Autumn leaves changing color on tree branches, with shades of yellow, orange, and brown.

Planetary Health

Dr. Ryznar leverages her expertise as a physician and professor to provide clear, engaging, and evidence-based information about how plastics harm ecosystems and human health. Her work centers around three themes:

Advocating for policy and business solutions

Providing education about plastics and health

Researching how plastics impact the brain

She also has expertise in planetary health topics more broadly. She is available for consultancies.

Solutions

Articles:

  • New Dietary Guidelines Neglect The Health Risks Of Food Processing And Packaging
    Health Affairs Forefront, 3/23/2026 (with Michael Shank)
    The recently updated dietary guidelines for Americans, released this January by the Department of Health and Human Services (HHS), rightfully emphasize whole foods over ultraprocessed foods. But the guidelines neglect to address how that food is delivered. “Real food” can still cause chronic disease if it contains harmful chemicals lingering from processing or packaging. Congress and federal agencies should commit to ensuring that all Americans have access to safe real food by strengthening federal oversight of chemicals in food processing and packaging.

  • Treaty failure is not the end of the fight against plastic pollution
    Al-Jazeera Opinion, 8/21/2025 (with Michael Shank)
    As global plastic treaty talks end in failure, with no agreement, all is not lost in the global momentum to cut plastic pollution. United States lawmakers recently introduced the Microplastics Safety Act, for example, mandating the Department of Health and Human Services to study microplastics exposure and health impacts. The bill reflects growing concern in Congress about the plastics health crisis and the broad bipartisan support to address it. However, given that plastic production, use, and hence exposure, continue to increase every year, we should not wait idly for the US report’s findings or more failed global plastic treaty talks. There is enough evidence to take action now. In this article, we highlight three areas that can help reduce everyone’s exposure to microplastics: culture, business and policy.

Testimony and Briefings:

  • Provided oral testimony as a medical expert in support of the Maryland Container Recycling Refund and Litter Reduction Program to the Montgomery County Delegation on 11/18/24, the Maryland House of Delegates on 2/14/25 and 2/11/2026, and the Maryland Senate on 2/18/25 and 2/10/2026

  • Provided written testimony in support of the Maryland Container Recycling Refund and Litter Reduction Program in 2025 and 2026, obtaining endorsement from several medical and public health organizations for the letter.

  • Featured speaker at a rally in support of the Maryland Bottle Bill in Annapolis on 2/14/2024

  • Co-authored “Plastic Pollution and Producer Responsibility,” a brief prepared by Environment Virginia and other organizations to inform 2026 Virginia state policy discussions

Medical Expert:

  • Quoted in Ocean’s campaign for the “Farewell to Foam” Act:
    “I became a doctor because I wanted to ensure that all people had the opportunity for a healthy and dignified life. Unfortunately, plastic pollution undermines this goal. For example, expanded polystyrene foam is made with a cancer-causing chemical. That is why I am proud to support the Farewell to Foam Act. This bill phases out expanded polystyrene from single-use food packaging, packing peanuts, and coolers, allowing safer products on the market. Twelve states have already enacted similar laws reducing plastic foam, and now it’s time to safeguard the health of all Americans from this hazardous pollutant.”

  • Panelist for Oceana’s webinar about plastic foam for state legislators (January 2026)

Education

Community Events:

  • Invited health expert on multiple panels addressing plastics and health, with a combined audience of 150 community members:

    • Children’s Environmental Health Day virtual presentation by Maryland Healthy Climate on 10/10/2024

    • Premiere of “Single-Use Planet” documentary by PBS and Habitat Media film on 4/9/2025

    • Maryland Bottle Bill Coalition presentation with Patagonia’s Baltimore store on 9/11/2025

  • Invited guest for the Beyond Plastics Volunteer Group Monthly Meeting (60 attendees)

Medical Audiences:

  • Published the first psychiatric article discussing how plastic pollution impacts the brain, featured as the cover story for Psychiatric Times’ 9/2024 issue.

  • Appointed to the American Psychiatric Association’s Committee on Climate Change and Mental Health in order to address the impacts of plastics on mental health

  • Introduced a plastics-related metric for the 2027-2028 version of the Planetary Health Report Card, a student-driven initiative to assess how well allied health professionals schools teach planetary health

  • Invited lecturer at 10 Psychiatry Departments at medical schools like Tufts, University of Nebraska, and Virginia Tech (combined audience of >900 psychiatrists, psychologists, social workers, and medical students) and 7 international neuropsychiatric or climate health groups (combined audience of >240 doctors, nurses, and other health professionals) since 12/2024

  • Invited guest for the Climate Psychiatry Alliance podcast (episode forthcoming).

  • Keynote speaker for the American Psychiatric Association’s District 1 Branch Annual Meeting on 4/17/2025 for psychiatrists in Toronto

  • Invited speaker for the Alzheimer’s Association Neuroscience Next Meeting in Costa Rica on 2/24/2026 (>120 attendees)

  • Advisory Board Member to the Physician and Scientist Network Addressing Plastics and Health (P-SNAP)

  • Introduced planetary health to a clinical audience via a monthly “Climate Corner” for Maryland Psychiatric Society 2024-2025 and for the general public via Sheppard Pratt’s website (on heat and plastics)

Media mentions:

  • “The microplastics research is really early, but I’m a firm believer in the precautionary principle. Our exposure is growing exponentially. We don’t want to wait 30 years for definitive proof – by then it’ll be too late and too many people will be harmed.” Quoted in: “What are the health impacts of plastics?” by Dr. Neha Pathak, Yale Climate Connections, 5/1/2025

  • “The triangle with the infinite loop was designed to make us think everything’s recyclable. They’re using psychology against us to increase profits.” Quoted in: “How to reduce microplastic exposure and protect your health” by Dr. Neha Pathak, Yale Climate Connections, 5/1/2025.

  • “Personal choices matter, but the scale of this problem requires policy and industry action. That means curbing unnecessary single-use plastics and capping overall production growth, while also investing in safer materials and reformulating additives to avoid endocrine disruptors. Setting standards for microfiber filtration in washing machines and for tire-wear particles would make a major difference, as would procurement changes in hospitals, schools, and cities to reduce plastic waste at the source. Clearer labeling and greater transparency are also essential so that consumers and clinicians can make informed choices. Finally, civic engagement truly works; asking local, state, and national representatives what they’re doing about plastics and health helps build the political will needed to act.” Interviewed by Dr. Burcin Ikiz for Psychology Today, 10/15/2025

Research

Current Projects:

  • Assembled an international team of 11 physicians and researchers to systematically review the scientific evidence how microplastics affect the brain (project 75% complete)

  • Manuscript describing the four mechanisms by which plastics harm brain health currently under submission

Publications: