TribLIVE's Daily and Weekly email newsletters deliver the news you want and information you need, right to your inbox. We have all heard the ongoing allegations of toxic pollution spewing from big business destroying our environment and killing us, cancer rates and respiratory diseases on the increase because of big businesses polluting for profit. These are some of the many emotionally charged allegations leveled by environmental groups. These types of allegations are many times overstated. Consider a couple of examples. Air quality The Clean Air Act required and the U.S. Environmental Protection Agency established national ambient air quality standards for pollutants considered harmful to public health and the environment. As a measure of the quality of air in our country, the U.S. EPA maintains data and statistics that quantify air quality over the past decades. Based on the U.S. EPA’s own data, the national ambient air quality standards for the target pollutants have all steadily and dramatically improved. As a national average: