Consumption of a weed, commonly sold in the city’s markets as a variety of leafy vegetable, could pose a health hazard, warns a recently-published research by the scientists at University of Hyderabad.
According to the researchers, the weed Alternanthera Philoxeroides, commonly referred to as ‘alligator weed’, is abundantly found in polluted swamps, lakes and drains. Given its easy availability and nutritional value, it is also widely sold in these parts of the country in the guise of ‘Ceylon spinach’. However, Ceylon spinach, a variety of spinach, is not considered a weed and is scientifically known as Basella Alba.
Despite its inherent nutrition value, the researchers say the alligator weed accumulates heavy metals from its surrounding water and soil, often in quantities more than the environmental norms set by the U.S. Environmental Protection Agency.
“When consumed as vegetable by humans and cattle as feed, it can cause serious health hazards and sometimes even lead to death,” the researchers concluded in the study that appeared in EuroBiotech Journal. “It spreads easily in aquatic and terrestrial ecosystems, and leads to biological diversity erosion, which favours the intrusion of invasive alien species and these invasive species compete with the native rare, endangered and threatened species.” For the study, its authors Sateesh Suthari, Boda Ravi Kiran and M.N.V. Prasad, from UoH’s Department of Plant Sciences, collected weed and soil samples from eight locations across the city, including the Musi river and Hussainsagar lake. The concentration of heavy metals was analysed in both the plant and soil samples.
The exercise showed that iron accumulation was higher than other metals detected, including manganese, zinc, lead and cadmium. Metal accumulation was highest in the root and lowest in the stem, with concentrations in leaves falling in between. The researchers attributed metal accumulation in the weed to the soil. They blamed heavy metal presence in discharge of domestic sewage and industrial effluents into water bodies. The scientists also found that the metal concentrations in soil varied at different locations, but correlated with that of weed concentrations.
For the same reason that it could be harmful, the scientists also pointed out that it can be used for removal of contaminants from soil or water, a process known as phytoremediation.