white black legal international law journal ISSN: 2581-8503

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“Acid Rain: A Legislative Lacuna” Authored By: Kritik Kumar Jain & Tushar Ahuja

“Acid Rain: A Legislative Lacuna”

  Authored By: Kritik Kumar Jain



Phone no.- 9770947322

E-mail- kritikjain1303@gmail.com

Co-Author: Tushar Ahuja




Serial No.


Full Forms































Supreme Court




Indian Meteorological Department


Union of India

United States of America

United States Environment

Protection Agency

Potential of Hydrogen

World War-II

With Respect To

Read With







1. Introduction

2. Formation (The chemistry behind Acid rain)

3. Kinds of Acid Rain

⦁          Wet deposition

⦁          Dry deposition

4. Issues/ Problems/ Impacts of Acid Rain

   i. Effects on Human life

   ii. Effects on Aquatic Ecosystem

   iii. Effects on Forest Ecosystem

   iv. Effects on Soil

   v. Effects on Buildings, Monuments and Statues

5. Leading Case laws

⦁          International

⦁          National

6. Current legislations governing this phenomenon

⦁          International

⦁          National

7. Acid Rain pounding the gates of Indian Parliament

8. Suggestions

9. Conclusion



The phrase “Acid Rain” was coined by Robert Angus Smith in 1852.He was a Scottish Chemist who was engaged in some investigation with regards to rainwater chemistry in the cities of England & Scotland. In the later half it became an integral part of his book Air & Rain: The Beginnings of a Chemical Climatology (1872)[1]. Thereafter this phenomenon started to find various scientists/researchers' attraction towards itself in the late 1960's & 1970's. It is believed that the first traces of Acid rain which were systematically studied were found in North America & in some regions of Canada.


Some experts in today's time believe it's better or more accurate to refer to it as ACID DEPOSITION.


Acid Rain can be simply defined as, a form of rain which is unusually Acidic in nature due to the presence of components like Sulphuric acid & Nitric acid (formed through SO2 & NO2 released in the atmosphere by Anthropogenic actions) due to which it has a very low PH value. YES, Acid Rain has a very low PH of about 4.0 whereas, the normal rainfall which is slightly acidic in nature due to the presence of CaCO3 (Carbonic acid) from CO2 present in the atmosphere, ranges about 5.0 - 5.5/5.6 on being measured using a PH scale.


USEPA defines it as; Acid rain, or acid precipitation, is a wider term that is inclusive of any form of precipitation with acidic components, such as weak sulphuric acid(H2SO4) or nitric acid (HNO3) that falls to the ground from the atmosphere in two forms, namely; wet or dry forms.  This can include rain, snow, fog, hail, sleet or even dust that is acidic[2].


Since the very beginning of the civilization man has used the Natural resources to satisfy his own needs. With the course of time, man started to evolve & the use of natural resources began even more in terms of quantity too. AS the energy was mainly produced by burning of the resources like coal, natural gas etc., it made our lives easier per se. But the cost of our lives being easier came with an evil cost of environmental pollution too. Generally, the burning of fossil fuels, industrialization, emissions from smelters, vehicular emissions etc. are some of the prime causes of Environmental disturbances as they implant various hazardous gases, elements in the atmosphere resulting in AIR POLLUTION. Acid Rain has far reaching consequences not only on the quality of human life but also on the Environmental equilibrium, Infrastructure & Feasibility of food thus resulting in Economic crisis. It would not be wrong to say that it had became an unforeseen threat unlike "COVID-19"


 Diagrammatic representation of a pH scale Fig 1.0



                                  Fig 1.1 Formation of Acid Rain.


The term Acid Rain is somewhat misleading in nature as some study's say, even the pure rainwater collected in some of the remote areas residing away from the population is found to be slightly acidic with a PH equivalent to 5.6 due to the presence of amount of CO2 which reacts with water to give out Carbonic Acid.

