Monitoring of heavy metals in vegetables and soil of agricultural fields of Kathmandu Valley

Abstract

Evaluation of heavy metals in vegetables and soil of agricultural fie1ds of Kathmandu valley was conducted. Highest accumulations of copper (65.5 mg kg-1;, lead 146.75m g kg-1) and cadmium( 2 mg kg-1) from Shankhamul; nickel (29.25mg kg-1) from Nakhu; cobalt (15.25mg kg-1) and manganese (675 mg kg-1; from Balkhu; chromium (73.75 mg kg-1; from Banasthali, zinc (162 mg kg-1) and iron (75636 mg kg-1; from Khusibun were recorded in soil of agricultural fields. Highest accumulations of Cu, Co and Zn were recorded in spinach and Pb in red radish; Ni, Cr and Fe was recorded in broad leaf mustard and Mn in cress leaf while considering the mean of each vegetables studied. Concentration of non-essential but toxic metal like Pb was higher than the normal plant value (0.1-10mg kg-1) in all the vegetables (except potato) collected from different sampling sites.Key words: Heavy metals; Soil; Vegetablesdoi: 10.3126/eco.v12i0.3189 Ecoprint: An International Journal of Ecology 12: 1-9, 2005

Risk Assessment of Heavy Metals via Consumption of Contaminated Vegetables Collected from Different Agricultural Fields and Market Sites

“…Based on the results of the mean concentration of all metals, Zn showed high and Pb low levels in all the vegetables collected from agricultural and market sites. Similar results reported by various researchers, Sharma and Chettri (2005) [32], Sharma et al (2009) [8] and Degheim et al (2004) [33]. The absorption of heavy metals from the soil depends on different factors such as pH, organic matter, soil metal availability, cation exchange capacity, plant species, plant growth stages and season and presence of other heavy metals in soil [34].…”

Assessment of Heavy Metals in Some Vegetables Sold in Urban Open Markets of Kathmandu Valley

“…However, the mean levels of Pb contamination in both the vegetables tested were exceptionally higher than the maximum permissible limits (Table 2&3) for vegetables as recommended by FAO/WHO (2001). Our results are in agreement with the study conducted by Sharma and Chettri (2005) who reported high Pb accumulation above 20 mg/kg in spinach and carrot grown along various riversides of Kathmandu Valley. Besides, they also found as high as 46.75 mg/kg of Pb in soil of those agriculture fields of the valley irrigated with polluted river water.…”

“…Besides, it was also found that the level of Cd in each of the vegetables tested from the markets of the Kathmandu valley exceeded the recommended permissible limits. Sharma and Chettri (2005) also reported similar findings in vegetables grown in agricultural fields along the main riversides of Kathmandu Valley. The high Cd concentration in the present study is possibly due to the use of contaminated river water for irrigation.…”

Screening of Vegetables for Phytoextraction of Heavy Metals

“…High uptake of Zn, Pb or Cu from the mixed metal treatments in the plants may be due to competitive uptake among the supplied cations. This result is further justified from the monitoring experiment where the Zn accumulation in S. oleracea (in all species) is high and have tendency of hyperaccumulation (Sharma and Chettri 2005).…”