**2. Materials and methods**

#### **2.1. Study area**

The two sampling sites were located in Katsina State, a state that falls within the Sudan Savanna eco-region of northern Nigeria (See Fig 1).

The Katsina Steel Rolling Mill (See Fig 2) was established in the mid 1970s with an installed capacity of 207, 000 mts per annum [20]

Zobe dam was constructed in 1977 to provide Portable water and for irrigation. It has a storage capacity of 170 Million cubic meters, a surface area of 39.6 km2 and supports 8137 ha of irrigated land (See Fig 3).


**Table 1.** Geographical Positioning Coordinates of sampling stations at Katsina Steel Rolling Mill environs and Zobe Dam catchment, Katsina state, north Western Nigeria.

Heavy Metal Deposition in Soils and Plants Impacted by Anthropogenic Modification of Two Sites in the Sudan… http://dx.doi.org/10.5772/57299 699

The effect of metals in living organisms could be chronic, due to exposures over a long period of time as a result of food chain transfer or acute poisoning due to ingestion or dermal contact [18]. The concentration of heavy metals in the shoot of plants may vary with season as a result of inherent growth dynamics of the plant; metal concentration and its bio-availability in the environment. Data on the response of plants to anthropogenic modification of the environ‐ ment, particularly in relation to soil and air pollution by heavy metals in northern Nigeria is limited and includes earlier assessments [3, 6, 15, 16] and more recently [19], in which an attempt was made to document the visual symptoms expressed by some ruderal plant species in relation to air pollution as a step towards developing a reference for field identification of

This study was carried out to determine the spatial and seasonal variations of heavy metal deposition in soils and plants in Nigeria's Sudan Savanna in order to assess the extent of pollution and to identify indigenous plant species that may be pollution tolerant and thus have

The two sampling sites were located in Katsina State, a state that falls within the Sudan Savanna

The Katsina Steel Rolling Mill (See Fig 2) was established in the mid 1970s with an installed

Zobe dam was constructed in 1977 to provide Portable water and for irrigation. It has a storage

**Table 1.** Geographical Positioning Coordinates of sampling stations at Katsina Steel Rolling Mill environs and Zobe

**Stations Longitude Latitude Altitude**

1 7 37 06. 46 E 12 57 24.72 N 557m 2 7 37 10. 23 E 12 57 10.23 N 553m 3 7 37 23.06E 12 57 23.07 N 556m

1 7 27 56.40 E 12 21 42. 18 N 510 m 2 7 27 4.8 E 12 21 19. 12 N 520 m 3 7 27 52.31 E 12 22 28. 19 N 520 m

and supports 8137 ha of irrigated

potential for use in phytorememediation of heavy metal polluted sites.

pollution events [19].

**2.1. Study area**

land (See Fig 3).

Katsina Steel Rolling Mill environs

Zobe Dam catchment

**2. Materials and methods**

698 Environmental Risk Assessment of Soil Contamination

eco-region of northern Nigeria (See Fig 1).

capacity of 207, 000 mts per annum [20]

**Location/Site Sampling**

Dam catchment, Katsina state, north Western Nigeria.

capacity of 170 Million cubic meters, a surface area of 39.6 km2

**Figure 1.** Katsina State, Nigeria showing approximate location of the Steel Rolling Mill and Zobe dam.

**Figure 2.** Environs of the Katsina Steel Rolling Mill Showing approximate sampling points.

**Figure 3.** Environs of Zobe Dam showing approximate sampling points

#### **2.2. Sample collection**

**Figure 2.** Environs of the Katsina Steel Rolling Mill Showing approximate sampling points.

700 Environmental Risk Assessment of Soil Contamination

Soil and plant samples were collected in both dry and wet seasons from three sampling stations per location in 5m by 5m quadrats. Soil samples were collected at 0-15cm depth using a soil auger. The shoot of herbaceous plants with relative abundance greater than five per quadrat, were clipped with a pair of secateurs for heavy metal analysis. Identification of plant samples were confirmed in the herbarium of the Department of Biological Sciences, Ahmadu Bello University, Zaria.
