Biology

Introduction
Acid rain is defined as a form of precipitation that has abnormal levels of nitric and sulfuric acids (Briney, 2010). The rain is caused by the reaction of sulfur dioxide and nitrogen oxide with the atmospheric air, resulting into the formation of nitric acid and sulfuric acid among other compounds (Briney, 2010). According to available information on acid rain, it can either be inform of wet or dry deposition depending on the weather conditions. Acid rains can be caused by natural andor man-made activities.

The major natural causes include volcanic activities and the decaying process of vegetation which have been identified to produce both nitric oxide and sulfur dioxide (Thinkquest, 2000). However, statistics claim that the contribution of these natural factors is quite negligible. Man-made activities cited for causing acid rains are the huge release of exhaust gases, especially sulfur dioxide and nitric acid, from production companies (USEPA, 2007). The major contributors here are industries using fossil fuel in the production process.

Effects of acidic rain
Acid rains have negative effects to almost all aspects of human life as they affect the environment and its habitants as well as poses health threats to mankind. Acid rain increases acidity of surface water thus threatening the lives of aquatic animals (Beildler, 2008). A pH of below 5 in surface water is required for ensuring the existence of fish and other aquatic animals (Thinkquest, 2000). The reason behind the death of fish and other aquatic animals is due to the low pH and high aluminum concentrations found in water as a result of acid rain (Briney, 2010). According to available information, acid rains have in the past led to the extinction of insects and fish species in some rivers, streams and lake waters.

The second effect of acid is the negative impact it has on the soil. The human community relies on soil for agricultural production for its food security. Soil on the other side is influenced by microbes as well as other chemicals such as calcium and magnesium for its sustainable fertility (USEPA, 2007). Acid rains lead to denaturing of some species of microbes due to the high acidity thus compromising their effective functioning (USEPA, 2007). Still, acid rains, with its hydronium ions react with aluminum, calcium and magnesium from the soils thus compromising the life of sensitive plant species (USEPA, 2007). All these means that the soil will be deprived both of its microbes for ensuring fertility and existing useful chemicals for sustaining plant life.

Another serious consequence of acid rain is seen on forests and other vegetations. According to scientific evidence in records, forests in high altitudes are particularly affected by acid rains. The main reason here is the fact that this forests are usually surrounded by clouds, fog and snow, forms, which acid rain can take (USEPA, 2007). The threat here is mainly posed by the nutritional implication acid rains have on the soil as well as leaf surface damages thus compromising the sustainable survival of the plants. The effects vary depending on the type of type as well as the level of acidity in the rains. For example, the leaching of calcium from red spruce compromises the plants ability to tolerate cold thus risking sustaining winter injury or death (Thinkquest, 2000). However, the effects of acid rains on food crops is found to be minimal due to agricultural practices like fertilizer and lime applications for the restoration of lost nutrients and soil pH respectively.

Although acid rains are not directly linked with health complications in the human body, acid air pollution do have serious health complications (Beildler, 2008). First, the problem of lung and breathing in asthmatic members of the community is has been closely attributed to acid air pollutions (Beildler, 2008). Still, to be noted is the fact that most of our nutrition comes from the soils. This has the logical implication that whatever we take as food or drink has been affected by acid pollutions. This is the reason behind most kind of sicknesses such as cancer and premature deaths.

Lastly, acid rain affects non-living things such as buildings, bridges and metallic structures (Briney, 2010). Areas like India and Italy among other countries are examples nations those structures have been affected by acid areas. Such rains lead to corrosion, discoloration and even fracturing of buildings (Briney, 2008). This makes acid rains a major threat to the long term existence of national monuments. On metallic structure damages by acid rains can be evident from the corrosion effect the acid rain brought to railways in some parts of Poland.

Conclusion
It has been established that acid rains are a major threat to the soil, surface water, and its habitants, forests and man-made structures such as building and infrastructure. They are thus a major threat to our sustainable social economic development. Despite this threat, mankind activities are the main cause of acid rains. Energy production using fossil fuels, production industries and cars are all to be blamed for causing acid rains (Briney, 2010). Such concerns for the safety of the world has resulted into safer production processes that limit the amount of acid gas released to the air by industries. Nevertheless, there is much need to device more effective ways of mitigating occurrence of acid rains in the global community.