ABSTRACT
Objective To study the real releasing of fluorine (F) and its effects on environmen in coalburning-borne fluorosis areas.Methods The coal,clay,briquette,cinder,fresh corn and roasted corn samples from 24 households were collected systematically in Zhaotong of City,Yunnan Province,and the F concentration in all samples was measured using the combustion hydrolysis/fluoride-ion selective electrode method,and the released amount and rate of F in briquette was calculated,and the relation between the released amount of F from briquette and the increase of F in roasted corn was analyzed.Results The F concentration of clay ranged from 266.4 to 2 536.7 mg/kg with a median of 1 087.1 mg/kg;the F concentration of briquette ranged from 115.9 to 635.0 mg/kg with a median of 308.8 mg/kg.The released amount of F in briquette ranged from 63.5 to 432.2 mg/kg with a median of 248.2 mg/kg.The releasing rate of F in briquette ranged from 30.3％ to 91.5％ with a average of 73.8％.The F concentration in fresh corn ranged from 0.43 to 2.00 mg/kg with a median of 1.31 mg/kg;the F concentration in roasted corn ranged from 2.21 to 44.88 mg/kg with a median of 10.49 mg/kg.The increased amount of roasted corn ranged 0.90 to 44.46 mg/kg.There was a significant correlation between the emission amounts of F from briquette and the F concentration in binder clay (r =0.714,P ＜ 0.01),but no correlation between the released amount of F from briquette and the increasing of F in roasted corn (r =-0.155,P ＞ 0.05).Conclusion The clay is an important source of F pollution,and the F increase in roasted corn is not only determined by the released amount of F in briquette,but also by several factors.
ABSTRACT
Objective To investigate whether there was arsenic and selenium pollution besides fluorine pollution in the capsicum and corn roasted by coal-combustion in Zhaotong fluorosis areas were collected,and the cumulation in human hair. Methods In September 2005,the capsicum and corn samples were collected before they were roasted and after roasted by coal-combustion,and the hair samples from people living in Zhaotong fluorosis areas were collected,and the fluorine,arsenic and selenium content in these samples were determined. Results The average arsenic and selenium content in the fresh capsicum not roasted by coal-combustion were 0.034 mg/kg and 0.079 mg/kg respectively. The average arsenic and selenium content in the capsicum roasted by coal-combustion were 0.463 mg/kg and 1.088 mg/kg respectively. The average arsenic and selenium content in the fresh corn were 0.019 mg/kg and 0.051 mg/kg respectively. The average arsenic and selenium content in the corn roasted by coal-combustion were 0.058 mg/kg and 0.085 mg/kg respectively. Except for the average selenium content of the capsicum roasted by coal-combustion,others were all within the limits of arsenic and selenium in foods. Conclusion There is not only fluorine pollution in the capsicum and corn roasted by coal-combustion,but also arsenic and selenium pollution. Furthermore,the selenium pollution level was higher than that of arsenic pollution. The arsenic and selenium pollution level in capsicum was higher than that in the corn. Though this arsenic pollution in the capsicum and corn may be harmful for the people living on these capsicum and corn roasted by coal-combustion to some extent,it was not harmful enough to result in arsenism. Comparing with the arsenic pollution,the selenium pollution in the capsicum and corn may be beneficial for the people eating the capsicum and corn roasted by coal-combustion.