Tag Archives: arsenic

Human exposure to arsenic in household water, Pakistan

Rasheed H, Kay P, Slack R, Gong YY, Carter A. Human exposure assessment of different arsenic species in household water sources in a high risk arsenic area. The Science of the total environment. 2017 Jan 25. pii: S0048-9697(17)30098-0. doi: 10.1016/j.scitotenv.2017.01.089.

Understanding arsenic speciation in water is important for managing the potential health risks associated with chronic arsenic exposure. Most arsenic monitoring studies to date have only measured total arsenic, with few looking at arsenic species. This study assessed 228 ground water sources in six unstudied villages in Pakistan for total, inorganic and organic arsenic species using ion chromatography inductively coupled plasma collision reaction cell mass spectrometry. The concentration levels approached 3090μgL-1 (95% CI, 130.31, 253.06) for total arsenic with a median of 57.55μgL-1, 3430μgL-1 (median=52) for arsenate (As+5) and 100μgL-1 (median=0.37) for arsenite (As+3). Exceedance of the WHO provisional guideline value for arsenic in drinking water (10μgL-1) occurred in 89% of water sources. Arsenic was present mainly as arsenate (As+5). Average daily intake of total arsenic for 398 residents living in the sampled houses was found up to 236.51μgkg-1day-1. This exposure estimate has indicated that 63% of rural residents exceeded the World Health Organization’s provisional tolerable daily intake (PTDI) of 2.1μgkg-1day-1 body weight. Average daily intake of As+5 was found to be 15.63μgkg-1day-1 (95% CI, 5.53, 25.73) for children ≤16 and 15.07μgkg-1day-1 (95% CI, 10.33, 18.02) for adults. A mean daily intake of 0.09μgkg-1day-1 was determined for As+3 for children and 0.26μgkg-1day-1 for adults. Organic arsenic species such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and Arsenobetaine (AsB) were found to be below their method detection limits (MDLs).

Drinking Water Arsenic Inversely Associated with Suicide Rates, Italy

Pompili M, Vichi M, Dinelli E, Erbuto D, Pycha R, Serafini G, Giordano G, Valera P, Albanese S, Lima A, De Vivo B, Cicchella D, Rihmer Z, Fiorillo A, Amore M, Girardi P, Baldessarini RJ. Arsenic: Association of regional concentrations in drinking water with suicide and natural causes of death in Italy. Psychiatry research. 2017 Jan 18;249:311-317. doi: 10.1016/j.psychres.2017.01.041.

Arsenic, as a toxin, may be associated with higher mortality rates, although its relationship to suicide is not clear. Given this uncertainty, we evaluated associations between local arsenic concentrations in tapwater and mortality in regions of Italy, to test the hypothesis that both natural-cause and suicide death rates would be higher with greater trace concentrations of arsenic. Arsenic concentrations in drinking-water samples from 145 sites were assayed by mass spectrometry, and correlated with local rates of mortality due to suicide and natural causes between 1980 and 2011, using weighted, least-squares univariate and multivariate regression modeling. Arsenic concentrations averaged 0.969 (CI: 0.543-1.396) µg/L, well below an accepted safe maximum of 10µg/L. Arsenic levels were negatively associated with corresponding suicide rates, consistently among both men and women in all three study-decades, whereas mortality from natural causes increased with arsenic levels. Contrary to an hypothesized greater risk of suicide with higher concentrations of arsenic, we found a negative association, suggesting a possible protective effect, whereas mortality from natural causes was increased, in accord with known toxic effects of arsenic. The unexpected inverse association between arsenic and suicide requires further study.

Dose-Response Assessment of Inorganic Arsenic and Lung Cancer, Taiwan

Hsu KH, Tsui KH, Hsu LI, Chiou HY, Chen CJ. Dose-Response Relationship between Inorganic Arsenic Exposure and Lung Cancer among Arseniasis Residents with Low Methylation Capacity. Cancer Epidemiol Biomarkers Prev. 2016 Dec 22. pii: cebp.0281.2016. doi: 10.1158/1055-9965.EPI-16-0281.

