The Study Of Biogeochemical Effect Mechanism In Aba Kashin-Beck Disease Areas

Kashin-Beck disease （KBD） is a violation of human articular cartilage, growthplate cartilage, leading to necrosis of the cartilage, bone, eventually end expansiondeformation of bone and joint disease, occurs mainly in children and adolescents. Inour country, Kashin-Beck disease mainly in the northeast to Tibet （ABa AutonomousRegion）a tall narrow cold zone. The geographical distribution is wide, but theecological and environmental characteristics of control, which are mainly distributedin Southeast China monsoon humid and arid zone of transition between the belt, theetiology of KBD has not been elucidated, biological environmental geochemistry thatthe disease is due to the environment of some elements missing, excess or imbalanceresult, in recent years tend to believe that the environment is low selenium KBDetiology, in addition to the poisoning of the organic compounds, food poisoning of themycotoxin, environmental factors and related virus theory etc.Aba Autonomous Region is located in Sichuan Province in the northwest, is theinfrequent high KBD ward. The etiology of KBD in the very great degree and localhydrological environment are closely related, KBD area environment geologicalconditions, especially the surface water and the prevalence rate of close ties existbetween. The thesis based on the Sichuan provincial government and the Ministry ofLand Resources which the sub-name is―the survey of the ecological geochemistry inAba Sichuan province（1212010913022）‖, identified in the water chemicalcharacteristics and elemental composition, contact the KBD in human hair elementanalysis, combined with the related pathogenic factor toxicology testing, can be apreliminary analysis of KBD biogeochemical effect mechanism, in vitro genotoxicitytests in the field of Geochemistry in the scope of application, for the toxicologicalmethods in geochemical research accumulation theory in resettlement for information, and offer a scientific proof for setting down the immigrant and digging well.The main achievements as below:1, the water in study place was mostly middle alkalinity and light mineralization.The Duke river had the highest mineralization among the all rives in search place, TheZequ river was the lowest. Water anion HCO₃^-dominant, cation Ca²⁺occupies themain status, major ion content of anionic HCO₃^->SO₄^2->Cl^-, the cations Ca²⁺>>Mg²⁺>K⁺+Na⁺,the water chemistyr’s type was HCO₃-Ca and HCO₃^-Ca Mg.2, water microelements of Fe, Co, Ni, Cd, Hg, Sr, Ba, Cu, Zn were little high, Aswas obvious enrichment, Cs and Se were lower. Zequ river Ni, Cd, Sr, Ba higher, Cs,Se lower was most obvious than other rivers. The element Cl was not different, theremaining were significant differences; microelements, As, Ba, Cr, Ni had significantdifference, Pb, Cu, Mn, Be had no statistical difference.3, in Aba Autonomous Region, Rangtang county had the highest prevalence rate;Nanmuda, Rongmuda, Gaduo, Zhongrangtang, Shangrangtang. The five townships ofprevalence rate was highest, four of them were in The Zequ river Valley, usingmultiple linear regression analysis, clustering analysis to judge the impact factor ofthe strength as well as proof that the data according to the basin of the reasonability ofthe classification, the results are as follows:The prevalence of factors affecting the maximal factor was As, TDS, Cd, K, Cs,Ni influencing factors, respectively, to X₁, X₂, X₃, X₄, X₅, X₆instead, thus can writemultiple linear regression equation was Y=0.14²⁺0.132X₁-0.001X²⁺1.700X₃-0.075X₄-0.773X₅⁺0.042X₆. Through multivariate regression coefficient of positiveand negative, can determine As, Cd, Ni had positive correlation with prevalence; TDS,K, Cs had negative correlation with prevalence. That is to say in the ABA in the fourriver region water As, Cd, Ni in higher level, KBD prevalence rate is higher; TDS, K,Cs in higher level, KBD prevalence is lower. The highest prevalence of The Zequriver Valley As, Cd, Ni levels were higher than those of the other three watersheds;while TDS, K, Cs levels were lower than those of the other three watersheds. The siximpact factors of the standardized regression coefficient absolute value to judge themon the prevalence rate of impact strength, the larger absolute value, the effect onmorbidity of more intense; otherwise the small. The factors of influence on KBDprevalence effect strength size order was As>TDS>K>Ni>Cs>Cd. Cluster analysisshowed that is very clear to classify water samples according to the above six factorsclustering, water was classified into four categories. The grouping method was areasonable classification method. 4, through the ICP-AES method for the determination of human hair samples of100patients in the10elements, the results showed that, the Aba Autonomous Region ofKBD in patients with human hair samples of As, Hg were significantly higher than inthe healthy population, on KBD had significant positive effect; while Se was lowerthan in the healthy population of KBD, had significant negative effects. While theother seven elements （Ca, Cr, F, I, Mn, Pb, Sr） in healthy individuals and patients withKBD and there was no significant difference between these elements, althoughdifferent, but to KBD produced no effect.5, using the comet assay for the detection of mercuric chloride （Hg⁺）, sodiumselenite (Se⁴⁺), mineralization （TDS） on the mutagenicity and antimutagenicity ofresults as below:（1） Mercury chloride （Hg⁺） in1g/ml above concentration to induce TK6cell DNAsingle-strand breaks, DNA damage, mercurous chloride （Hg⁺） have certainmutagenicity.（2） Sodium selenite (Se⁴⁺) in1g/ml to10g/ml doses can inhibit K2Cr2O7inducedTK6cell DNA single-strand breaks, can reduce DNA damage, sodium selenite (Se⁴⁺)concentration in a certain range antimutagenicity.（3） The degree of water mineralization in160mg/L following can induce TK6cellDNA damage, low mineralized water has certain mutagenicity.6, the in vitro micronuclei test for the detection of mercuric chloride （Hg⁺）,sodium selenite(Se⁴⁺), mineralization （TDS） on the mutagenicity and antimutagenicityof results as below:（1） mercury chloride （Hg⁺） in about10g/ml dose induced TK6cell micronucleus rateincreased role, prompting Hg⁺on chromosome has obvious damage, mercurouschloride （Hg⁺） have certain mutagenicity.（2） sodium selenite (Se⁴⁺) in1g/ml to10g/ml dose antagonist MMC inducedTK6cell micronucleus rate increased role, suggesting that Se4⁺concentration in acertain range of chromosome has obvious protection to prevent damage; but theconcentration of too much may produce cytotoxic leads cell death.（3） The degree of water mineralization in160mg/L following have induced TK6cellmicronucleus rate of increase the role of chromosome, has obvious damage effect.Combination of two methods of toxicological test, high concentrations of Hg andlow mineralized water on human cell damage, and Se in a certain concentration rangeto protect cells prevent damage; these virulence factors are probably involved in KBDpathological damage of molecular mechanisms of cartilage cell, leading to a series of pathological changes and the occurrence of cartilage cell degeneration necrosis havedirect or indirect effect. The research for the further study of KBD pathogenesis willprovide experimental basis.