Precision Environmental Health (PEH) research is anchored in elucidating how exposure leads to adverse outcomes. The CEIM Core has two Units to support PEH research, one that provides facilities and expertise for controlled exposures experiments and a second for informatics and systems computational modeling of exposures and effects. The Controlled Exposure (CE) Unit provides platforms for exposing healthy and diseased individuals and animals to specific, controlled conditions for biomarker discovery and validation. The Informatics/Modeling (I/M) Unit provides computational tools for large-scale environmental and biological data analytics as well as mechanistic-systems modeling of environmental and biological processes and interactions. The Core thus provides powerful tools for building and implementing a crucial component of PEH research. The CE Unit provides CEED investigators with the capability of collecting real-time exposure data from human subjects and experimental animals in a controlled setting using defined atmospheres that mimic environmental or occupational exposures, while limiting confounders. The CE Unit supports studies on interactions between chemical exposures and variables such as temperature, humidity, exercise, psychosocial stress, and pre- existing disease (e.g., asthma). Physiological and behavioral responses of humans and rodents can be measured simultaneously to the exposure administered in either the human Controlled Exposure Facility or the Animal Exposure Facility. State-of-the-art pollutant generation and monitoring systems are used for both. The I/M Unit provides informatics expertise and computational support for the integrative analysis of large heterogeneous data sets from multiple sources, using emerging science, engineering, and technology. These data sets include health outcomes and exposure-relevant information from both public and proprietary sources. The I/M Unit provides resources to address the many challenges presented by the volume of data that are rapidly becoming available from new sources being used in exposure science and the biomedical fields. It also supports CEED investigators need to model mechanisms involved in the source to dose to exposure to effect process. The I/M Unit fills these needs by providing access to high-level data integration and analytics and systems modeling tools that can be used to estimate exposure and dose, and identify or predict early biological responses, for the purpose of designing intervention and prevention strategies that modify risk of disease. The Unit is integral to CEEDs focus on populations and communities, as it can inform decisions about alternative prevention and remediation strategies that arise from our community-researcher partnerships. Additionally, the I/M Unit provides support to CoEC through computational tools (e.g. interactive visualization and mapping relevant to exposures and outcomes) that facilitate interactions between scientists, community members and organizations, and regulators.