wetlands remediation.

Evaluate Dioxin and Furan Accumulation in Aquatic Species. A confidential client asked Dr. Smith to address regulator concerns that specific marine species would accumulate persistent chlorinated organic compounds and pose a risk of harm to humans and other marine species.  Dr. Smith critically reviewed the scientific literature for evidence of the bioconcentration and bioaccumulation of 2,3,7,8-substituted dioxins and furans in marine biota.  Specific issues of interest included differential uptake, metabolism, and accumulation in several aquatic species.  Dr. Smith’s work aided the selection of sentinel species for evaluation of potential ecological health risks.

Evaluated the Toxic Effects of PCBs to Plants and Wildlife.  In support of an ecological risk assessment for a confidential client concerned with the release of polychlorinated biphenyl (PCB) compounds into the Housatonic River, Dr. Smith critically reviewed the scientific literature for evidence concerning uptake, accumulation, and toxic effects of PCBs in plants, invertebrates, and aquatic vertebrate species indigenous to the area.  Preparation of a PCB toxicity profile included a scientific argument against the use of an indigenous fern species as a sentinel species. Dr. Smith considered published reports of PCB-induced effects during the haploid period of the ferns life cycle as inappropriate measurement endpoint for evaluating ecological health risk.  A subsequent evaluation of ecological risk precluded the need to assess hazard based on effects in this fern species.

 

Scientific Review and Evaluation

Evaluate Mercury Toxicity and Exposure. Regulatory authorities ordered a 5-floor Hoboken apartment building vacated after residents discovered pools of liquid mercury beneath floor boards during renovations.  Elemental mercury in the building was responsible for relatively high levels of mercury detected in indoor air and in the urine of residents.  State and federal authorities brought legal action against a former owner of the facility in order to force remediation of the property.  At the request of counsel, Dr. Smith reviewed the potential health effects associated with mercury vapors detected in indoor air and urinary mercury levels.  The review indicated substantial scientific uncertainty regarding a “safe” level of mercury in indoor air and whether any adverse effects would be associated with current resident urine mercury levels.  U.S. EPA and State authorities proposed demolition and disposal of the building as the only acceptable remedial option.  Dr. Smith developed scientific arguments in defense of less costly and less destructive remedial actions.  These arguments provided the client with additional legal options and an ability to challenge the decisions of regulatory authorities.

Evaluate Endocrine Disrupting Metals. Members of the International Council on Metals and the Environment (ICME) were concerned with the popularized notion that some metals had endocrine disrupting properties.  Dr. Smith evaluated the scientific evidence for metals as endocrine disrupters with specific focus on mercury.  Dr. Smith’s report included a synopsis of the then current global regulatory environment for endocrine disrupting chemicals.  ICME published this report.

Systems Analysis and Software Testing.  While working at the U.S. EPA’s, Environmental Criteria and Assessment Office (ECAO), now known as the National Center for Environmental Assessment (NCEA), Dr. Smith performed systems analysis, Quality Assurance and Quality Control, and beta testing of an object-oriented program designed to enhance and standardize ECAO calculations appearing in reportable quantity (RQ), reference dose (RfD/RfC), drinking water, and health and environmental effects documents (HEEDs).  Dr. Smith developed, programmed, and implemented an IBM PC model upon which the object-oriented programming effort was based.  Dr. Smith developed a program in dBase IV to track HEEDs for program management within ECAO.  Dr. Smith proposed revisions to the RQ methodology, using RfD/RfC and CSF values as a means of standardizing RQ derivation.  Dr. Smith standardized ECAO review of responses to Office of Health and Environmental Assessment (OHEA) comments on HEEDs.

 

Toxicological Evaluation

Evaluation of Dioxin Immunotoxicity.  At the request of a confidential client concerned that U.S. EPA would propose lower remedial goals for dioxin based on immune system toxicology endpoints, Dr. Smith critically reviewed the scientific literature relating to dioxin-mediated immune system toxicity in humans and animals.  Dr. Smith identified a maximum human “no observed adverse effect level” (NOAEL) based on delayed-type hypersensitivity.  Using this NOAEL in a comparison with animal NOAEL for the same endpoint, Dr. Smith determined humans are at least ten-times less sensitive to dioxin-mediated immunological effects than monkeys, and more than ten thousand-times less sensitive to dioxin-mediated immune effects than either mice or rats.  Since no low observed adverse effect level (LOAEL) is identified, sensitivity of humans to the immune system effects of dioxin is likely to be even lower than that identified in Dr. Smith’s analysis.  The results suggests that animal evidence of dioxin immunotoxicity is not a useful endpoint from which to derive dioxin levels protective of human health.

