Air Quality
Overview
Air quality refers to the condition of the air within our surroundings. Good air quality pertains to the degree to which the air is clean, clear and free from pollutants such as smoke, dust, odours, and gases. On the other hand, poor air quality is determined by high levels of pollutants in the air. The quality of air has a direct impact on the health and overall wellbeing of humans, as well as the environment.
Air Pollutants
Air pollutants are substances in the air that can cause harm to humans and the environment. They are classified into two categories: primary and secondary pollutants. Primary pollutants are those that are directly emitted from a process, such as ash from a volcanic eruption or the carbon monoxide gas from a motor vehicle exhaust. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant. Some pollutants may be both primary and secondary: that is, they are both emitted directly and formed from other primary pollutants.
Measurement of Air Quality
Air quality is measured with the Air Quality Index (AQI), a system used globally to standardize the measurement of pollutants in the air. The AQI categorizes air quality according to a scale from 0-500, where a higher AQI value represents higher levels of pollutants and therefore poorer air quality. The AQI considers five major air pollutants regulated by the Clean Air Act: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
Health Impacts
Poor air quality can have a significant impact on human health, particularly for individuals with pre-existing respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD). Short-term health effects of poor air quality can include irritation of the eyes, nose and throat, headaches, dizziness, and fatigue. Long-term health impacts can include respiratory and heart diseases, and can even be life-threatening.
Environmental Impacts
Air quality also has a significant impact on the environment. Pollutants in the air can damage trees, crops, other plants, lakes, and animals. In addition to damaging structures like buildings and monuments, air pollution can impact the climate, contributing to climate change by increasing the levels of greenhouse gases in the atmosphere.
Air Quality Management
Air quality management involves the assessment, analysis and mitigation of air quality problems. It includes the development and implementation of strategies and policies aimed at reducing air pollution and maintaining good air quality. This can involve legislation and regulation, urban planning, and public awareness campaigns.