Correlation between hair and urinary arsenic and selenium level and seriousness of patients with arseniasis in coal-burning-borne arsenic areas / 中华地方病学杂志

ABSTRACT

Objective To investigate the relationship between levels of arsenic and selenium in hair and urine of patients with arsenic poisoning caused by coal-burning.Methods Based on the Standard of Diagnosis for Endemic Arsenism (WS/T 211-2001),about fifty arsenism or suspicious patients over 40 years old were separately selected from Haoping Town and Shuang'an Town of Ziyang County,and the high-arsenic stone coal of Haoping Town was consumed in these two towns,all patients were divided into suspicious,light,moderate,and severe groups.Five coal samples were collected from homes of patients with arsenic poisoning,which were crushed to pieces and sufficiently mixed,0.5 kg of the crushed coal was collected by quartering method to determine arsenic and selenium content;at the same time,5 water samples were collected in homes of patients with arsenic poisoning to determine arsenic and selenium content;in each investigation site,5 ploughs were selected according to the five directions as east,west,south,north and centre,to collect 15-30 cm soil of plough layer,after blending with four points method of shrinkage,1.0 kg was collected to determine arsenic and selenium content in the soil;the urine of all patients instantly and 0.5 g hair sample within 20 mm from the scalp on occiput were collected to determine arsenic and selenium content.Dual channel atomic fluorescence spectrophotometer was used to measure the arsenic and selenium content in the coal,water,soil,urine and hair samples.The contents of arsenic and selenium in coal,water and soil were expressed as （x） ± s;the contents of arsenic and selenium in urine and hair were expressed as medium (M) and quartile range (QR).Results The patients with arseniasis in moderate and severe groups from Shuang'an Town accounted for 9.8％ (5/51) of the total number of patients;the patients in moderate and severe groups from Haoping Town accounted for 39.2％ (20/51).Compared between the two towns of the proportion of arsenic poisoning clinical index,the difference was statistically significant (x2 =31.224,P ＜ 0.01).Compared between Haoping Town and Shuang'an Town,the arsenic contents of soil [(150.71 ± 127.10),(71.10 ± 22.75) mg/kg],water [(0.004 1 ± 0.000 2),(0.006 3 ± 0.000 4) mg/L],urine [0.025 2 (0.023 2),0.026 7 (0.025 6) mg/L] and hair [2.54 (3.52),2.81 (5.98) mg/kg] were not significantly different (Z =-0.913,-1.776,-0.079,-0.544,all P ＞ 0.05).The selenium contents of soil [(5.93 ± 5.76) mg/kg],water [(0.036 9 ± 0.001 8) mg/L],urine [0.056 3 (0.152 2) mg/L] and hair [3.65 (5.43) mg/kg] in Shuang'an Town were higher than those of Haoping Town [(2.41 ± 1.03) mg/kg,(0.006 1 ± 0.000 6) mg/L,0.015 6 (0.013 4) mg/L and 1.52 (2.05) mg/kg],the differences were statistically significant (Z =-2.619,-2.611,-4.765,-2.485,all P ＜ 0.01).There was a positive correlation between hair arsenic and arsenic in clinical grading (r =0.874,P ＜ 0.01);there was a negative correlation between hair selenium and arsenic in clinical grading (r =-0.400,P ＜ 0.01).Conclusions High selenium environment affects the severity of patients with arsenic poisoning,indicating that selenium may promote arsenic metabolism and reduce arsenic accumulation in vivo.Selenium may have an antagonist effect on arsenic.