Support an Alternative Reference Dose for Aroclor 1254 (PCBs).  General Electric was concerned that U.S. EPA would use poorly performed scientific studies to justify a chronic oral reference dose (RfD) for Aroclor 1254® of less than 5 mg/kg-day.  Dr. Smith critically evaluated all of the available information regarding immunological, reproductive, teratogenic, and morphological effects related to Aroclor 1254 exposure.  His evaluation primarily focused on immunological methodologies used to assess Aroclor 1254 toxicity in primates.  Dr. Smith successfully used information derived from his evaluation to support an alternative RfD for Aroclor 1254 that is 4-fold higher than that originally proposed by the U.S. EPA.

Evaluated Sensitive Population Cancer Incidence.  A Native American population living in the southwest claims increased incidence of certain cancers associated with exposure to byproducts of uranium-mine operations.  At the request of legal counsel representing the interests of this population, Dr. Smith evaluated the biological basis of epidemiological studies reporting increased cancer incidence resulting from exposure to products associated with uranium mining operations.  Additional tasks involved the identification of potential chemical and radiological agents associated with past uranium mining operations that are plausibly linked to increased cancer incidence in various target organs.  Additional tasks associated with this project included review of similar legal cases for potential relevance. Because of cultural differences and the lack of appropriate cancer incidence data, Dr. Smith was unable to provide attorneys with a finding that the byproducts of uranium mining operations ,ore likely than not caused certain target organ cancers.

Evaluate Organochlorine Trends in Wildlife.  Dr. Smith researched and evaluated the published literature for organochlorine compound concentration trends in fish, shellfish, and wildlife tissues in North America and Europe, and in human food and human tissues (i.e., fat, milk, fetal tissues) from the Great Lakes region of North America.  Dr. Smith’s evaluation included information on PCBs, polychlorinated dioxins (PCDDs) and furans (PCDFs), chlordane, DDT, DDD and DDE, hexachlorobenzene, hexachlorocyclohexanes (i.e., lindane), mirex, kepone, and toxaphenes.  Dr. Smith documented a general decline in organochlorine concentration in human and wildlife tissues during the last 25 years.  This research was published by the Chemical Manufacturers Association.

Differential Species Sensitivity to Dioxin.  Dr. Smith observed dioxin response elements (DRE) associated with the phosphoenolpyruvate carboxykinase (PEPCK) gene in rats but not humans.  Because the PEPCK gene is negatively regulated by dioxin in rats, Dr. Smith theorizes that the lack of DREs associated with the human gene explains why body weight loss, wasting, and death is not observed in humans exposed to high levels of dioxin. Dr. Smith suggests that species specificity to dioxin-mediated effects is determined, in large part, at the level of individual gene regulatory elements.  Consequently, estimates of human health risk based on rodent toxicity bioassays may significantly overstate human health risk.

Quantitative Structure Activity Relationship Program. While at the U.S. EPA Environmental Criteria and Assessment Office (ECAO), now known as the National Center for Environmental Assessment (NCEA), Dr. Smith provided critical review of models of quantitative structure activity relationships (QSAR), developed QSAR policy initiatives, identified appropriate methodological and validation concerns, and developed an integrated approach for using QSAR results in hazard identification and risk assessment . Dr. Smith also assisted in the direction and development of a QA/QC program for QSAR model validation and introduced mechanistic biological modeling to QSAR methodologies adopted by ECAO. 

Reviewed, Evaluated, Derived Environmental Criteria.  While at the U.S. EPA Environmental Criteria and Assessment Office (ECAO), now known as the National Center for Environmental Assessment (NCEA), Dr. Smith’s provided critical evaluation of U.S. EPA documents supporting health-based criteria such as drinking water equivalency levels, DWELs; 1-day health advisories (HAs), 1-day HAs; 10-day HAs, and long-term health advisories; chronic oral reference doses and chronic inhalation reference concentrations (RfD and RfC, respectively); reportable quantities (RQ); and cancer potency factors (CPF, CSF, or q1*); and unit risk (UR) estimates.  Dr. Smith also compiled and summarized agency reviewer comments on World Health Organization/International Programme for Chemical Safety Monographs and Health Safety Documents.

