During the warmer months, people tend to increase their exposure to air pollution because more people are outside more often – working in the yard, swimming, doing sports and summer camps, and camping. In Southeastern Wisconsin we have a geographic feature that can raise pollution levels. It’s called Lake Michigan. Here is what happens:
When there is a warm, humid summer day with little or no wind, the cool air over Lake Michigan drifts over land. Exhaust from cars, factories, and power plants collect in the cooler, shallow air mass but cannot rise into the warmer air above. It remains trapped under an “inversion”. The sun and heat act on these pollutants to form ozone. These are the days when Southeastern Wisconsin’s air quality becomes a concern.
Air pollution, especially ozone, affects thousands of people each year – some severely enough to require hospitalization. You can’t see or smell ozone, but your lungs are still affected by it. At low levels, this may not cause any symptoms, but special tests may reveal inflammation and decreased airflow. At higher levels, symptoms can include shortness of breath, coughing, wheezing, and chest tightness or pain. People who are exercising outdoors may find that their stamina is diminished. Many scientific studies have demonstrated the effects of ozone. With higher levels of ozone, people report more respiratory symptoms, use more respiratory medications, make more emergency room visits, and are hospitalized more.
Poor air quality doesn’t just pose risks to human health. It can also harm our environment. Ground-level ozone is damaging to plant life. It interferes with the ability of plants to produce and store food, so that growth, reproduction and overall plant health are compromised. By weakening sensitive vegetation, ozone makes plants more susceptible to disease, pests, and environmental stresses. Ground-level ozone has also been shown to reduce agricultural yields for many economically important crops, like soybeans, wheat and cotton. Animal life can also be harmed. One of the key components of ozone, nitrogen oxide, contributes to fish kills and algae blooms in sensitive waterways. By protecting our environment from the harmful effects of ozone and smog, we also protect the quality of life for future generations in Wisconsin. (source: EPA, Office of Air and Radiation)
Measuring Air Quality with the AQI
The Air Management section at the Wisconsin Department of Natural Resources (DNR) is responsible for measuring air pollutant levels throughout the state of Wisconsin. The air monitors across the state gather daily air samples of the following pollutants: particulate matter (PM), sulfur dioxide (SO), carbon monoxide (CO), nitrogen dioxide (NO) and ozone (03). The technical measurements are then converted into an easy to understand color-coded scale called the Air Quality Index (AQI). The colors represent different levels of health concern: Green for Good air quality, Yellow for Moderate, once the color hits orange or red, air quality is considered unhealthy. At first for sensitive groups like children, the elderly, those with respiratory conditions like asthma, and then as the pollutant grows, more of the public will experience symptoms. In addition, the AQI can advise the public about the general health effects associated with different pollution levels and describe possible precautionary steps to be taken if air pollution rises into the unhealthy ranges.
At GreendaleWeather the Air Quality Index and Air Quality Forecasts are available on the Air Quality page.
About the Air Quality Index
The AQI is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health concerns you should be aware of. To make the AQI as easy to understand as possible, the U.S. EPA has divided the AQI scale into six categories. Each category corresponds to a different level of health concern. For example, when the AQI for a pollutant is between 51 and 100, the health concern is “Moderate.”
About Air Quality Advisories
Wisconsin Department of Natural Resources notifies Wisconsin residents about unhealthy air quality using an Air Quality Advisory. The system includes the two main pollutants likely to cause health problems in Wisconsin — ozone and particle pollution (PM2.5). An Air Quality Advisory is when air quality has become unhealthy at least for individuals in sensitive groups.
The GreendaleWeather Air Quality page also includes alerts of air quality advisories.