Urinary arsenic metabolites of subjects exposed to elevated arsenic present in coal in Shaanxi Province, China

In contrast to arsenic (As) poisoning caused by naturally occurring inorganic arsenic-contaminated water consumption, coal arsenic poisoning (CAP) induced by elevated arsenic exposure from coal combustion has rarely been reported. In this study, the concentrations and distributions of urinary arsenic metabolites in 57 volunteers (36 subjects with skin lesions and 21 subjects without skin lesions), who had been exposed to elevated levels of arsenic present in coal in Changshapu village in the south of Shaanxi Province (China), were reported. The urinary arsenic species, including inorganic arsenic (iAs) [arsenite (iAsIII) and arsenate (iAsV)], monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV), were determined by high-performance liquid chromatography (HPLC) combined with inductively coupled plasma mass spectroscopy (ICP-MS). The relative distributions of arsenic species, the primary methylation index (PMI=MMAV/iAs) and the secondary methylation index (SMI=DMAV/MMAV) were calculated to assess the metabolism of arsenic. Subjects with skin lesions had a higher concentration of urinary arsenic and a lower arsenic methylation capability than subjects without skin lesions. Women had a significantly higher methylation capability of arsenic than men, as defined by a higher percent DMAV and SMI in urine among women, which was the one possible interpretation of women with a higher concentration of urinary arsenic but lower susceptibility to skin lesions. The findings suggested that not only the dose of arsenic exposure but also the arsenic methylation capability have an impact on the individual susceptibility to skin lesions induced by coal arsenic exposure.     

Monitoring of arsenic exposure with speciated urinary inorganic arsenic metabolites for ion implanter maintenance engineers

For wafer fabrication in the semiconductor industry, maintenance engineers are potentially exposed to hazards during their work of disassembling machine components for cleanup. One special concern is the presence of arsenic or arsenic compounds in the working environment. This study analyzed speciated urinary inorganic arsenic metabolites of the maintenance engineers using high-performance liquid chromatography-hydride generation atomic absorption spectrometry to study the potential arsenic exposure during their maintenance work. In total, from six wafer fabrication facilities, 30 maintenance engineers were recruited as the exposed group and another 12 office-based engineers served as the control group. First morning-voided urine samples of each study subject were collected for 7 consecutive days. The levels of total urinary inorganic arsenic metabolites for the exposed group were 1.7+/-1.4, 1.4+/-1.1, 6.2+/-6.7, 20.2+/-14.1, and 29.5+/-17.2 micro g/L for As3+, As5+, monomethylarsonic acid, dimethylarsinic acid, and total inorganic arsenic, respectively. Both the concentration of monomethylarsonic acid and its percentage in total urinary inorganic arsenic metabolites showed significantly ascending trends for the control group, for the engineers without preventative maintenance work prior to their urine sampling, and for the engineers with such work prior to their urine sampling (P<0.05 and P<0.0005, respectively). The data also suggested that, at low-level occupational arsenic exposure, the concentration of total urinary inorganic arsenic metabolites might be misleading due to the confounding effect resulting from intake of seafood, such as arsenosuger. Nevertheless, monitoring of urinary arsenic species by using the percentage change of monomethylarsonic acid in total urinary inorganic arsenic metabolites as an indicator for the verification of arsenic exposure is helpful and appropriate in such cases.     

Chronic low-level arsenic exposure reduces lung function in male population without skin lesions

Objectives

The respiratory effects of chronic low-level arsenic exposure from groundwater have been investigated in West Bengal, India.

Methods

The participants (834 non-smoking adult males) were subdivided in two groups: an arsenic-exposed group (n = 446, mean age 35.3 years) drinking arsenic-contaminated groundwater (11–50 μg/L) and a control group of 388 age-matched men drinking water containing <10 μg/L of arsenic. Arsenic in water samples was measured by atomic absorption spectroscopy. The prevalence of respiratory symptoms was documented by structured, validated questionnaire. Pulmonary function test (PFT) was assessed by portable spirometer.

Results

Compared with control, the arsenic-exposed subjects had higher prevalence of upper and lower respiratory symptoms, dyspnea, asthma, eye irritation and headache. Besides, 20.6 % of arsenic-exposed subjects had lung function deficits (predominantly restrictive and combined types) compared with 13.6 % of control (p < 0.05). A positive association was observed between arsenic concentration in drinking water and the prevalence of respiratory symptoms, while a negative association existed between arsenic level and spirometric parameters.

Conclusions

The findings suggest that even low-level arsenic exposure has deleterious respiratory effects.     

Exposure Assessment of Organochlorine Pesticides, Arsenic, and Lead in Children From the Major Agricultural Areas in Sonora, Mexico

There is a lack of information of exposure to organochlorine pesticides (OCP) and some metals, such as lead (Pb) and arsenic (As), both of which were used as arsenicals pesticides, in children living in the major agricultural areas of Mexico. The objective of this study was to assess the exposure of children to different OCP, As, and Pb in the Yaqui and Mayo valleys of Sonora to generate population baseline levels of these toxins. A cross-sectional study was undertaken in 165 children (age 6–12 years old) from 10 communities from both valleys during 2009. Blood samples were analyzed for OCP and Pb and first morning void urine for inorganic As (InAs). All of the blood samples had detectable levels of dichlorodiphenyltrichloroethylene (p,p′-DDE) ranging from 0.25 to 10.3 μg/L. However lindane, dichlorodiphenyltrichloroethane (p,p′-DDT), aldrin, and endosulfan were detected in far less of the population (36.4, 23.6, 9.1, and 3 %, respectively). Methoxychlor and endrin were not found in any sample. The average value of Pb in this population was 3.2 μg Pb/dL (range 0.17–9.0) with 8.5 % of the samples having levels <5.0 μg Pb/dL. Urinary As levels ranged from 5.4 to 199 μg As/L with an average value of 31.0 μg As/L. Levels > 50 μg/L were observed in 12.7 % of the samples. Our results show that is important to start a risk-reduction program to decrease exposure to these toxins in Mexican communities. In addition, the results can be used to establish the baseline levels of exposure to these toxins in this agricultural region and may be used as a reference point for regulatory agencies.     

砷冶炼厂工人皮肤损害与尿中砷甲基化产物的关系

目的探讨职业砷接触致皮肤病发生与尿中砷甲基化产物的关系。方法选择偏远山区冶炼厂为研究现场,暴露组为91名工人,对照组58人。监测作业场所工作岗位中砷化合物浓度,进行健康监护体检和尿砷形态分析,计算3种砷化合物百分率及一、二级甲基化指数。结果冶炼厂所有检测岗位砷化合物浓度均超过国家职业卫生标准,91名工人中36人存在明显慢性砷中毒样皮肤损害,尿中3种砷化合物(无机砷、甲基砷酸、二甲基砷酸)浓度(Log10)分别为(2.18±0.40)、(2.26±0.35)和(2.77±0.31)μg/g肌酐,明显示高于接砷但无皮肤损害的工人及对照组工人,差异均有统计学意义,冶炼厂存在皮肤损害的工人尿中甲基砷酸浓度占总砷百分率和二级甲基化指数均明显高于其他工人。结论尿中甲基化产物在冶炼厂工人皮肤损害中具有重要作用,二级甲基化指数与砷致皮肤损害有关。     

Assessing Arsenic Exposure from Consumption of Seafood from Vieques-Puerto Rico: A Pilot Biomonitoring Study Using Different Biomarkers

