The Air Quality Index (AQI) serves as a standardized tool used by health organizations and governments to communicate complex air pollution measurements to the public. This index translates the concentrations of various pollutants, such as ground-level ozone and fine particulate matter, into a single, understandable number. The AQI is color-coded, allowing individuals to quickly gauge the potential health risks in their area at a glance. Understanding this color scale helps people make informed decisions about their daily activities and health protection.
Defining the Red Air Quality Index
The color red on the Air Quality Index scale corresponds to a numerical range of 151 to 200, which is officially described as “Unhealthy.” This designation signifies a substantial increase in air pollution levels that poses a clear risk to public health. At this level, the concentration of airborne pollutants, particularly fine particulate matter (PM2.5) and ozone, is high enough to affect a wide range of people.
The overall AQI value is determined by the pollutant with the highest measured concentration, making it the one posing the greatest health threat. Fine particulate matter (PM2.5), which are tiny particles less than 2.5 micrometers in diameter, and ground-level ozone are the two pollutants that most frequently drive the AQI into the Red category.
Health Risks of Unhealthy Air
When the AQI is in the Red range, the entire population faces an increased likelihood of experiencing health effects. Exposure to this level of pollution can trigger respiratory irritation, such as coughing and throat soreness, even in generally healthy adults. Individuals engaging in prolonged or strenuous outdoor activities are particularly susceptible to noticing difficulty breathing and reduced endurance.
The risk is far more serious for people considered to be in sensitive groups, including children, older adults, pregnant people, and those with pre-existing heart or lung conditions. These individuals may experience more severe and immediate effects, such as aggravation of asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases. High pollution exposure can also increase the risk of heart attacks and strokes in people with cardiovascular disease. The fine particulate matter is especially hazardous because it is small enough to travel deep into the lungs and potentially enter the bloodstream, leading to systemic health problems.
Protective Measures During Red Air Quality
The most effective action to take during a Red air quality day is to reduce time spent outdoors and limit strenuous physical activity. Since the health effects are directly related to the duration and intensity of exposure, avoiding outdoor exercise is a primary recommendation for everyone. Shifting workouts to an indoor setting, such as a gym or home, can substantially decrease the intake of harmful pollutants.
Managing indoor air quality becomes a focus when the AQI is Red, requiring windows and doors to remain closed to create a barrier against outside air. Using a high-efficiency particulate air (HEPA) filter or a portable air cleaner can help remove airborne particles within the home.
For those with central heating, ventilation, and air conditioning (HVAC) systems, set the unit to recirculate air and ensure a high-efficiency filter is installed to prevent outdoor air from being drawn inside. If a person must venture outside, wearing a properly fitted N95 or KN95 mask is advised. These respirator-type masks are capable of filtering out the fine particles that pose the greatest danger.