Urinary Inorganic Arsenic Concentration Research Articles

Urinary arsenic and spontaneous pregnancy loss – a hypothesis-generating case-control investigation in western Romania

Arsenic occurs as a natural contaminant of drinking water supplies in arsenic endemic areas, posing a threat to public health. Our aim was to evaluate the relationship between urinary arsenic concentrations and spontaneous pregnancy loss in a population with low-moderate level drinking water arsenic exposure (mostly <10 μg/L). We enrolled 150 women with incident spontaneous pregnancy losses and 150 controls with ongoing pregnancies matched by gestational age. We measured arsenic species in urine using high performance liquid chromatography paired to inductively coupled plasma mass spectrometry. Urinary arsenic was not related to spontaneous pregnancy loss in conditional logistic regression models adjusted for confounding factors. However, a 10 μg/L increase in urinary arsenic (III + V) salt concentrations was associated with 8.00-fold (95% CI: 0.68, 3.35 × 105) greater odds of spontaneous loss among women using prenatal vitamins in an interaction model (P for interaction = 0.07), although the effect estimate was imprecise. In an additional interaction model, prenatal vitamin use was associated with lower odds of loss (OR = 0.30; 95% CI: 0.13, 0.66), although the association was diminished in the presence of a 10 μg/L increase in urinary inorganic arsenic (OR = 0.44; 95% CI: 0.70, 3.22). Total urinary arsenic was associated with 1.48-fold (95% CI: 0.20, 11.35) greater odds for loss among women with urinary cotinine >50 μg/L in another interaction model (P for interaction = 0.07). These results suggest a potential modest increase in the odds of pregnancy loss associated with increased total urinary arsenic among women smoking during pregnancy (urinary cotinine >50 μg/L). Prenatal vitamin use may act as a protective factor for arsenic exposure associated pregnancy loss, but appears to be less protective with increasing urinary inorganic arsenic concentrations.

Associations of total urinary arsenic with total cholesterol and high-density lipoprotein among 12-17-year-old participants from the 2009-2016 NHANES cycles: A cross-sectional study.

Hypertension and diabetes are highly prevalent among US adults. Arsenic exposure is associated with these cardiometabolic morbidities but the relationship between arsenic exposure and cholesterol markers of cardiometabolic disease has not been elucidated, especially at younger ages, when many chronic diseases may initiate. This study examined the association of total urinary arsenic with total cholesterol (TC) and high-density lipoprotein cholesterol (HDL) and explored effect modification by weight status. The study sample consisted of 12-17-year-old participants with complete data from the 2009-2016 National Health and Nutrition Examination Survey cycles. The cross-sectional associations of creatinine-adjusted total urinary arsenic with TC and HDL were assessed using multivariable linear regression models with survey weights. Three models were built, adjusting for varying combinations of age, gender, race/ethnicity, weight status, survey cycle, family income to poverty ratio, reference person education level, arsenobetaine, and dimethylarsinic acid (DMA). Model adjustments for arsenobetaine approximated inorganic arsenic exposure, and further adjustment for DMA approximated unmethylated inorganic arsenic exposure. We also explored weight status (underweight/healthy, overweight, and obese) as a potential effect modifier of these relationships using stratified analyses and interaction tests. The final analytical sample consisted of 1,177 12-17-year-old participants. After adjusting for covariates and arsenobetaine, creatinine-adjusted arsenic was positively associated with HDL levels (β=0.063; 95% CI: 0.007, 0.119). Upon further adjustment for DMA, creatinine-adjusted arsenic was positively associated with HDL levels (β=0.079; 95% CI: 0.015, 0.143) and TC levels (β=0.258; 95% CI: 0.002, 0.515). No effect modification by weight status was observed. We found a positive association of approximated unmethylated inorganic arsenic exposure with TC, and contrary to our expectation, with HDL. There was no effect modification by weight status. Our findings should be confirmed by conducting longitudinal studies among adolescents exposed to low-level arsenic and focusing specifically on urinary inorganic arsenic concentrations.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Cohort profile: health effects monitoring programme in Ndilǫ, Dettah and Yellowknife (YKHEMP)

PurposeThe Yellowknife Health Effects Monitoring Programme (YKHEMP) was established to examine the relationship of exposure to arsenic and other chemicals of potential concern such as antimony, cadmium, lead, manganese and...