The various toxic effects associated with inorganic arsenic (iAs) warrants that exposure sources be identified. This pilot study evaluated if greater seafood consumption from Vieques-Puerto Rico is associated with increased exposure to iAs. Nail, hair, and urine samples were used as biomarkers of iAs exposure in adult women and men from Vieques classified as high (n = 31) and low (n = 21) seafood consumers, who reported eating fish and/or shellfish ≥1 time per week and once per month or less, respectively. The sum of urinary iAs (As III + As V), monomethylarsonic acid (MA[V]), and dimethylarsinic acid (DMA[V]), denoted as SumAs, fluctuated from 3.3 µg/g Cr (1.2 μg/L) to 42.7 μg/g Cr (42 μg/L) (n = 52). Levels of As in nail samples (n = 49) varied from 0.04 to 0.82 μg/g dry weight (dw), whereas in hair (n = 49) As was only detected in 49 % of the samples with a maximum value of 0.95 μg/g dw. None of the biomarkers of exposure to As exceeded exposure reference values for urine (50 μg/g Cr or 50 μg/L), nails (1 μg/g), or hair (1 μg/g). However, median (10.0 μg/g Cr; 10.6 μg/L) and 95th percentile (31.9 μg/g Cr; 40.4 μg/L) of urinary SumAs were higher in Vieques samples than in the those from the general population of other countries. Among the three biomarkers of exposure, nail samples reflected better the exposure to iAs from seafood consumption with significantly higher average As concentrations in high (0.24 μg/g) than low (0.12 μg/g) seafood consumers. Multivariate results for As in nail samples (R ² = 0.55, p < 0.0001) showed a positive association with fish consumption, particularly for men, with levels increasing with years of residency in Vieques.     

Relation between airborne arsenic trioxide and urinary excretion of inorganic arsenic and its methylated metabolites.

The relation between exposure to As2O3 fumes and dust, and the urinary excretion of inorganic arsenic metabolites (monomethylarsonic acid, dimethylarsinic acid, unchanged inorganic arsenic) has been studied in 18 workers from a sulphuric acid producing plant. The concentration of arsenic in the breathing zone of each worker was measured during five consecutive days and urine samples were obtained after one shift and before the next. The collection efficiency of the air sampling system exceeded 95%. The time weighted average exposure (TWA) concentrations of As2O3 ranged from 6 to 502 micrograms As/m3 and were log normally distributed. Although exposure probably occurred by ingestion as well as inhalation, statistically significant correlations (log scales) were found between airborne TWA of As2O3 and the inorganic arsenic metabolites in urine collected immediately after the shift, or just before the next shift. For a TWA of 50 micrograms As/m3, the mean concentration of the sum of the three inorganic arsenic metabolites in a postshift urine sample amounted to about 55 micrograms arsenic/g creatinine (95% confidence interval (95% CI) 47-62). Higher estimates of urinary arsenic reported by other authors are probably due either to the influence of dietary organoarsenicals when total arsenic is measured in urine or to a low retention efficiency of the air sampling system for As2O3 in the vapour phase.     

Relation between airborne arsenic trioxide and urinary excretion of inorganic arsenic and its methylated metabolites.

The relation between exposure to As2O3 fumes and dust, and the urinary excretion of inorganic arsenic metabolites (monomethylarsonic acid, dimethylarsinic acid, unchanged inorganic arsenic) has been studied in 18 workers from a sulphuric acid producing plant. The concentration of arsenic in the breathing zone of each worker was measured during five consecutive days and urine samples were obtained after one shift and before the next. The collection efficiency of the air sampling system exceeded 95%. The time weighted average exposure (TWA) concentrations of As2O3 ranged from 6 to 502 micrograms As/m3 and were log normally distributed. Although exposure probably occurred by ingestion as well as inhalation, statistically significant correlations (log scales) were found between airborne TWA of As2O3 and the inorganic arsenic metabolites in urine collected immediately after the shift, or just before the next shift. For a TWA of 50 micrograms As/m3, the mean concentration of the sum of the three inorganic arsenic metabolites in a postshift urine sample amounted to about 55 micrograms arsenic/g creatinine (95% confidence interval (95% CI) 47-62). Higher estimates of urinary arsenic reported by other authors are probably due either to the influence of dietary organoarsenicals when total arsenic is measured in urine or to a low retention efficiency of the air sampling system for As2O3 in the vapour phase.     

