8 | The Institute + The Guild

treatment. In fact, significant levels of Cd were found in well tested at the dumpsite, although the concentrations of heavy metals in the sample decreased when the sampling distances from the dumpsite decreased.

In addition, the Pb concentration was ascertain to be higher than the standard with sample A, B and C recording higher with 1.00ppm, 0.20ppm and 0.16ppm respectively, while sample D and the control was slightly different with 0.11 and 0.001 for control. The above result showed that the disposal of hospital wastes on NOHE environment may affect water quality of the vicinity and hence make the water unfit for human consumption. This was in line with the work of (Oje, 2008, Onwuemesi, 2012 and Akanwa, 2014). Water for consumption should not contain trace of heavy metals because bioaccumulation of heavy metal in the body system is dangerous as it causes health related problems to the consumers. According to WHO (2006) accumulation of water polluted with Pb over a period of time could cause cancer, interference with Vitamin D metabolism, affect mental development in infants, toxic to the central and peripheral nervous systems. Based on this, the location of hospital waste at the study area should be changed to another confined area.

vegetables seems to imply that different types of vegetables have different abilities to accumulate metals. Different types of vegetable species accumulate different metals depending on environmental conditions, metal species and plant available forms of heavy metals (Lokeshwari and Chandrappa, 2006).

TABLE 5.9: heavy metals in vegetable from the two hospitals in ppm

Parameters (ppm)

Type of plants UNTH NOHE Control FAO STD 2010

Pb Water melon

garden egg leave Cucumber

0.87 0.74 0.27

0.62 0.89 0.05

0.15 0.33 0.01

0.30

Cr Water melon

garden egg leave Cucumber

1.16 0.13 0.15

0.18 0.14 0.12

0.09 0.10 0.08

0.10

Mn Water melon

garden egg leave Cucumber

0.17 0.14 0.12

0.15 0.13 0.10

0.11 0.10 0.06

500.00

Ni Water melon

garden egg leave Cucumber

0.33 0.20 0.16

2.06 2.04 2.02

0.28 0.02 0.10

67.00

Co Water melon

garden egg leave Cucumber

0.16 0.24 0.36

1.27 2.08 2.05

0.14

1.00 50.00

Arsenic Water melon garden egg leave Cucumber

0.04 0.01 0.03

0.01 0.01 0.02

0.001 0.001 0.002

0.10

Aluminum Water melon garden egg leave Cucumber

0.06 0.29 0.23

0.02 0.11 0.23

0.001 0.09 0.19

- Chromium Water melon

garden egg leave Cucumber

0.04 0.21 0.36

0.45 0.34 0.23

0.03 0.17 0.11

0.06 -

Cd Water melon

garden egg leave Cucumber

0.04 0.38 0.45

0.22 0.27 0.31

0.002

0.14 0.10

Calcium Water melon garden egg leave Cucumber

0.161 0.145 0.026

0.132 0.111 0.140

0.121

0.010 -

Source: Author’s computation (2017)

From Table 5.9, the analyzed samples showed that the concentration of Pb in cucumber ranges from 0.27-0.05ppm of wet samples. The concentration of Pb in water melon and garden egg leave was more than the maximum limit recommended by (FAO, 2010) in both hospitals with 0.87-0.62 and 0.74-0.89ppm of dry samples respectively. A similar study by Chove, 2006) showed

that Pb concentrations ranged from 0.15 to 0.41 mgKg^-1 dry weight samples which was closer to the data obtained in this study. Other scholars like Yu, (2006) Miller (2004) and Farooq (2008) showed that high level of Pb concentration in samples could be deadly to human and hence, unfit for human consumption.

In contrast the concentration of Pb in the study was below the maximum limits. In agreement with the result, Fisscha (1998) reported that cucumber, garden egg leave and water melon were generally the least accumulator of heavy metals as compared to other vegetable. The amount of Pb in the leaves of these vegetable could be explained to be as a result of Pb uptake by the pH of soil and level of organic matter in the study area where these vegetables were grown.

The heavy metal concentration of chromium (Cr) was also ascertained in the table. The table further showed that samples contain traces of Cr in the two hospitals samples with water melon ranging from 1.16- 0.18ppm, garden egg leave 0.13-0.14ppm and cucumber 0.15-0.12ppm of the wet samples respectively. Comparing the concentration levels at National Orthopaedic Hospital and University of Nigeria Teaching Hospital Ituku/Ozalla, the result showed that water melon concentration at UNTH was 1.16ppm and at NOHE is 0.18ppm. This showed that the concentration was higher at NOHE but the vegetable cultivated at close to the two hospital dump contains heavy metal (pb)

above the permissible limit and based on that, farming at the area should be discouraged and wastes treated before disposal.

In a similar study by Sharma (2006), it confirmed that heavy metal contents in different vegetables grown in the land irrigated with wastewater contains heavy metals as a result of wastewater. In the present study, the level of Cr in the samples from the hospitals dumpsite were observed to be within the permissible limits of 0.10 by FAO/WHO. The possible explanation of the above result is that the transportation of Cr in root is very slow. This was in agreement with the works of Skeffington (1996) and Baltrenaite and Butkus, (2004) accounting for the low levels of Cr in the tops of plant. The absorption of chromium to soil depends primarily on the clay content of the soil and, to a lesser extent, on waste and the organic content of soil according to them.

In line with the above, the concentration of cadmium in the samples were also ascertained. The table showed that the level of cadmium observed to be varying between 0.234 to 0.375ppm. From the table, it was observed that the concentration of Cd was higher in watermelon and lower in garden egg leave and cucumber. The concentration of Cr was relatively higher than the permissible limit in the three vegetables. In agreement with the present study findings, Prabu (2009) found that the Cd accumulation was more in leafy vegetables such as garden egg leave, lettuce, swiss chard and spinach. Similarly, Jamali (2007) also reported that the concentration of Cd in vegetable grown from domestic waste water was ranging between 0.14mgkg^-1 spinach and

0.30mgkg^-1 brinjal. Moreover, Demirezen and Ahmed (2006) analyzed various vegetables (cucumber, tomato, green pepper, lettuce, parseley, onion, bean, egg-plant, pepper mint, pumpkin and okra) from Turkey and reported that the Cd content (0.24-0.97mgkg^-1) was in high concentration and not suitable for human consumption in all the vegetables under study.

In addition, the level of Mn, Ni, Co, Arsenic, Aluminum, and Cobalt was investigated in the study. Table 5.9 further showed that accumulation of these metals in leafy vegetable could possibly lead to human health problems. From the table, the concentration of these metals were slightly above the recommended limit by FAO (2010). Table 5.9 further showed that the concentration of the heavy metals in the samples could be as a result of disposal of hospital wastes on the environment where the study vegetables were grown.

Furthermore, the bacteriological content of vegetable from the study hospitals were also analyzed in the Table 5.10 in order to show the concentrations of some bacteria in the leafy vegetable.