Background: Exposure to inorganic arsenic (InAs) has been documented as a risk factor for lung cancer. This study examined the association between InAs exposure, its metabolism, and lung cancer occurrence.

Methods: We followed 1300 residents from an arseniasis area in Taiwan, determined urinary InAs metabolites, and identified 39 lung cancer cases. Cox proportional hazard model was performed.

Results: The results demonstrated that participants with either the primary methylation index (monomethylarsonic acid [MMA]/InAs) or the secondary methylation index (dimethylarsinic acid[DMA]/MMA) lower than their respective median values were at a higher risk of lung cancer (hazard ratios from 3.41 to 4.66) than those with high methylation capacity. The incidence density of lung cancer increased from 79.9/100000 (year-1) to 467.4/100000 (year-1) for residents with low methylation capacity and from 0 to 158.5/100000 (year-1) for residents with high methylation capacity when the arsenic exposure dose increased from 2-10 ppb to ≥200 ppb, respectively. The analyses revealed a dose-response relationship between lung cancer occurrence and increasing arsenic concentrations in drinking water as well as cumulative arsenic exposure (monotonic trend test; P < .05 and P < .05, respectively) among the residents with low methylation capacity. The relationship between arsenic exposure and lung cancer among high methylaters was not statistically significant.

Conclusions: Hypomethylation responses to InAs exposure may dose-dependently increase lung cancer occurrence.

Impact: The high-risk characteristics observed among those exposed should be considered in future preventive medicine and research on arsenic carcinogenesis.

480 Million India Inhabitants Exposed to Elevated Arsenic and Fluoride

Chakraborti D, Rahman MM, Chatterjee A, Das D, Das B, Nayak B, Pal A, Chowdhury UK, Ahmed S, Biswas BK, Sengupta MK, Lodh D, Samanta G, Chakraborty S, Roy MM, Dutta RN, Saha KC, Mukherjee SC, Pati S, Kar PB. Fate of over 480 million inhabitants living in arsenic and fluoride endemic Indian districts: Magnitude, health, socio-economic effects and mitigation approaches. Journal of trace elements in medicine and biology. 2016 Dec;38:33-45. doi: 10.1016/j.jtemb.2016.05.001.

During our last 27 years of field survey in India, we have studied the magnitude of groundwater arsenic and fluoride contamination and its resulting health effects from numerous states. India is the worst groundwater fluoride and arsenic affected country in the world. Fluoride results the most prevalent groundwater related diseases in India. Out of a total 29 states in India, groundwater of 20 states is fluoride affected. Total population of fluoride endemic 201 districts of India is 411 million (40% of Indian population) and more than 66 million people are estimated to be suffering from fluorosis including 6 million children below 14 years of age. Fluoride may cause a crippling disease. In 6 states of the Ganga-Brahmaputra Plain (GB-Plain), 70.4 million people are potentially at risk from groundwater arsenic toxicity. Three additional states in the non GB-Plain are mildly arsenic affected. For arsenic with substantial cumulative exposure can aggravate the risk of cancers along with various other diseases. Clinical effects of fluoride includes abnormal tooth enamel in children; adults had joint pain and deformity of the limbs, spine etc. The affected population chronically exposed to arsenic and fluoride from groundwater is in danger and there is no available medicine for those suffering from the toxicity. Arsenic and fluoride safe water and nutritious food are suggested to prevent further aggravation of toxicity. The World Health Organization (WHO) points out that social problems arising from arsenic and fluoride toxicity eventually create pressure on the economy of the affected areas. In arsenic and fluoride affected areas in India, crisis is not always having too little safe water to satisfy our need, it is the crisis of managing the water.

Health Risk of Arsenic in Groundwater, Taiwan

Liang CP, Wang SW, Kao YH, Chen JS. Health risk assessment of groundwater arsenic pollution in southern Taiwan. Environ Geochem Health. 2016 Dec;38(6):1271-1281.

