Blackfoot Disease Endemic Area Research Articles

Primary Intracerebral Hemorrhage Mortality Reduction After Installation of a Tap-Water Supply System in an Arseniasis-Endemic Area in Southwestern Taiwan

Mortality and morbidity of vascular diseases, including stroke, are known to be associated with chronic exposure to inorganic arsenic through drinking water. A tap-water supply system was implemented in the early 1960s in the blackfoot disease (BFD) endemic areas of Taiwan. The objective of this study was to examine whether mortality attributed to stroke decreased among residents living in the BFD-endemic areas after the curtailment of arsenic exposure. Further it was of interest to determine whether arsenic exposure was related to a specific type of stroke. Standardized mortality ratios (SMRs) for stroke were calculated for the BFD endemic area for the years 1971–2000. The study results show that mortality due to primary intracerebral hemorrhage (PIH) declined gradually after the improvement of drinking-water supply system by elimination of arsenic exposure through removal of artesian well water. Based on the reversibility and specificity criteria, the association between arsenic exposure and mortality due to PIH is likely to be causal.

Does Arsenic Exposure Increase the Risk of Development of Peripheral Vascular Diseases in Humans?

Arsenic has been well documented as a major risk factor in the development of blackfoot disease (BFD), a unique peripheral vascular disease (PVD) endemic to the southwestern coast of Taiwan, where residents imbibed artesian well water containing excessive amounts of arsenic for more than 50 yr. Long-term arsenic exposure was also reported to be associated with mortality attributed to PVD. A tap-water supply system was implemented in the early 1960s in the BFD endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study was to examine whether mortality attributed to PVD decreased after the consumption of artesian well water containing high concentrations of arsenic ceased and, if so, when the reduction occurred. Standardized mortality ratios (SMRs) for PVD were calculated for the BFD endemic area for the years 1971–2003. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. Data showed that mortality due to PVD declined gradually for approximately 25 to 27 yr following cessation of consumption of this arsenic artesian well water. Based on the reversibility criterion, the association between arsenic exposure and PVD-attributed mortality is likely to be causal.

Authors?? Response

To the Editor: We thank Lamm et al1 for responding to our article.2 They recalculated our data only for the period 1980–2000 (excluding 1971–1979) and this led to an estimate of similar significant negative slope for diabetes mellitus (DM) standardized mortality ratios (SMRs) for males and females. They dispute our conclusion that there is a gender difference in temporal pattern (only during the 1980s and 1990s). Because inorganic arsenic has been reported to be associated with an increased mortality from DM, it is logical to expect that a reduction of arsenic exposure through improvement in the water supply system would lead to a decrease in mortality rates from DM in both males and females living in the Blackfoot disease (BFD) endemic areas. We feel that their argument, however, provides further evidence that the association between arsenic exposure and DM was causal. Their point of criticism regarding the use of DM listed on the death certificate as the underlying cause of death has already been addressed in the discussion section of our article. We agree with Lamm et al that small numbers of DM deaths will provide much less stability to the analysis, particularly during the 1970s. To minimize this statistical variability, the 3-year moving averages of the SMR were calculated for this study. Lamm et al argue that fluorescent compounds (humic substances) in the artesian well water are a potential causative agent for BFD; thus, the decline in diabetes mortality may be the consequence of withdrawal of a water-borne factor, but whether arsenic is that factor is not clear. In our opinion, in the BFD endemic areas, the main exposure to inorganic arsenic is through ingestion of artesian well water containing high concentrations of arsenic. Physical and chemical characteristics of drinking water have been intensively studied in both BFD endemic and nonendemic areas.3 In artesian well water, the only chemical component exceeding the daily maximum allowable limit was arsenic. Although fluorescent compounds, known as humic substances, have been suggested to exert an initiator role in the development of BFD,4,5 there has been no epidemiologic evidence to show a correlation between exposure to humic substances and development of DM. The association between humic substances and BFD might be due to the confounding effect of an association between BFD and arsenic exposure.6 Thus, the reduction in DM mortality in the study area may result from the withdrawal of arsenic exposure through improvements in the water supply system as reflected by a change in water source. Hui-Fen Chiu, PhD Department of Pharmacology College of Medicine Kaohsiung Medical University Kaohsiung, Taiwan Chih-Ching Chang, MD, PhD Institute of Public Health College of Health Sciences Kaohsiung Medical University Kaohsiung, Taiwan Shang-Shyue Tsai, PhD Department of Healthcare Administration I-Shou University Kaohsiung County, Taiwan Chun-Yuh Yang, PhD, MPH Institute of Public Health College of Health Sciences Kaohsiung Medical University Kaohsiung, Taiwan

