Abstract
There has been a rapidly increasing urbanization and industrialization as well as increased usage of agrochemicals in the recent few years which have resulted in accumulation of heavy metals in cultivated food, soils and water. This research aimed at establishing the levels of Zn2+, Cd2+, Cu2+, Cr2+, Mn2+, Fe2+ and Pb2+ metal ions in kales, soil and irrigation water on farms along river Moiben. Twenty seven samples of vegetables, soil and water samples were collected using purposive sampling method, that is, the samples were collected from the households who had kales in their farms. Samples were then dried, grounded, digested and analyzed using Inductive Couple Plasma-Optical Emission Spectroscopy (ICP-OES). The results showed that the Fe had the highest mean in soil and water with the values of 250.22 ± 85.37 and 0.72 ± 0.33 mg/kg respectively, while in kales Zn value was highest with a value of 0.0154 ± 0.007 mg/kg. The metal ion concentrations in the soils and the irrigation water were higher than in kales. The concentrations on the metal ions were following this order Fe > Mn > Zn > Cu > Cr > Pb > Cd for soil as well as for water but for the kales sample it followed slightly different order Zn > Fe > Mn > Cu > Cr > Pb > Cd. In soil samples, metal ions concentrations (mg/kg) were found to be high compared to the levels in water and kales. ANOVA tests revealed that the mean difference in heavy metals concentration from different stations within the area was insignificant (p > 0.05) with an exception of Cd (p = 0.001) in water samples, Fe (p = 0.007) in kales samples, Zn (p = 0.016) and Cd (p = 0.011) in the samples of soil. Results were compared to the acceptable levels set by World Health Organization (WHO) and the study showed that for kales, concentrations of the metal ions were all lower than the (WHO) set standards. For water samples, Fe, Pb, Mn metal ions were above the WHO set standards. The presence of the investigated heavy metals in the samples could be pointed to excessive use of agrochemicals as indicated by our earlier survey on the use of agrochemicals. We therefore recommend thorough investigations and monitoring of the said heavy metals in the commercially distributed agrochemicals.
Highlights
The main path of heavy metal introduction for human beings is through food chain pollution (Khan et al, 2008)
It is evident that Moiben sub-county is relatively concentrated with the heavy metals
The results pointed out that all the metal ions (Fe, Zn, Mn, Pb, Cd, Cr, and Cu) were present in all the samples collected though the concentrations of heavy metals detected in the samples were quite different
Summary
The main path of heavy metal introduction for human beings is through food chain pollution (Khan et al, 2008). A number of metals are indispensable micronutrients for the health of human beings and may be very lethal when they are over consumed (Fytianos et al, 2001). Cadmium, lead and mercury have unknown value to humans and are known to be injurious if exposure elevated levels. Copper and zinc are essential within some levels at elevated levels bring about oxidative trauma by redox reactions (Halliwell, 2006; Gaetke & Chow, 2003; Rotilio et al, 2000). Lead toxicity is associated with oxidative trauma and in growing infants it brings about hinders mental development (Ab Latif Wani & Usmani, 2015; Hou et al, 2013). Persistent contact with cadmium is known to spoil glomerula as well as changing the metabolism of Zn, Cu and Se (Noël et al, 2004; Matović et al, 2011) whereas a few oxidative varieties of chromium Cr (VI) are carcinogenic (Costa & Klein, 2006)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
