An air quality data analysis system for interrelating effects, standards, and needed source reductions: Part 12. Effects on man, animals, and plants as a function of air pollutant impact.

The impact-effect mathematical model, developed in 1991, improves on a previous mathematical model, and was developed to predict biological response as a function of air pollutant impact. Impact is defined here as exposure duration multiplied by air pollutant concentration raised to an exponent (t.cd). This paper's purpose is to plot and regress example biological effects as a function of air pollutant impact to determine how well the plotted data fit the impact-effect model for three target populations: man, animals, and plants (a wide range of life forms). The three biological effects are: for man, lung function decrease after exposure to ozone (O3); for animals, mouse mortality after exposure to nitrogen dioxide (NO2); and for plants, leaf injury after exposure to O3. The three resultant regression equations account for a substantial amount of the data variance: 95 percent for lung function, 92 percent for leaf injury, and 73 percent for mouse mortality. The model fits the animal and plant data that cover both acute and chronic exposures. The animal exposures ranged from 6 min to 1 yr. The plant exposures ranged from 0.75 to 552 h.