CO2(g) + H2O(l) = H2CO3(aq)

 Water and carbonic acid react to generate low concentration ions of carbonate and hydronium,

2H2O(l) + H2CO3(aq) = CO32-(aq) + 2H3O(aq)

Carbonic acid is generally a weak acid.[3] It brings down the pH of the rainwater. With pH levels ranging between 6.0-5.2, the rainwater is quite acidic, but still not hazardous. It comes under the category of reversible reaction. At times it leads to the pH levels going as low as 2. This phenomenon of acidic rainwater deposition is termed as Acid rain. Rain, snow, sleet, freezing rain, hail, fog & dew are some other forms of precipitation. Generally Acid rain is a clement combination of the two ingredients, sulphuric & nitric acid. Only trace quantities of sulphureous & nitrous acids are present. The issue arises when rainfall interacts with sulphur, nitrogen, phosphoric, & hydrochloric acid mists. The latter two & sulphur are released into the atmosphere from automobile exhausts, industries & electric power plants.


Sulphuric acid is formed by the help of following equations:

1. Sulphur released into the atmosphere combines with the atmospheric oxygen to give out; Sulphur dioxide (SO2)

S(g) + O2 (g) = SO2(g)


2. Sulphur dioxide reacts with atmospheric water to give out sulphurous acid;

SO2 (g) + H20 (l) = H2SO3 (l)

3. Sulphur dioxide oxidises over the time to form Sulphur trioxide (SO3);

2SO2 (g) + O2 (g) = 2SO3 (g)

4. Sulphur trioxide then reacts with water to form Sulphuric acid (H2SO4);

SO3 (g) + H2O (l) = H2SO4 (aq)

Nitrogen is a major component of atmospheric composition. It amounts to 78%(approx.) of the earth's atmosphere. These chemicals result in diminishing the pH value of rain up to, 5.6-3.5.

Nitric Acid (HNO3) is formed as follows:

1. Nitrogen reacts with atmospheric oxygen to give out nitrogen dioxide (NO2);

N2(g) + O2(g) = 2NO(g)

2. Nitrogen dioxide combines with water to form nitrous acid (HNO2) & nitric acid (HNO3);

2NO2 (l) + H2O (l) = HNO2(aq) + HNO3 (aq) [4]



KINDS (Categorization)                                      


                                 Fig. 1.2 Wet & Dry Deposition     

Wet deposition;

It may generally occur in the form of acidic rain, fog or snow. It occurs when the acid chemicals present in the atmosphere are blown up to a wet area, then that acid may fall onto the earth's surface in various forms (i.e., rain, snow or fog). This deleterious acid water creates ecological disturbance after falling on the surface, it is responsible for degrading the land & quality of soil, threatening the life of plants, animals, fishes etc. The degree of harm caused depends on several facets; the acidity (pH value) of the water, the buffering capacity of the soil, the topography of the area, the types of species of various flora and fauna's relying on that water.


The wet deposition also may occur in two forms,

1. Above the clouds or Rainout, it happens when the particles are incorporated into water drops which fall towards the surface.

2. Below the clouds or Washout, As the name suggests it occurs when the particles under the cloud are dragged by the rain, snow falling towards the earth's surface.


Dry deposition;

It generally occurs in those areas where the weather is dry, the acid compounds in the atmosphere may form into dust particles, gases, smoke etc. and fall to the surface of earth in form of Dry deposition. These gases and dust particles stick to the vegetations, homes, lands, cars, water bodies, buildings etc. or might build up a hazardous reaction with the atmospheric particulates which may be unfavorable for human health. Rainstorms can wash away dry deposited gases and particles from these surfaces, resulting in enhanced runoff. This discharge water raises the acidity of the resultant combination. About half of the planet's acidity is returned to it via dry deposition. The amount of acid in the atmosphere that falls to the ground as dry deposits relies upon the number of rainfalls in a given area, for instance deserts have a higher ratio of dry deposition as compared to the places which experiences moderate rainfall per annum.