Urinary Inorganic Arsenic Concentration and Attention Deficit-Hyperactivity Disorder: A Population-Based Analysis in Arica, Chile

Urinary Inorganic Arsenic Concentration and Attention Deficit-Hyperactivity Disorder: A Population-Based Analysis in Arica, Chile

Factors Associated with Low Level of Urinary Inorganic Arsenic Concentration

Introduction: Population in Arica's city has been exposed to arsenic of natural and anthropogenic origin. In 2009, an environmental health center was created in order to surveillance exposure to polimetals, provide medical care to exposed population and propose intervention measures. Objective: To assess factors that predict the urine arsenic concentration in population served at the environmental health center in the period 2009-2015. Method: The population analyzed was recruited at the environmental health center of Arica, Chile between 2009 and 2015. The database provided included sociodemographic information, dwelling characteristics, urinary inorganic arsenic concentration and creatinine. We conduct linear regression analysis to assess association with variables included in final model. Results: Complete data was available for 10.437 people. The geometric mean of inorganic arsenic was 17.4 &amp;#956;g/L (min 1.99, max 477 &amp;#956;g/L). The variables that explained the urine inorganic arsenic concentration were urinary creatinine (&amp;#946; 1.86 CI95% 1.82-1.91), alcohol consumption (&amp;#946; 1.24 CI95% 1.00-1.53), drinking water consumption (&amp;#946; 1.07 CI95% 1.04-1.11), the household material (&amp;#946; 1.10 CI95% 1.03-1.17) and the soil discovered in yard (&amp;#946; 1.01 CI95% 1.00-1.10). Conclusion: Although we identified variables that were significantly associated with urine arsenic concentration, they explain in a low proportion the arsenic variability. It is necessary to extend the study to identify variables that allow propose intervention measures to reduce exposure.

Urinary Inorganic Arsenic Concentration and Type 2 Diabetes Mellitus and Hypertension Development: A Population-Based Analysis in Arica, Chile

Introduction: Studies that evaluated the association between type 2 diabetes mellitus and hypertension has been consistent in population exposed to high levels of arsenic. However, the evidence is no clear regarding low levels of exposure. The aim of this study was to explore the association between the concentration of inorganic arsenic in urine and the development of type 2 diabetes mellitus and hypertension. Methods: Data analysis of 10.340 individuals over the age of 14, of the population register of people exposed to polymetals, evaluated between 2009 and 2015. Outcome variable: Self-report of diagnosis of type 2 diabetes mellitus (T2DM) and hypertension (HBP). Exposure variable: Concentration of inorganic arsenic in urine. To evaluate association, we used multiple logistic regression models adjusted for creatinine, age, and body mass index. Results: Average age 40 years. The prevalence of diabetes was 8% (CI95% 0.073-0.085) and hypertension 15% (CI95% 0.143-0.159), (31% lost data). The median of inorganic arsenic was 18 &amp;#956;g/L (p25-p75 11-27 &amp;#956;g/L). The adjusted model showed a modest association between inorganic arsenic and T2DM (OR: 1.008, 95% CI 1.003-1.013). Regarding the relationship with HBP, the association was not significant (OR: 0.99, IC95% 0.993-1.004). Conclusion: The results support the hypothesis that low levels of arsenic exposure could be associated with T2DM; however, should be considered with caution due limitations as the way of measuring the outcome variable, the % of lost data and the lack of information from other confounding.