Pitfalls in the Study Using Death Certificates to Demonstrate the Reversibility of Mortality From Diabetes in the Blackfoot Disease Endemic Areas in Taiwan

Pitfalls in the Study Using Death Certificates to Demonstrate the Reversibility of Mortality From Diabetes in the Blackfoot Disease Endemic Areas in Taiwan

Does Arsenic Exposure Increase the Risk for Diabetes Mellitus?

Long-term arsenic exposure has been reported to associated with prevalence, incidence, and mortality of diabetes mellitus (DM). A tap water supply system was implemented in the early 1960s in the blackfoot disease (BFD) endemic areas. The objective of this study is to examine whether DM mortality decreased after the improvement of drinking water supply system through elimination of arsenic exposure from artesian well water. Standardized mortality ratios (SMRs) for DM were calculated for the BFD endemic area for the years 1971-2000. The study results show that mortality from DM declined in females (but not in males) gradually after the improvement of drinking water supply system. Based on the reversibility criterion, the association between arsenic exposure and DM is likely to be casual for females but not in males.

Aurora-A overexpression associates with Ha- ras codon-12 mutation and blackfoot disease endemic area in bladder cancer

Our data revealed that 59.4% of the bladder cancer specimens showed Aurora-A overexpression, of which 31.8% also had Ha-ras codon-12 mutation; 45.5% were from blackfoot-disease endemic areas in which arsenic exposure is a major environment factor associated with various cancer formation. We further demonstrated that arsenic treatment of the immortalized bladder cell line, E7, increased Aurora-A expression. All together, co-existence of Aurora-A overexpression and Ha-ras mutation suggests a possible additively effect on the tumorigenesis of bladder cancer. In addition, Aurora-A overexpression and up-regulated by arsenic exposure opens a new direction for exploring the occurrence of bladder cancer occurrence in Taiwan.

ASSOCIATION BETWEEN ARSENIC IN DRINKING WATER AND CEREBRAL ISCHEMIC STROKE IN BLACKFOOT DISEASE ENDEMIC AREA

ISEE-401 Introduction: Stroke is the second leading cause of death in Taiwan and can be caused by cerebral atherosclerosis. Long-term exposure to arsenic can cause atherosclerosis and lead to blackfoot disease (BFD), which is an unique endemic peripheral vascular occlusive disease developed in the southwestern coast of Taiwan. Residents who lived in this so called“blackfoot disease endemic area”were exposed to drinking water from wells with high arsenic concentration before. However, limited literatures with controversial results are focused on the association between arsenic and stroke. Methods: A hospital-based case-control study was conducted from April 2002 to November 2002. One hundred acute ischemic stroke patients, including 36 patients from BFD endemic area as cases and 64 matched patients from outside the BFD endemic area as internal controls, were enrolled; and 71 matched persons free of stroke were also recruited as external controls. Participants received a questionnaire interview on drinking water history, tests on serum level of epidermal growth factor receptor (EGFR), and determination of arsenic species in urine as indicators of methylation capacity. Data of arsenic level in well water from a previous survey were used to estimate the arsenic exposure of each individual. Results: All the individuals had low total arsenic concentration in urine and there were no statistical differences in arsenic methylation capacity between case and external control groups.There were statistically significant differences in EGFR concentrations among the three groups, but all the levels were less than 15 fm/mL. Discussion: The association between high arsenic exposure and ischemic stroke should be further explored, and EGFR overexpression was not a biomarker for ischemic stroke.

