A community located downwind from a coal-fired power plant has seen a recent increase in the number of dead and dying trees. A so scientist measured values for the following parameters before and after the trees died off. Which of the following oil data should be used to determine if the coalfired power plant emiations were the cause of the damage to the trees a. Moisture content and water retention
b. Parent material composition
c. Pesticide and herbicide residue levels
d. Calcium and aluminum levels

Option D, Calcium and Aluminum levels

Explanation:

The coal fired power plant releases huge amount of particulate and gaseous emissions such as mercury, sulphur dioxide, nitrogen oxide etc. When there is rain, these gaseous and particulate matter comes to the ground along with rain water and pollute the soil. There are also chances of acid rain due to the presence of sulphur dioxide. Polluted soil and acid rain negatively impact the growth of the plants and causes leaching of Aluminium thereby decreasing the availability of calcium for the plants. Thus, the trees die. Hence, if the amount of Aluminium and Calcium in soil is determined, one can easily deduce the cause of death of trees.

Hence, option D is correct