Noxious gases are harmful substances in the air that can cause health problems for humans and animals. Common examples include carbon monoxide, sulfur dioxide, and nitrogen oxides. These gases can be produced by vehicles, industrial processes, and burning fossil fuels, contributing to air pollution. Exposure to noxious gases can lead to respiratory issues, headaches, and other serious health effects. In high concentrations, they can be life-threatening. Monitoring air quality is essential to protect public health and the environment, and regulations often aim to limit the release of these harmful substances into the atmosphere.