Abstract:
Excessive accumulation of heavy metals in tea plantations may not
only result in environmental contamination but also affect the
quality and safety of tea production in Sri Lanka. Thus, the prime
aim of this study is to assess the levels of Potassium (K), Magnesium
(Mg), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Lead (Pb),
and Cadmium (Cd) in fresh tea leaves (green), processed (black) tea
samples and soil of herbicides applied and non-applied tea
plantation plots in Dambetenna tea estates, Sri Lanka. Soil and tea
leave samples were collected using simple random sampling
technique representing both the herbicide applied (treated) and the
non-applied (controlled) tea plantation plots within six months
period of time (n=36). The Microwave digestion system and Atomic
Absorption Spectrometer (AAS) were used to analyse the levels of
metal concentrations and the data were statistically analysed using
the student’s t-test (95% confidence interval) in order to compare
two plots in terms of heavy metal concentrations. Results revealed
that in herbicides applied plots, the concentrations of heavy metals
viz. Zn, Fe, and Pb are significantly higher (p<0.05) in soil and the
levels of Pb are slightly higher (p<0.05) in green tea leaves and black
tea samples. Overall, the present study gives insights into the heavy
metal contamination levels in tea estate soil, green tea leaves, and
black/processed tea samples under chemical weeding systems in
Sri Lanka.
