Environment (General) Expert Witnesses: 21

Paul E. Rosenfeld, M.S., Ph.D., is the Founder and Principal Scientist of RoseyFields LLC and a nationally recognized forensic environmental scientist and plaintiff expert witness. Over 25 years, his work has spanned complex toxic-tort and class-action litigation — including MTBE, PFOA/PFAS, asbestos, FELA railroad exposure, air-dispersion modeling, epidemiology, toxicology, industrial contamination, and pesticide exposure matters — with an aggregate case value of approximately $14 billion, and he has been deposed approximately 150 times in 31 states.

Litigation Support

Dr. Rosenfeld's opinions are based on established scientific methodologies, quantitative exposure models, peer-reviewed scientific literature, published technical methods, and reproducible calculations that can be independently evaluated and tested, providing a rigorous scientific foundation for expert opinions under Daubert and related standards for the admissibility of scientific evidence. He has authored and contributed to books and technical publications concerning environmental contamination, exposure assessment, and risk evaluation and has applied these scientific methods in expert reports, litigation, depositions, regulatory proceedings, and trial testimony.

Methodologies & Scientific Approach

Dr. Rosenfeld's air dispersion modeling work applies EPA-approved and peer-reviewed models, including AERMOD, CALPUFF, and ALOHA, to reconstruct historical emissions, source attribution, and community-level exposure pathways. His exposure and dose reconstruction methods integrate environmental sampling data, regulatory exposure factors, and published toxicological and epidemiological literature to quantify human exposure to chemicals including benzene, PFAS/PFOA, TCE, hexavalent chromium, and crystalline silica, among others. Each methodology is applied transparently, allowing the underlying calculations, data inputs, and modeling assumptions to support general cuasation opinions. 

Publications & Court Qualifications

Dr. Rosenfeld has authored six books and dozens of peer-reviewed publications on environmental contamination and risk assessment. He has been qualified as an expert under Daubert and analogous standards in federal and state courts nationwide reflecting consistent application of scientifically defensible methodologies under prevailing standards for expert testimony admissibility.

Areas of Expertise:

Gregory L. Kelly is a Structural Expert with over 25 years of experience in the design, preservation, restoration, and construction of buildings and industrial structures. Mr. Kelly has teamed with major architectural and engineering institutions, including Columbia University and NYU, to teach classes and lead research teams studying novel building systems.

Litigation Support - Mr. Kelly specializes in areas such as forensic engineering, coastal design, historic preservation, and blast engineering. He provides an invaluable perspective on construction defects, disputes, and structural failures. His experience includes Structural Engineering for over 20 million square feet of new construction and building renovations and work with the New York City Green Codes Task Force to modernize the building code. 

Areas of Expertise:

Mr. Kelly actively engages with the community through teaching, speaking engagements, and collaboration with government agencies such as Mayor Bloomberg's Green Codes Task Force to shape policy and effect change. His work has been showcased in National Geographic, Scientific American, and various architecture, construction, and engineering (ACE) industry publications. Mr. Kelly's portfolio includes structural engineering projects totaling 8 billion dollars in construction costs and over 20 million sq. ft. of floor area.

John Booth, the Principal Consultant and Practice Director of Sylvanus Arboricultural Consultants Ltd., is a Chartered Aboricuturalist and Chartered Environmentalist and one of the UK’s most widely qualified Arboricultural Consultants. He has over 25 years experience in both the private and public sectors and has written numerous articles and papers for respected publications including the International Journal of Urban Forestry for which he is also a referee.

Mr. Booth and Sylvanus Ltd. are regularly instructed by both developers and Local Planning Authorities (LPA’s) who are keen to ensure a satisfactory outcome from the planning process, (i.e. an appropriate balance between tree retention and realizing a site's development potential). All such work is carried out in accordance with the guiding principles of British Standard 5837 ‘Trees in Relation to Construction – Recommendations.’ 

Mr. Booth is a Bond Solon/Cardiff University trained Expert Witness and a member of the Expert Witness Institute. He has many years of experience in both courtroom and planning enquiries. Services Include:

• Tree Inspection & Survey - Single Tree, Large Population, Mortgage Lending, Safety and Subsidence Issues
• Tree Preservation Orders (TPO's) and Conservation Areas - Detailed Specifications for Tree Work Applications for Trees with Statutory Protection
• Trees and Development - Tree Surveys for Submission with Planning Applications, Tree Constraints Plans (TCP’s), Tree Protection Plans (TPP’s), Arboricultural Impact Assessments (AIA), Arboricultural Method Statements (AMS)

Professor Christopher J. Tennant, PhD, CIH, has over 40 years of experience in the field of Environmental Health and Industrial Hygiene. He is Board Certified in the Comprehensive Practice of Industrial Hygiene. Dr. Tennant is currently President, CEO, and Principal Consultant at San Joaquin Environmental, in Fresno California, where he consults with Federal, State, County, City, various public agencies, and private industry sectors from public housing to Aerospace. His services are available in all 50 US States and the United Kingdom.

Dr. Tennant also serves as Professor Emeritus for the Department of Public Health at Fresno State University where he's taught Environment Health, Industrial Hygiene, and Occupational Health and Safety for 35 years at both undergraduate and post graduate levels.

Litigation Support - Dr. Tennant has been retained by numerous insurances companies and law firms on various Industrial Hygiene matters throughout the US, including workers compensation, property damage, personal injury, and wrongful death. He has testified as an expert witness in Federal Court, Superior Court, and Workers Compensation Appeals Board over 100 times. He's been deposed many more times. 

Areas of Expertise:

I bring diverse, combined education, licensing, and credentialing in geology, biology, and hazardous materials management. Indoor air quality as related to asbestos, mold, lead, building hazards, vapor intrusion, OSHA worker and occupant complaints.

I manage a firm of environmental and industrial hygiene professionals while serving as an expert in my diverse field; I have over 85 retained cases complete. I can cost effectively support engagements that may require extensive data gathering across an expanded time frame. I apply my capabilities and credentials across commercial, industrial, and oil & gas settings, with a technical focus on highly regulated industry and real estate.

I have been steadily retained for expert witness services since 1995.

I specialize in structural fire forensic investigation and testing, routinely leverage post-flood emergency response expertise in buildings, specific to microbial disinfection, mold mitigation, and source mold under forensic methods of investigation that may exist under alleged building construction defects. I possess expertise in building systems and mitigating hazards from structures in advance of demolition for asbestos, lead, and other regulated materials.  I prepare, implement (and/or critically review) asbestos specifications, mold remediation protocols, OSHA-driven lead specifications, and remediation soil management plans.

I have evaluated diverse workplaces following loss reports due to alleged safety and public health concerns and offered mitigation strategies for worker safety under OSHA complaints, especially regarding respiratory protection. I have served as an expert for multiple worker injury and wrongful death allegations within the context of environmental exposure.  

View Ms. Franks' Consulting Profile.

Professional expert in the field of Electromagnetics and Compatibility (EMC) with nearly 45 years working in applied engineering design, testing, certification, education and consulting.  Author of five books on EMC design and application making this complex field easy to understand, "EMC Made Simple". 

Major focus is on engineering principles in all facets of electrical engineering regardless of end use environment. Patent infringement, biological harm, disruption of services are his expertise.