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Determination of total arsenic, inorganic and organic arsenic species in wine.

Forty-five wine samples from the south of Spain of different alcoholic strength were analysed for total arsenic and its inorganic [As(III), As(V)] and organic (monomethylarsonic acid [MMAA], dimethylarsinic acid [DMAA]) species. The As levels of the wine samples ranged from 2.1 to 14.6 microg l(-1). The possible effect of the alcoholic fermentation process on the levels of the total arsenic and arsenical species was studied. The average total arsenic levels for the different samples were very similar, without significant differences between all types of wines. In table wines and sherry, the percentages of total inorganic arsenic were 18.6 and 15.6%, with DMAA or MMAA being the predominant species, respectively. In most samples, DMAA was the most abundant species, but the total inorganic aresenic fraction was considerable, representing 25.4% of the total concentration of the element. The estimated daily intakes of total arsenic and total inorganic arsenic for average Spanish consumers were 0.78 and 0.15 microg/person day(-1), respectively. The results suggest that the consumption of these types of wines makes no significant contribution to the total and inorganic arsenic intake for normal drinkers. However, wine consumption contributes a higher arsenic intake than through consumption of beers and sherry brandies.

Arsenic↗

Developmentally restricted genetic determinants of human arsenic metabolism: association between urinary methylated arsenic and CYT19 polymorphisms in children.

We report the results of a screen for genetic association with urinary arsenic metabolite levels in three arsenic metabolism candidate genes, PNP, GSTO, and CYT19, in 135 arsenic-exposed subjects from the Yaqui Valley in Sonora, Mexico, who were exposed to drinking water concentrations ranging from 5.5 to 43.3 ppb. We chose 23 polymorphic sites to test in the arsenic-exposed population. Initial phenotypes evaluated included the ratio of urinary inorganic arsenic(III) to inorganic arsenic(V) and the ratio of urinary dimethylarsenic(V) to monomethylarsenic(V) (D:M). In the initial association screening, three polymorphic sites in the CYT19 gene were significantly associated with D:M ratios in the total population. Subsequent analysis of this association revealed that the association signal for the entire population was actually caused by an extremely strong association in only the children (7-11 years of age) between CYT19 genotype and D:M levels. With children removed from the analysis, no significant genetic association was observed in adults (18-79 years). The existence of a strong, developmentally regulated genetic association between CYT19 and arsenic metabolism carries import for both arsenic pharmacogenetics and arsenic toxicology, as well as for public health and governmental regulatory officials.

Adolescent↗

Folate, homocysteine, and arsenic metabolism in arsenic-exposed individuals in Bangladesh.

Chronic exposure to arsenic is occurring throughout South and East Asia due to groundwater contamination of well water. Variability in susceptibility to arsenic toxicity may be related to nutritional status. Arsenic is methylated to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) via one-carbon metabolism, a biochemical pathway that is dependent on folate. The majority of one-carbon metabolism methylation reactions are devoted to biosynthesis of creatine, the precursor of creatinine. Our objectives of this cross-sectional study were to characterize the relationships among folate, cobalamin, homocysteine, and arsenic metabolism in Bangladeshi adults. Water arsenic, urinary arsenic, urinary creatinine, plasma folate, cobalamin, and homocysteine were assessed in 1,650 adults; urinary arsenic metabolites were analyzed for a subset of 300 individuals. The percentage of DMA in urine was positively associated with plasma folate (r = 0.14, p = 0.02) and negatively associated with total homocysteine (tHcys; r = -0.14, p = 0.01). Conversely, percent MMA was negatively associated with folate (r = -0.12, p = 0.04) and positively associated with tHcys (r = 0.21, p = 0.0002); percent inorganic arsenic (InAs) was negatively associated with folate (r = -0.12, p = 0.03). Urinary creatinine was positively correlated with percent DMA (r = 0.40 for males, p < 0.0001; 0.25 for females, p = 0.001), and with percent InAs (r = -0.45 for males, p < 0.0001; -0.20 for females, p = 0.01). Collectively, these data suggest that folate, tHcys, and other factors involved in one-carbon metabolism influence arsenic methylation. This may be particularly relevant in Bangladesh, where the prevalence of hyperhomocysteinemia is extremely high.