Assessment of occupational exposure to inorganic arsenic based on urinary concentrations and speciation of arsenic

An analytical speciation method, capable of separating inorganic arsenic (As (V), As (III] and its methylated metabolites (MMAA, DMAA) from common, inert, dietary organoarsenicals, was applied to the determination of arsenic in urine from a variety of workers occupationally exposed to inorganic arsenic compounds. Mean urinary arsenic (As (V) + As (III) + MMAA + DMAA) concentrations ranged from 4.4 micrograms/g creatinine for controls to less than 10 micrograms/g for those in the electronics industry, 47.9 micrograms/g for timber treatment workers applying arsenical wood preservatives, 79.4 micrograms/g for a group of glassworkers using arsenic trioxide, and 245 micrograms/g for chemical workers engaged in manufacturing and handling inorganic arsenicals. The maximum recorded concentration was 956 micrograms/g. For the most exposed groups, the ranges in the average urinary arsenic speciation pattern were 1-6% As (V), 11-14% As (III), 14-18% MMAA, and 63-70% DMAA. The highly raised urinary arsenic concentrations for the chemical workers, in particular, and some glassworkers are shown to correspond to possible atmospheric concentrations in the workplace and intakes in excess of, or close to, recommended and statutory limits and those associated with inorganic arsenic related diseases.     

A study of factors influencing urinary arsenic excretion in exposed workers

This study was designed to evaluate the influence of occupational and non-occupational factors on urinary arsenic excretion in workers exposed to iAs (inorganic arsenic) in the dismantlement of a factory which once produced fertilisers. We measured iAs and its methylated metabolites in 108 urinary samples of workers exposed to iAs in July 2006. A total of 13.9% of the samples showed levels higher than the Biological Exposure Index (BEI) of 35 μg/l (mean value 23.9 μg/l). After the improvement of working conditions, in August–October 2006 we collected urinary samples from each of the 108 workers enrolled. We also administrated a questionnaire, in order to investigate the influence of occupational and non-occupational factors on the urinary arsenic excretion. A significant difference was observed in relation with seafood consumption and age stratification. We have found a significant reduction of urinary arsenic excretion between the two phases of biological monitoring, probably due to appropriate hygiene work-related interventions.     

Assessment of occupational exposure to inorganic arsenic based on urinary concentrations and speciation of arsenic.

An analytical speciation method, capable of separating inorganic arsenic (As (V), As (III] and its methylated metabolites (MMAA, DMAA) from common, inert, dietary organoarsenicals, was applied to the determination of arsenic in urine from a variety of workers occupationally exposed to inorganic arsenic compounds. Mean urinary arsenic (As (V) + As (III) + MMAA + DMAA) concentrations ranged from 4.4 micrograms/g creatinine for controls to less than 10 micrograms/g for those in the electronics industry, 47.9 micrograms/g for timber treatment workers applying arsenical wood preservatives, 79.4 micrograms/g for a group of glassworkers using arsenic trioxide, and 245 micrograms/g for chemical workers engaged in manufacturing and handling inorganic arsenicals. The maximum recorded concentration was 956 micrograms/g. For the most exposed groups, the ranges in the average urinary arsenic speciation pattern were 1-6% As (V), 11-14% As (III), 14-18% MMAA, and 63-70% DMAA. The highly raised urinary arsenic concentrations for the chemical workers, in particular, and some glassworkers are shown to correspond to possible atmospheric concentrations in the workplace and intakes in excess of, or close to, recommended and statutory limits and those associated with inorganic arsenic related diseases.     

Evidence for induction of oxidative stress caused by chronic exposure of Chinese residents to arsenic contained in drinking water

Exposure of experimental animals or cultured cells to arsenic induces oxidative stress, but, to date, no examination of this phenomenon in humans has been reported. In this study we conducted a cross-sectional study in Wuyuan, Inner Mongolia, China, to explore the relationship between chronic arsenic exposure from drinking water and oxidative stress in humans. Thirty-three inhabitants who had been drinking tube-well water with high concentrations of inorganic arsenic (mean value = 0.41 mg/L) for about 18 years constituted the high-exposure group, and 10 residents who lived nearby but were exposed to much lower concentrations of arsenic in their drinking water (mean value = 0.02 mg/L) were selected as the low-exposure comparison group. Results of the present study indicated that although the activity for superoxide dismutase (SOD) in blood did not differ significantly between the two groups, the mean serum level of lipid peroxides (LPO) was significantly higher among the high-exposed compared with the low-exposed group. Elevated serum LPO concentrations were correlated with blood levels of inorganic arsenic and its methylated metabolites. In addition, they showed an inverse correlation with nonprotein sulfhydryl (NPSH) levels in whole blood. The subjects in the high-arsenic-exposure group had mean blood NPSH levels 57.6% lower than those in the low-exposure group. Blood NPSH levels were inversely correlated with the concentrations of inorganic arsenic and its methylated metabolites in blood and with the ratio of monomethylarsenic to inorganic arsenic. These results provide evidence that chronic exposure to arsenic from drinking water in humans results in induction of oxidative stress, as indicated by the reduction in NPSH and the increase in LPO. Some possible mechanisms for the arsenic-induced oxidative stress are discussed.     

