Air pollution is a result of natural phenomena or human activities that can cause the release of harmful substances in the environment, leading to adverse health outcomes among living beings. Pollution is associated with adverse health impacts on multiple organ systems among humans. While the respiratory and cardiovascular systems are mainly affected, there are other health issues related to the eyes, skin, brain, blood, immunity, behavioral/mental well-being, and reproduction among exposed individuals. Air pollutants can especially have higher health impacts on people at the extremes of their ages (children and elderly) and on those suffering from underlying respiratory and heart issues. Pollutants such as ozone, sulfur dioxide, particulate matter, and nitrogen dioxide have respiratory effects among children and adults and are associated with increased respiratory diseases, asthma exacerbations, and related hospitalizations. Carbon monoxide interferes with transporting oxygen by forming carboxyhemoglobin leading to cardiovascular, neurological, and respiratory problems. Particulate matter is a heterogeneous mixture of tiny particles of varying compositions found in the atmosphere and has a wide variety of severe health effects. Particulate matter emits from combustion, diesel engines, power generation, and wood-burning, and certain industrial activities. Lead is considered neurotoxic and has more severe consequences among children. Here we summarize characteristics of six criteria air pollutants and associated air quality risk assessment parameters known as the Pollutant Standard Index (PSI). The present manuscript also examines the impact of air pollution on human behavior, mental well-being, and neurological health consequences, as air pollution has been associated with cognitive decline, hyperactivity, dementia, anxiety, depression, aggression, and Alzheimer’s disease-related changes. Lastly, we also attempt to look into any relationship between air pollutants and Coronavirus disease (COVID-19) and examine its possible association with a higher COVID-19 incidence, complications, and mortality.