 1.Effects on Human life

Acid rain mimics the normal Rainfall in terms of appearance, texture and taste. The rainwater's acid content is too diluted to have any noticeable direct consequences, thereby it does not have any direct grave effect on humans. But the significant constituents of acid rain (H2SO4, HNO3) do have an ill effect on human health. These gases interact with the atmospheric particles and can easily be blown away by the winds to distant areas, or to the areas where the human population might inhale these gases onto their lungs causing respiratory distresses. Asthma and bronchitis are among the lung conditions exacerbated by elevated levels of small particulate matter in the air. Acids are quite diminutive particles. Chronic bronchitis, lung emphysema, and cancer are some of the direct impacts of acid rain seen in humans. Several scientific studies have come to the same conclusion: there is a link between excessive levels of fine particles and greater illness or early mortality owing to heart and pulmonary difficulties. With regards to deterioration of human health, this phenomenon (SO2, NO2 emissions) was historically governed under, Clean Air Act (1970) [4]including the Acid Rain Program by USEPA[5] and 1985 Helsinki Protocol on the Reduction of Sulphur Emissions.[6]

Wandering in acidic rain or even diving in an acidic pond, is no more harmful to people than wandering or diving in the normal rainwater.


2. Effects on Aquatic Ecosystem

It would not at all be wrong to say that they are the ones who are deeply distressed by the acid rain. Most of the rivers, lakes, streams etc., which are left untouched from the issues like Acid rain & Pollution ought to have a higher pH value (about 6.5) than the ones in distress. The Acid rain primarily affects the aquatic ecosystem in two ways, directly; as when it falls (in form of rains, snow etc.) directly on water surfaces, secondly Indirectly; via the lands(grounds). Acid rain pours off the land and mixes with water inlets such as lakes, streams, and marshes, making it difficult for aquatic flora and fauna to even survive. This doesn't stop here, it also enumerates the release of intolerable substances like Al (Aluminum) into the water from the soil, which takes these sufferings to another level. Freshwater shrimp, snails and mussels are the ones that are fastest affected by acidification, followed by the fishes like; minnows, salmon and roach. The acidic water proves to be very hard on the eggs of fishes, it is believed that in water having pH around 5, the eggs will not hatch properly and may even lead to death of certain big fishes too. Unlike all other ecosystems, here too the producers and consumers go hand in hand for their survival, but if the unfavorable conditions continue to affect a particular species and another species which was directly or indirectly dependent on that species, this may even lead to rapid extinction of species and, in the end of the whole ecosystem.


 3. Effects on Forst Ecosystem

Acid Rain can be a nightmare for the module of forest ecosystem. The acid rain which drips onto the earth's surface has the capacity to dissolve the nutrients (such as calcium and magnesium) required for the growth of trees/plants. They amount of corrosion doesn't stop here, as discussed earlier in the "Aquatic ecosystem", the acid rain is capable of releasing the aluminum (Al) which in turn is harmful for the soil as well as hinders the growth of various trees, deteriorates the living of microbes etc. The tree(forests) located at the higher altitudes (i.e., mountainous regions) are generally at a higher risk as compared to the forests at plateaus. Since they share greater exposure with the acidic clouds and fogs, as they are bulked up with the acid rain, snow, fog etc. Fog and acidic clouds rob the leaves and needles of their essential nutrients. This loss of the vital nutrients weakens the tree making it exposed to various infections by pathogens, droughts, insect epidemic etc.


Acid rain's effect on the Fauna is not direct per se, thus making it hard to maintain records. But it does not mean that acid rain spares the wildlife, it shall be noted that acid rain has an indirect effect on the wildlife w.r.t their fertility and survival. Acid rain implants various unwanted compounds in the soil, which later flow into lakes, ponds, streams thus affecting the aquatic ecosystem, which may be gulped by the birds which feed on the fishes, thus resulting in toxication of the whole food web.


4. Effects on Soil

Acid rain is supposed to have an obvious effect on the soil. The acid rain takes away the fertility of soil, leaving behind the harmful elements which in turn results in soil acidification. It occurs when the base cations (such as K, Ca, Na, Mg) are washed out of the soil and are replaced by the hydrogen cations, which generally lowers the pH value of soil. Some of these cations (magnesium and calcium) are required for the proper growth of plants. As a result of these processes, the Soil chemistry is drastically declined as when these cations are being interchanged, they result in formation of compounds of Mercury, Aluminum etc. These are easily absorbed by the plants. Such elements are not only disadvantageous to the flora but also to the fauna's who feed on them. It could be summed up that it disrupts the whole food chain. Soil chemistry and biology are majorly ruined by acid deposition.

