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Trusted. Passionate. Science-driven. Meet the 9F team.

Our team of world-class scientists delivers unparalleled expertise on healthy buildings.

Joe Allen, DSc, MPH, CIH portrait

Joe Allen, DSc, MPH, CIH

CEO / Founder

Dr. Joseph G. Allen, DSc, MPH, CIH is Associate Professor and Director of the Healthy Buildings Program at Harvard T.H. Chan School of Public Health and CEO and Founder of 9 Foundations, Inc. He is the coauthor of Healthy Buildings: How Indoor Spaces Can Make You Sick—or Keep You Well. Dr. Allen serves on Harvard’s Presidential Committee on Sustainability, he keynoted the White House’s first ever Indoor Air Quality Summit, and during the COVID-19 pandemic, served as Commissioner of The Lancet COVID-19 Commission and Chair of its Safe Work, Safe Schools, and Safe Travel Task Force. In 2023, Allen was featured on the 60 Minutes episode, The Air We Breathe, spotlighting the value of healthy indoor air quality for virus mitigation. He has authored over 100 peer-reviewed scientific papers, and regularly contributes to the New York Times, Washington Post, Harvard Business Review and The Atlantic.

9 Foundations 9F logo

Uncompromising on the science.
Delivering excellence for our clients.

Health Science

Marissa Rainbolt, MPH portrait

Marissa Rainbolt, MPH

Vice President / Health Scientist

The strategic guide of 9F, Marissa manages complex client projects and leads executive responsibilities.

Linnea Champ, MPH portrait

Linnea Champ, MPH

Project Executive / Health Scientist

Applying the fundamentals of environmental health into practice, Linnea oversees research, content development, and program management for 9F clients.

Natalie Daranyi, MPH portrait

Natalie Daranyi, MPH

Project Manager / Health Scientist

A systems thinker, Natalie crafts individualized project plans and leads strategic program implementation for 9F clients.

Maya Bliss, MPH portrait

Maya Bliss, MPH

Health Scientist

A healthy buildings practitioner, Maya leverages environmental health principles to support projects across the 9F Health Science Team and sustainability initiatives at 9F.

Nicole Hill, MPH portrait

Nicole Hill, MPH

Health Scientist

Diligent and detailed, Nicole supports key projects at 9F.

Advanced Analytics

Emily Jones, PhD portrait

Emily Jones, PhD

Director of Advanced Analytics

Dr. Jones leverages her expertise in the built environment, statistical analysis, advanced modeling techniques, and environmental sampling to manage the Advanced Analytics Team.

Katie Vilardi, PhD portrait

Katie Vilardi, PhD

Senior Scientist

An environmental engineer with expertise in data analysis, Dr. Vilardi utilizes statistical analysis and data visualizations to evaluate building health.

Morgan Davis, MPH portrait

Morgan Davis, MPH

Data Analyst

As a member of the Advanced Analytics Team at 9F, Morgan translates information into impact.

Harry Maher portrait

Harry Maher

Data Analyst

Harry is a data analyst at 9F. He supports analytics needs across the company, with a focus on data from real-time indoor air quality sensors.

Rahul Hosalli, MPH  portrait

Rahul Hosalli, MPH

Data Analyst

Through data analysis and visualization, Rahul explores real-time indoor air quality data from sensors and translates it into trackable insights for clients to use to improve their indoor spaces.

Occupational Health

Eli Miller, MPH, CIH portrait

Eli Miller, MPH, CIH

Senior Industrial Hygienist

A core member of the Occupational Health Team at 9F, Eli embodies the science of protecting the health and safety of people in the workplace.

Leslie Cadet, MD, MPH portrait

Leslie Cadet, MD, MPH

Medical Advisor

Dr. Cadet is a medical consultant for 9F.

James McDevitt, PhD, CIH portrait

James McDevitt, PhD, CIH

Senior Health Scientist

An environmental health and industrial hygiene expert, Dr. McDevitt has expertise in the airborne transmission of respiratory viruses.


Katie Giasullo, MBA portrait

Katie Giasullo, MBA

Director of Operations / Executive Assistant to CEO

Adeptly managing two intersecting dimensions of 9 Foundations, Katie directs the day-to-day administration of 9F and shapes the strategic operations that propel the company forward.

Sarah Pappas, MLA portrait

Sarah Pappas, MLA

Director of Communications

Sarah leads 9F’s external and internal communications.

Kristen Pfeffer portrait

Kristen Pfeffer

Administrative Assistant

Kristen supports strategic operations at 9F. She maintains human resources projects and onboarding processes.

Our Advisors

Juliette Kayyem portrait

Juliette Kayyem

Resiliency | Policy

Professor Kayyem is an international leader in crisis management and homeland security.

Carl Howell, M.S. portrait

Carl Howell, M.S.

Community | Residential | DEI

Carl Howell has over two decades of experience in the not-for-profit sector, dedicating his career to mitigating the impacts of poverty and the disparities across social determinants of health.

Maureen Ehrenberg, FRICS, CRE, LAI portrait

Maureen Ehrenberg, FRICS, CRE, LAI

Corporate Real Estate | ESG

Maureen Ehrenberg is CEO of Blue Skrye, Innovation in the Built Environment.

About Us
About Us

9F Drives scientific research into practice and leads evidence-based approaches to healthy buildings.

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Meet Our Experts
Meet Our Experts

Learn more about the 9F team of world-class scientists and indoor environmental experts.

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Career Opportunities
Career Opportunities

9F is always on the lookout for extraordinary public health talent. If you are an expert in environmental health, industrial hygiene, climate science, or the built environment and are committed to advancing health and sustainability, we want to hear from you.

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Contact Us
Contact Us

For prospective clients, employees and media inquiries. Please complete this form to get in touch with the 9F team.

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