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Air Pollution, Global Warming and Cognition

Yale Public Health Magazine, Focus: Spring 2024
by Xi Chen


Cognition is critical to our well-being, as it determines an individual’s ability to contribute to society, make important decisions, and even run daily errands. But our decision-making and learning processes are vulnerable to environmental stressors.

Cognitive activities often rely on regions in the brain that are sensitive to hot weather. Exposure to heat waves reduces the flow of blood to the brain, causing oxygen deficiency and heat-related fatigue. Also, fine particles in the air often remain airborne longer, and can penetrate buildings. Because they are so small, they are easily inhaled and can accumulate within brain tissue. Over time, this can cause neuroinflammation, leading to symptoms of Alzheimer’s disease, one of the most terrifying and expensive forms of cognitive decline, and other forms of dementia.

Extreme temperatures and pollution increase the risk for strokes and then vascular dementia, damage the immune system, hinder neurological development, and impair neuron behavior, which contributes to memory formation.

Air pollution and extreme temperatures disrupt cognitive functioning through psychological pathways as well. Thermal stress may diminish a person’s attention, working memory, and information retention and processing. A high concentration of pollutants is associated with headaches, psychiatric distress, and an increased risk of feeling unhappy and depressed.

Studies assessing the impacts of air pollution and high temperatures on cognitive ability often focus on school-age children and young adults, showing that exposure to air pollution lowers both verbal and math skills, while high temperatures mostly disrupt math skills. More recent studies find that such harmful effects become more pronounced as people age, especially for males and less educated individuals, and get worse with continued exposure.

Transitory exposures to polluted air or high temperatures have been found to undermine decision-making in the health insurance market and the stock market, and even encourage the decision to commit a crime or engage in conflict, due to changes in risk attitudes and impulsivity.

Short-term measures like wearing face masks on polluted days, using air conditioning during heat waves, and flexibly scheduling important tests help offset some of the negative effects of air pollution and high temperatures. But because the ill effects accumulate with continued exposure, short-term interventions can be less effective than improving long-term air quality and addressing global warming.

The profound implications of poor cognitive function may understate the real costs of air pollution and global warming. Realizing the severity of this issue, the U.S. Environmental Protection Agency has called for more research to assess the impact of air pollutants on the central nervous system, and to address the adequacy of the national ambient air quality standards that have been based on narrowly defined health assessments.

Government agencies are often called upon to implement environmental regulations to reduce air pollution and slow down global warming. When introducing more stringent regulations, governments need to gauge the monetary value of better air quality and milder temperatures in order to compare it with the cost of environmental regulations. Because air quality and climate are not standard goods for sale, evaluating their values presents great challenges. Recent economic evaluations estimate an individual’s willingness to pay for cleaner air and milder temperatures. With such scientific evidence, policy and interventions will optimize stringent environmental regulations.

Your Action Item For Change:

Buy Fewer Things. Buying fewer new clothes, and other consumer goods, can reduce your carbon footprint.

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