Daily vegetable consumption was obtained through a formal survey conducted
in the study area. An interview of 25 persons of 30–50 years age group and of 60–
70 kg body weight was conducted at each market site regarding their daily consumption
rate of vegetables tested. Each person represents a household having
P5 individuals, and thus a total of 125 persons were effectively interviewed. An
average consumption rate of each vegetable per person per day was calculated.
The percent contributions to dietary intake of heavy metals by the urban population
through the consumption of the vegetables tested in this study were calculated by
dividing the daily consumption rates of the heavy metals with the values of provisional
tolerable daily intake (Joint FAO/WHO Expert Committee on Food Additives,
1999).