Chemistry Reference
In-Depth Information
The order of concentration of each heavy metal in the bitter leaf harvested from all the
studied locations is: iron (Fe) in bitter leaf harvested along Akpajo - Eleme Junction Road
soil > Refinery - Akpajo Junction Road soil > Port Harcourt - Aba Road soil > Kina Gbara
Street soil (Bori); lead (Pb) in bitter leaf harvested along Akpajo Road soil - Eleme Junction
Road soil > Refinery - Akpajo Junction Road soil > Port Harcourt - Aba Road soil > Kina
Gbara street soil (Bori); chromium (Cr) in bitter leaf harvested along Akpajo-Eleme Junction
Road soil > Refinery - Akpajo Junction Road soil > Port Harcourt Aba Road soil > Kina
Gbara street(Bori).
Zinc (Zn) in Refinery - Akpajo Junction Road soil > Akpajo - Eleme Junction Road soil >
Port Harcourt - Aba Road soil > Kina Gbara street soil (Bori). The results further reveal that;
the high concentration of iron (Fe), lead (Pb), chromium (Cr) and Zinc (Zn) found in the
leaves of the bitter leaf may be due to the high levels of exhaust emission from the vehicles
plying these roads, (Edem et al., 2009).This view is further supported by the relative lower
concentrations of the heavy metals found in the control sample collected in Bori. The level of
concentration of Fe in the control sample in addition to the low concentration of toxic heavy
metals makes it suitable for human consumption (Ifon, 1977). The high concentration of iron
in bitter leaf might be attributed to the nature of the soil and sometimes by the presence of
some bacterial that depends on Fe
2+
for source of energy.
The results of the study indicate that the bitter leaf harvested along Akpajo - Eleme Junction
Road had the highest concentration of iron (Fe), lead (Pb) and chromium (Cr), compared to
the one from Bori (control), while Refinery-Akpajo Junction Road had the second highest
concentration of iron (Fe) lead (Pb) and chromium (Cr). The highest concentration of zinc
(Zn) was also recorded along this route.
The findings of this study agree with the results of Edem et al. (2009) on levels of heavy
metals in pumpkin leaves harvested in streets with heavy vehicular traffic in Cross River
State and the report on the investigation of the deposit of lead on the bark of trees planted in
areas of high traffic volume in Benin carried out by Ademoronti (1986).
The mean concentration of Pb (0.325) and Cr (0.041) in the sampled bitter leaf were above
the WHO tolerable limit of 0.005 - 0.1 and 0.005 - 0.01 respectively. The bioaccumulation of
these heavy metals has adverse health implications to man, especially in children and
pregnant women (Dupler, 2001).
The high concentration of Fe reported in this study is in conformity with that published by
Hart et al. (2005) on concentrations of trace metals (Pb, Fe, Cu and Zn) in crops harvested in
some oil prospecting locations in Rivers State. The likely reason given for this high value of
iron is the participation of green vegetables in the synthesis of ferrodoxin. However, the
mean concentration of Fe (3.22) falls within the acceptable range (1.0 - 4.0mg/100g) as
published by Platt (1980). The mean concentration of Zn (1.03) is also within the acceptable
limit. However, from WHO (1984) report, excessive intake of Fe and Zn is capable of causing
vomiting, dehydration, electrolytic imbalance and lack of muscular co-ordination.