Adult↗

Arsenic speciation in human organs following fatal arsenic trioxide poisoning--a case report.

The aim of this investigation was to study the distribution of arsenic species in human organs following fatal acute intoxication by arsenic trioxide. The collected autopsy samples of most organs were ground and dried, and the total arsenic was measured by electrothermal atomic absorption spectrometry (ETAAS). The arsenic species--inorganic arsenic, in the form of arsenite [As(III)] and arsenate [As(V)], and its metabolites [monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)]--were quantified by ETAAS after extraction with methanol/water (1:1, by volume) and separation by HPLC. The results indicate that after acute intoxication, the liver and kidneys show the highest concentrations of total arsenic and that the total concentration in blood is 7- to 350-fold less concentrated than in organs. In all organs, As(III) is the predominant species, and MMA is more concentrated than DMA. MMA and DMA are more prevalent in lipidic organs (49% of total arsenic) compared with other organs (25% of total arsenic). As(V) was found in small quantities in the liver, kidneys, and blood.

Adult↗

Fate and bioavailability of arsenic in organo-arsenical pesticide-applied soils. Part-I: incubation study.

A laboratory incubation study was conducted to estimate geochemical speciation and in vitro bioavailability of arsenic as a function of soil properties. Two chemically-variant soil types were chosen, based on their potential differences with respect to arsenic reactivity: an acid sand with minimal arsenic retention capacity and a sandy loam with relatively high concentration of amorphous Fe/Al-oxides, considered a sink for arsenic. The soils were amended with dimethylarsenic acid (DMA) at three rates: 45, 225, and 450 mg/kg. A sequential extraction scheme was employed to identify the geochemical forms of arsenic in soils, which were correlated with the "in vitro" bioavailable fractions of arsenic to identify the most bioavailable species. Arsenic bioavailability and speciation studies were done at 0 time (immediately after spiking the soils with pesticide) and after four-months incubation. Results show that soil properties greatly impact geochemical speciation and bioavailability of DMA; soils with high concentrations of amorphous Fe/Al oxides retain more arsenic, thereby rendering them less bioavailable. Results also indicate that the use of organic arsenicals as pesticides in mineral soils may not be a safe practice from the viewpoint of human health risk.

Aluminum Oxide↗

Exposure to inorganic arsenic in drinking water and total urinary arsenic concentration in a Chilean population.

The relationship of inorganic arsenic exposure through drinking water and total urinary arsenic excretion in a nonoccupationally exposed population was evaluated in a cross-sectional study in three mayor cities of Chile (Antofagasta, Santiago, and Temuco). A total of 756 individuals in three population strata (elderly, students, and workers) provided first morning void urine specimens the day after exposure and food surveys were administered. Arsenic intake from drinking water was estimated from analysis of tap water samples, plus 24-h dietary recall and food frequency questionnaires. Multilevel analysis was used to evaluate the effects of the age group and city factors adjusted by predictor variables. Arsenic levels in drinking water and urine were significantly higher in Antofagasta compared with the other cities. City-and individual-level factors, 12% and 88%, respectively, accounted for the variability in urinary arsenic concentration. The main predictors of urinary arsenic concentration were total arsenic consumption through water and age. These findings indicate that arsenic concentration in drinking water continues to be the principal contributing factor to exposure to inorganic arsenic in the Chilean population.

Adolescent↗

Stability of arsenic metabolites, arsenic triglutathione [As(GS)3] and methylarsenic diglutathione [CH3As(GS)2], in rat bile.

