Particulate matter, especially fine particles (PM2.5), can penetrate deep into the lungs and cause various respiratory issues.

Industrial activities, particularly those involving the burning of fossil fuels, are the main source of sulfur dioxide emissions.

Ozone, formed by the reaction of sunlight with other pollutants, is a major component of smog and can cause various health effects.

Motor vehicles, particularly those with internal combustion engines, are the primary source of carbon monoxide emissions.

Nitrogen oxides, emitted by motor vehicles and industrial activities, react with sunlight to form ground-level ozone.

Motor vehicles, particularly diesel engines, are the primary source of nitrogen dioxide emissions.

Sulfur dioxide, emitted by industrial activities and power plants, is a major contributor to acid rain.

Particulate matter can come from various sources, including motor vehicles, industrial activities, residential heating, and natural sources such as dust and pollen.

Carbon dioxide, emitted by human activities such as burning fossil fuels, is a major greenhouse gas contributing to climate change.

VOCs can come from various sources, including motor vehicles, industrial activities, residential heating, and natural sources such as trees and plants.

Formaldehyde, emitted from various household products and building materials, is a major contributor to indoor air pollution.

Motor vehicles, particularly diesel engines, are the primary source of black carbon emissions.

Sulfur dioxide, emitted by industrial activities and power plants, is a major contributor to acid rain.

Industrial activities, particularly those involving the burning of fossil fuels and mining, are the primary source of mercury emissions.

Ozone, formed by the reaction of sunlight with other pollutants, is a major component of smog and can cause various health effects.