Urinary arsenic concentration adjustment factors and malnutrition

This study aims at evaluating the suitability of adjusting urinary concentrations of arsenic, or any other urinary biomarker, for variations in urine dilution by creatinine and specific gravity in a malnourished population. We measured the concentrations of metabolites of inorganic arsenic, creatinine and specific gravity in spot urine samples collected from 1466 individuals, 5-88 years of age, in Matlab, rural Bangladesh, where arsenic-contaminated drinking water and malnutrition are prevalent (about 30% of the adults had body mass index (BMI) below 18.5 kg/m(2)). The urinary concentrations of creatinine were low; on average 0.55 g/L in the adolescents and adults and about 0.35 g/L in the 5-12 years old children. Therefore, adjustment by creatinine gave much higher numerical values for the urinary arsenic concentrations than did the corresponding data expressed as microg/L, adjusted by specific gravity. As evaluated by multiple regression analyses, urinary creatinine, adjusted by specific gravity, was more affected by body size, age, gender and season than was specific gravity. Furthermore, urinary creatinine was found to be significantly associated with urinary arsenic, which further disqualifies the creatinine adjustment.     

Low-level arsenic excretion in breast milk of native Andean women exposed to high levels of arsenic in the drinking water

Objective: To investigate the excretion of arsenic in breast milk of lactating native Andean women living in a village in northwestern Argentina with high concentrations of arsenic in the drinking water (about 200 μg/l) and to assess the exposure of children to arsenic during the very first period of life. Methods: The study included ten lactating women and two nursing babies. Hydride-generation atomic absorption spectrometry (HG-AAS) was used to determine the concentration of arsenic in samples of human milk, drinking water, blood, and urine. Results: The concentrations of arsenic detected in maternal blood (total arsenic) and urine (metabolites of inorganic arsenic) were high, averaging 10 and 320 μg/l, respectively. In subjects without known exposure to arsenic the average concentrations found in blood and urine are 1–2 and about 10 μg/l, respectively. The metabolites of inorganic arsenic constituted more than 80% of the total arsenic in the urine, which shows that inorganic arsenic was the main form of arsenic ingested. The average concentration of arsenic detected in human milk was 2.3 μg/kg fresh weight (range 0.83–7.6 μg/kg). Although data on background levels of arsenic in human breast milk are scarce, the present concentrations seem to be slightly elevated. However, considering the high levels of arsenic exposure in the mothers, the total arsenic concentrations measured in human milk were low. In concordance with the low concentrations of arsenic found in the milk, the concentrations of arsenic metabolites measured in the urine of two of the nursing babies were low: 17 and 47 μg/l, respectively. Conclusions: The low concentrations of arsenic detected in the breast milk and urine of the two nursing babies in relation to the high level of maternal exposure to arsenic indicate that inorganic arsenic is not excreted in breast milk to any significant extent. This is a very important reason for long breast-feeding periods. Received: 27 February 1997 / Accepted: 6 June 1997     

Association between arsenic exposure from a coal-burning power plant and urinary arsenic concentrations in Prievidza District,Slovakia

To assess the arsenic exposure of a population living in the vicinity of a coal-burning power plant with high arsenic emission in the Prievidza District, Slovakia, 548 spot urine samples were speciated for inorganic As (Asinorg), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and their sum (Assum). The urine samples were collected from the population of a case-control study on nonmelanoma skin cancer (NMSC). A total of 411 samples with complete As speciations and sufficient urine quality and without fish consumption were used for statistical analysis. Although current environmental As exposure and urinary As concentrations were low (median As in soil within 5 km distance to the power plant, 41 micro g/g; median urinary Assum, 5.8 microg/L), there was a significant but weak association between As in soil and urinary Assum(r = 0.21, p < 0.01). We performed a multivariate regression analysis to calculate adjusted regression coefficients for environmental As exposure and other determinants of urinary As. Persons living in the vicinity of the plant had 27% higher Assum values (p < 0.01), based on elevated concentrations of the methylated species. A 32% increase of MMA occurred among subjects who consumed homegrown food (p < 0.001). NMSC cases had significantly higher levels of Assum, DMA, and Asinorg. The methylation index Asinorg/(MMA + DMA) was about 20% lower among cases (p < 0.05) and in men (p < 0.05) compared with controls and females, respectively.     