Inorganic arsenicals such as arsenite (iAs(III)) and arsenate (iAs(V)) are well-known human carcinogens. Arsenic is metabolized by repetitive reduction and oxidative methylation, and is excreted mainly in urine as monomethylated arsenicals (MMAs) and dimethylated arsenicals (DMAs). Recently, it has been shown that iAs(III) administered intravenously or orally is excreted into bile as arsenic-glutathione (As-GSH) complexes such as arsenic triglutathione [As(GS)(3)] and methylarsenic diglutathione [CH(3)As(GS)(2)]. In order to carry out the speciation of As-GSH complexes, it is important to understand their stability. The present study was designed to clarify the stability of As-GSH complexes in rat bile, and the role of GSH in stabilizing these complexes. Arsenic species were separated on an anion-exchange column and were analyzed by high-performance liquid chromatography-inductively coupled argon plasma mass spectrometry (HPLC-ICP MS). As(GS)(3) and CH(3)As(GS)(2) were unstable in bile and were hydrolyzed to iAs(III) and monomethylarsonous acid (MMA(III)) in the absence of GSH. As(GS)(3) appeared to be stable in the presence of 10mM GSH. Exogenously added GSH also stabilized CH(3)As(GS)(2) in bile at the concentrations of 5mM or higher. It has been suggested that trivalent arsenicals, especially MMA(III), are more toxic than corresponding pentavalent ones. These results suggest that GSH plays an important role in preventing hydrolysis of As-GSH complexes and the generation of well-known toxic trivalent arsenicals.

Animals↗

Arsenic and other heavy metals in soils from an arsenic-affected area of West Bengal, India.

Domkal is one of the 19, out of 26 blocks in Murshidabad district where groundwater contains arsenic above 0.05 mg/l. Many millions of cubic meters of groundwater along with arsenic and other heavy metals are coming out from both the hand tubewells, used by the villagers for their daily needs and shallow big diameter tubewells, installed for agricultural irrigation and depositing on soil throughout the year. So there is a possibility of soil contamination which can moreover affect the food chain, cultivated in this area. A somewhat detailed study was carried out, in both micro- and macrolevel, to get an idea about the magnitude of soil contamination in this area. The mean concentrations (mg/kg) of As (5.31), Fe (6740), Cu (18.3), Pb (10.4), Ni (18.8), Mn (342), Zn (44.3), Se (0.53), Mg (534), V (44.6), Cr (33.1), Cd (0.37), Sb (0.29) and Hg (0.54) in fallow land soils are within the normal range. The mean As (10.7), Fe (7860) and Mg (733) concentrations (mg/kg) are only in higher side whereas Hg (0.17 mg/kg) is in lower side in agricultural land soils, compared to the fallow land soils. Arsenic concentrations (11.5 and 28.0 mg/kg respectively) are high in those agricultural land soils where irrigated groundwater contains high arsenic (0.082 and 0.17 mg/l respectively). The total arsenic withdrawn and mean arsenic deposition per land by the 19 shallow tubewells per year are 43.9 kg (mean: 2.31 kg, range: 0.53-5.88 kg) and 8.04 kg ha(-1) (range: 1.66-16.8 kg ha(-1)) respectively. For the macrolevel study, soil arsenic concentration decreases with increase of distance from the source and higher the water arsenic concentration, higher the soil arsenic at any distance. A proper watershed management is urgently required to save the contamination.

Agriculture↗

Survey of arsenic and other heavy metals in food composites and drinking water and estimation of dietary intake by the villagers from an arsenic-affected area of West Bengal, India.