 

Litigation Experience

Deposition & Expert Witness Testimony - Exposure to MtBE and Benzene. Dr. Smith developed health protective risk-based remedial goals under Pennsylvania’s ACT 2 Hazardous waste regulations for MtBE and benzene in groundwater.  Development of remedial goals considered the aggregate of conservative estimates of compound concentrations in indoor and outdoor air, sediment, and surface water to which residential receptors may be exposed at a location down gradient from the point of compliance.   Litigation pursued under the authority of the Environmental Quality Board, between the client and the Pennsylvania Department of Environmental Protection, included Dr. Smith’s expert witness testimony for the client (defendant).  The court accepted Dr. Smith’s testimony as credible.  The state declined to challenge Dr. Smith’s testimony.

Deposition & Expert Witness Testimony - Exposure to Amorphous Silica Gel. Plaintiff contended harm to his family’s health from the application of a pesticide product containing amorphous silica gel.  The plaintiff sought remediation of his condominium and health related medical costs from the pesticide applicator and manufacturer.  In a related legal action, the plaintiff sued the homeowner’s association, responsible for common areas of his condominium complex, for negligence in failing to notify and remediate the health threat caused by the pesticide and indoor mold resulting from a leaky roof.  Dr. Smith provided 20 hours of deposition testimony relating to the toxicology of amorphous silica gel and the ability of mold to suppress immune system function.  Dr. Smith provided approximately 7 hours of testimony in the jury trial. The jury found for the defendants. This case is under appeal.

Deposition & Expert Witness Testimony - PCBs. Attorneys representing a newly constructed Charter School (plaintiff) filed legal action against the City of Somerville, Massachusetts, for failure to provide a Certificate of Occupancy.  The City denied the Certificate of Occupancy based on their perception of the potential health hazard posed to students by hazardous waste, specifically polychlorinated biphenyls (PCBs) and mold, located nearby.  Dr. Smith testified that there was no health hazard to children or adults from PCBs and related current understanding regarding the lack of environmental standards for molds.  The judge found Dr. Smith’s expert witness testimony persuasive and credible and instructed the City to issue the Certificate of Occupancy to the Charter School.

Deposition - Accidental Pesticide Poisoning. Dr. Smith provided a written deposition expressing his expert opinion concerning plaintiffs poisoning by lindane during his use of a poorly labeled pesticide product.  The deposition recalled facts in the case as those consistent with lindane poisoning, dose reconstruction based on reported pesticide product use, and an opinion regarding the adequacy of the pesticide product’s label to protect human health.  The deposition was instrumental in negotiating a settlement with the plaintiff’s insurance company.

Class Action Suit Consultant - Cancer Caused by Uranium Mine Tailings ? Attorneys in New York employed Dr. Smith as an consultant for a possible future class action suit against the U.S. Government.  The class action suit contends that specific cancers within Native American populations residing in the Four Corners area of the western U.S. (i.e., New Mexico, Arizona, Utah, and Colorado) are the result of exposure to uranium mine tailings.  Dr. Smith clearly described the scientific information required to demonstrate a causal relationship between agent exposure and relatively rare cancer incidence within uncharacterized Native American populations.   Confounding factors included: 1) the lack of information concerning background cancer incidence in Native Americans, an incidence that appears to be very different from the general population; 2) difficulties in dose-reconstruction from demographic data and work histories; and 3) cultural differences that resulted in differences in reporting of disease and mortality incidence. This case is still being researched.

Deposition & Expert Witness Testimony - Amorphous Silica Gel. Plaintiff sued a pesticide applicator and apartment unit owners for costs associated with cleaning her property and relocation after a pesticide application device exploded in her apartment.  Dr. Smith provided 8 hours of deposition testimony and 4 hours of jury trial testimony relating to the toxicology of the pesticide, amorphous silica gel.  Plaintiff lost the case.