Gender and age differences in the metabolism of inorganic arsenic in a highly exposed population in Bangladesh

Although genetic polymorphisms have been shown to explain some of the large variation observed in the metabolism of inorganic arsenic there may be several other factors playing an important role, e.g. nutrition. The objective of this study was to elucidate the influence of various factors on current arsenic exposure and metabolism in Matlab, a rural area in Bangladesh, where elevated water arsenic concentrations and malnutrition are prevalent. In total 1571 individuals, randomly selected from all inhabitants above 5 years of age, were investigated by measuring arsenic in urine and drinking water. In a subset of 526 randomly selected individuals, arsenic metabolites were speciated using HPLC coupled to inductively coupled plasma mass spectrometry (HPLC-HG-ICPMS). A significant association was observed between arsenic in urine and drinking water (R2=0.41). The contribution to urinary arsenic from arsenic exposure from food and other water sources was calculated to be almost 50microg/L. The individuals in the present study had remarkably efficient methylation, in spite of high exposure and prevalence of malnutrition. Gender and age were major factors influencing arsenic metabolism in this population with a median of 77microg/L of arsenic in urine (range: 0.5-1994microg/L). Women had higher arsenic methylation efficiency than men, but only in childbearing age, supporting an influence of sex hormones. Overall, exposure level of arsenic, gender and age explained at most 30% of the variation in the present study, indicating that genetic polymorphisms are the most important factor influencing the metabolism of inorganic arsenic.     

Reduction in urinary arsenic with bottled-water intervention

The study was conducted to measure the effectiveness of providing bottled water in reducing arsenic exposure. Urine, tap-water and toenail samples were collected from non-smoking adults residing in Ajo (n=40) and Tucson (n=33), Arizona, USA. The Ajo subjects were provided bottled water for 12 months prior to re-sampling. The mean total arsenic (microg/L) in tap-water was 20.3+/-3.7 in Ajo and 4.0+/-2.3 in Tucson. Baseline urinary total inorganic arsenic (microg/L) was significantly higher among the Ajo subjects (n=40, 29.1+/-20.4) than among the Tucson subjects (n=32, 11.0+/-12.0, p<0.001), as was creatinine-adjusted urinary total inorganic arsenic (microg/g) (35.5+/-25.2 vs 13.2+/-9.3, p<0.001). Baseline concentrations of arsenic (microg/g) in toenails were also higher among the Ajo subjects (0.51+/-0.72) than among the Tucson subjects (0.17+/-0.21) (p<0.001). After the intervention, the mean urinary total inorganic arsenic in Ajo (n=36) dropped by 21%, from 29.4+/-21.1 to 23.2+/-23.2 (p=0.026). The creatinine-adjusted urinary total inorganic arsenic and toenail arsenic levels did not differ significantly with the intervention. Provision of arsenic-free bottled water resulted in a modest reduction in urinary total inorganic arsenic.     

Airborne arsenic and urinary excretion of metabolites of inorganic arsenic among smelter workers

