Arsenic - Toxicology of Metals - page 377

in cohort and case-control studies in southwestern
Taiwan (Chen et al ., 1996). In a recent ecological study,
the prevalence of coronary artery disease among
diabetic and nondiabetic residents was signifi cantly
higher in arseniasis-endemic than nonendemic areas
in southwestern Taiwan (Wang et al ., 2003). Myocar-
dial infarction has been related to high-arsenic drink-
ing water in several autopsy studies in Antofagasta,
Chile (Chen et al ., 1997a; Engel et al ., 1994). But details
of arsenic exposure and population at risk were not
available for further evaluation of the dose-response
relationship.
The association between long-term exposure to
arsenic and increased mortality from cardiovascular
disease has also been reported among copper-smelter
worker in the United States and Sweden, among
chimney sweeps in Sweden and Denmark, among
glassblowers in Sweden, and among workers and
neighboring residents of an arsenic refi nery in Japan
(Chen et al ., 1997a; Engel et al ., 1994; IARC, 2004; WHO,
1981; 2001).
A signifi cant reverse dose-response relationship
was observed between arsenic-induced ischemic heart
disease and serum level of

observed (Wang et al ., 2002). The biological gradients
remained signifi cant after adjustment for age, gender,
hypertension, diabetes mellitus, cigarette smoking,
alcohol consumption, waist-to-hip ratio, and serum
levels of total cholesterol and low-density lipoprotein
cholesterol.

7.4.6 Hypertension

A cross-sectional study in southwestern Taiwan
has reported an increased prevalence of hyperten-
sion among residents in the arseniasis-endemic area
than those in nonendemic area, as well as a dose-
response relationship between ingested inorganic
arsenic and prevalence of hypertension (Chen et al .,
1995). The biological gradient remained signifi cant
after adjustment for age, gender, diabetes mellitus,
proteinuria, body mass index, and serum triglycer-
ide levels. Another study in Bangladesh also found a
dose-response relationship between ingested arsenic
and hypertension prevalence after adjustment for
age, gender, and body mass index (Rahman et al .,
1999b). Increased hypertension prevalence was also
observed among patients affected with arsenic-
induced skin lesions in the area where well water
had a high arsenic concentration in Chile (Borgono
et al ., 1977; Zaldivar, 1980). Arsenic-exposed workers
were reported to have a higher systolic blood pres-
sure than unexposed workers in Denmark (Jensen
and Hansen, 1998).

-carotene after adjust-
ment for age, gender, body mass index, hypertension,
as well as the ratio between total cholesterol and high-
density lipoprotein cholesterol (Hsueh et al ., 1998).

α - and β

7.4.4 Stroke

A survey carried out in I-Lan County of north-
eastern Taiwan showed a signifi cant dose-response
relationship between arsenic concentration in drink-
ing water and the prevalence of strokes, especially
cerebral infarction (Chiou et al ., 1997). The biologi-
cal gradient of stroke by arsenic in drinking water
remained statistically signifi cant after adjustment
for age, gender, body mass index, disease status of
hypertension and diabetes mellitus, cigarette smok-
ing, and alcohol consumption. In an ecological study
in southwestern Taiwan, an increased mortality from
stroke was observed for residents who lived in arsenia-
sis-endemic area of southwestern Taiwan (Tsai et al .,
1999). In a recent ecological study, the prevalence of
coronary artery disease among diabetic and nondia-
betic residents was signifi cantly higher in arsenia-
sis-endemic than nonendemic area in southwestern
Taiwan (Wang et al ., 2003).

7.4.7 Microcirculation Abnormality

Based on the laser Doppler fl owmetry, seemingly
normal men living in villages where Blackfoot disease
was hyperendemic were found to have poorer periph-
eral microcirculation than matched ones in nonendemic
areas (Tseng et al ., 1995b). However, the dose-response
relationship between ingested inorganic arsenic and
abnormality of peripheral microcirculation was not
examined.

7.4.7.1 Microvascular Diseases
In a recent ecological study, the prevalence of micro-
vascular diseases, including renal disease, retinopa-
thy, and neurological disorders among diabetic and
nondiabetic residents, was signifi cantly higher in arse-
niasis-endemic than nonendemic area in southwestern
Taiwan (Wang et al ., 2003).
A signifi cant ecological correlation between the
arsenic content in drinking water and the mortality
from cancer of the nasal cavity was reported recently
(Chen and Wang, 1990). Although perforation of the
nasal septum has been documented among smelter
workers exposed to high levels of inorganic arsenic

7.4.5 Carotid Atherosclerosis

In a cross-sectional survey of residents in south-
western Taiwan, a dose-response relationship between
prevalence of carotid atherosclerosis and long-term
exposure to arsenic from drinking well water was