The experienced Risk Assessment Scientist will work with Leidos Project Managers and Senior Staff and interface with multiple Leidos offices. The Risk Assessment Scientist should be comfortable working in a team environment, and demonstrate excellent written and strong verbal communication, as well as organizational skills. Frequent collaboration with the project manager and project team members is expected. The successful candidate will be dedicated to working full-time in support of document preparations and will be an initiative-focused, goals-oriented individual, requiring some supervisory oversight to start. This position is flexible regarding work location (on-site Leidos office locations in Reston, VA; Twinsburg, OH; or St. Louis, MO or remote location).Must be able to obtain access to, and conduct work on, U.S. Government installations. U.S. Citizenship or U.S. Permanent Resident status is required.The salary range for this role is anticipated to be between $85,000 and $120,000 annually.The Challenge:<ul><li>Take the lead and assist in conducting human health risk assessments, including development of conceptual site models, selection of appropriate toxicity values, calculation of cancer risks and noncancer hazards, and analysis of uncertainties associated with the risk evaluations.</li><li>Author risk-related sections of technical reports, including work plans/sampling plans, human health risk assessments, remedial investigation (RI) reports, feasibility studies (FS), proposed plans (PP), and records of decision (ROD).</li><li>May assist in conducting ecological risk assessments.</li><li>Provide technical support in evaluating and interpreting quantitative and qualitative environmental sampling data acquired during site investigations.</li><li>Willing and able to work on a variety of risk assessment- and non-risk assessment-related tasks.</li><li>Willing and able to travel periodically to Leidos offices and/or project locations.</li><li>Must be able to obtain access to, and conduct work on, U.S. Government installations. U.S. Citizenship or U.S. Permanent Resident status is required.</li></ul>Required Education and Experience:<ul><li>BS or MS degree in Environmental Sciences, Earth Sciences, Biological Sciences, Chemistry, Toxicology, Ecology, or related scientific field with 4+ (BS) or 2+ years (MS) of professional experience in the performance of human health risk assessments of exposures to chemicals in environmental media.</li><li>Strong working knowledge of EPA human health risk assessment guidance and methods within the framework of the CERCLA RI/FS/PP/ROD process.</li><li>Experience calculating human health cancer/noncancer risks and risk-based screening levels using spreadsheets and online calculators.</li><li>Authors human health risk-related text including methodology, reporting, and interpretation of calculated risks.</li><li>Ability to compile, manage, and interpret environmental investigation and monitoring data for organic and inorganic chemical parameters.</li><li>Working knowledge of environmental statistical methods (e.g., calculation of UCLs, trend analysis) and experience with statistical software tools (e.g., EPA ProUCL, SAS, etc.).</li><li>Understanding of data validation qualifiers indicating usability.</li><li>Some experience working with federal environmental regulators.</li><li>Proficiency in MS Office tools (Excel, Word, Outlook, PowerPoint).</li></ul>Desired Qualifications:<ul><li>Knowledge and experience with data and/or risk analyses of per- and polyfluoroalkyl substances (PFAS).</li><li>Experience working with radiological data, as well as human health radiological risk and dose assessments in accordance with the EPA, DOE, and NRC regulatory framework.</li><li>Working knowledge of EPA ecological risk assessment guidance and professional experience in conducting ecological risk assessments.</li><li>RCRA and CERCLA process documents knowledge (Corrective Action Plans/Reports; RI/FS/PP/ROD).</li><li>Professional experience working on federal contracts is preferred.</li><li>Professional experience working with state regulators.</li><li>Doctoral degree with professional experience conducting human health risk assessments.</li></ul>At Leidos, we don’t want someone who fits the mold—we want someone who melts it down and builds something better. This is a role for the restless, the over-caffeinated, the ones who ask, “what’s next?” before the dust settles on “what’s now.”If you’re already scheming step 20 while everyone else is still debating step 2… good. You’ll fit right in.<h2></h2><h2></h2><h2>Original Posting:</h2>October 21, 2025<div><div><div><div><div><div><div>For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.</div></div></div></div></div></div></div><div></div><h2>Pay Range:</h2>Pay Range $72,150.00 - $130,425.00The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.

Leidos Holdings

Human Health Risk Assessment Scientist 6314 Remote/Teleworker US

Leidos Holdings