Exposure to particulate matter PM in polluted air can have significant adverse effects on human respiratory health, particularly in terms of lung function and the risk of respiratory diseases such as asthma and lung cancer. Particulate matter is a complex mixture of solid and liquid particles suspended in the air, which can vary in size, composition, and origin. The most concerning particles for human health are those with a diameter of 10 micrometers PM10 or smaller, as they can be inhaled deep into the lungs.1. Lung function: When inhaled, particulate matter can cause inflammation and irritation in the airways and lung tissue. This can lead to a reduction in lung function, as the airways may become narrower and less elastic, making it more difficult for air to flow in and out of the lungs. Over time, this can result in a decrease in lung capacity and a decline in overall respiratory health. People with pre-existing lung conditions, such as chronic obstructive pulmonary disease COPD or asthma, may experience worsening of their symptoms due to exposure to particulate matter.2. Asthma: Exposure to particulate matter can increase the risk of developing asthma, particularly in children. PM can cause inflammation and irritation in the airways, which can lead to increased sensitivity to allergens and other asthma triggers. This can result in more frequent asthma attacks and a worsening of asthma symptoms. Additionally, long-term exposure to PM can contribute to the development of new-onset asthma in individuals who were previously healthy.3. Lung cancer: There is a well-established link between exposure to particulate matter and an increased risk of lung cancer. The International Agency for Research on Cancer IARC has classified outdoor air pollution and particulate matter as Group 1 carcinogens, meaning they are known to cause cancer in humans. The exact mechanisms by which PM contributes to lung cancer development are not fully understood, but it is believed that the particles can cause DNA damage and mutations in lung cells, which can lead to the formation of cancerous tumors.In conclusion, exposure to particulate matter in polluted air can have significant negative effects on human respiratory health, including reduced lung function and an increased risk of respiratory diseases such as asthma and lung cancer. Reducing exposure to air pollution and implementing strategies to improve air quality are essential for protecting public health and reducing the burden of respiratory diseases.