Residents of the Pingtung Plain, Taiwan, use groundwater for drinking. However, monitoring results showed that a considerable portion of groundwater has an As concentration higher than the safe drinking water regulation of 10 μg/L. Considering residents of the Pingtung Plain continue to use groundwater for drinking, this study attempted to evaluate the exposure and health risk from drinking groundwater. The health risk from drinking groundwater was evaluated based on the hazard quotient (HQ) and target risk (TR) established by the US Environmental Protection Agency. The results showed that the 95th percentile of HQ exceeded 1 and TR was above the safe value of threshold value of 10-6. To illustrate significant variability of the drinking water consumption rate and body weight of each individual, health risk assessments were also performed using a spectrum of daily water intake rate and body weight to reasonably and conservatively assess the exposure and health risk for the specific subgroups of population of the Pingtung Plain. The assessment results showed that 0.01-7.50 % of the population’s HQ levels are higher than 1 and as much as 77.7-93.3 % of the population being in high cancer risk category and having a TR value >10-6. The TR estimation results implied that groundwater use for drinking purpose places people at risk of As exposure. The government must make great efforts to provide safe drinking water for residents of the Pingtung Plain.

Arsenic and Fluoride Toxicity to Human Umbilical Vein Cells

Ma Y, Ma Z, Yin S, Yan X, Wang J. Arsenic and fluoride induce apoptosis, inflammation and oxidative stress in cultured human umbilical vein endothelial cells. Chemosphere. 2016 Oct 14;167:454-461. doi: 10.1016/j.chemosphere.2016.10.025.

Excessive amount of inorganic arsenic (iAs) and fluoride (F) coexist in drinking water in many regions, which is associated with high risk of vascular diseases. However, the underlying mechanisms are not well studied. The present study was to evaluate the effects of iAs and F individual or combined exposure on endothelial activation and apoptosis in vitro. Primary human umbilical vein endothelial cells (HUVECs) were exposed to 5 μM As2O3 and/or 1 mM NaF. Changes in endothelial cell apoptosis, inflammation, oxidative stress and nitric oxide (NO) production were analyzed. The results showed that iAs and/or F induced significant increase in endothelial cell apoptosis and inflammation as indicated by the increase of mRNA and protein expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and pentraxin 3. Furthermore, iAs and/or F exposure induced intracellular reactive oxygen species and malondialdehyde generation. Results showed iAs and/or F exposure increased the activity of NADPH oxidase (NOX) and up-regulated the mRNA expression of NOX subunits p22phox. The results indicated that activation of NOX was related to oxidative stress induced by iAs and/or F. Also, iAs and/or F reduced NO production in HUVECs. The up-regulation of inflammation genes expression and oxidative stress in iAs and F co-exposed ECs were less pronounced as compared to single F-exposed cells, which showed an antagonistic effect between iAs and F. In conclusion, endothelial activation and apoptosis induced by iAs and/or F are potential mechanisms in their vascular toxicity. Oxidative stress and impaired NO production are involved in their pro-inflammatory and pro-apoptotic effects.

Risk of Lung Disease Associated with Early-Life Arsenic Exposure, Chile

Steinmaus C, Ferreccio C, Acevedo J, Balmes JR, Liaw J, Troncoso P, Dauphiné DC, Nardone A, Smith AH. High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile. Toxicol Appl Pharmacol. 2016 Oct 8;313:10-15. doi: 10.1016/j.taap.2016.10.006

BACKGROUND: Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited.

METHODS: We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860μg/L) from 1958 to 1970; Iquique, which had long-term arsenic water concentrations near 60μg/L; and Arica, with long-term water concentrations ≤10μg/L.

RESULTS: Compared to adults never exposed >10μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath=5.56, 90% confidence interval (CI): 2.68-11.5), and decreases in pulmonary function (e.g., 224mL decrease in forced vital capacity in nonsmokers, 90% CI: 97-351mL). Subjects with long-term exposure to arsenic water concentrations near 60μg/L also had increases in some pulmonary symptoms and reduced lung function.

CONCLUSIONS: Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed.