POTENTIAL ETIOLOGICAL AGENTS OF BLACKFOOT DISEASE CAUSED BY DRINKING GROUNDWATER IN TAIWAN: AN OVERVIEW
JEAN, Jiin-Shuh, Earth Sciences, National Cheng Kung University, #1 University Road, Tainan, 70101, Taiwan, email@example.com and LEE, Ming-Kuo, Department of Geology, Auburn Univ, Auburn, AL 368492006 Philadelphia Annual Meeting (22–25 October 2006)
General Information for this Meeting
"The blackfoot disease (BFD), which was endemic peripheral vascular disease in southwestern Taiwan before the 1990s, has known to be caused by drinking arsenic-contaminated groundwater. Although arsenic has been regarded as the most important determinant BFD, several compounds are found in the high arsenic well water, including ergotamine, organic chloride, and fluorescent humic substances. In addition, trace elements such as molybdenum, mercury, copper, and cadmium, were reported to be higher in the serum and/or urine of BFD patients and in the groundwater. The etiological agent of the BFD is rather complicate and remains unclear up to present. Intriguingly, the symptoms for the patients that drank groundwater from the artesian well water in the southwestern coast of Taiwan (Chia-Nan plain) were significantly different from those in the northeastern coast of Taiwan (Ilan plain) due to the differences in the constituents and biochemical structures of potential etiological agents. The symptoms for the patients in the Chia-Nan plain was characterized particularly by BFD, skin diseases (e.g., hyperkeratosis, skin cancer, etc.) and internal cancers (e.g., lung, bladder, prostate, etc.) that were caused by arsenic and lesser amounts of fluorescent humic substances in the groundwater, while those in the Ilan plain was characterized particularly by skin diseases and internal cancers but not BFD that were caused by arsenic and considerable amounts of fluorescent humic substances in the groundwater. The humic substances having a benzene rings could possess polymers of many ions (COOH group, C=O group, and OH group) presenting chelating ability, thereby easily combining with arsenic and other metal groups (e.g., iron, manganese, strontium, lead, zinc, nickel, etc.), fatty acids, phthalate esters, some unknowns, and free radicals to form an organometallic complex. The health effects in the Chia-Nan and Ilan plains were serious with water from artesian wells that tapped groundwater under reducing conditions, and they were absent with water from shallow wells that tapped groundwater under phreatic conditions. In general, in the blackfoot disease-endemic area in Taiwan, artesian wells contained higher arsenic and fluorescent humic substances relative to shallow wells."
Water-related diseases - Arsenicosis
"Drinking water rich in arsenic over a long period leads to arsenic poisoning or arsenicosis. Many waters contain some arsenic and excessive concentrations are known to naturally occur in some areas. The health effects are generally delayed and the most effective preventive measure is supply of drinking water low in arsenic concentration.
Arsenicosis is the effect of arsenic poisoning, usually over a long period such as from 5 to 20 years. ..."
Journal of Environmental Science and Health, Part C, Volume 23, Issue 1 April 2005 , pages 55 - 74
"Blackfoot disease (BFD) is an endemic peripheral vascular disease confined to the southwestern coast of Taiwan. This article reviews the epidemiology, clinical manifestations and diagnosis, pathology, etiology and pathogenesis of this disease. Sporadic cases of BFD occurred as early as in the early 20th century, and peak incidence was noted between 1956 and 1960, with prevalence rates ranging from 6.51 to 18.85 per 1,000 population in different villages. Typical clinical symptoms and signs of progressive arterial occlusion mainly found in the lower extremities, but in rare cases, the upper extremities might also be involved. Ulceration, gangrene and spontaneous or surgical amputation were typical fate. An extensive pathological study concluded that 30% of the BFD patients had histologic lesions compatible with thromboangiitis obliterans and 70% showed changes of arteriosclerosis obliterans. Epidemiologic studies carried out since mid-20th century revealed that BFD was associated with the consumption of inorganic arsenic from the artesian wells. Recent studies confirmed the existence of preclinical peripheral vascular disease, subclinical arterial insufficiency and defects in cutaneous microcirculation in the residents of the endemic villages. A more recent study suggested that the methylation capacity of arsenic can interact with arsenic exposure in the development of peripheral vascular disease among residents of BFD-endemic areas. The incidence of BFD decreased dramatically after the implementation of tap water in these villages over the past 2-3 decades. The atherogenicity of arsenic could be associated with its effects of hypercoagulability, endothelial injury, smooth muscle cell proliferation, somatic mutation, oxidative stress, and apoptosis. However, its interaction with some trace elements and its association with hypertension and diabetes mellitus could also explain part of its higher risk of developing atherosclerosis. Although humic substances have also been suggested as a possible cause of BFD, epidemiologic studies are required to confirm its etiologic role."