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Toxicological information

Exposure related observations in humans: other data

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Administrative data

Endpoint:
exposure-related observations in humans: other data
Type of information:
other: human data
Adequacy of study:
key study
Study period:
2000-10-22 to 2002-05-19
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Arsenic exposure from drinking water and risk of premalignant skin lesions in Bangladesh: Baseline results from the health effects of arsenic longitudinal study
Author:
Ahsan, H. et al.
Year:
2006
Bibliographic source:
American Journal of Epidemiology, Vol. 163 (12): 1138-1148

Materials and methods

Type of study / information:
This publication describes a cross sectional study.
Endpoint addressed:
carcinogenicity
Principles of method if other than guideline:
A cross-sectional analysis was conducted to assess the relationship between arsenic exposure in drinking water and premalignant skin lesions involving baseline data from Health Effects of Arsenic Longitudinal Study (HEALS), a prospective cohort study on 11746 participants in Araihazar, Bangladesh in the period between 2000–2002.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Ethical approval:
confirmed, but no further information available
Details on study design:
TYPE OF EXPOSURE MEASUREMENT:
- Type: Interview
- Details: Well owners were interviewed to create a roster of all users of these wells. Trained study teams and physicians visited directly to participants for interviews. In addition, participants were clinically assessed for skin lesions and other health conditions. Biologic samples (blood and urine) were also collected.

EXPOSURE LEVELS: Drinking water containing 8.1-40:0, 40.1-91.0, 91.1-175.0, and 175.1-864.0 µg/L of arsenic

STUDY PERIOD: From October 22, 2000 to May 19, 2002

STUDY POPULATION
- Total population (Total no. of persons in cohort from which the subjects were drawn): 14828
- Selection criteria: Married (18-75 years); residing in the study area for at least 5 years prior to recruitment; primary user of one of the 5966 tube wells, designated as the ‘index’ well, for at least 3 years.
- Total number of subjects participating in study: 11746 (5042 men and 6704 women)
- Sex/age/race: Male and female / 18-75 years / Asian
- Smoker/nonsmoker: 70.9% smokers/ 29.1% nonsmokers

COMPARISON POPULATION
- Type: Reference group
- Details: Comparing participants with arsenic exposure and more susceptible attribute (e.g., male gender) with the reference group [Reference group: Participants with the lowest arsenic exposure level and a less susceptible attribute (e.g., female gender)]

HEALTH EFFECTS STUDIED
- Disease(s): Arsenicosis (premalignant skin lesions)
- Diagnostic procedure: Total urinary arsenic concentration was measured by graphite furnace atomic absorption using the Analyst 600 graphite furnace system. Urinary creatinine levels were assayed by a colorimetric Sigma Diagnostics Kit (Sigma, St. Louis, USA) for adjustment of urinary total arsenic concentration.

OTHER DESCRIPTIVE INFORMATION ABOUT STUDY:
- Water arsenic concentrations were analysed by graphite furnace atomic absorption or inductively coupled plasma-mass spectrometry.
- Statistics: Data were analysed using GMBO module of the EPICURE software and Statistical Analysis Software, version 8.0 (SAS Institute, Inc., Cary, USA).
Exposure assessment:
measured

Results and discussion

Results:
Discussion: The most relevant and sensitive study is from Ahsan et al. (2006) conducted in Bangladesh, investigating the dose-response relationship between arsenic exposure from drinking water and premalignant skin lesions. 11,746 participants were enrolled in the period 2000-2002. Arsenic exposure was assessed for each participant on the basis of (i) drinking water arsenic concentrations as well as well use patterns, and (ii) creatinine-corrected urinary arsenic excretion. The control population were exposed to drinking water with <8.1 µg/L of arsenic. Drinking water containing 8.1-40:0, 40.1-91.0, 91.1-175.0, and 175.1-864.0 µg/L of arsenic was associated with adjusted prevalence odds ratios (OR) of skin lesions of 1.91 (95% confidence interval (CI): 1.26, 2,89), 3.03 (95% CI: 2.05, 4.50), 3.71 (95% Cl: 2,53, 5.44), and 5.39 (95% CI: 3.69, 7.86), respectively.

Any other information on results incl. tables

Confounding factors

- Age, gender, cigarette smoking, socioeconomic status indicators, sun exposure, and body mass index

Strength and weaknesses

Strengths: (i) addresses a large number of subjects (n=11,746), (ii) covers a wide range of arsenic concentrations in drinking water (0.1-864 ug/L), and (iii) exposure to arsenic was well characterised: not only the arsenic in well water was analysed, but also drinking water consumption monitored and most relevant, creatinine-adjusted urinary arsenic excretion as monitored for each participant enrolling in the study.


Applicant's summary and conclusion