Air pollution contributes to nearly 7 million premature deaths each year, and its effects go far beyond the lungs. Breathing in wildfire smoke or automobile-related city smog doesn’t just increase the risk of asthma and heart disease — it may also contribute to brain conditions as diverse as Alzheimer’s and autism. Scientists have discovered how a chemical change in the brain — which can be triggered by inflammation and aging as well as toxins found in air pollution, pesticides, wildfire smoke and processed meats — disrupts normal brain cell function. Known as S-nitrosylation, this chemical change prevents brain cells from making new connections and ultimately results in cellular death, the team discovered.