Heavy metal accumulation by roadside vegetation and implications for pollution control

Area of Science:

• Environmental Science
• Botany
• Ecotoxicology

Background:

• Vehicular emissions are a major source of heavy metal pollution, negatively impacting ecosystems and roadside vegetation.
• Wild plants possess the capacity to absorb substantial amounts of heavy metals from their environment.
• This absorption capability suggests a potential role for wild flora in mitigating heavy metal contamination.

Purpose of the Study:

• To investigate the heavy metal absorption capacity of specific wild plant species found along roadsides.
• To quantify the accumulation of lead (Pb2+), zinc (Zn2+), nickel (Ni2+), manganese (Mn2+), and iron (Fe3+) in selected plant species.

Main Methods:

• Four wild plant species (Acacia nilotica, Calotropis procera, Ricinus communis, Ziziphus mauritiana) were selected.
• Leaf samples were collected from four distinct sites: Control, New Lahore, Nawababad, and Fatehabad.
• Atomic absorption spectroscopy was used to analyze heavy metal accumulation (Pb2+, Zn2+, Ni2+, Mn2+, Fe3+) in the collected leaf samples.

Main Results:

• Acacia nilotica, Ziziphus mauritiana, and Calotropis procera showed significant lead (Pb) accumulation, particularly at the New Lahore site.
• Ricinus communis and Acacia nilotica exhibited higher accumulation of manganese (Mn), zinc (Zn), and iron (Fe) at Nawababad and New Lahore sites.
• Ziziphus mauritiana demonstrated the highest nickel (Ni) accumulation across all studied sites compared to other species.
• Soil surface was identified as a contributing factor to heavy metal uptake in plant leaves.

Conclusions:

• Wild plants growing along roadsides effectively accumulate significant levels of heavy metals.
• These plant species hold potential for phytoremediation strategies to control heavy metal pollution from vehicular emissions.
• Strategic planting of these wild species near roadsides can aid in reducing heavy metal pollution in urban and industrial areas.