Summary The relationship between airborne concentrations of arsenic and the urinary excretion of inorganic arsenic metabolites (inorganic arsenic + methylarsonic acid + dimethylarsinic acid) have been studied among smelter workers exposed to arsenic trioxide. The urinary concentrations of arsenic metabolites were found to increase steadily during the first day of the working week (after 2–3 d off from work), whereafter they reached a steady state. The concentration in the late evening after a day of exposure was very similar to that in the early morning after. Both were well correlated to the total daily excretion. In the second part of the study, comprising 18 subjects, the first-void morning urine of each participant was collected for 2 to 3 d during the steady-state phase. Total concentration of arsenic in the breathing zones was measured by personal air samplers. Airborne arsenic (8-h values) varied between 1 and 194 g As/m³, and urinary arsenic between 16 and 328 g As/g creatinine. With the urinary arsenic concentrations (mean values of 2–3 d for each subject) plotted against the corresponding airborne arsenic concentrations, the best fit was obtained by a power curve with the equation y = 17 x x^0.56. However, four of the participants were found to excrete far more (105–260%) arsenic in the urine than possibly could have been inhaled, most likely due to oral intake of arsenic via contaminated hands, cigarettes or snuff. If these four were excluded, the best fit was obtained by a straight regression line with the slope 2.0 and the intercept 29 g As/g creatinine (coefficient of correlation 0.92; P < 0.001).     

Effects of Repeated Seafood Consumption on Urinary Excretion of Arsenic Species by Volunteers

Arsenic (As) is a known human carcinogen and widely distributed in the environment. The main route of As exposure in the general population is through food and drinking water. Seafood harvested in Korea contains high-level organoarsenics such as arsenobetaine, arsenocholine, and arsenosugars, which are much less harmful than inorganic arsenics. However, for those who eat large amounts of seafood it is important to understand whether seafood consumption affects urinary levels of inorganic As metabolites such as arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). In this study we investigated urinary As metabolites (inorganic As, MMA[V], DMA[V]) and some biological indexes such as AST, GSH, GPX, lipid peroxidation, and uric acid in volunteer study subjects (seven males and nine females). Total urinary As metabolites were analyzed by the hydride generation method, followed by arsenic speciation using HPLC with ICP-mass spectrometry. Study subjects refrained from eating seafood for 3 days prior to the first urine collection and then ingested seafood daily for 6 consecutive days. The first voided urine of the morning was collected from each subject the first day of the consecutive 6 days of seafood ingestion but prior to the first seafood meal. The first voided urine of the morning was also collected on days 1, 2, 3, 4, 5, 6, 7, 10, and 14 after seafood ingestion. The daily mean intake of total As was 6.98 mg, comprised of 4.71 mg of seaweed (67%), 1.74 mg of flat fish (25%), and 0.53 mg of conch (8%). We observed a substantial increase in total urinary As metabolites for subjects consuming seafood from day 1, which recovered to control level at day 10. The increase in total urinary As metabolites was attributed to the increase in DMA, which is a more harmful metabolite than organoarsenics. However, no significant changes in response biological indexes were observed. These results suggest that it is necessary to evaluate As metabolism when assessing the exposure to inorganic As and potential chronic health effects of seafood consumption in Korea.     

Lifetime exposure to arsenic in residential drinking water in Central Europe

Objective

Methods and results are presented for an arsenic exposure assessment integral to an epidemiological case–control study of arsenic and cancer—the European Commission funded ASHRAM (Arsenic Health Risk Assessment and Molecular Epidemiology) study carried out in some counties of Hungary, Romania and Slovakia.

Methods

The exposure history of each participant (N = 1,392) was constructed by taking into account how much water they consumed (as water, in drinks and in food), sources of drinking water in their various residences over their lifetime, and the concentrations of arsenic in their various water supplies measured by Hydride Generation-Atomic Absorption Spectrometry (HG-AAS). Concentrations of arsenic in previous water supplies were either derived from contemporary analyses of the same source, or from routine historical data from measurements performed by the authorities in each country. Using this approach, 80% of the recorded lifetime residential history was matched to an arsenic concentration. Seven indices of current, life time, and peak exposure were calculated.

Results

The exposure indices were all log-normally distributed and the mean and median lifetime average concentrations were in Hungary 14.7 and 13.3 μg l^?1, Romania 3.8 and 0.7 μg l^?1 and in Slovakia 1.9 and 0.8 μg l^?1, respectively. Overall 25% of the population had average concentrations over 10 μg l^?1 and 8% with exposure over 50 μg l^?1.

Conclusions

Careful assessment of arsenic in drinking water supplies (both current and previous) enabled the majority of study participants’ cumulative lifetime of potential exposure to arsenic in residential water to be characterised.