Urinary Inorganic Arsenic Concentration and Gestational Diabetes Mellitus in Pregnant Women from Arica, Chile

Introduction: The association of total arsenic exposure with impaired glucose tolerance and gestational diabetes has been shown; however, evidence regarding urinary inorganic arsenic in pregnant women is still limited. Our aim was to evaluate the association between urinary inorganic arsenic concentration and gestational diabetes among pregnant women living in Arica, Chile. Methods: Cross-sectional study of pregnant women receiving care at primary health centers in urban Arica. The exposure was urinary inorganic arsenic concentration, while gestational diabetes was the outcome. The association was evaluated using multiple logistic regression models adjusted by age, education level, ethnicity, and pre-pregnancy body mass index. Results: 244 pregnant women were surveyed. The median urinary inorganic arsenic was 14.95 μg/L, and the prevalence of gestational diabetes was 8.6%. After adjusting, we did not find a significant association between gestational diabetes and inorganic arsenic exposure tertiles (Odds ratio (OR) 2.98, 95% CI = 0.87–10.18), (OR 1.07, 95% CI = 0.26–4.33). Conclusion: This study did not provide evidence on the relationship between urinary inorganic arsenic concentration and gestational diabetes. Further research is needed to elucidate the factors underlying this association.

Urinary arsenic species concentration in residents living near abandoned metal mines in South Korea.

BackgroundArsenic is a carcinogenic heavy metal that has a species-dependent health effects and abandoned metal mines are a source of significant arsenic exposure. Therefore, the aims of this study were to analyze urinary arsenic species and their concentration in residents living near abandoned metal mines and to monitor the environmental health effects of abandoned metal mines in Korea.MethodsThis study was performed in 2014 to assess urinary arsenic excretion patterns of residents living near abandoned metal mines in South Korea. Demographic data such as gender, age, mine working history, period of residency, dietary patterns, smoking and alcohol use, and type of potable water consumed were obtaining using a questionnaire. Informed consent was also obtained from all study subjects (n = 119). Urinary arsenic species were quantified using high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP/MS).ResultsThe geometric mean of urinary arsenic (sum of dimethylarsinic acid, monomethylarsonic acid, As3+, and As5+) concentration was determined to be 131.98 μg/L (geometric mean; 95% CI, 116.72–149.23) while urinary inorganic arsenic (As3+ and As5+) concentration was 0.81 μg/L (95% CI, 0.53–1.23). 66.3% (n = 79) and 21.8% (n = 26) of these samples exceeded ATSDR reference values for urinary arsenic (>100 μg/L) and inorganic arsenic (>10 μg/L), respectively. Mean urinary arsenic concentrations (geometric mean, GM) were higher in women then in men, and increased with age. Of the five regions evaluated, while four regions had inorganic arsenic concentrations less than 0.40 μg/L, one region showed a significantly higher concentration (GM 15.48 μg/L; 95% CI, 7.51–31.91) which investigates further studies to identify etiological factors.ConclusionWe propose that the observed elevation in urinary arsenic concentration in residents living near abandoned metal mines may be due to environmental contamination from the abandoned metal mine.Trial registrationNot Applicable (We do not have health care intervention on human participants).

Abstract P064: Inverse Associations Between Inorganic Arsenic and Obesity: Findings From the National Health and Nutrition Examination Survey

