Total arsenic and speciation analysis of saliva and urine samples from individuals living in a chronic arsenicosis area in China.

BACKGROUND: It is generally acknowledged that the determination of harmful chemical compounds excreted into saliva is useful for assessing their exposure levels. The aim of the present study was to compare the total arsenic and its species in saliva and urine samples collected from the people residing in an arsenic-contaminated area of China and to further verify the feasibility of using salivary arsenic as a new biomarker of arsenic exposure. METHODS: Total arsenic and speciation analyses in urine and saliva samples among 70 residents exposed to arsenic from drinking water in Shanxi, China were carried out by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP/MS). RESULTS: The result showed that, total arsenic concentration in saliva was relatively lower than in urine samples, but it existed a strong positive correlation with total urinary arsenic, drinking water arsenic and different skin lesions. For arsenic metabolism analyses, AsIII, AsV, MMA, and DMA were detected in all of the urine samples with the dominating species of DMA (73.2%). Different with urinary arsenic species, most arsenic species in saliva were not methylated. The major species in saliva was iAs (AsIII + AsV, 76.18%), followed by DMA (13.08%) and MMA (9.13%). And the primary methylation index (PMI), second methylation index (SMI) and proportion of the four different species (AsIII, AsV, MMA, and DMA) in saliva showed no significant positive relationship with that of in urine. CONCLUSIONS: These findings indicated saliva may be used as a useful tool for biological monitoring of total arsenic exposure in the crowd rather than an efficient tool for assessing arsenic metabolism in human body after exposed to arsenic.

[Dimethylarsinous acid-promoted skin tumorigenesis through the induction of oxidative stress in mice].

OBJECTIVE: To investigated the relationship between skin-tumor promotion and oxidative stress caused by dimethylated arsenic in mice. METHODS: The experimental animal model was used to examine the effect of dimethylated arsenic, a metabolite of DMA(V), dimethylarsinous acid (DMA(III)) in skin tumorigenesis in mice. The 8-oxo-2'-deoxyguanosine (8-oxodG) analysis of epidermis was based on the method of HPLC. RESULTS: When mice were topically treated with trivalent dimethylated arsenic (DMA(III)), a further reductive metabolite of DMA(V), not only an increase in skin tumors but also an elevation of 8-oxodG in epidermis were observed. CONCLUSION: These results suggest that tumor promotion due to DMA(V) administration is mediated by DMA(III) through the induction of oxidative stress.

[Investigation and analysis of neonate deformity in water arsenic exposure areas].

OBJECTIVE: To explore the level and feature of neonate deformity in water arsenic exposure areas, as to finding out an evidence for the study and prevention of the arsenic exposure. METHODS: The birth situation of neonate was surveyed from 1998 to 2004 in water arsenic exposure areas according to cross-sectional survey. The results were classified in accordance with ICD-10 and common surveillance of china. The population of Shanyin County served as the common people and the data were analyzed by SPSS 11.5 for windows. RESULTS: The neonates surveyed were 2467 cases. There were 49 neonates deformity found in this investigation, giving a neonate deformity rate of 198.62 per 10,000 cases, which was shown significantly higher in water arsenic exposure areas than in the normal (U = 3.23, P < 0.01), with types of nervous system deformity, limbs deformity and congenital heart disease as in system classification. There was no significant difference of deformity rate in different sex neonates (chi2 = 0.32, P > 0.05). CONCLUSION: The drinking high-arsenic water over a long period of time should be a risk factor of neonate deformity. Prevention and treatment of endemic arsenic exposure should be urgently needed.

[An overview on biomarkers of arsenic-induced health hazardsan].

