The Air Quality Health Index (AQHI) is an indicator that can help estimate the risk of developing certain health conditions, such as stroke, heart disease, respiratory disease and lung cancer, from exposure to air pollutants. Unlike the traditional Air Quality Index (AQI), which reports air quality based on each pollutant separately, AQHI provides more comprehensive information, presenting potential health risks resulting from the combined effects of a mixture of pollutants in a particular area.
The AQHI was designed to measure numerous pollutants found in the air, categorize the level of danger they may pose to the public and offer advice on how to be as healthy as possible in the respective areas.
The AQHI is calculated by measuring the presence of potentially hazardous pollutants in the air, including nitrogen dioxide, ozone and particulate matter. The levels at which these pollutants are present, as well as which combinations are detected, determine how the area ranks on the AQHI scale.
The scale ranges from 1 to 10+, with 1 representing little or no threat and 10 or more representing serious potential problems. The scale is further divided by categories that represent different levels of potential health risk.
- 1-3 represents a low health risk, meaning the entire population can enjoy their usual activities safely.
- A moderate score of 4-6 indicates that at-risk members of the population should think about rescheduling or reducing their amount of time in that area. It also means the rest of the general public can go about their outdoor activities as usual unless they experience throat irritation, coughing or similar symptoms while in the area.
- An AQHI score between 7 and 10 indicates that at-risk individuals, as well as children and the elderly, should seriously consider a major reduction of activity or a change of schedule, and everyone should do the same if they ever experience the aforementioned symptoms of failing health.
- A score above 10 means that children, the elderly and all at-risk individuals should avoid physical activity in this area, and the rest of the public should be prepared to do the same if they run into any of the previously mentioned symptoms.
The United States Environmental Protection Agency (EPA) calculates AQHI for five air pollutants: particle pollution, ground-level ozone, carbon monoxide, nitrogen dioxide, and sulfur dioxide. As claimed by the same agency, particle pollution and ground-level ozone pose the greatest threat to human health. While particle pollution consists of a mixture of liquid and solid, organic and inorganic particles (e.g. sulfates, nitrates, ammonia, mineral dust, etc.), ozone at ground level is one of the components of photo-chemical smog, resulted from the reaction between certain pollutants (e.g. nitrogen oxides, vehicle and industry emissions, etc.) and sunlight. Since negative health effects increase as air pollution worsens, prolonged exposure to air pollutants contributes to the risk of developing respiratory and cardiovascular diseases, even in healthy individuals.
Although the health effects of air pollution depend on the health status, genetic background, individual reaction, type and concentration of pollutants, and duration of exposure, the elderly, children, and people suffering from acute and chronic heart and lung diseases are most affected.
The national air quality standards along with the indoor air quality programs included in green building practices and AQHI have become critical requirements for an accurate air quality assessment. Additionally, AQHI allows experts to project potential health improvements that could be obtained if air pollution is reduced.
We cannot talk about AQHI without referring to green building concepts. Focusing on reducing resource use, waste, water pollution and air pollution, among others, these concepts encourage organizations to implement and promote environmentally sustainable work practices that will not only help save the environment, but also protect public health. By complementing green building practices with AQHI, a company can contribute to a sustainable future.