Introduction: Arsenic is ubiquitous in the environment as an element of the earth’s crust. Human exposure predominantly occurs through ingestion of contaminated drinking water and arsenic-rich foods such as seafood and rice. Chronic exposure to inorganic arsenic has been associated with certain cancers, and more recently with cardiovascular disease and diabetes that are common among the obese. However, little is known about the specific relationship between inorganic arsenic exposure and obesity. Hypothesis: We assessed the hypothesis that inorganic arsenic exposure was correlated with obesity in the general population of the United States. Methods: We analyzed a representative sample of 4,105 adults from the U.S. population using data from the 2007-2010 National Health and Nutrition Examination Survey (NHANES). Arsenobetaine and arsenocholine concentrations, which are forms of organic arsenic, were subtracted from total urinary arsenic concentrations to estimate the amount of inorganic arsenic in urine as a biomarker of exposure. These values were standardized by urinary creatinine to control for hydration status. Obesity was assessed using measured body mass index (BMI) in kg/m 2 and waist circumference in cm. Crude and adjusted survey-weighted linear regression models were performed. Results: Creatinine-adjusted urinary inorganic arsenic concentrations were inversely associated with log-transformed BMI (p for trend = 0.0003) and log-transformed waist circumference (p for trend = 0.0001). The highest quintile of inorganic arsenic concentration (&gt;10.4 to 483.3 μg/L) was associated with a 5% (95% CI: 3 to 8%) lower BMI and a 4% (95% CI: 2 to 6%) smaller waist circumference compared to the lowest quintile (0 to 2.3 μg/L). Adjustments for age, gender, race, thyroid problems, diabetes, smoking status, seafood consumption, rice consumption, red blood cell folate, serum folate, socioeconomic status, and survey cycle did not appreciably alter these results. There was no evidence of effect modification between urinary inorganic arsenic concentrations and covariates on obesity. Conclusions: While inorganic arsenic exposure has generally been positively associated with obesity-related diseases, we observed a negative association between urinary inorganic arsenic concentrations and obesity in this representative cross-sectional analysis. It is unclear if this is a true association in which inorganic arsenic exposure is protective against obesity, or if this finding reflects differential arsenic absorption, metabolism, or storage by adiposity level.

A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations.

The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m(3) of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m(3) iAs exposure, respectively.

Urinary inorganic arsenic concentrations and semen quality of male partners of subfertile couples in Tokyo

ABSTRACTInorganic arsenic (iAs) has been known as a testicular toxicant in experimental rodents. Possible association between iAs exposure and semen quality (semen volume, sperm concentration, and sperm motility) was explored in male partners of couples (n = 42) who visited a gynecology clinic in Tokyo for infertility consultation. Semen parameters were measured according to WHO guideline at the clinic, and urinary iAs and methylarsonic acid (MMA), and dimethylarsinic acid concentrations were determined by liquid chromatography-hydride generation-ICP mass spectrometry. Biological attributes, dietary habits, and exposure levels to other chemicals with known effects on semen parameters were taken into consideration as covariates. Multiple regression analyses and logistic regression analyses did not find iAs exposure as significant contributor to semen parameters. Lower exposure level of subjects (estimated to be 0.5 μg kg−1 day−1) was considered a reason of the absence of adverse effects on semen parameters, which were seen in rodents dosed with 4–7.5 mg kg−1.

Arsenic methylation capacity and obesity are associated with insulin resistance in obese children and adolescents

The goal of the present study was to compare the arsenic methylation capacities in elementary school and junior high school students in an area of Taiwan with low arsenic exposure, and explore the influence of both arsenic methylation capacity and obesity on insulin resistance in these children and adolescents using the HOMA-IR index. We recruited 303 elementary school students and 319 junior high school students in Taipei City from September 2007 to November 2011. Concentrations of inorganic arsenic (arsenite + arsenate), monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) were determined by a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Insulin resistance was determined by HOMA-IR. Elementary school students had significantly lower inorganic arsenic percentage and a higher DMAV percentage than junior high school students. It seems that the former had better arsenic methylation capability than the latter. The HOMA-IR value was significantly and positively related to the sum of the urinary inorganic and methylated arsenic (TotalAs) concentrations and also the BMI Z score, with the regression coefficients (β) being 0.058 (p < 0.001) and 0.001 (p = 0.027), respectively. The higher BMI values and higher TotalAs concentration were associated with higher HOMA-IR values in children and adolescents in Taiwan.

