CAD risk tended to increase with an increase in frequency and duration of drinking.
No trend was observed for increasing level, except for duration of drinking.
Information on lifetime alcohol consumption included the type of alcoholic beverage used, age at which drinking commenced, amount of alcohol consumed per day, the frequency with which the subject consumed each type of alcoholic beverage, the duration during which each type of alcoholic beverage was consumed and total duration of drinking.
Data on individual drinking time and duration of drinking bouts (experiment 2, period 3) were analyzed using a mixed model analysis of variance with type of water dispenser as fixed effect, and group was specified as a random effect in the model.
The water intake from the two dispensers (period 3) and individual drinking time and duration of drinking bouts (experiment 2, period 3) were also analysed using a paired comparison t-test.
We derived time-weighted arsenic concentration (TWA) as a function of drinking water duration from each well and well arsenic concentration: TWA in micrograms per liter = ∑ Ci Ti/∑ Ti, where Ci and Ti denote the well arsenic concentration and drinking duration from each well, respectively (Ahsan et al. 2006b).
We systematically sought to determine the onset and duration of drinking and the average daily alcohol consumption.
We took the amount of alcohol consumed per week, the duration of drinking or the age at the start drinking as explanatory variables.
Nonetheless, the duration of drinking artesian well water was available for all participants, and we observed a positive association between the duration of drinking artesian well water and pterygium.
We also collected self-reported information on duration of drinking water from these selected tube wells.
However, we do not believe that this led to significant exposure misclassification, as the duration of drinking water from the surveyed well greatly exceeded the duration of drinking water from an alternate well.
