ACID RAIN                      earth in a number of different ways.                                            Natural rain is already slightly        Acid rain is an expression used         acidic ,because of its reaction th      every day in our lives but not          carbon dioxide which is already in      everybody knows what it is and          the atmosphere;it is assumed to         where it comes from.It is caused        have a pH value of about 5.4 .The       when coal or oil is burned.Both         rain that falls over Britian has an     fules contain a certain amount of       average range of pH 4 to pH 4.7 .       sulphur ,which when burned ,            The most acid rainfall ever             releases a gas into the air;this is     recorded in the U.K was at Pitochry     sulphur dioxide (so2).These fules       in 1974 and its pH value was as low     also contain nitrogen ,which is         as pH 2.4 .These have been more         similary released as nitrogen oxide.    extreme cases espically in the USA ,    But acid rain is not just rain:it       where acid fogs in California have      includes rain ,snow ,sleet ,hail ,      been know to have a pH value of         mists fogs ,gases ,and dry              only 1.6 ,and it is calculated that     particles.The great london smogs        the great London fog of 1952 which      were one such example of acid rain.     killed over 4,000 people had a pH       Now there is so much pollutant          value of 1.7 ( almost the strength      currently being created - about 40      of battery acid ) .The following is     million tonnes per year over Europe     a brief history of acid rain.           alone - that it returns to the                                                                                                                                                                                                                  1840 Industrial Revolution begins       to the removal of power stations        in the U.K 1850 Certain Scottish        from cities rebuilt in the country      lakes begin to become more acidic       with tall chimneys 1967 Thousands       1862 Black rain observed in             of Scandinavian lakes dead.Swedish      Scotland 1872 Acid Rain first used      scientist Svante Oden develops the      to describe rain in manchester 1880     consept of acid rain to describe        London smog kills over 1200 people      the international import / export       1911 Fish loss first observed in        of pollutants 1972 U.N Conference       Norwegian rivers.Fish losses spread     on the environment debates acid         through southern Scandinavia over       rain.Diplomatic pressure begins for     following decades.                      environmental clean up.Large                                                    research programmes start 1979          1945 Reconstruction of European         Thirty Three countries sign the         industry after World War II.Massive     Geneva Convention ,long range           industrialisation leads to doubling     transport of Air Pollutants ,           of Sulphur Dioxide and Nitrogen         deploring acid rain ,but no             Dioxide emissions over next 25          concrete measures are taken at this     years 1940s Swedes start European       time 1982 Survey shows that 7.7 %       Air Chemistry network to find out       of West German forests are damaged.     what is happening in the rain 1952      German public opinion starts to         Great London fog claims over 4,000      mobilize 1983 Revised survey shows      lives 1956 U.K Clean Air Act leads      that 34 % of West German forests                                                                                                                                                                        damaged.German pressure begins                                                  through E.C 1984 Survey shows that      AUTUMN 1991 FOREST DAMAGED BY ACID      50 % of West German forests damaged.    RAIN                                    Thirty Per Cent Club formed in          ------------------------------------    march :Ten nations belong ,             ---- Germany 58 % of forests            expanding to twenty by the autumn .     damaged Switzerland 36 % damaged        They decide to cut their emissions      Austria 17 % damaged Netherlands 52     of so2 by 30 % between 1980 and         % damaged Luxembourg 21 % damaged       1993 1987 Nordic Council scientists     Poland 8 to 41 % damaged                advocate 80 % reduction in European     Czechoslavia 28 % damaged Hungary       so2 emissions ,50 to 75 % reduction     12 % damaged France 23 % damaged        in Nitrogen Dioxide emissions 1988      Belgium 19 % on German Border           U.N figures indicate that Britians      Yugoslavia 480,000 Hectares Rumania     trees are among the most damaged in     175,000 Hectares Spain 24,000           Europe 1989 U.K acid waters review      Hectares Denmark 1,250 Hectares         group publishes evidence of                                                     acidified lakes and streams in          LAKES DAMAGED BY ACID RAIN              large areas of the U.K :and             -------------------------- Norway       comments that 90 % reduction in         37,500 square kilometres of             acid deposition is necessary to         lakeland affected ,with a loss of       return most surface waters to near      more than 55 % of the Trout             pristine conditions                     population Sweden 19,000 of 85,000                                                                                                                                                                      lakes acidified ,4,500 severely ( i.    Greece argued that its weak economy     e ..unable to support life )            prevented it from doing anything to     Scotland at least 24 major lakes        provide a solution to the growing       acidified wales Most small rivers       problem.The other non-members ..the     in central and west Wales acidified     U.K ,Eire ,Spain and portugal took      England Duddon and Usk in Cumbria ,     advantage of the clean air arriving     and parts of the lake district          from the Atlantic ,polluted it and      acidified                               then sent it over the rest of                                                   Europe ,a fact that for one ,I am       Although all countries create acid      not proud of.If the environment of      rain ,some create more than others.     Europe is to be protected ,greater      In Western Europe ,the biggest          reductions than those pledged by        polluter is Britian pumping out         the Thirty Per Cent Club are            about 20 % of the regions so2           necessary.By looking at the problem     emissions.Pouring industrial            from an enviromental prospective ,      garbage into the air is probably        scientists have now worked out how      the cheapest form of waste disposal     much Sulphur and acid pollution the     ,so long as the winds take it over      Earth can tolerate.To protect the       someone elses back yard.At this         Earth from over pollution we need       time there were still 5 western         to make a reduction of 80 to 90 %       European countries which had not        in our so2 emissions and at least a     joined the Thirty Per Cent Club .       75 % reduction in NOx emissions ,                                                                                                                                                                       maybe then we might have a chance                                               of making it to 2000                                                                                                                                                                                                                            The reason it is called acid rain is not because it is acid , but more          acidic than it should be. Acidity is measured on the pH scale , which           runs from ph 14 very alkaline , through pH 7 neutral , to pH 1 very acid.       Natural rain                                                                    has a pH 5.5 , as shown on the scale below.                                                                                                                    pH scale                                                                        < 10  9  8  7  6  5  4  3  2  1                                                  --------------------------------                                               < Alkaline <-   ^   ^     ^  ^ ^                                                                ^   ^     ^  ^ ^                                                                                                                                                ^   ^     ^  ^ Battery acid                                                     ^   ^     ^  Acid mists                                                         ^   ^     Pilochry                                                              ^   British rain                                                                Natural rain                                                                                                                                                                                                 End.