Arsenic exposure and age and sex-specific risk for skin lesions: a population-based case-referent study in Bangladesh.
BACKGROUND
The objective of this population-based case-referent study in Matlab, Bangladesh, was to assess the susceptibility to arsenic-induced skin lesions by age and sex, in a population drinking water from As-contaminated tube wells.


METHODS
Identification of As-related skin lesions was carried out in three steps: a) screening of the entire population > 4 years of age (n = 166,934) by trained field teams; b) diagnosis of suspected As-related cases by physicians; and c) confirmation by experts based on physicians' records and photographs. A total of 504 cases with skin lesions were confirmed. We randomly selected 2,201 referents from the Matlab health and demographic surveillance system; 1,955 were eligible, and 1,830 (94%) were available for participation in the study. Individual history of As exposure was based on information obtained during interviews and included all drinking-water sources used since 1970 and concentrations of As (assessed by atomic absorption spectrophotometry) in all the tube wells used.


RESULTS
Cases had been exposed to As more than referents (average exposure since 1970: male cases, 200 microg/L; female cases, 211 microg/L; male referents, 143 microg/L; female referents, 155 microg/L). We found a dose-response relationship for both sexes (p < 0.001) and increased risk with increasing socioeconomic status. Males had a higher risk of obtaining skin lesions than females (odds ratio 10.9 vs. 5.78) in the highest average exposure quintile (p = 0.005). Start of As exposure (cumulative exposure) before 1 year of age was not associated with higher risk of obtaining skin lesions compared to start of As exposure later in life.


CONCLUSIONS
The results demonstrate that males are more susceptible than females to develop skin lesions when exposed to As in water from tube wells.
Rahman
Mahfuzar
M
ICDDR, B: Centre for Health and Population Research, Mohakha, Dhaka, Bangladesh. mahfuzar@icddrb.org
Vahter
Marie
M
Sohel
Nazmul
N
Yunus
Muhammad
M
Wahed
Mohammad Abdul
MA
Streatfield
Peter Kim
PK
Ekström
Eva-Charlotte
EC
Persson
Lars Ake
LA
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001151:Arsenic / Q000032:analysis*; D001459:Bangladesh / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D017678:Sex Distribution; D012871:Skin Diseases / Q000139:chemically induced* / Q000453:epidemiology; D012959:Socioeconomic Factors; D014867:Water / Q000032:analysis; D014876:Water Pollution / Q000009:adverse effects / Q000032:analysis
D014867:Water; D001151:Arsenic