Air pollution

"Outdoor is a major global public health issue (Cohen et al., 2017), leading to 4.14 million non-accidental premature deaths in both urban and rural areas worldwide in 2019 alone (Global Burden of Disease, 2019). In 2016, 54 % of the world's population lived in urban areas (United Nations, 2018), where ground-level (O3), particles with an aerodynamic diameter lower than 2.5 (), and (NO2) are the most harmful air pollutants for human health (Pascal et al., 2013; McDuffie et al., 2021; Anenberg et al., 2022). By 2050, 70 % of the world's population will reside urban areas (United Nations, 2018), and outdoor air pollution would lead to about 6.6 million premature deaths (Lelieveld et al., 2015). Air pollution also adversely affects biodiversity, ecosystems, and ecosystem services, such as (Agathokleous et al., 2020; Hu et al., 2022; Perring et al., 2022)."

"There are numerous ways to approach air pollution. s may think of how contaminants in the air affect living things. Within biology, the subdisciplines vary in their interests. s are often interested in how exposure to air pollutants affect biodiversity and overall ecosystem health. s are concerned about the diseases associated with various air contaminants. ... s are interested in how the exposure and effects of air pollutants differ in time and space. They may observe a and associate this with a source of air pollution. Or, they may observe a change in disease occurrence over time that tracks with changes in the type and amount of pollution released in an area."

"The global response to the has resulted in unprecedented reductions in . We find that, after accounting for meteorological variations, lockdown events have reduced the population-weighted concentration of and levels by about 60% and 31% in 34 countries, with mixed effects on . Reductions in transportation sector emissions are largely responsible for the NO2 anomalies."

") air pollution has recently been recognized as a risk factor for . ... Fine particulate matter may affect cognitive function via as a result of systemic inflammation or following lung irritation. ... It has also been proposed that the smallest particles, often coated with neurotoxic chemicals, ... can enter the brain through the or cross the . ... Unlike many other common risk factors for dementia (eg, hypertension, stroke, and ), exposures to air pollution can be modified at the population level, making it a prime target for large-scale prevention efforts."