Winter 2025

Indoor Air Pollution Is Also Harming  Brain Health

Most adults and many families spend over 80% of their time indoors, mostly at home. (15-16)  Based on the evidence of neurological (1-6) and other health associations (7-14) from outdoor air pollution, we can infer proportionate health effects expected from indoor PM2.5, NO2 and other pollutants. While there are many potential  sources of indoor air pollution (17), new research is shedding light on one source with potentially the most potent health consequences for many homes: our gas stoves. 

Cooking with gas stoves (even with ventilation hoods operating) can cause very unsafe levels of NO2 which in some homes can linger for hours even in bedrooms away from the kitchen. This disproportionately affects people of color and low income whose homes often do not have outside ventilating hoods. (18-19)  Gas cooking also emits benzene, a known cause of cancer. (20)

Additionally, indoor air pollution can consist of over 60% infiltration from outdoor air. Especially when outdoor air quality is poor (e.g. high pollution days or wildfires,) pollutants can enter through windows, doors, cracks, chimneys and vents. (21-22)  

People with chronic conditions (like cardiovascular disease, mild cognitive impairment or dementia, and lung disease), children and pregnant mothers and those already exposed to high levels of pollution by proximity (often people of color or low income) can have even higher risk from indoor pollution. (23-25)  By one estimate, childhood asthma in the US could be reduced by 13-20% by switching to electric stoves. (26)

Here are some high yield tips for improving indoor air quality for our families and at-risk patients: We can rid the kitchen/house of NO2 pollution from gas cooking by using electric stoves (induction stoves are the most efficient). Using hoods that ventilate outside or opening windows also can help. Avoiding elevated PM2.5 levels in the kitchen ( especially from burning/cooking at high temperatures) by using hoods, lower cooking temperatures, high smoke point oils and HEPA air purification. It is also recommended to follow the outside AQI and consider home PM2.5 monitoring. To protect from high outside air pollution burden, use a HEPA air purifier and avoid outside exercise on yellow or above poor AQI days. Consider well-fitting KN95 masks with a one-way valve especially for at-risk populations (with dementia or cardiovascular disease) on very high AQI days.

Despite this concerning evidence, indoor air pollution remains unregulated with most physicians and the public unaware of the risks. Perhaps 2/3rds of Californians (with likely similar numbers nationwide) don’t use their ventilation hoods while cooking with gas and a substantial number of households don’t have outside ventilating hoods. (27)

More research is needed, but policies supporting wide use of outside ventilating hoods, HEPA indoor air filtration and the electrification of cooking and other home appliances is justified to improve health and air quality.

References Links (References also listed below)

For a more detailed discussion, here is Bret's presentation from November: Neurological Associations with Air Pollution and Health Benefits of Building Electrification, San Francisco Bay Physicians for Social Responsibility Series  RECORDING,  SLIDES

Good News from 2025 and simple actions you can take to make a difference: 

Effective Climate Communication is Key:                    At least 90% of us agree, so how do we make climate solutions a priority?                                             See: Jonathan Foley Project Drawdown YouTube:   (Recommend to jump to minute 36:10)

Yale Climate Change Communication Report: Climate Change in the American Mind: Politics & Policy, Fall 2025

Good News on Climate in 2025:                                from Bloomberg Green

Feeling Like you need a boost to participate?        Consider joining the MSCCH, or it's local affiliates in your state or other organizations to engage in advocacy with colleagues and community.

See Our Advocacy Page                                                 See Our Quick Advocacy Links Table below 

Recent Climate Neurology Publications

Bai L, et al. Associations of ambient particulate matter and nitrogen dioxide with hospital admissions for Parkinson's disease: A nationwide case-crossover study in China. [Environ Pollut., 09/2025]  DOI:10.1016/j.envpol.2025.127062   - Finds NO2 has a significant association for PD as well as PM2.5

Kim B, et al. Ambient Air Pollution and the Severity of Alzheimer Disease Neuropathology. [JAMA Neurol., 09/2025]  DOI:10.1001/jamaneurol.2025.3316   - Potential direct brain effect over a primarily vascular mechanism? 

Zhou A, Wu Z, et al. The mediating role of inflammation and oxidative stress, as well as vascular-related factors, in the association between air pollution and dementia or related cognitive outcomes: A systematic review. [J Alzheimers Dis., 09/2025]  DOI:10.1177/13872877251361862   - Due to insufficient studies, a primary mechanism is unclear

Canning T, Arias-de la Torre J, Fisher HL, et al. Associations between life course exposure to ambient air pollution with cognition and later-life brain structure: a population-based study of the 1946 British Birth Cohort. [Lancet Healthy Longev., 07/2025]  DOI:10.1016/j.lanhl.2025.100724  - All pollutants assocd w lower cognitive test results, NO2 and PM10 assocd w slowed processing speed larger ventricular volume and higher NO2 assocd w smaller hippocampal volume.

