Mary Manibusan
Mary Ko Manibusan, M.P.H.
Senior Managing Scientist
Chemical Regulation & Food Safety
  • District of Columbia

Ms. Manibusan has previously led the USEPA Endocrine Disruption Program and she brings a broad range of expertise in pesticide toxicology, carcinogenicity, structure activity relationship, cumulative assessment, mode of action, risk characterization, development of science policies and alternative testing strategies. She has over 20 years of experience in conducting human health risk assessments, evaluating complex toxicology studies, applying weight of evidence, developing mode(s) of action and risk-based assessments of environmental chemicals. She has particular expertise regarding endocrine disrupting chemicals, methyl mercury, arsenic, disinfection byproducts, carbon tetrachloride and perchlorate.

Ms. Manibusan has over 20 years of experience as a regulatory toxicologist/risk assessor focused on:

  • Implementing the USEPA Endocrine Disruptor Screening Program under FFDCA and SDWA, 1996.
  • Leading the OECD Metabolism Pathway (MetaPath) Users Group focused on the global population of MetaPath using pesticide metabolism data and developing a metabolic simulator.
  • Developing guidance on implementing new emerging risk assessment tools that target the goals of the NAS “Toxicity Testing in 21st Century.”
  • Integrating human epidemiology and animal toxicity data to develop mode(s) of action (e.g., Peroxisome Proliferating Activation Receptor Agonist for Rodent Liver Tumors).
  • Leading expert review committees, Cancer Assessment Review Committee, Residue of Concern Knowledge-based Subcommittee and the Hazard Identification Assessment Committee.

Serving as a regulatory toxicologist since 1995, Ms. Manibusan has extensive experience in evaluating complex scientific issues involved in reviewing toxicological data for chemical risk assessments. She is able to efficiently integrate and synthesize a broad range of biological data from various disciplines, including mechanistic, in vitro, in vivo, and human data. Internationally, Ms. Manibusan has served as the lead US toxicologist on the first global pesticide assessment that achieved harmonization across multiple countries. She also served as the United States Lead Representative on the OECD Expert Panel for Test Guideline(s) for Chronic, Cancer Bioassays (451, 452 and 453). She has developed scientific rationales to support pesticide data waivers and data exemptions. Ms. Manibusan has published numerous documents on chemical risk assessments, quantiative structure activity relationship methods, cancer mode(s) of action, pooled and meta-analyses of human epidemiology data, and endocrine screening and testing strategies.

CREDENTIALS & PROFESSIONAL HONORS

  • M.P.H., Toxicology, University of Michigan, Ann Arbor
  • B.A., Biological Sciences, University of California, Santa Barbara
  • Outstanding University of Michigan Graduate Alumni Award, 2012

    Led a cross-Agency team to a Silver Medal Award for accomplishing four complex Scientific Advisory Panel meetings on the USEPA Endocrine Disruption Screening Program, 2014

    Bronze Medal for Leading the Metabolism Pathway OECD Project involving multiple countries to development of a unified metabolism database with global application, 2012

    Council of Excellence in Government Distinguished Senior Fellows Award. This award recognizes the excellent leadership exhibited in the global pesticide review and harmonization achieved by Mary Manibusan on the first multi-lateral review of a novel pesticide, 2009

    USEPA Office of Pesticide Programs Science Award for Excellence. This award recognizes outstanding leadership during the international reviews of two new active ingredients in which the US EPA had the lead for the toxicology review for the first global review and first trilateral joint review to include the European Union, 2008

    Environmental Analysis and Data Team Agency's Silver Medal for evaluating floodwater and sediment data during the Hurricane Response, 2007

Publications

Manibusan M, Hauchman F. Environmental justice research roadmap. Office of Research and Development, USEPA, Washington, DC, 2015.

Manibusan M, Green T. Endocrine disruption screening program comprehensive management plan. Office of Science, Coordination and Policy, USEPA, Washington, DC, 2013.

Manibusan M, Paterson J, Kent R, Chen. NAFTA quantitative structure activity relationship guidance document for pesticide risk assessors, November 30, 2012.

Lo Piparo E, Worth A, Manibusan M, Yang C, Schilter B, Mazzatorta P, Jacobs MN, Steinkellner H, Mohimont L. Use of computational tools in the field of food safety. Regulatory Toxicology and Pharmacology 2011 Aug; 60(3):354–362.

