THE EFFECTS OF ACID RAIN

Over 1,000,000 square kilometres of Europe's forests have suffered the effects of acid rain, with conifers being damaged the most. The sulphur dioxide from burning fossil fuels may damage and kill many trees, but this is compounded as acid rain reacts with vital plant nutrients, preventing their uptake through root systems.

Even slight damage to a mature tree caused by pollution can be enough to kill it because it reduces the trees frost hardiness and its resistance to fungal and pest attack.

American studies have indicated that even where forests are showing none of the easily visible external signs of acid rain damage, pollution is nevertheless limiting their growth.

Other plants can also be damaged by acid rain, but the effect on food crops is minimized by the application of lime and fertilizers to replace lost nutrients. In cultivated areas, limestone may also be added to increase the ability of the soil to keep the pH stable, but this tactic is largely unusable in the case of wilderness lands. When calcium is leached from the needles of red spruce, these trees become less cold tolerant and exhibit winter injury and even death.

Acid rain can also damage buildings and historic monuments and statues, especially those made of rocks, such as limestone and marble, that contain large amounts of calcium carbonate. Acids in the rain react with the calcium compounds in the stones to create gypsum, which then flakes off.

The effects of this are commonly seen on old gravestones, where acid rain can cause the inscriptions to become completely illegible. Acid rain also increases the corrosion rate of metals, in particular iron, steel, copper and bronze.

Acid rain does not directly affect human health as the acid in the rainwater is too dilute to have a direct adverse effect. However, the particles responsible for acid rain (sulphur dioxide and nitrogen oxides) can have an adverse effect because increased amounts of fine particulate matter in the air contribute to heart and lung problems including asthma and bronchitis.

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THE EFFECTS OF ACID RAIN
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