An investigation of arsenic, copper, nickel, manganese, zinc and selenium concentration in foodstuffs and drinking water, collected from 34 families and estimation of the average daily dietary intake were carried out in the arsenic-affected areas of the Jalangi and Domkal blocks, Murshidabad district, West Bengal where arsenic-contaminated groundwater (mean: 0.11 mg/l, n=34) is the main source for drinking. The shallow large diameter tubewells, installed for agricultural irrigation contain an appreciable amount of arsenic (mean: 0.094 mg/l, n=10). So some arsenic can be expected in the food chain and food cultivated in this area. Most of the individual food composites contain a considerable amount of arsenic. The mean arsenic levels in food categories are vegetables (20.9 and 21.2 microg/kg), cereals and bakery goods (130 and 179 microg/kg) and spices (133 and 202 microg/kg) for the Jalangi and Domkal blocks, respectively. For all other heavy metals, the observed mean concentration values are mostly in good agreement with the reported values around the world (except higher zinc in cereals). The provisional tolerable daily intake value of inorganic arsenic microg/kg body wt./day) is: for adult males (11.8 and 9.4); adult females (13.9 and 11); and children (15.3 and 12) in the Jalangi and Domkal blocks, respectively (according to FAO/WHO report, the value is 2.1 microg/kg body wt./day). According to WHO, intake of 1.0 mg of inorganic arsenic per day may give rise to skin lesions within a few years. The average daily dietary intake of copper, nickel and manganese is high, whereas for zinc, the value is low (for adult males: 8.34 and 10.2 mg/day; adult females: 8.26 and 10.3 mg/day; and children: 4.59 and 5.66 mg/day) in the Jalangi and Domkal blocks, respectively, compared to the recommended dietary allowance of zinc for adult males, adult females and children (15, 12 and 10 mg/day, respectively). The average daily dietary intake of selenium microg/kg body wt./day) is on the lower side for the children (1.07 and 1.22), comparable for the adult males (0.81 and 0.95) and slightly on the higher side for the adult females (1.08 and 1.26), compared to the recommended value (1.7 and 0.9 microg/kg body wt./day for infants and adults, respectively).

Adolescent↗

Increase in rice grain arsenic for regions of Bangladesh irrigating paddies with elevated arsenic in groundwaters.

Concern has been raised by Bangladeshi and international scientists about elevated levels of arsenic in Bengali food, particularly in rice grain. This is the first inclusive food market-basket survey from Bangladesh, which addresses the speciation and concentration of arsenic in rice, vegetables, pulses, and spices. Three hundred thirty aman and boro rice, 94 vegetables, and 50 pulse and spice samples were analyzed for total arsenic, using inductivity coupled plasma mass spectrometry (ICP-MS). The districts with the highest mean arsenic rice grain levels were all from southwestern Bangladesh: Faridpur (boro) 0.51 > Satkhira (boro) 0.38 > Satkhira (aman) 0.36 > Chuadanga (boro) 0.32 > Meherpur (boro) 0.29 microg As g(-1). The vast majority of food ingested arsenic in Bangladesh diets was found to be inorganic; with the predominant species detected in Bangladesh rice being arsenite (AsIII) or arsenate (AsV) with dimethyl arsinic acid (DMAV) being a minor component. Vegetables, pulses, and spices are less important to total arsenic intake than water and rice. Predicted inorganic arsenic intake from rice is modeled with the equivalent intake from drinking water for a typical Bangladesh diet. Daily consumption of rice with a total arsenic level of 0.08 microg As g(-1) would be equivalent to a drinking water arsenic level of 10 microg L(-1).

Arsenates↗

Tissue distribution of arsenic after subcutaneous implantation of arsenic trioxide pellet in rats.

In control rats, the arsenic level in the spleen and blood cells was 1.59 and 10.79 microgram/g wet tissue, respectively. In the kidney, lung, heart, brain, and hair, the arsenic level was lower than 1.1 microgram/g wet tissue. In rats in which a pellet containing 2 mg of arsenic tsioxide was implanted subcutaneously, the arsenic level in the spleen and blood cells was markedly high for at least 2 months after implantation; after 67 days of implantation, the arsenic level in the spleen and blood cells was 16.79 and 66.34 microgram/g wet tissue, respectively. In the kidney, liver, lung, heart, brain, and hair, the increase in arsenic after implantation was smaller than that in the spleen. In the plasma, arsenic was not detected before and after arsenic implantation. It is concluded that arsenic implanted subcutaneously concentrates in the blood cells, possibly in the red cells, in rats.

Animals↗

Urinary excretion of arsenic metabolites after long-term oral administration of various arsenic compounds to rats.