Experience with Primary Urethral Carcinoma from the Blackfoot Disease-Endemic Area of South Taiwan: Increased Frequency of Bulbomembranous Adenocarcinoma?

Objectives: To describe and compare primary urethral carcinomas in South Taiwan with those in the USA and to explore the influence of chronic arsenic exposure. Methods: From 1988 to 2001, there were 21 pathologically proven primary urethral carcinomas diagnosed and treated at our hospital (14 males, 7 females). Seven of 14 male patients were chronically exposed to arsenic in drinking water for an average of 23 years. We compared our cases to three studies in the USA (80 males, 179 females), and analyzed the influence of chronic arsenic exposure by onset age, histology, staging, and outcome. Results: Male patients with localized tumors had better survival compared to those with advanced tumors (p = 0.0045 in males, p = 0.07 in females). In comparison to the three studies in the USA, there was an unusual higher frequency of bulbomembranous adenocarcinoma at our center (43 vs. 18%, 2 and 0%, respectively, p < 0.0001), particularly among those with chronic arsenic exposure (73 vs. 14%, p = 0.031). Conclusions: In South Taiwan, there was a high frequency of bulbomembranous urethral adenocarcinoma, which might be associated with chronic arsenic exposure. Although the implications of such an observation are minimal owing to its rarity, it is worth exploring.

Decreasing Trend in Renal Disease Mortality after Cessation from Arsenic Exposure in a Previous Arseniasis-Endemic Area in Southwestern Taiwan

Arsenic has been well documented as a major risk factor for blackfoot disease (BFD), a unique peripheral vascular disease that was endemic in the southwestern coast of Taiwan, where residents imbibed artesian well water containing excessive amounts of arsenic for more than 50 yr. Long-term arsenic exposure has also been reported to be associated with mortality attributed to renal disease. A tap-water supply system was implemented in the early 1960s in the BFD endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study was to examine whether mortality attributed to arsenic-induced renal diseases decreased after the improvement of the drinking-water supply system through elimination of arsenic exposure from artesian well water. Standardized mortality ratios (SMRs) for renal diseases were calculated for the BFD endemic area for the years 1971–2000. Results show that mortality from renal disease declined gradually after improvement of the drinking-water supply system to eliminate arsenic from artesian well water. Based on the reversibility criterion, the association between arsenic exposure and mortality attributed to renal disease is likely to be positively correlated. This study was partly supported by a grant from the National Science Council, Executive Yuan, Taiwan (NSC-92-2320-B-037-046).

DOES ARSENIC EXPOSURE INCREASE THE RISK FOR LIVER CANCER? 1

Arsenic has been well documented as the major risk factor for development of blackfoot disease (BFD), a unique peripheral vascular disease that was once endemic to the southwestern coast of Taiwan, where residents imbibed artesian well water containing high concentrations of arsenic for more than 50yr. Long-term arsenic exposure has also been reported to be associated with increased incidence of liver cancer in a dose-responsive manner. A tap-water supply system was implemented in the early 1960s in the BFD endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study was to examine whether liver cancer mortality rates were altered after the consumption of high-arsenic artesian well water ceased and, if so, when the reduction occurred. Standardized mortality ratios (SMRs) for liver cancer were calculated for the BFD endemic area for the years 1971–2000. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. The study results show that mortality from liver cancer in females declined starting 9yr after the cessation of consumption of high-arsenic artesian well water. However, data show fluctuations in male liver cancer mortality rates. Based on the reversibility criterion, the association between arsenic exposure and liver cancer mortality is likely to be causal for females but not in males.