5. Effects on Buildings, Monuments and Statues

Acid rain can have damaging effects on various kinds of objects, namely; Buildings, monuments, bridges, statues etc. Acid rain reacts with calcium carbonate (CaCO3) to spill out, Calcium bicarbonate (CaHCO3). Calcium bicarbonate exists in aqueous form and can easily be washed away by the rain. This is the manner in which acid rains have almost decimated some of the world's important tourists' attractions like, Taj Mahal in India, Statue of Liberty in New York, The colosseum of Rome, The Leaning Tower of Pisa, etc. The chemicals of acid rain are so harsh that they could, corrode the towers(metals), peel off the paints, wash off the limestones (thus resulting in severe damages to various statues etc.) and make the stone statutes look old and torn. It could be expressed as, CaCO3(s) + H2O(l) + CO2(g) = Ca (HCO3)2 (aq)



Fig 1.4 Religious medieval sculpture when encountered Acid deposition; located in Dresden, Germany.




Trail smelter case (USA vs. Canada) [7]

This case was one of the first cases of its time, it became famous for the landmark judgement which was enumerated out of it. It is also one of a few fine cases in which the Polluter Pays Principle was instated. It all began with the Transboundary Pollution caused by the Canadian Consolidated Mining and Smelting Company Limited on the valley of Columbia River of the United States, upon which both the countries shared a common border. The issue that arised between the two countries was that the smelter located on the Canadian side of the border was emitting SO2 and thereby disrupting the land (forest area) on the U.S. side of the border, and thereby the U.S government held the Canadian smelter liable for eroding its forestlands and demanded for the compensation of $350,000. The USA claimed that: yellow pines, Douglas firs, larch, and cedar were the most impacted species. Alfalfa, wheat, and oat harvests were also affected. At last, the judgement given was in the favour of USA in the second round of arbitration out of the two arbitrations held and the Canadians were held liable and were charged by the authorities to pay $78000 at closure of the deal, also the smelter was transferred to another prominent location. Also, the US Secretary of State offered to repay $8828 back to the Canadian authorities which was allotted to them with regards to the compensation amount.[8]


Georgia vs. Tennesse Copper Co. [9]

Justice Holmes says;

"It is a fair and reasonable demand on the part of a sovereign that the air over its territory should not be polluted on a great scale by sulphureous acid gas, that the forests on its mountains, be they better or worse, and whatever domestic destruction they have suffered, should not be further destroyed or threatened by the act of persons beyond its control, that the crops and orchards on its hills should not be endangered from the same source".

Long before the Trail Smelters case this judgement was given by the Supreme Court of US with regards to the issue of Transboundary Air pollution.



 MC Mehta vs. U.O.I (Taj trapezium case) [10]

This case shall be deemed to be one of the most esteemed landmark judgement which was granted not only after considering the Prestigiousness of Taj Mahal, but also elevated the International principle i.e. Polluter Pays Principle and enshrined its meaning abundantly in accordance with the Indian Constitution, whereby the apex court commanded the industries(292) that during their relocating period the workers must not suffer and shall be paid as if they were working at the time of relocation. The problem arises when it was observed by the petitioner that, the chemical industries, foundries and refineries operating in Mathura region, in the Taj trapezium zone (TTZ) were emitting sulphur dioxide (SO2) abruptly as a result of which there were severe damages to the Taj Mahal which became quite visible; all these factors, resulted in Acid Rain over the Taj Mahal whereby the acid rain had a corroding impact on the beauty of the monument. The impacts of Acid rain were viewed as; Firstly, the shine of the white marble was turning into pale yellow color, secondly it also developed some brownish/black spots which resulted in corroding the beauty of one of the seven wonders of the world. The judgement enumerated by Justice Kuldeep Singh, based on the reports by NEERI (National Environmental Engineering Research Institute) and Vardharanjan Committees report, stated that all the industries operating in the TTZ should shift to Natural gas, and the ones which didn't comply with the orders of Apex court were either asked to relocate themselves or were shut down. This judgement was a highlighted one as it was the only judgement addressing the problems caused w.r.t Acid Rain.

Note: It shall be the duty of every citizen residing within the territory of India to preserve its rich cultural heritage as per Art 51A(f) R/W Art 49 of the Indian Constitution.