Air pollution affects plants through various ways including acidification, eutrophication and ground-level ozone. Chemicals react with air to form compounds that cause harm to vegetation. Air pollutants, including sulfuric acid, mix with water droplets that form clouds. The resulting acidic rain is harmful to trees, fish, animals and other organisms.
Air pollution leads to losses in crops, trees, vegetation and ornamental plants. Human commercial and industrial activities lead to air pollution, which has drastic effects on both plants and animals. The effects of air pollution on plants may be evident in a number of ways. Foliage develops injuries that, with time, appear as necrotic lesions. Yellowing of leaves (chlorosis) may also be an effect of acidification. Other symptoms include mottling, bronzing, reddening and stunted growth. When sulfur dioxide and nitrogen oxides combine with water in the atmosphere, they form acid rain, which intoxicates the soil and waters where it falls, causing damage to plants. Acid rain weakens trees by destroying their leaves, decreasing the nutrients available to them. The toxic substances released from the soil also poisons the plants. Acid water dissolves nutrients and other important minerals in the soil and washes them away before they can be consumed by plants. Additionally, Ozone holes in the upper atmosphere allow excessive infiltration of ultraviolet radiation from the sun to the Earth causing harm to plants. Similarly, Ozone in the lower atmosphere prevents plant respiration by clogging stomata and hinders plant’s photosynthesis rates, hence stunting the plant's ability to grow.