MassDEP’s ORS reaffirms TCE cardiac endpoint in toxicity assessment

Massachusetts Department of Environmental Protection officials said the Office of Research and Standards (ORS) has reviewed a 2023 technical request from the Licensed Site Professional Association (LSPA) and affirmed the use of congenital cardiac malformations as a serious health endpoint in TCE toxicity assessments.

Greg Braun, chief of the ORS risk analysis division, told the advisory committee the current TCE hazard index remains set at 1 because ORS considers the congenital heart defect endpoint and thyroid effects to provide a protective assessment. Braun said ORS reviewed the LSPA white paper and underlying literature, including questions raised about a 2003 Johnson study and a 2019 DeSoso paper; ORS concluded there is still sufficient evidence to treat the cardiac endpoint as significant.

The committee noted EPA’s 2020 TSCA review found the thyroid effect (reduced thyroid weight) supported toxicity values but also recognized that the cardiac fetal endpoint merited consideration. ORS said its review included examination of the DeSoso study and other materials beyond EPA’s assessment; ORS staff Tom Angus and Sandy Baird were identified as technical contacts for detailed toxicology questions.

During Q&A, a member asked whether ORS performed an independent reanalysis or relied mainly on EPA. Greg Braun said ORS conducted its own review of the white paper and related studies. A committee member suggested MassDEP consider additional uncertainty factors to account for study limitations; ORS said it would bring that idea back for deliberation and follow up.