Litigation projects

I provide consulting services on a variety of issues including exposure assessment, environmental forensics, indoor air assessment, product stewardship, including Proposition 65, and site and human health risk assessments.

Some of the key litigation projects that I am currently working on or have consulted on in the past are provided below. These projects span assessments for multiple chemicals such as PFAS, including PFOA and PFOS, ethylene oxide, formaldehyde, radionuclides, formaldehyde, phthalates, lead, arsenic, and acrylamide.

A full list of litigation and non-litigation projects, along with my contact information, is provided in my CV. Alternatively, you message me via the contact form.

PFAS Contamination in Drinking Water

I have been actively involved in the ongoing PFAS litigation, including for aqueous film form foam (AFFF), in multiple districts around the U.S. I have evaluated toxicology and epidemiology of various PFAS, particularly PFOA and PFOS but also PFHxS, PFHpS, PFHpA, PFNA, and PFDA, to characterize long-term human health impacts of these chemicals. I am also intimately familiar with transport and fate of PFAS (including fractionation debate around PFOA) and have evaluated in detail the basis of state and federal regulatory values such as the latest EPA MCL guidance for PFOA and PFOS published in 2022.

I have also managed sampling and data analysis programs to assess levels of PFAS in water, soil, and sediment. I have analyzed those data using traditional statistical methods and with advanced tools such as PCA and clustering methods to infer possible patters in source attribution studies. I also created dashboards using R Shiny with interactive mapping tools and interactive graphs for visualization purposes and to aid in analysis during various litigation phases.

Ethylene Oxide Exposures and Cancer Risk Assessment

This has been an active area of my focus over the past few years largely spawned on by the new EPA IRIS inhalation unit risk (IUR) value published in 2016. I have evaluated the basis of the IRIS value, the key NIOSH epidemiology studies that EPA relied upon (Steenland et al. 2013, 2014) and the exposure reconstruction model used therein. I have extensive knowledge of the epidemiology and the adduct biomarker literature and other issues related to exposure and cancer risk of ethylene oxide.

I have done assessments based on both NATA analysis (released in 2017 using 2014 emissions data) and Air Toxics Screening (released in 2022 using 2017 emissions data) to assess potential cancer risks from ethylene oxide emissions. I have also created an online dashboard for the public to visualize cancer risks from ethylene oxide.

Formaldehyde Exposures from Laminate Flooring

I led a team of several scientists (analytical chemists, polymer scientists, exposure assessors, and air modelers) to assess formaldehyde exposures from laminate flooring installed in people’s homes. We collected the largest ever consumer product data set collected to-date for these products in order to ultimately model and predict the rate of decay in formaldehyde emissions overtime from laminate flooring. The mathematical model we developed, along with multiple other home-specific factors, was used for estimating time-weighted average indoor air formaldehyde concentrations in a home to determine cancer risk relative to established benchmarks, e.g., California Proposition 65 NSRL for formaldehyde.

This work was presented to US Consumer Product Safety Commission (CPSC) and published in peer-reviewed literature. An online dashboard is also available for calculating indoor air concentrations specific to a person’s home.

Human Health Risk Assessment (HHRA) from Coal Ash Spill

I evaluated exposures to community from a coal ash spill and to workers involved in the subsequent cleanup. I reviewed site health plans, IH summaries, exposure histories, sampling plans, site reports and agency reports to understand in detail the cleanup at the site and conditions that the workers were exposed to. I also analyzed years of air monitoring data at and near the site from permanent and mobile monitors to characterize concentrations of chemicals (lead, arsenic, and silica) of concern spatially and temporally.

California Proposition 65

I have 10+ years of conducting Prop 65 assessments for numerous chemicals including the most litigated ones, i.e., lead, cadmium, phthalates (e.g., DEHP, DINP, DIDP), BPA, and acrylamide, in various consumer products and food products.

Indoor Air Quality Assessments

I have conducted numerous indoor and ambient air quality assessments using low cost sensors, active sampling, exposure chambers, etc. to determine exposure to pollutants such as benzene, formaldehyde, volatile organic compounds (VOCs) and asbestos among others.

Risk Assessment from Radionuclides

I conducted assessments to estimate potential health risks from widespread radionuclide contamination in groundwater and soil at a CERCLA Supefund site.