The metabolism of arsenic compounds in rats was studied by comparing urinary metabolites of arsenic compounds administered for 1 wk or 7 mo. Male F344/DuCrj rats were given 100 mg As/L as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), trimethylarsine oxide (TMAO), or arsenobetaine (AsBe), or 10 mg As/L as arsenite [As(III)] via drinking water for 7 mo. Urine was collected by forced urination after 1 wk or 7 mo. Arsenic metabolites in urine were analyzed by ion chromatography with inductively coupled plasma mass spectrometry. In the case of As(III) ingestion, a small portion of all arsenic excreted in urine (about 6%) was excreted in inorganic form, while most arsenic was excreted as methylated arsenic metabolites. Following MMA treatments for 1 wk or 7 mo, the predominant products excreted were unchanged MMA and DMA accompanied by small amounts of TMAO and tetramethylarsonium (TeMA). In the case of DMA treatment the urinary compounds found were mainly the parent DMA and TMAO with minute amounts of TeMA. TMAO was methylated to TeMA to a slight extent after 1 wk and 7 mo of administration, although most TMAO was excreted in the form of unchanged TMAO. AsBe was predominantly eliminated in urine without any transformation. Two unidentified metabolites were detected in urine after 7 mo of arsenic species exposure; the amounts of these metabolites increased in the order DMA > MMA > TMAO with only small quantities of these detected in the As(III)-treated group. These results suggest that these unidentified metabolites are formed during a demethylation process, and not during methylation. Our findings indicate that long-term exposure to As(III), MMA, or DMA decreases the proportion of TMAO elimination in urine and increases that of DMA, M-1, and M-2, and that further methylation to TMAO to TeMA does occur to a slight extent following long-term exposure to arsenical compounds in rats.

Administration, Oral↗

[Metabolism of arsenic (15). Influence of arsenic antidotes on intestinal absorption of arsenic trioxide].

A loop ligated at both sides was made in the ilecoecal portion of rabbit intestine. As2O3 solution was infused into this loop and the blood circulating around this loop was collected from the cannulated vein. As2O3 content absorbed in blood as well as that remaining in this loop were determined. In control rabbits on no drugs, approx. 30% of As2O3 infused was absorbed into the blood in 60 minutes. However, in rabbits on parenteral dimercaprol (BAL) or thioctic acid (TA), the content of As2O3 absorbed into the blood decreased remarkably while the content of As2O3 remaining in the loop increased. On the other hand, even when BAL or TA were added directly into thip loop containing As2O3, the content of As2O3 absorbed in blood decreased markedly, compared with that of the control group. Thus it was demonstrated that BAL or TA combined with AsO3(3-) after being excreted into the intestinal tract from the bile-duct, bringing about inhibition of the enteral absorption of As2O3.

Animals↗

Spatial dependency of Buruli ulcer prevalence on arsenic-enriched domains in Amansie West District, Ghana: implications for arsenic mediation in Mycobacterium ulcerans infection.

BACKGROUND: In 1998, the World Health Organization recognized Buruli ulcer (BU), a human skin disease caused by Mycobacterium ulcerans (MU), as the third most prevalent mycobacterial disease. In Ghana, there have been more than 2000 reported cases in the last ten years; outbreaks have occurred in at least 90 of its 110 administrative districts. In one of the worst affected districts, Amansie West, there are arsenic-enriched surface environments resulting from the oxidation of arsenic-bearing minerals, occurring naturally in mineral deposits. RESULTS: Proximity analysis, carried out to determine spatial relationships between BU-affected areas and arsenic-enriched farmlands and arsenic-enriched drainage channels in the Amansie West District, showed that mean BU prevalence in settlements along arsenic-enriched drainages and within arsenic-enriched farmlands is greater than elsewhere. Furthermore, mean BU prevalence is greater along arsenic-enriched drainages than within arsenic-enriched farmlands. CONCLUSION: The results suggest that arsenic in the environment may play a contributory role in MU infection.

Journal Article↗