Fill in the blank:
AQI values above ______ indicate unhealthy air quality for sensitive groups.
Show answer & explanation
Correct answer: A
Explanation
Correct Answer
100
Explanation
The baseline threshold value used globally and by various national environmental agencies to separate satisfactory air from air that poses an active risk to vulnerable populations is an Air Quality Index (AQI) of 100. When the AQI values cross above 100, the ambient air quality enters categories that demand caution, primarily starting with sensitive groups.
The overarching goal of the AQI scale (which typically ranges from 0 to 500) is to provide an easy-to-understand, color-coded shorthand for complex multi-pollutant atmospheric data. An AQI value of exactly 100 generally corresponds to the short-term National Ambient Air Quality Standard set by environmental protection regulators to protect public health. Any reading below 100 is generally deemed acceptable for daily outdoor exposure, whereas any reading above 100 serves as an indicator that the air is becoming progressively unhealthy, starting immediately with individuals who possess underlying physiological sensitivities.
Key Points
The range immediately above 100 (specifically 101 to 150) is formally designated as "Unhealthy for Sensitive Groups" and is usually represented by the color orange. Sensitive groups are explicitly defined to include children, older adults, pregnant women, and individuals suffering from pre-existing cardiovascular or respiratory conditions such as asthma, bronchitis, or chronic obstructive pulmonary disease (COPD). While an AQI in this baseline elevated range might cause minor or no noticeable symptoms in the healthy general public, it can trigger breathing discomfort, coughing, and reduced lung capacity in vulnerable demographics, necessitating an immediate reduction in heavy or prolonged outdoor activities.
Important Questions and Answers
Question: What specific health category name is assigned to the AQI range running from 101 to 150?
Answer: Unhealthy for Sensitive Groups.
Question: Which specific demographics are considered part of the sensitive groups most vulnerable to an AQI above 100?
Answer: Children, older adults, pregnant women, and individuals with heart or lung diseases (like asthma).