Machiwa, John F.
Description:
A survey of paddy fields in Lake Victoria Basin (LVB) wetlands was conducted at a wider scale
in different locations including closer to mining and within urbanized areas in Tanzania. The
objective of the study was mainly to assess the present situation with regard to levels of heavy
metals in O. sativa grains harvested locally as well as to set the baseline levels of some heavy
metals in paddy fields. The results showed that the levels of Cadmium, Chromium, Copper,
Lead, Zinc and total Mercury in brown rice are generally within the acceptable levels for human
food. However, higher concentration of Hg was found in the husks, suggesting the significance of
atmospheric dispersal of Hg in the basin. It is also worthwhile noting that all the sampled
paddy fields in LVB have heavy metal concentrations within limits for production of safe rice for
human consumption.