**6.2 Results**

The result indicates that there was no significant difference in heavy metal concentration (F1, 58 = 0.24, P > 0.05) in soils collected from dump sites in mangrove and non-mangrove soils. Copper, lead and zinc had higher concentrations in non-mangrove soils whereas cadmium had the highest concentration in mangrove soil (**Figure 4**). Dump sites contain all kinds of waste such as domestic, industrial, hospital, municipal and electronic waste (e-waste). These materials had made the heavy metal concentration to be high in both soils, which is not good for the ground water aquifer and organisms that inhabit the soil. Arsenic is a poisonous chemical that has teratogenic effect on man. The result of heavy metal concentration from e-waste in mangroves and farm soil further illustrate the ability of mangrove forest to retain high heavy metal concentration, which is far above the required standards (**Table 1**). Waste materials that have high arsenic content can be disastrous to organisms that reside in the forest. The problem is

#### **Figure 4.**

*Heavy metal concentration in soils collected from dump sites situated in mangrove and non-mangrove forest in selected sites in the Niger Delta, Nigeria.* 

*DOI: http://dx.doi.org/10.5772/intechopen.83809*  **Heavy metals FMENV limit (mg/l) Farm soil Mangrove soil** 

*Municipal Solid Waste Disposal in Mangrove Forest: Environmental Implication…* 


#### **Table 1.**

*Comparison of heavy metal concentration from study and Federal Ministry of Environment (FMENV) maximum concentration for ground water protection.* 

 that some organisms that are found in the mangrove forest are consumed by man. For example crabs, periwinkle, fish, etc. Another study using crab shell and tissue (*Goniopsis pelii*) show that the distribution of heavy metals in the body parts was highest in claw tissue: zinc (1894.5 mg/l), cadmium (28.0 mg/l), lead (283.0 mg/l) followed by gills: zinc (116.0 mg/l), cadmium (12.0 mg/l), lead (173.5 mg/l), and gut: zinc (38.0 mg/l), cadmium (2.8 mg/l), lead (27.4 mg/l). This can be attributed to accumulation of heavy metals that come from e-waste (mobile phones) in mangrove forest soil (*in press*). This can lead to biomagnification in man thereby causing health problems. It is also environmentally damaging when pollutants enter the food chain.