Differential DNA Methylation in Umbilical Cord Blood of Infants Exposed to Low Levels of Arsenicin Utero

Background: There is increasing epidemiologic evidence that arsenic exposure in utero, even at low levels found throughout much of the world, is associated with adverse reproductive outcomes and may contribute to long-term health effects. Animal models, in vitro studies, and human cancer data suggest that arsenic may induce epigenetic alterations, specifically by altering patterns of DNA methylation.Objectives: In this study we aimed to identify differences in DNA methylation in cord blood samples of infants with in utero, low-level arsenic exposure.Methods: DNA methylation of cord-blood derived DNA from 134 infants involved in a prospective birth cohort in New Hampshire was profiled using the Illumina Infinium Methylation450K array. In utero arsenic exposure was estimated using maternal urine samples collected at 24–28 weeks gestation. We used a novel cell mixture deconvolution methodology for examining the association between inferred white blood cell mixtures in infant cord blood and in utero arsenic exposure; we also examined the association between methylation at individual CpG loci and arsenic exposure levels.Results: We found an association between urinary inorganic arsenic concentration and the estimated proportion of CD8+ T lymphocytes (1.18; 95% CI: 0.12, 2.23). Among the top 100 CpG loci with the lowest p-values based on their association with urinary arsenic levels, there was a statistically significant enrichment of these loci in CpG islands (p = 0.009). Of those in CpG islands (n = 44), most (75%) exhibited higher methylation levels in the highest exposed group compared with the lowest exposed group. Also, several CpG loci exhibited a linear dose-dependent relationship between methylation and arsenic exposure.Conclusions: Our findings suggest that in utero exposure to low levels of arsenic may affect the epigenome. Long-term follow-up is planned to determine whether the observed changes are associated with health outcomes.

A Guillain‐Barré Syndrome‐like Neuropathy Associated with Arsenic Exposure

We report on a patient presenting with an isolated polyneuropathy mimicking Guillain-Barré syndrome (GBS) associated with arsenic exposure. A 43-year-old man visited our emergency room complaining of progressive quadriparesis over the prior 5 days. His clinical course with laboratory data was typical of GBS. However, because of his recent use of herbal medication, we screened for the presence of several heavy metals. Serial analyses of urinary inorganic arsenic concentrations confirmed exposure to arsenic. He was diagnosed as arsenic neuropathy mimicking GBS without any systemic manifestation of arsenic intoxication. The present case study emphasizes the need to consider arsenic intoxication in patients presenting with acute demyelinating neuropathies and histories of herbal medication use.

Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

Risk factors for increased urinary inorganic arsenic concentrations from low arsenic concentrations in drinking water

A large number of drinking water supplies worldwide have greater than 50 μg l − 1 inorganic arsenic in drinking water, and there is increasing pressure to reduce concentrations. Few studies have specifically considered low concentrations of arsenic in water supplies and the significance of other factors which may contribute to increased exposure. This study aimed to investigate risk factors for increased urinary inorganic arsenic concentrations, in a population exposed to 10 - 100 μg l − 1 of arsenic in drinking water, as well as a control population with lower arsenic concentrations in their drinking water. Inorganic arsenic in urine was used as the measure of exposure. The median drinking water arsenic concentration in the exposed population was 43.8 μg l − 1 (16.0 - 73 μg l − 1) and less than the analytical limit of detection of 1 μg l − 1 ( < DL) (range < DL − 8.0 μg l − 1) in the control group. The geometric mean urinary inorganic arsenic concentration for the exposed group was 4.24 μg l − 1 (range < DL − 18.8 μg l − 1) and for the control group was 1.18 μg l − 1 ( < DL − 4.49 μg l − 1). In a random effects linear regression model, drinking water was the significant predictor of urinary inorganic arsenic concentrations with factors such as age, season and drinking water consumption important risk factors. These results show that concentrations of arsenic in drinking water, even at lower concentrations, make an important contribution to exposure. Further work is required to define the potential for absorption at these lower levels.

