Jiayang Chien, M.P.H.
Senior Environmental Scientist
Ms. Chien is a senior environmental scientist specializing in human health risk assessment and exposure science. Her work at Gradient includes human health risk assessments at contaminated sites, critical review of epidemiological and toxicological literature, electric and magnetic field (EMF) modeling for electric utilities projects, and California Proposition 65 evaluations. She provides risk assessment support in a variety of contexts, chemical compliance projects, and product safety assessments. Before joining Gradient, Ms. Chien worked as a scientist at an environmental consulting firm, where she conducted human health risk characterizations under state and federal regulatory frameworks in support of site assessment and closure activities.
Human Health Risk Assessment: Conducted a human health risk assessment using US EPA guidance for a former MGP site currently divided into multiple residential and commercial properties.
Hazard Assessment: Performed hazard assessments for various chemicals using data in accordance with United Nations Globalized Harmonized System (GHS) guidelines.
Risk Assessments for Former Manufacturing Plant: Conducted human health risk assessments for five sites associated with a former paint manufacturing plant. Evaluated worker and residential exposures to constituents in multiple environmental media.
Prop 65 Evaluation of Styrene in an Industrial Product: Evaluated potential worker exposure to styrene from an industrial product. Modeled worker exposure to styrene via inhalation and incidental ingestion. Compared estimated intakes to the Prop 65 Safe Harbor Limit.
Li, W; Chien, J; Cohen, JM. 2025. “The relationship between air lead and blood lead in a modern US lead-acid battery facility: A longitudinal study.” J. Occup. Health 67(1):uiae073. doi: 10.1093/joccuh/uiae073.
Skarkas, T; Chien, J; Hixon, M; Boomhower, SR. 2025. “Adaptation of a Physiologically Based Pharmacokinetic (PBPK) Model to Evaluate Intermittent or Variable Cadmium Exposure.” Toxicologist 204(S1):259-260. Abstract 3494. Presented at the Society of Toxicology (SOT) 64th Annual Meeting and ToxExpo, Orlando, FL, March 16-20.
Boomhower, SR; Chien, J; Mattuck, R; Beck, BD. 2024. “Evaluating the Potential for Reproductive Effects from Intermittent Lead Exposures Using Blood Lead Modeling Under Proposition 65.” Toxicologist 198(S1):119. Abstract 3054. Presented at the Society of Toxicology (SOT) 63rd Annual Meeting and ToxExpo, Salt Lake City, UT, March 10-14.
Boomhower, SR; Kerper, LK; Chien, J; Beck, BD. 2020. “A Comparison of PFAS Serum Concentrations in the General Population to Points of Departure Used in Regulatory Guidance.” Abstract prepared for presentation at the Society of Toxicology (SOT) 59th Annual Meeting and ToxExpo, (conference canceled).
Chien, J. 2017. “Benzo(a)pyrene Toxicity Value Updates Implications for Human Health Risk Assessment.” Presented at the Society for Risk Analysis Annual Meeting, Arlington, VA, December 10.
Campe, L; McIntosh, L; Chien, J. 2015. “In Flux – A Case Study of Vapor Intrusion Site Transitioning from Active to Passive Sub Slab Depressurization Systems (SSDS).“ Presented to the Association for Environmental Health and Sciences (AEHS) Foundation 31st Annual International Conference on Soils, Sediments, Water and Energy, Amherst, MA, October 22.