Study On Relationship Between Fluorosis And Hydro-geochemical Of Endemic Fluorosis Area In West Of JiLin Province

Fluorine is one of the necessary trace elements for human health. The appropriateconcentration of fluorine in drinking water is0.5-1.0mg/l, outside this range will haveill effects. High fluoride containing groundwater is the groundwater which fluorideconcentration is higher than national sanitary standard for drinking water and makespeople have fluorosis.While the level of fluorine is not the only factor effectting onthe fluorosis rate, this article analysised the relationship between the fluorosis and thefluorine, all kinds of chemistry elements forms in different groundwaterhydrodynamics conditions and found some regularity and irregularity conclusions.â‘´The uniformity between fast or slow of groundwater flow and mild or seriousof fluorosis.From intake area passes through runoff area to catchment area,the degree offluorosis,has gradually changed from mild to serious along with the changing of flowof groundwater from fast to slow,and the content of ion fluorine (F-) is from65.7percent of fluoride (F) increasing to85percent of it.Although,the dynamic conditionof groundwater which we should not considered it as an essential factor to cause thechanging on degree of fluorosis and redistribution of substance,but it is merely animportant environmental factor.⑵It may be correlation or not among the degree of fluorosis and the contentfluoride (F) or ion fluorine (F-).A conclusion that it is positive correlation between the degree of fluorosis(included dental and skeletal fluorosis) and the content of fluoride (F) have beengenerally accepted in china and abroad.Because there are two questions have not beenpaid attention by some researchers,the questions are as follows:It had not to make a systematic study for the hydrogeological conditions in thecourse to study fluorosisï¼›and do not study the chemical forms of fluorine. First,proceed from point of view of groundwater system,we have studied respectivelythose relationships among hydrogeochemical comditions and fluorosis in intake area, runoff area as well as catchment area of groundwater,and then,have calculatedrespectively the chemical form of elements according to the system of fluoride (F),HCO₃,SO₄and CL. The results are (a) The high fluoride water (F>1mg/l) in theintake area can not to cause fluorosis or only caused a few mild dental fluorosis,andthe content of fluoride does not correlation with fluorosis in the runoff area,and arising tend for the degree of fluorosis along with increasing of content of fluoride incatchment area but it has not statistical significance.And (b) on ion fluorine (F-)whichhave occurred a rising tend along with the dental fluorosis,but not clear for skeletalfluorosis in runoff area;and clear positive correlation for dental and skeletal fluorosisin catchment area.According to the calculation of geochemical thermodynamics,element Ca in runoff area which is60percent of all positive ions, with ion form Ca²⁺occurred mainly in groundwatwer and limited to absorb the fluoride and ion fluorinewith its ion force action. Ion form magnesium (Mg²⁺) had have same action as Ca²⁺.This is a such hydrogeochemical area to limit the toxicity of fluoride and ion fluorine,therefore where they are not correlation with the fluorosis and the content of ionfluorine (F-) is65.7percent of fluoride In the catchment aera,where the content ofmany elements have greatly increased and changed into a special hydroghocemicalfield withHCO3, Cl-,Na+and Ca²⁺as main parts. Among positive ion, the ion Na+is80-90%of element Na, Ca²⁺in30-40percent of element Ca; among the negative ions,SO2-4more than95%of total SO₄and CL-in20-30%of total CL. A comparison of ionsintensity bassed on the resistance system with Mg²⁺andSO₄^2-as dominant andcoordination system with Na+as dominant, which their strength are at balance state,so it is positive correlation among the fluorosis with content of fluoride and ionfluorine.⑶The rate F(mg/1)/Ca+Mg(mot/l-%) can be used as a essential criterion tojudge the groundwater whether causing fluorosis or not.Based on the statistics of a great number of data in different dynamic area ofgroundwater flow in a large region show that the ratio is0.0013--0.0015. This ratio issuitable for different areas of dynamic condition. â‘·Under the control of the hydrogeochemical condition the relationship ofresistance and coordination of other elements to fluoride and fluorine cantransformation.The view that Ca and Mg can resist to fluoride and Na can cooperate to fluoridehas been widely accepted all over the world,.and the action will be controlling allcourse indifferent content of them. But our result show that this relationship willchange along with the changing of hydrogeochemical conditions, for example, incatchment area, the skeletal fluorosis occurrence are negative correlation with elementNa, ion form Na⁺and Ca²++Mg²⁺in certain area. Ca²⁺+Mg²⁺with capacity ofresistance have get a stronger ion force and take it to counteract the coordinationcapacity of Na⁺. In addition, Na⁺can combine with HCO-into NaHCO, andprecipitated down, as a result,the correlation between the Na+and the prevelance ratehave been changed to negative correlation. In the runoff area, there is a positivecorrelation relation between the content of etement Ca and the skeletal fluorosis,because where a grest quantily of ion form Ca²⁺have been combined with Cl-intoCaCl2which resulted and in decrease of the content Ca²⁺and its resistance capacity.This effect have advanced that the element F changed into ion form F-, so the positivecorrelation between them is actually a pseudomorph.⑸The thermodynamic method of geochemistry is a scientific and economicmethod for quantitative and nearly quantitative appraisal the:relation among fluoride(F) and fluorine (F-) with fluorosis.Under many condition, someone does not intresting on the relation betweengeochemistry and fluorosis, but they are always to pay great attention on the relationbetween fluorosis and the content of fluoride therefore have made an unreasonableconclusion that relation between them is always positive correlation, but the fact isthat fluorfine (F-) and (F) can not to be absorbed fully by human body,because whichthey are affected by Ca²⁺,Mg²⁺,Cl,HCO3,SO₄^2-, Fe,Al SiO2and even trace elements,therefore After determining the chemical form of elements, especially these ofmacro--element, we can make appraisal them in quantitative and nealy qauntitative. ⑹When we study the relation between fluorosis and content of fluoride fordrinking water, except considering content of fluoride and fluorine, have to acomprehensive research and:appraisal for content of each element and it chemicalform in every hydrogeochemical field.⑺Under the control of hydrogeologic condiction,the correlation between thefluorosis and the content of trace, element can change, while On the effect of elementto fluoride absorbed, macro-elements are larger than trace elements.