A series of molecular environmental epidemiological studies have been carried out to elucidate biomarkers of exposure, effect, and susceptibility for arsenic-related health hazards in Taiwan area in China. Arsenic levels in urine, hair, and nail could be biomarkers for short-term internal dose, skin hyperpigmentation and palmoplantar hyperkeratosis could be biomarkers for long-term (many years) internal dose, and percentage of monomethylarsonic acid in total metabolites of inorganic arsenic in urine could be considered as an exposure marker for biologically effective dose. The biomarkers of early biological effects of ingested inorganic arsenic could include blood levels of reactive oxidants and antioxidant capacity, genetic expression of inflammatory molecules, as well as cytogenetic changes including sister chromatid exchange, micronuclei, and chromosome aberrations of peripheral lymphocytes. Biomarkers of susceptibility to arsenic-induced health hazards could include genetic polymorphisms of enzymes involved in xenobiotic metabolism, DNA repair, and oxidative stress, as well as serum level of carotenoids. Gene-gene and gene-environment interactions could be involved in arsenic-induced health hazards through toxicological mechanisms including genomic instability and oxidative stress.

[Inhibition of (-)epigallocatechin gallate on dimethylarsinic acid promoting lung tumorigenesis through the induction of oxidative stress in mice].

OBJECTIVE: To investigate inhibition of ((-)epigallocatechin gallate, EGCG) on lung-tumor promotion and oxidative stress caused by administration of dimethylarsinic acid (DMA(V)) in mice. METHODS: The experimental animal model, which is induced by lung tumor initiator (4NQO) and promoter (DMA(V)) in mice, was used to examine the effect of EGCG on DMA(V) promoting lung tumorigenesis. The 8-oxo-2'-deoxyguanosine (8-oxodG) analysis of lungs were used of HPLC. RESULTS: The incidence of lung tumors induced by lung tumor initiator (4NQO) and promoter (DMA (V)) were, as well as 8-oxodG, suppressed by cotreatment with (-)epigallocatechin gallate (EGCG). CONCLUSION: EGCG can inhibit the tumor promotion, which is associated with its inhibition of oxidative stress induced by DMA.

Arsenic and fluoride exposure in drinking water: children's IQ and growth in Shanyin county, Shanxi province, China.

BACKGROUND: Recently, in a cross-sectional study of 201 children in Araihazar, Bangladesh, exposure to arsenic (As) in drinking water has been shown to lower the scores on tests that measure children's intellectual function before and after adjustment for sociodemographic features. OBJECTIVES: We investigated the effects of As and fluoride exposure on children's intelligence and growth. METHODS: We report the results of a study of 720 children between 8 and 12 years of age in rural villages in Shanyin county, Shanxi province, China. The children were exposed to As at concentrations of 142 +/- 106 microg/L (medium-As group) and 190 +/- 183 microg/L (high-As group) in drinking water compared with the control group that was exposed to low concentrations of As (2 +/- 3 microg/L) and low concentrations of fluoride (0.5 +/- 0.2 mg/L). A study group of children exposed to high concentrations of fluoride (8.3 +/- 1.9 mg/L) but low concentrations of As (3 +/- 3 microg/L) was also included because of the common occurrence of elevated concentrations of fluoride in groundwater in our study area. A standardized IQ (intelligence quotient) test was modified for children in rural China and was based on the classic Raven's test used to determine the effects of these exposures on children's intelligence. A standardized measurement procedure for weight, height, chest circumference, and lung capacity was used to determine the effects of these exposures on children's growth. RESULTS: The mean IQ scores decreased from 105 +/- 15 for the control group, to 101 +/- 16 for the medium-As group (p < 0.05), and to 95 +/- 17 for the high-As group (p < 0.01). The mean IQ score for the high-fluoride group was 101 +/- 16 and significantly different from that of the control group (p < 0.05). Children in the control group were taller than those in the high-fluoride group (p < 0.05); weighed more than the those in the high-As group (p < 0.05); and had higher lung capacity than those in the medium-As group (p < 0.05). CONCLUSIONS: Children's intelligence and growth can be affected by high concentrations of As or fluoride. The IQ scores of the children in the high-As group were the lowest among the four groups we investigated. It is more significant that high concentrations of As affect children's intelligence. It indicates that arsenic exposure can affect children's intelligence and growth.