Are 24-Hour Urine Samples and Creatinine Adjustment Required for Analysis of Inorganic Arsenic in Urine in Population Studies?

Compliance with 24-h urine samples can be low in population-based studies and first morning void urine samples are often collected for convenience. Interpretation of arsenic concentrations in urine is influenced by a range of factors unrelated to exposure. To reduce the influence of such factors, creatinine adjustment is routinely used. This study aimed to determine whether first morning void urinary inorganic arsenic concentrations approximate 24-h urinary arsenic concentrations and whether creatinine adjustment improved the correlation between environmental arsenic concentrations and urinary inorganic arsenic concentrations. One hundred sixty spot samples and corresponding 24-h urine samples were collected from people living in areas with a range of environmental arsenic concentrations and analyzed for inorganic arsenic using borohydride arsine generation followed by atomic absorption spectrophotometry. There were no significant differences between the urinary inorganic arsenic concentrations for the different sample types or whether creatinine adjusted or not. Significant correlations were observed between adjusted and unadjusted samples. The data set was highly skewed and when only detectable arsenic samples were considered, the relationship between sample types became nonsignificant. The results of this study suggest that spot samples may be adequate for measuring short-term exposure, using inorganic arsenic as the outcome variable; however, additional work on a larger data set is required. Creatinine adjustment of urinary inorganic arsenic concentrations may not be required in population studies investigating environmental exposure.

The study of biological monitoring of inorganic arsenic exposure

This review will describe method for biological monitoring of inorganic arsenic exposure, that delineates the chemical species of arsenic measured in urine. The studies established a method for exposure-level-dependent biological monitoring of inorganic arsenic exposure. Low-level exposure could be monitored only by determining the urinary inorganic arsenic concentration. High-level exposures clearly produced increased urinary inorganic arsenic, methylated arsenic (MA), dimethylated arsenic (DMA) and the sum of urinary inorganic arsenic and its metabolites (inorganic arsenic+MA+DMA) could be determined. Urinary arsenobetaine proved to be specifically seafood-derived arsenic, which could be distinguished from occupational arsenic exposure. There is increased use of gallium arsenide and indium arsenide in the semiconductor industry today. The determination of arsenic in ambient air is difficult to carry out in semiconductor factories. Monitoring arsenic exposure by determining the arsenic in the hair appeared to be of value only when used for environmental monitoring of arsenic rather than for biological monitoring.

Biological Monitoring of Arsenic exposure of Gallium Arsenide- and Inorganic Arsenic-Exposed Workers by Determination of Inorganic Arsenic and Its Metabolites in Urine and Hair

In an attempt to establish a method for biological monitoring of inorganic arsenic exposure, the chemical species of arsenic were measured in the urine and hair of gallium arsenide (GaAs) plant and copper smelter workers. Determination of urinary inorganic arsenic concentration proved sensitive enough to monitor the low-level inorganic arsenic exposure of the GaAs plant workers. The urinary inorganic arsenic concentration in the copper smelter workers was far higher than that of a control group and was associated with high urinary concentrations of the inorganic arsenic metabolites, methylarsonic acid (MAA) and dimethylarsinic acid (DMAA). The results established a method for exposure level-dependent biological monitoring of inorganic arsenic exposure. Low-level exposures could be monitored only by determining urinary inorganic arsenic concentration. High-level exposures clearly produced an increased urinary inorganic arsenic concentration, with an increased sum of urinary concentrations of inorganic arsenic and its metabolites (inorganic arsenic + MAA + DMAA). The determination of urinary arsenobetaine proved to determine specifically the seafood-derived arsenic, allowing this arsenic to be distinguished clearly from the arsenic from occupational exposure. Monitoring arsenic exposure by determining the arsenic in the hair appeared to be of value only when used for environmental monitoring of arsenic contamination rather than for biological monitoring.