atmospheric structure(The gaseous area surrounding the planet is divided into several concentric spherical strata (layers, like shells) separated by narrow transition zones. The boundaries are know as "pause". More than 99% of the total atmospheric mass is concentrated in the first 40 km from the Earth's surface. Atmospheric layers are characterized by differences in chemical composition that produce variations in temperature)
atrazine(Herbicide belonging to the triazine group, widely employed and particularly in maize crops. It is highly toxic for phytoplancton and freshwater algae and, being highly soluble in water, it easily contaminates aquifers)