Bladder cancer mortality reduction after installation of a tap-water supply system in an arsenious-endemic area in southwestern Taiwan

Arsenic has been well documented as the major risk factor for blackfoot disease (BFD), a unique peripheral vascular disease that was endemic in the southwestern coast of Taiwan, where residents had consumed high-arsenic artesian well water for more than 50 years. Long-term arsenic exposure has also been reported to be associated with bladder cancer mortality in a dose–response relationship. A tap water supply system was implemented in the early 1960s in the BFD endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study is to examine whether bladder cancer mortality decreased after the improvement of the drinking water supply system through elimination of arsenic exposure from artesian well water. Standardized mortality ratios (SMRs) for bladder cancer were calculated for the BFD endemic area for the years 1971–2000. The study results show that mortality from bladder cancer declined gradually after the improvement of the drinking water supply system to eliminate arsenic exposure from artesian well water. Based on the reversibility criterion, this finding strengthened the likelihood of the observed association between arsenic exposure and bladder cancer being causal.

ISCHEMIC HEART DISEASE MORTALITY REDUCTION IN AN ARSENIASIS-ENDEMIC AREA IN SOUTHWESTERN TAIWAN AFTER A SWITCH IN THE TAP-WATER SUPPLY SYSTEM

Arsenic has been identified as a major contributing risk factor for development of blackfoot disease (BFD), a unique peripheral vascular disease that was endemic to the southwestern coast of Taiwan, where residents imbibed artesian well water continuing high amounts of arsenic for more than 50 yr. Chronic arsenic exposure was found to be associated with ischemic heart disease (CHD) in a dose-dependent manner. A tap-water supply system was implemented in the early 1960s in the BFD-endemic areas. Artesian well water was no longer used for drinking and cooking after the mid-1970s. The objective of this study was to examine whether CHD-related mortality decreased after consumption of high-arsenic-containing artesian well water ceased and, if so, when the reduction occurred. Standardized mortality ratios (SMRs) for CHD were calculated for the BFD endemic area for the years 1971–2000. Cumulative-sum techniques were used to detect the occurrence of changes in the SMRs. Data show that mortality attributed to CHD declined gradually for approximately 17 to 20 yr following cessation of consumption of high-arsenic artesian well water. Based on the reversibility criterion, the association between arsenic exposure an1rd CHD-related mortality is likely to be causal.

Clinical and urographic presentation of transitional cell carcinoma of the ureter in a blackfoot disease endemic area in southern Taiwan.

We reviewed the clinical, radiographic, and pathologic findings of ureteral transitional cell carcinoma (TCC) in a blackfoot disease (BFD) endemic area in southern Taiwan to increase understanding of tumor behavior in this area, which has a high incidence of urothelium carcinoma. From August 1995 to February 2002, 28 histologically proven ureteral TCCs from this area were eligible for study. There was an unusual female predominance (male:female ratio, 1:1.333). The urographic filling defects in the 28 ureteral TCCs were classified into four categories. An ovoid filling defect was significantly associated with non-invasive tumors (p = 0.003) and a trend toward low tumor grades (p = 0.073). The risk of ureteral TCC in this BFD endemic area of southern Taiwan remained high between August 1995 and February 2002. Urographic surveillance provides a simple, clear, inexpensive method to study the extent, location, and morphology of the ureteral mass. Detailed assessment of the image could be useful for preoperative planning and predicting prognosis. Large-scale, randomized, prospective clinical trials are needed to validate our results.

Inhibition of human plasmin activity using humic acids with arsenic

In this study, we examined the effects of natural humic acid (HA) purified from drinking well-water in Blackfoot disease (BFD) endemic areas, using synthetic humic acid (SHA), such as protocatechuic acid, ferulic acid, vanillic acid or catechol, and trivalent arsenic on human plasmin activity. Data in this report indicated that both HA and SHA inhibited human plasmin activity by 20–80 and 5–95%, respectively, at concentrations of 20–480 μg/ml. Organometallic complexes composed of HA and arsenic show enhanced inhibition of plasmin activity as compared with either HA or arsenic alone. Monomers of HA or arsenic alone do not inhibit plasma activity. Oxidative stress may play a role in the inhibition of plasma activity, as various free-radical scavengers, such as ascorbic acid, α-tocopherol, catalase and superoxide dismutase (SOD), abrogate the inhibitory effects of HA and HA–arsenic complexes. The notion that HA/organometallic complexes (HA/OR) impaired plasmin activity was significant, due to the fact that both of these agents (HA and arsenic) are etiological factors in the development of peripheral vascular diseases, such as BFD. This report substantiates the inhibitory effects of HA/OR on plasmin activity, and thus provides evidence for the partial mechanism of action of HA/OR in BFD.