Walsh S, Klee M, Hui EK, et al. Social determinants of dementia: A scoping review. [Alzheimers Dement, 07/2025] DOI:10.1002/alz.70524   -air pollution acknowledged as a top SDOD along with education, socioeconomic status, ethnicity

Kashtan Y, Jackson R et al. Integrating indoor and outdoor nitrogen dioxide exposures in US homes nationally by ZIP code. PNAS Nexus. 12/2025  -frist comparison of indoor and outdoor nitrogen dioxide sources nationally, highlighting that indoor pollution is a critical, neglected issue

Mirmosayyeb O, Vaheb S, Afshari-Safavi A, et al. Long-term effects of air pollution on the incidence and progression of multiple sclerosis: A population cohort study in Isfahan, Iran. [PLoS One, 2025] DOI:10.1371/journal.pone.0327635  -positive correlation

AbuAlrob MA, Itbaisha A. Integrating Climate Change Into Neurology Education: Preparing Future Physicians for a Warming World. [Neurology Educ, 09/2025] DOI:10.1212/ne9.0000000000200235 

Jury-Garfe N, Sánchez-Rubio M, Nardocci G, et al. Urban air pollution reduces H3K9me2/me3 in hippocampal and olfactory neurons, correlating with memory and social deficits. [Sci Total Environ. 08/2025] DOI:10.1016/j.scitotenv.2025.180145   -mice exposed to air pollution show behavioral changes and air pollution reduced repressive epigenetic markers in the hippocampus and olfactory bulb

Our Recent Book Contributions:

• Alexander M, Longoni M, Saad A. Climate change and the profound disabilities: Spinal cord injury, multiple sclerosis, and amyotrophic lateral sclerosis. In: Alexander M, Fogarty CF, Leochico CF, eds. Climate Change and Disability: A Collaborative Approach to a Sustainable Future. 1st ed. Chantilly, VA: Elsevier Science & Technology; 2025:69.

• Saad A, Leochico CFD. Climate change and traumatic and nontraumatic brain disorders in adults. In: Alexander M, Fogarty CF, Leochico CF, eds. Climate Change and Disability: A Collaborative Approach to a Sustainable Future:129

• Malow B. Communicating effectively about climate change—Political considerations. In: Alexander M, Fogarty CF, Leochico CF, eds. Climate Change and Disability: A Collaborative Approach to a Sustainable Future:205.

• Teshner D, Mallow B, Robinson B. Beyond the Politics of Contempt: Practical Steps to Build Positive Relationships in Divided Times. Together Across Differences LLC. 2025

Our Last Quarter Activities: 

• Climate Health and Brain Health, Stanford University Neurology, 12/5/25 (Larry and Bret) Recording,  Slides,  Stanford Advocacy Links

• Neurological Associations with Air Pollution and Health Benefits of Building Electrification, SF Bay Physicians for Social Responsibility (Bret) 11/5/25 Recording, Slides

• Climate and Neurology, Weill Cornell Medical College Qatar (Ali) 10/26/25

• Environmental Effects on Brain Health, Illinois Neurological Society (Ali) 10/25/25

• Climate and Brain Health, NYU Neurology (Larry) 10/14/25

• Climate Change and Brain Health, What We Know and What We Can Do, University of Rochester NY Neurology (Bret) 09/24/25 Recording

• The Co-Benefits of a Healthy Diets, Diploma in Climate Medicine (Ali) 07/16/25 Recording

• Climate Change and Brain Health, What We Know and What We Can Do, Duke University Neurology (Beth and Bret) 09/10/25

• Bridging the Gap: Climate & Brain Health Research Opportunities for Neurologists at Every Career Stage, NICHe Quarterly Meeting, (Burcin Ikiz PhD) 09/08/25 Recording

• Climate Health and Brain Health, Project ECHO (Larry and Bret) 09/03/25

Links to Previous Newsletters:

• First Quarterly Newsletter, November 4, 2024 (Fall/Winter)
• Second Quarterly Newsletter, February 13, 2025 (Winter/Spring)
• Third Quarterly Newsletter, May 27, 2025 (Spring/Summer)
• Spr/Fall Quarterly Newsletter, Sept 2, 2025