Manibusan M, Odin M, Eastmond D. A postulated carbon tetrachloride mode of action: Review. Journal of Environmental Science and Health Part C 2007; 25:1–25.

Manibusan M, Donohue J, Odin M. A postulated mode of action for carbon tetrachloride liver toxicity. The Toxicologist 2006. 

Manibusan M, et al. Examination of EPA risk assessment principles and practices. Office of Science Advisor, USEPA. Washington, DC, 2004. 

Manibusan M, Flowers L, Gift J, Wong D, Du J. Harmonization of noncancer and cancer effects in U.S. EPA’s Integrated Risk Information System (IRIS). Society of Risk Analysis, Palm Springs, CA, 2004. 

Schulman A, Manibusan M, Abernathy C, Messner M, Gaylor D. Arsenic drinking water regulatory impact analysis: The Arsenic “Cessation Lag” Model. The Toxicologist 2004. 

Woo YT, Lai D, McLain JL, Manibusan MK, Dellarco V. Use of mechanism-based structure-activity relationships analysis in carcinogenic potential ranking for drinking water disinfection by-products. Environmental Health Perspectives 2002; 110(1):75–87. 

Schoeny R, Manibusan M, Borum D, Winchester E. Water quality criterion for the protection of human health: Methylmercury. EPA-823-R-01-001. Office of Water, Office of Science and Technology, Health and Ecological Criteria Division, Washington, DC, 2001. 

Manibusan M. Epidemiologic literature on cancer and exposure to chlorinated drinking water. Office of Water, Office of Science and Technology, Health and Ecological Criteria Division, Washington, D.C., 2001. 

Manibusan M, Moilanen L. Quantitative cancer assessment for MX. The Toxicologist 2000. 

Manibusan M, Follansbee M, Abernathy C. Factors affecting the activity and expression of human cytosolic glutathione s-transferase (GST) isoforms. The Toxicologist 2000. 

Woo YT, Lai DY, Manibusan MK, McLain JL, Dellarco VL. Risk assessment of drinking water disinfection byproducts (DBPs): Use of structure-activity relationship (SAR) analysis in ranking of carcinogenic potential and prioritization for testing. The Toxicologist 2000. 

Jarabek AM, Bruins R, Choudhury H, Clegg E, Crofton K, Dellarco V, Geller A, Kimmel G, Manibusan M, Smialowicz R, Suter G. Draft-perchlorate environmental contamination: Toxicological review and risk characterization based on emerging information. National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C., 1999. 

Schoeny R, Borum D, Manibusan MK, Sappington K. Development of human health criteria for methyl mercury. V International Conference on Mercury as a Global Pollutant, Rio de Janeiro, Brazil, 1999. 

Manibusan M, Cox, M. Quantification of bladder cancer risk from exposure to chlorinated drinking water. USEPA, Washington, D.C. The Toxicologist 1998. 

Manibusan M. Notice of data availability (NODA): Health summaries for chlorine and chlorinated waters. USEPA, Washington, D.C. 

Manibusan M. Standard operating procedure for the quality assurance of the Superfund Chemical Data Matrix (SCDM - Database). USEPA Superfund Site Assessment, DynCorp I&ET, Alexandria, VA, 1997. 

Professional Affiliations

Society of Toxicology—SOT

Society for Risk Analysis—SRA

Knowledge

News & Events

CREDENTIALS & PROFESSIONAL HONORS

  • M.P.H., Toxicology, University of Michigan, Ann Arbor
  • B.A., Biological Sciences, University of California, Santa Barbara
  • Outstanding University of Michigan Graduate Alumni Award, 2012

    Led a cross-Agency team to a Silver Medal Award for accomplishing four complex Scientific Advisory Panel meetings on the USEPA Endocrine Disruption Screening Program, 2014

    Bronze Medal for Leading the Metabolism Pathway OECD Project involving multiple countries to development of a unified metabolism database with global application, 2012

    Council of Excellence in Government Distinguished Senior Fellows Award. This award recognizes the excellent leadership exhibited in the global pesticide review and harmonization achieved by Mary Manibusan on the first multi-lateral review of a novel pesticide, 2009

    USEPA Office of Pesticide Programs Science Award for Excellence. This award recognizes outstanding leadership during the international reviews of two new active ingredients in which the US EPA had the lead for the toxicology review for the first global review and first trilateral joint review to include the European Union, 2008

    Environmental Analysis and Data Team Agency's Silver Medal for evaluating floodwater and sediment data during the Hurricane Response, 2007