Induction of Oxidative Stress by Humic Acid through Increasing Intracellular Iron: A Possible Mechanism Leading to Atherothrombotic Vascular Disorder in Blackfoot Disease

Humic acid (HA), a potential toxin that has penetrated the drinking well water of blackfoot disease-endemic areas in Taiwan, has been implicated as an etiological factor of this disease. In this study, we investigated the effects of HA on the generation of reactive oxygen species (ROS) in cultured human umbilical vein endothelial cells (HUVECs). The generation of ROS was monitored by flow cytometry. Pretreatment of HUVECs with HA induced reactive oxygen species in a dose- and time-dependent manner. Xanthine oxidase inhibitor (Allopurinol), NADPH oxidase inhibitor (diphenylene iodomium) and calcium chelator (BAPTA) could not reduce the generation of ROS. Protein kinase C inhibitor (H7) could reduce the generation of ROS slightly, but the intracellular antioxidant glutathione monoethyl ester and the iron chelator desferrioxamine (DFO) could inhibit the generation of ROS completely. HA also enhanced the expression of ferritin and induced intracellular chelatable iron; however, HA reduced the expression of transferrin receptor. Pretreatment with DFO inhibited HA-mediated increases of ferritin synthesis and intracellular chelatable iron, but caused recovery of the inhibitory effect on transferrin receptor. Cotreatment with iron and HA induced more ROS and intracellular chelatable iron than iron or HA treatment alone. Furthermore, HA enhanced the accumulation of iron in endothelial cells. These data demonstrate that HA can increase the generation of ROS through enhancing the accumulation of intracellular iron. Taken together, our findings suggest that iron mediates HA-associated oxidative stress in endothelial cells, which may be a possible mechanism leading to atherothrombotic vascular injury observed for patients with blackfoot disease.

Speciation of As in the blackfoot disease endemic area.

Speciation of arsenic (As) in well water and contaminated soil in the blackfoot disease endemic area has been studied by extended X-ray absorption fine structural (EXAFS) spectroscopy in the present work. Experimentally, we found that arsenic in the well water possessed an As-O bond distance of 1.72 A with a coordination number (CN) of 4.3. In the blackfoot disease area, arsenic with a high oxidation state (As(V)) was also observed in the contaminated soil. In the early stage (after 90 minutes) of the electrokinetic remediation (EKR) of the contaminated soil, the in-situ EXAFS data indicated that the CN of As-O (1st shell) decreased slightly, that may be due to the perturbation of the incompact As atoms in the outer shells by EKR.

The association between arsenic methylation ability and the risk of bladder cancer in blackfoot disease endemic area in Taiwan

The association between arsenic methylation ability and the risk of bladder cancer in blackfoot disease endemic area in Taiwan

Humic Acid Suppresses the LPS-Induced Expression of Cell-Surface Adhesion Proteins through the Inhibition of NF-κB Activation

Humic acid (HA), a potential toxin when penetrating the drinking well water of blackfoot disease-endemic areas in Taiwan, has been implicated as one of the etiological factors of this disease. In this study, we investigated the effects of HA on the expression of human vascular endothelial-leukocyte adhesion molecules and the activation of nuclear factor kappa B (NF-κB) in cultured human umbilical vein endothelial cells (HUVECs). The expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin was monitored by flow cytometry. Pretreatment of HUVECs with HA inhibited the lipopolysaccharide (LPS)-induced expression of these three adhesion molecules in a dose- and time-dependent manner. Since NF-κB can regulate the expression of these adhesion molecules, NF-κB activation was assessed by electrophoretic mobility shift assay (EMSA). Our results reveal that the activation of NF-κB by LPS is suppressed by HA in a dose- and time-dependent manner. Furthermore, HA reduces NF-κB binding to DNA slightly, but completely inhibits the degradation of IκBα at a concentration of 100 μg/ml. Thus, all our data demonstrate that HA can inhibit the LPS-induced expression of adhesion molecules through the inhibition of NF-κB activation. HA may also suppress the immune or inflammatory reaction of HUVECs responsible for endotoxin, which could be one possible explanation for the causes of the infection and inflammation observed for patients with blackfoot disease. Our results also suggest that immune or inflammatory disturbance occurs for patients with blackfoot disease and that NF-κB may be a critical molecule in the pathogenesis of this disease.

Mutational spectrum of p53 gene in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan.

To understand the role of p53 tumour suppressor gene in the carcinogenesis of arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan, we collected tumour samples from 23 patients with Bowen's disease, seven patients with basal cell carcinomas (BCC) and nine patients with squamous cell carcinomas (SCC). The result showed that p53 gene mutations were found in 39% of cases with Bowen's disease (9/23), 28.6% of cases with BCC (2/7) and 55.6% of cases with SCC (5/9). Most of the mutation sites were located on exon 5 and exon 8. Moreover, the results from direct sequencing indicated that missense mutations were found at codon 149 (C→T) in one case, codon 175 (G→A) in three cases, codon 273 (G→C) in three cases, codon 292 (T→A) in one case, codon 283 (G→T) in one case, codon 172 (T→C) in one case and codon 284 (C→A) in one case. In addition, silent mutations were also found in four cases. These mutations were located at codons 174, 253, 289 and 298 respectively. In immunohistochemistry analysis, p53 overexpression was found in 43.5% (10/23) of cases with Bowen's disease, 14% (1/7) of cases with BCC and 44% (4/9) of cases with SSC. These findings showed that p53 gene mutation rate in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan is high and that the mutation types are different from those in UV-induced skin cancers. © 1999 Cancer Research Campaign

Analysis of Environmental and Occupational Risk Factors in Bladder Cancer

Along with the high level of economic and industrial development, lifestyles of the Taiwan people have also changed. Smoking and exposures to certain environment and occupations are some major carcinogenic factors. Bladder cancer though is not one of the ten leading causes of cancer deaths in Taiwan, some 500 people die of this cancer each year and the trend is increasing. Risk factors of bladder cancer, according to available literature, are male, aged above 60, smoking, with exposure to aromatic amines, chemical dye stuff, rubber and arsenic. Exposures to other substances such as coal tar, petrol exhaust fumes,polycyclic aromatic hydrocarbons(PHAs),fluorinated drinking water,analgesics,lifestyles(including diet, coffee, tea, and artificial food additives),infection of the urinary system, and family genetics may also be carcinogenic factors. Workers of some special industries such as dyes, rubber, petrol, paints, textile and leather, and truck drivers have more risks to bladder cancer. Studies show that about 20-25% of all risk factors of bladder cancer is attributable to environmental and occupational exposures. Since the incubation period of bladder cancer can be as long as 25 years after exposure and the identification of hazardous substances is not easy, few eqidemiological studies on the environmental and occupational risk factors and cases of bladder cancer have been reported in Taiwan. The present study used the case-control approach in a comparative study of bladder cancer patients(313) and their controls(346) in two medical centers in the northern and southern parts of Taiwan in the last few years. By adjusting confounding effects, it was noted that individuas who had lived in the black-foot disease endemic areas, who smoked, had high risk occupational exposure and Special food habits (eating of salt-preserved food),and were with history of bladder infection and family history of bladder cancer and kidney cancer would have higher risk of bladder cancer. Drinking of alcoholic beverage, coffee, tea and drinking of well water were not found to be statistically associated with the disease. Further analysis by unconditional logistic regression showed that factors such as living experience in the black –foot disease endemic areas, smoking, special food habits (regular use of artificial sweeteners and highly salty food), and history of bladder infection or family history of bladder cancer and renal cancer were significantly associated with bladder cancer. In addition, urinary cell carcinoma in the black-foot disease endemic areas was not associated with either smoking or high-risk occupations. However, smoking was still a major risk factor of urinary cell carcinoma on non black-foot disease areas in Taiwan.